WorldWideScience

Sample records for multidimensional optical probes

  1. Optical probe

    International Nuclear Information System (INIS)

    Denis, J.; Decaudin, J.M.

    1984-01-01

    The probe includes optical means of refractive index n, refracting an incident light beam from a medium with a refractive index n1>n and reflecting an incident light beam from a medium with a refractive index n2 [fr

  2. Optical Multidimensional Switching for Data Center Networks

    DEFF Research Database (Denmark)

    Kamchevska, Valerija

    2017-01-01

    . Software controlled switching using an on-chip integrated fiber switch is demonstrated and enabling of additional network functionalities such as multicast and optical grooming is experimentally confirmed. Altogether this work demonstrates the potential of optical switching technologies...... for the purpose of deploying optical switching within the network. First, the Hi-Ring data center architecture is proposed. It is based on optical multidimensional switching nodes that provide switching in hierarchically layered space, wavelength and time domain. The performance of the Hi-Ring architecture...... is evaluated experimentally and successful switching of both high capacity wavelength connections and time-shared subwavelengthconnections is demonstrated. Error-free performance is also achieved when transmitting 7 Tbit/s using multicore fiber, confirming the ability to scale the network. Moreover...

  3. Optical Multidimensional Switching for Data Center Networks

    OpenAIRE

    Kamchevska, Valerija; Galili, Michael; Oxenløwe, Leif Katsuo; Berger, Michael Stübert

    2017-01-01

    Optical switches are known for the ability to provide high bandwidth connectivity at a relatively low power consumption and low latency. Several recent demonstrations on optical data center architectures confirm the potential for introducing all-optical switching within the data center, thus avoiding power hungry optical-electrical-optical conversions at each node. This Ph.D. thesis focuses precisely on the application of optical technologies in data center networks where optics is not only u...

  4. Characterization of near-field optical probes

    DEFF Research Database (Denmark)

    Vohnsen, Brian; Bozhevolnyi, Sergey I.

    1999-01-01

    Radiation and collection characteristics of four different near-field optical-fiber probes, namely, three uncoated probes and an aluminium-coated small-aperture probe, are investigated and compared. Their radiation properties are characterized by observation of light-induced topography changes...... in a photo-sensitive film illuminated with the probes, and it is confirmed that the radiated optical field is unambigiously confined only for the coated probe. Near-field optical imaging of a standing evanescent-wave pattern is used to compare the detection characteristics of the probes, and it is concluded...... that, for the imaging of optical-field intensity distributions containing predominantly evanescent-wave components, a sharp uncoated tip is the probe of choice. Complementary results obtained with optical phase-conjugation experiments with he uncoated probes are discussed in relation to the probe...

  5. Characterization of Fiber Optic CMM Probe System

    Energy Technology Data Exchange (ETDEWEB)

    K.W.Swallow

    2007-05-15

    This report documents a study completed on the fiber optic probe system that is a part of the Werth optical CMM. This study was necessary due to a lack of documentation from the vendor for the proper use and calibration of the fiber probe, and was performed in support of the Lithographie Galvanoformung Abformung (LIGA) development program at the FM&T. As a result of this study, a better understanding of the fiber optic probe has been developed, including guidelines for its proper use and calibration.

  6. A review of snapshot multidimensional optical imaging: Measuring photon tags in parallel

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Liang, E-mail: gaol@illinois.edu [Department of Electrical and Computer Engineering, University of Illinois at Urbana–Champaign, 306 N. Wright St., Urbana, IL 61801 (United States); Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana–Champaign, 405 North Mathews Avenue, Urbana, IL 61801 (United States); Wang, Lihong V., E-mail: lhwang@wustl.edu [Optical imaging laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Dr., MO, 63130 (United States)

    2016-02-29

    Multidimensional optical imaging has seen remarkable growth in the past decade. Rather than measuring only the two-dimensional spatial distribution of light, as in conventional photography, multidimensional optical imaging captures light in up to nine dimensions, providing unprecedented information about incident photons’ spatial coordinates, emittance angles, wavelength, time, and polarization. Multidimensional optical imaging can be accomplished either by scanning or parallel acquisition. Compared with scanning-based imagers, parallel acquisition–also dubbed snapshot imaging–has a prominent advantage in maximizing optical throughput, particularly when measuring a datacube of high dimensions. Here, we first categorize snapshot multidimensional imagers based on their acquisition and image reconstruction strategies, then highlight the snapshot advantage in the context of optical throughput, and finally we discuss their state-of-the-art implementations and applications.

  7. Multidimensional quantum entanglement with large-scale integrated optics.

    Science.gov (United States)

    Wang, Jianwei; Paesani, Stefano; Ding, Yunhong; Santagati, Raffaele; Skrzypczyk, Paul; Salavrakos, Alexia; Tura, Jordi; Augusiak, Remigiusz; Mančinska, Laura; Bacco, Davide; Bonneau, Damien; Silverstone, Joshua W; Gong, Qihuang; Acín, Antonio; Rottwitt, Karsten; Oxenløwe, Leif K; O'Brien, Jeremy L; Laing, Anthony; Thompson, Mark G

    2018-04-20

    The ability to control multidimensional quantum systems is central to the development of advanced quantum technologies. We demonstrate a multidimensional integrated quantum photonic platform able to generate, control, and analyze high-dimensional entanglement. A programmable bipartite entangled system is realized with dimensions up to 15 × 15 on a large-scale silicon photonics quantum circuit. The device integrates more than 550 photonic components on a single chip, including 16 identical photon-pair sources. We verify the high precision, generality, and controllability of our multidimensional technology, and further exploit these abilities to demonstrate previously unexplored quantum applications, such as quantum randomness expansion and self-testing on multidimensional states. Our work provides an experimental platform for the development of multidimensional quantum technologies. Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

  8. Optical Probes for Neurobiological Sensing and Imaging.

    Science.gov (United States)

    Kim, Eric H; Chin, Gregory; Rong, Guoxin; Poskanzer, Kira E; Clark, Heather A

    2018-04-13

    Fluorescent nanosensors and molecular probes are next-generation tools for imaging chemical signaling inside and between cells. Electrophysiology has long been considered the gold standard in elucidating neural dynamics with high temporal resolution and precision, particularly on the single-cell level. However, electrode-based techniques face challenges in illuminating the specific chemicals involved in neural cell activation with adequate spatial information. Measuring chemical dynamics is of fundamental importance to better understand synergistic interactions between neurons as well as interactions between neurons and non-neuronal cells. Over the past decade, significant technological advances in optical probes and imaging methods have enabled entirely new possibilities for studying neural cells and circuits at the chemical level. These optical imaging modalities have shown promise for combining chemical, temporal, and spatial information. This potential makes them ideal candidates to unravel the complex neural interactions at multiple scales in the brain, which could be complemented by traditional electrophysiological methods to obtain a full spatiotemporal picture of neurochemical dynamics. Despite the potential, only a handful of probe candidates have been utilized to provide detailed chemical information in the brain. To date, most live imaging and chemical mapping studies rely on fluorescent molecular indicators to report intracellular calcium (Ca 2+ ) dynamics, which correlates with neuronal activity. Methodological advances for monitoring a full array of chemicals in the brain with improved spatial, temporal, and chemical resolution will thus enable mapping of neurochemical circuits with finer precision. On the basis of numerous studies in this exciting field, we review the current efforts to develop and apply a palette of optical probes and nanosensors for chemical sensing in the brain. There is a strong impetus to further develop technologies capable of

  9. Probing Protein Multidimensional Conformational Fluctuations by Single-Molecule Multiparameter Photon Stamping Spectroscopy

    Science.gov (United States)

    2015-01-01

    Conformational motions of proteins are highly dynamic and intrinsically complex. To capture the temporal and spatial complexity of conformational motions and further to understand their roles in protein functions, an attempt is made to probe multidimensional conformational dynamics of proteins besides the typical one-dimensional FRET coordinate or the projected conformational motions on the one-dimensional FRET coordinate. T4 lysozyme hinge-bending motions between two domains along α-helix have been probed by single-molecule FRET. Nevertheless, the domain motions of T4 lysozyme are rather complex involving multiple coupled nuclear coordinates and most likely contain motions besides hinge-bending. It is highly likely that the multiple dimensional protein conformational motions beyond the typical enzymatic hinged-bending motions have profound impact on overall enzymatic functions. In this report, we have developed a single-molecule multiparameter photon stamping spectroscopy integrating fluorescence anisotropy, FRET, and fluorescence lifetime. This spectroscopic approach enables simultaneous observations of both FRET-related site-to-site conformational dynamics and molecular rotational (or orientational) motions of individual Cy3-Cy5 labeled T4 lysozyme molecules. We have further observed wide-distributed rotational flexibility along orientation coordinates by recording fluorescence anisotropy and simultaneously identified multiple intermediate conformational states along FRET coordinate by monitoring time-dependent donor lifetime, presenting a whole picture of multidimensional conformational dynamics in the process of T4 lysozyme open-close hinge-bending enzymatic turnover motions under enzymatic reaction conditions. By analyzing the autocorrelation functions of both lifetime and anisotropy trajectories, we have also observed the dynamic and static inhomogeneity of T4 lysozyme multidimensional conformational fluctuation dynamics, providing a fundamental

  10. Multidimensional quantum entanglement with large-scale integrated optics

    DEFF Research Database (Denmark)

    Wang, Jianwei; Paesani, Stefano; Ding, Yunhong

    2018-01-01

    -dimensional entanglement. A programmable bipartite entangled system is realized with dimension up to 15 × 15 on a large-scale silicon-photonics quantum circuit. The device integrates more than 550 photonic components on a single chip, including 16 identical photon-pair sources. We verify the high precision, generality......The ability to control multidimensional quantum systems is key for the investigation of fundamental science and for the development of advanced quantum technologies. We demonstrate a multidimensional integrated quantum photonic platform able to generate, control and analyze high...

  11. Probing molecular potentials with an optical centrifuge

    Science.gov (United States)

    Milner, A. A.; Korobenko, A.; Hepburn, J. W.; Milner, V.

    2017-09-01

    We use an optical centrifuge to excite coherent rotational wave packets in N2O, OCS, and CS2 molecules with rotational quantum numbers reaching up to J ≈465 , 690, and 1186, respectively. Time-resolved rotational spectroscopy at such ultra-high levels of rotational excitation can be used as a sensitive tool to probe the molecular potential energy surface at internuclear distances far from their equilibrium values. Significant bond stretching in the centrifuged molecules results in the growing period of the rotational revivals, which are experimentally detected using coherent Raman scattering. We measure the revival period as a function of the centrifuge-induced rotational frequency and compare it with the numerical calculations based on the known Morse-cosine potentials.

  12. Probing noncommutative theories with quantum optical experiments

    Directory of Open Access Journals (Sweden)

    Sanjib Dey

    2017-11-01

    Full Text Available One of the major difficulties of modern science underlies at the unification of general relativity and quantum mechanics. Different approaches towards such theory have been proposed. Noncommutative theories serve as the root of almost all such approaches. However, the identification of the appropriate passage to quantum gravity is suffering from the inadequacy of experimental techniques. It is beyond our ability to test the effects of quantum gravity thorough the available scattering experiments, as it is unattainable to probe such high energy scale at which the effects of quantum gravity appear. Here we propose an elegant alternative scheme to test such theories by detecting the deformations emerging from the noncommutative structures. Our protocol relies on the novelty of an opto-mechanical experimental setup where the information of the noncommutative oscillator is exchanged via the interaction with an optical pulse inside an optical cavity. We also demonstrate that our proposal is within the reach of current technology and, thus, it could uncover a feasible route towards the realization of quantum gravitational phenomena thorough a simple table-top experiment.

  13. Imaging optical probe for pressurized steam-water environment

    International Nuclear Information System (INIS)

    Donaldson, M.R.; Pulfrey, R.E.

    1979-01-01

    An air-cooled imaging optical probe, with an outside diameter of 25.4 mm, has been developed to provide high resolution viewing of flow regimes in a steam-water environment at 343 0 C and 15.2 MPa. The design study considered a 3-m length probe. A 0.3-m length probe prototype was fabricated and tested. The optical probe consists of a 3.5-mm diameter optics train surrounded by two coaxial coolant flow channels and two coaxial insulating dead air spaces. With air flowing through the probe at 5.7 g/s, thermal analysis shows that no part of the optics train will exceed 93 0 C when a 3-m length probe is immersed in a 343 0 C environment. Computer stress analysis plus actual tests show that the probe can operate successfully with conservative safety factors. The imaging optical probe was tested five times in the design environment at the semiscale facility at the INEL. Two-phase flow regimes in the high temperature, high pressure, steam-water blowdown and reflood experiments were recorded on video tape for the first time with the imaging optical probe

  14. Dynamic size tuning of multidimensional optically bound matter

    Czech Academy of Sciences Publication Activity Database

    Brzobohatý, Oto; Karásek, Vítězslav; Čižmár, T.; Zemánek, Pavel

    2011-01-01

    Roč. 99, č. 10 (2011), 101105:1-3 ISSN 0003-6951 R&D Projects: GA ČR GA202/09/0348; GA ČR GPP205/11/P294 Institutional research plan: CEZ:AV0Z20650511 Keywords : binding * light * array Subject RIV: BH - Optics, Masers, Lasers Impact factor: 3.844, year: 2011

  15. Allocation of spectral and spatial modes in multidimensional metro-access optical networks

    Science.gov (United States)

    Gao, Wenbo; Cvijetic, Milorad

    2018-04-01

    Introduction of spatial division multiplexing (SDM) has added a new dimension in an effort to increase optical fiber channel capacity. At the same time, it can also be explored as an advanced optical networking tool. In this paper, we have investigated the resource allocation to end-users in multidimensional networking structure with plurality of spectral and spatial modes actively deployed in different networking segments. This presents a more comprehensive method as compared to the common practice where the segments of optical network are analyzed independently since the interaction between network hierarchies is included into consideration. We explored the possible transparency from the metro/core network to the optical access network, analyzed the potential bottlenecks from the network architecture perspective, and identified an optimized network structure. In our considerations, the viability of optical grooming through the entire hierarchical all-optical network is investigated by evaluating the effective utilization and spectral efficiency of the network architecture.

  16. Optical characterication of probes for photon scanning tunnelling microscopy

    DEFF Research Database (Denmark)

    Vohnsen, Brian; Bozhevolnyi, Sergey I.

    1999-01-01

    The photon scanning tunnelling microscope is a well-established member of the family of scanning near-field optical microscopes used for optical imaging at the sub-wavelength scale. The quality of the probes, typically pointed uncoated optical fibres, used is however difficult to evaluate...

  17. Design of fiber optic probes for laser light scattering

    Science.gov (United States)

    Dhadwal, Harbans S.; Chu, Benjamin

    1989-01-01

    A quantitative analysis is presented of the role of optical fibers in laser light scattering. Design of a general fiber optic/microlens probe by means of ray tracing is described. Several different geometries employing an optical fiber of the type used in lightwave communications and a graded index microlens are considered. Experimental results using a nonimaging fiber optic detector probe show that due to geometrical limitations of single mode fibers, a probe using a multimode optical fiber has better performance, for both static and dynamic measurements of the scattered light intensity, compared with a probe using a single mode fiber. Fiber optic detector probes are shown to be more efficient at data collection when compared with conventional approaches to measurements of the scattered laser light. Integration of fiber optic detector probes into a fiber optic spectrometer offers considerable miniaturization of conventional light scattering spectrometers, which can be made arbitrarily small. In addition static and dynamic measurements of scattered light can be made within the scattering cell and consequently very close to the scattering center.

  18. An Evanescent Field Optical Microscope. Scanning probe Microscopy

    NARCIS (Netherlands)

    van Hulst, N.F.; Segerink, Franciscus B.; Bölger, B.; Bölger, B.; Wickramasinghe, H. Kumar

    1991-01-01

    An Evanescent Field Optical Microscope (EFOM) is presented, which employs frustrated total internal reflection on a highly localized scale by means of a sharp dielectric tip. The coupling of the evanescent field to the sub-micrometer probe as a function of probe-sample distance, angle of incidence

  19. Logarithmic axicon characterized by scanning optical probe system.

    Science.gov (United States)

    Cao, Zhaolou; Wang, Keyi; Wu, Qinglin

    2013-05-15

    A scanning optical probe system is proposed to measure a logarithmic axicon (LA) with subwavelength resolution. Multiple plane intensity profiles measured by a fiber probe are interpreted by solving an optimization problem to get the phase retardation function (PRF) of the LA. Experimental results show that this approach can accurately obtain the PRF with which the optical path difference of the generated quasi-nondiffracting beam in the propagation is calculated.

  20. Multi-dimensional fiber-optic radiation sensor for ocular proton therapy dosimetry

    International Nuclear Information System (INIS)

    Jang, K.W.; Yoo, W.J.; Moon, J.; Han, K.T.; Park, B.G.; Shin, D.; Park, S-Y.; Lee, B.

    2012-01-01

    In this study, we fabricated a multi-dimensional fiber-optic radiation sensor, which consists of organic scintillators, plastic optical fibers and a water phantom with a polymethyl methacrylate structure for the ocular proton therapy dosimetry. For the purpose of sensor characterization, we measured the spread out Bragg-peak of 120 MeV proton beam using a one-dimensional sensor array, which has 30 fiber-optic radiation sensors with a 1.5 mm interval. A uniform region of spread out Bragg-peak using the one-dimensional fiber-optic radiation sensor was obtained from 20 to 25 mm depth of a phantom. In addition, the Bragg-peak of 109 MeV proton beam was measured at the depth of 11.5 mm of a phantom using a two-dimensional sensor array, which has 10×3 sensor array with a 0.5 mm interval.

  1. MODA: a new algorithm to compute optical depths in multidimensional hydrodynamic simulations

    Science.gov (United States)

    Perego, Albino; Gafton, Emanuel; Cabezón, Rubén; Rosswog, Stephan; Liebendörfer, Matthias

    2014-08-01

    Aims: We introduce the multidimensional optical depth algorithm (MODA) for the calculation of optical depths in approximate multidimensional radiative transport schemes, equally applicable to neutrinos and photons. Motivated by (but not limited to) neutrino transport in three-dimensional simulations of core-collapse supernovae and neutron star mergers, our method makes no assumptions about the geometry of the matter distribution, apart from expecting optically transparent boundaries. Methods: Based on local information about opacities, the algorithm figures out an escape route that tends to minimize the optical depth without assuming any predefined paths for radiation. Its adaptivity makes it suitable for a variety of astrophysical settings with complicated geometry (e.g., core-collapse supernovae, compact binary mergers, tidal disruptions, star formation, etc.). We implement the MODA algorithm into both a Eulerian hydrodynamics code with a fixed, uniform grid and into an SPH code where we use a tree structure that is otherwise used for searching neighbors and calculating gravity. Results: In a series of numerical experiments, we compare the MODA results with analytically known solutions. We also use snapshots from actual 3D simulations and compare the results of MODA with those obtained with other methods, such as the global and local ray-by-ray method. It turns out that MODA achieves excellent accuracy at a moderate computational cost. In appendix we also discuss implementation details and parallelization strategies.

  2. Note: Folded optical system for narrow forward looking probe

    International Nuclear Information System (INIS)

    Hou, Hsuan-Chao; Hah, Dooyoung; Kim, Jeonghwan; Feldman, M.

    2014-01-01

    An optical system is described in which a laser beam makes three passes through a single graded index lens, forming a focus along the optic axis. It has important applications in endoscopic probes, where the forward looking characteristic permits the avoidance of obstacles and the narrow structure makes it minimally invasive

  3. Novel optical probe for quantum Hall system

    Indian Academy of Sciences (India)

    to explore Landau levels of a two-dimensional electron gas (2DEG) in modulation doped ... Keywords. Surface photovoltage spectroscopy; quantum Hall effect; Landau levels; edge states. ... An optical fibre carries light from tunable diode laser.

  4. In-line optical fiber metallic mirror reflector for monolithic common path optical coherence tomography probes.

    Science.gov (United States)

    Singh, Kanwarpal; Reddy, Rohith; Sharma, Gargi; Verma, Yogesh; Gardecki, Joseph A; Tearney, Guillermo

    2018-03-01

    Endoscopic optical coherence tomography probes suffer from various artifacts due to dispersion imbalance and polarization mismatch between reference and sample arm light. Such artifacts can be minimized using a common path approach. In this work, we demonstrate a miniaturized common path probe for optical coherence tomography using an inline fiber mirror. A common path optical fiber probe suitable for performing high-resolution endoscopic optical coherence tomography imaging was developed. To achieve common path functionality, an inline fiber mirror was fabricated using a thin gold layer. A commercially available swept source engine was used to test the designed probe in a cadaver human coronary artery ex vivo. We achieved a sensitivity of 104 dB for this probe using a swept source optical coherence tomography system. To test the probe, images of a cadaver human coronary artery were obtained, demonstrating the quality that is comparable to those obtained by OCT systems with separate reference arms. Additionally, we demonstrate recovery of ranging depth by use of a Michelson interferometer in the detection path. We developed a miniaturized monolithic inline fiber mirror-based common path probe for optical coherence tomography. Owing to its simplicity, our design will be helpful in endoscopic applications that require high-resolution probes in a compact form factor while reducing system complexity. Lasers Surg. Med. 50:230-235, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. Optical sensors and their applications for probing biological systems

    DEFF Research Database (Denmark)

    Palanco, Marta Espina

    There is a great interest in exploring and developing new optical sensitive methodologies for probing complex biological systems. In this project we developed non-invasive and sensitive biosensor strategies for studying physiologically relevant chemical and physical properties of plant and mammal......There is a great interest in exploring and developing new optical sensitive methodologies for probing complex biological systems. In this project we developed non-invasive and sensitive biosensor strategies for studying physiologically relevant chemical and physical properties of plant...... of a trapped cell. The project could provide new insights into the desired biosensor for future membrane-protein cell studies....

  6. Light distribution analysis of optical fibre probe-based near-field optical tweezers using FDTD

    Energy Technology Data Exchange (ETDEWEB)

    Liu, B H; Yang, L J; Wang, Y [School of Mechanical and Electrical Engineering, Harbin Institute of Technology, Heilongjiang, Harbin, 150001 (China)], E-mail: richelaw@163.com

    2009-09-01

    Optical fibre probe-based near-field optical tweezers overcomes the diffraction limit of conventional optical tweezers, utilizing strong mechanical forces and torque associated with highly enhanced electric fields to trap and manipulate nano-scale particles. Near-field evanescent wave generated at optical fibre probe decays rapidly with the distance that results a significant reduced trapping volume, thus it is necessary to analyze the near-field distribution of optical fibre probe. The finite difference time domain (FDTD) method is applied to characterize the near-field distribution of optical fibre probe. In terms of the distribution patterns, depolarization and polarization, the near-field distributions in longitudinal sections and cross-sections of tapered metal-coated optical fibre probe are calculated. The calculation results reveal that the incident polarized wave becomes depolarized after exiting from the nano-scale aperture of probe. The near-field distribution of the probe is unsymmetrical, and the near-field distribution in the cross-section vertical to the incident polarized wave is different from that in the cross-section parallel to the incident polarized wave. Moreover, the polarization of incident wave has a great impact on the light intensity distribution.

  7. Gold nanocone probes for near-field scanning optical microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Zeeb, Bastian; Schaefer, Christian; Nill, Peter; Fleischer, Monika; Kern, Dieter P. [Institute of Applied Physics, University of Tuebingen, Auf der Morgenstelle 10, 72076 Tuebingen (Germany)

    2010-07-01

    Apertureless near-field scanning optical microscopy (ANSOM) provides the possibility to collect simultaneously high-resolution topographical and sub-diffraction limited optical information from a surface. When optically excited, the scanning probes act as optical antennae with a strong near-field enhancement near the tip apex. Spatial resolution and optical near-field enhancement depend strongly on the properties and geometry of the scanning probe - in particular on very sharp tip radii. Various possibilities for fabricating good antennae have been pursued. Most commonly, scanning probes consist of electrochemically etched gold wires which are sharp but not well-defined in geometry. We present two different approaches for ultra sharp and well-defined antennae based upon fabricating gold nanocones with a tip radius smaller than 10 nm which can be used in ANSOM. A transfer process is presented that can be used to attach single gold nanocones to non-metallic probes such as sharp glass fiber tips. Alternatively, new processes are presented to fabricate cones directly on pillars of different materials such as silicon or bismuth, which can be applied to cantilever tips for ANSOM scanning applications.

  8. Software Defined Networking (SDN) controlled all optical switching networks with multi-dimensional switching architecture

    Science.gov (United States)

    Zhao, Yongli; Ji, Yuefeng; Zhang, Jie; Li, Hui; Xiong, Qianjin; Qiu, Shaofeng

    2014-08-01

    Ultrahigh throughout capacity requirement is challenging the current optical switching nodes with the fast development of data center networks. Pbit/s level all optical switching networks need to be deployed soon, which will cause the high complexity of node architecture. How to control the future network and node equipment together will become a new problem. An enhanced Software Defined Networking (eSDN) control architecture is proposed in the paper, which consists of Provider NOX (P-NOX) and Node NOX (N-NOX). With the cooperation of P-NOX and N-NOX, the flexible control of the entire network can be achieved. All optical switching network testbed has been experimentally demonstrated with efficient control of enhanced Software Defined Networking (eSDN). Pbit/s level all optical switching nodes in the testbed are implemented based on multi-dimensional switching architecture, i.e. multi-level and multi-planar. Due to the space and cost limitation, each optical switching node is only equipped with four input line boxes and four output line boxes respectively. Experimental results are given to verify the performance of our proposed control and switching architecture.

  9. Demonstration of a Fiber Optic Regression Probe

    Science.gov (United States)

    Korman, Valentin; Polzin, Kurt A.

    2010-01-01

    The capability to provide localized, real-time monitoring of material regression rates in various applications has the potential to provide a new stream of data for development testing of various components and systems, as well as serving as a monitoring tool in flight applications. These applications include, but are not limited to, the regression of a combusting solid fuel surface, the ablation of the throat in a chemical rocket or the heat shield of an aeroshell, and the monitoring of erosion in long-life plasma thrusters. The rate of regression in the first application is very fast, while the second and third are increasingly slower. A recent fundamental sensor development effort has led to a novel regression, erosion, and ablation sensor technology (REAST). The REAST sensor allows for measurement of real-time surface erosion rates at a discrete surface location. The sensor is optical, using two different, co-located fiber-optics to perform the regression measurement. The disparate optical transmission properties of the two fiber-optics makes it possible to measure the regression rate by monitoring the relative light attenuation through the fibers. As the fibers regress along with the parent material in which they are embedded, the relative light intensities through the two fibers changes, providing a measure of the regression rate. The optical nature of the system makes it relatively easy to use in a variety of harsh, high temperature environments, and it is also unaffected by the presence of electric and magnetic fields. In addition, the sensor could be used to perform optical spectroscopy on the light emitted by a process and collected by fibers, giving localized measurements of various properties. The capability to perform an in-situ measurement of material regression rates is useful in addressing a variety of physical issues in various applications. An in-situ measurement allows for real-time data regarding the erosion rates, providing a quick method for

  10. Endoscopic optical coherence tomography with a focus-adjustable probe.

    Science.gov (United States)

    Liao, Wenchao; Chen, Tianyuan; Wang, Chengming; Zhang, Wenxin; Peng, Zhangkai; Zhang, Xiao; Ai, Shengnan; Fu, Deyong; Zhou, Tieying; Xue, Ping

    2017-10-15

    We present a focus-adjustable endoscopic probe for optical coherence tomography (OCT), which is able to acquire images with different focal planes and overcome depth-of-focus limitations by image fusing. The use of a two-way shape-memory-alloy spring enables the probe to adjust working distance over 1.5 mm, providing a large scanning range with high resolution and no sensitivity loss. Equipped with a homemade hollow-core ultrasonic motor, the probe is capable of performing an unobstructed 360 deg field-of-view distal scanning. Both the axial resolution and the best lateral resolution are ∼4  μm, with a sensitivity of 100.3 dB. Spectral-domain OCT imaging of phantom and biological tissues with the probe is also demonstrated.

  11. Evaluation of insertion characteristics of less invasive Si optoneural probe with embedded optical fiber

    Science.gov (United States)

    Morikawa, Takumi; Harashima, Takuya; Kino, Hisashi; Fukushima, Takafumi; Tanaka, Tetsu

    2017-04-01

    A less invasive Si optoneural probe with an embedded optical fiber was proposed and successfully fabricated. The diameter of the optical fiber was completely controlled by hydrogen fluoride etching, and the thinned optical fiber can propagate light without any leakage. This optical fiber was embedded in a trench formed inside a probe shank, which causes less damage to tissues. In addition, it was confirmed that the optical fiber embedded in the probe shank successfully irradiated light to optically stimulate gene transfected neurons. The electrochemical impedance of the probe did not change despite the light irradiation. Furthermore, probe insertion characteristics were evaluated in detail and less invasive insertion was clearly indicated for the Si optoneural probe with the embedded optical fiber compared with conventional optical neural probes. This neural probe with the embedded optical fiber can be used as a simple and easy tool for optogenetics and brain science.

  12. Valley-selective optical Stark effect probed by Kerr rotation

    Science.gov (United States)

    LaMountain, Trevor; Bergeron, Hadallia; Balla, Itamar; Stanev, Teodor K.; Hersam, Mark C.; Stern, Nathaniel P.

    2018-01-01

    The ability to monitor and control distinct states is at the heart of emerging quantum technologies. The valley pseudospin in transition metal dichalcogenide (TMDC) monolayers is a promising degree of freedom for such control, with the optical Stark effect allowing for valley-selective manipulation of energy levels in WS2 and WSe2 using ultrafast optical pulses. Despite these advances, understanding of valley-sensitive optical Stark shifts in TMDCs has been limited by reflectance-based detection methods where the signal is small and prone to background effects. More sensitive polarization-based spectroscopy is required to better probe ultrafast Stark shifts for all-optical manipulation of valley energy levels. Here, we show time-resolved Kerr rotation to be a more sensitive probe of the valley-selective optical Stark effect in monolayer TMDCs. Compared to the established time-resolved reflectance methods, Kerr rotation is less sensitive to background effects. Kerr rotation provides a fivefold improvement in the signal-to-noise ratio of the Stark effect optical signal and a more precise estimate of the energy shift. This increased sensitivity allows for observation of an optical Stark shift in monolayer MoS2 that exhibits both valley and energy selectivity, demonstrating the promise of this method for investigating this effect in other layered materials and heterostructures.

  13. Optically probing torsional superelasticity in spider silks

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Bhupesh; Thakur, Ashish; Panda, Biswajit; Singh, Kamal P. [Department of Physical Sciences, IISER Mohali, Sector 81, Manauli, Mohali 140306 (India)

    2013-11-11

    We investigate torsion mechanics of various spider silks using a sensitive optical technique. We find that spider silks are torsionally superelastic in that they can reversibly withstand great torsion strains of over 10{sup 2−3} rotations per cm before failure. Among various silks from a spider, we find the failure twist-strain is greatest in the sticky capture silk followed by dragline and egg-case silk. Our in situ laser-diffraction measurements reveal that torsional strains on the silks induce a nano-scale transverse compression in its diameter that is linear and reversible. These unique torsional properties of the silks could find applications in silk-based materials and devices.

  14. Optically probing torsional superelasticity in spider silks

    International Nuclear Information System (INIS)

    Kumar, Bhupesh; Thakur, Ashish; Panda, Biswajit; Singh, Kamal P.

    2013-01-01

    We investigate torsion mechanics of various spider silks using a sensitive optical technique. We find that spider silks are torsionally superelastic in that they can reversibly withstand great torsion strains of over 10 2−3 rotations per cm before failure. Among various silks from a spider, we find the failure twist-strain is greatest in the sticky capture silk followed by dragline and egg-case silk. Our in situ laser-diffraction measurements reveal that torsional strains on the silks induce a nano-scale transverse compression in its diameter that is linear and reversible. These unique torsional properties of the silks could find applications in silk-based materials and devices

  15. Miniature fibre optic probe for minimally invasive photoacoustic sensing

    Science.gov (United States)

    Mathews, Sunish J.; Zhang, Edward Z.; Desjardins, Adrien E.; Beard, Paul C.

    2016-03-01

    A miniature (175 μm) all-optical photoacoustic probe has been developed for minimally invasive sensing and imaging applications. The probe comprises a single optical fibre which delivers the excitation light and a broadband 50 MHz Fabry-Pérot (F-P) ultrasound sensor at the distal end for detecting the photoacoustic waves. A graded index lens proximal to the F-P sensor is used to reduce beam walk-off and thus increase sensitivity as well as confine the excitation beam in order to increase lateral spatial resolution. The probe was evaluated in non-scattering media and found to provide lateral and axial resolutions of < 100 μm and < 150 μm respectively for distances up to 1 cm from the tip of the probe. The ability of the probe to detect a blood vessel mimicking phantom at distances up to 7 mm from the tip was demonstrated in order to illustrate its potential suitability for needle guidance applications.

  16. Optically Levitated Microspheres as a Probe for New Interactions

    Science.gov (United States)

    Rider, Alexander; Moore, David; Blakemore, Charles; Lu, Marie; Gratta, Giorgio

    2016-03-01

    We are developing novel techniques to probe new interactions at micron distances using optically levitated dielectric microspheres. Levitated microspheres are an ideal probe for short-range interactions because they are suspended using the radiation pressure at the focus of a laser beam, which means that the microspheres can be precisely manipulated and isolated from the surrounding environment at high vacuum. We have performed a search for unknown charged particles bound within the bulk of the microspheres. Currently, we are searching for the presence of a Chameleon field postulated to explain the presence of dark energy in the universe. In the future we plan to use optically levitated microspheres to search for micron length-scale gravity like interactions that could couple between a microsphere and another mass. We will present resent results from these experiments and plans for future searches for new interactions.

  17. Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology

    Science.gov (United States)

    Chullen, Cinda

    2015-01-01

    Advancement of Miniature Optic Gas Sensor (MOGS) Probe Technology" project will investigate newly developed optic gas sensors delivered from a Small Business Innovative Research (SBIR) Phase II effort. A ventilation test rig will be designed and fabricated to test the sensors while integrated with a Suited Manikin Test Apparatus (SMTA). Once the sensors are integrated, a series of test points will be completed to verify that the sensors can withstand Advanced Suit Portable Life Support System (PLSS) environments and associated human metabolic profiles for changes in pressure and levels of Oxygen (ppO2), carbon dioxide (ppCO2), and humidity (ppH2O).

  18. Local probing and stimulation of neuronal cells by optical manipulation

    Science.gov (United States)

    Cojoc, Dan

    2014-09-01

    During development and in the adult brain, neurons continuously explore the environment searching for guidance cues, leading to the appropriate connections. Elucidating these mechanisms represents a gold goal in neurobiology. Here, I discuss our recent achievements developing new approaches to locally probe the growth cones and stimulate neuronal cell compartments with high spatial and temporal resolution. Optical tweezers force spectroscopy applied in conjunction with metabolic inhibitors reveals new properties of the cytoskeleton dynamics. On the other hand, using optically manipulated microvectors as functionalized beads or filled liposomes, we demonstrate focal stimulation of neurons by small number of signaling molecules.

  19. Processing of Graphene combining Optical Detection and Scanning Probe Lithography

    Directory of Open Access Journals (Sweden)

    Zimmermann Sören

    2015-01-01

    Full Text Available This paper presents an experimental setup tailored for robotic processing of graphene with in-situ vision based control. A robust graphene detection approach is presented applying multiple image processing operations of the visual feedback provided by a high-resolution light microscope. Detected graphene flakes can be modified using a scanning probe based lithographical process that is directly linked to the in-situ optical images. The results of this process are discussed with respect to further application scenarios.

  20. Multidimensional gray-wavelet processing in interferometric fiber-optic gyroscopes

    International Nuclear Information System (INIS)

    Yang, Yi; Wang, Zinan; Peng, Chao; Li, Zhengbin

    2013-01-01

    A multidimensional signal processing method for a single interferometric fiber-optic gyroscope (IFOG) is proposed, to the best of our knowledge, for the first time. The proposed method, based on a novel IFOG structure with quadrature demodulation, combines a multidimensional gray model (GM) and a wavelet compression technique for noise suppression and sensitivity enhancement. In the IFOG, two series of measured rotation rates are obtained simultaneously: an in-phase component and a quadrature component. Together with the traditionally measured rate, the three measured rates are processed by the combined gray-wavelet method. Simulations show that the intensity noise and non-reciprocal phase fluctuations are effectively suppressed by this method. Experimental comparisons with a one-dimensional GM(1, 1) model show that the proposed three-dimensional method achieves much better denoising performance. This advantage is validated by the Allan variance analysis: in a low-SNR (signal-to-noise ratio) experiment, our method reduces the angle random walk (ARW) and the bias instability (BI) from 1 × 10 −2  deg h −1/2 and 3 × 10 −2  deg h −1 to 1 × 10 −3  deg h −1/2 and 3 × 10 −3  deg h −1 , respectively; in a high-SNR experiment, our method reduces the ARW and the BI from 9 × 10 −4  deg h −1/2 and 5 × 10 −3  deg h −1 to 4 × 10 −4  deg h −1/2 and 3 × 10 −3  deg h −1 , respectively. Further, our method increases the dimension of the state-of-the-art IFOG technique from one to three, thus obtaining higher IFOG sensitivity and stability by exploiting the increase in available information. (paper)

  1. Multidimensional gray-wavelet processing in interferometric fiber-optic gyroscopes

    Science.gov (United States)

    Yang, Yi; Wang, Zinan; Peng, Chao; Li, Zhengbin

    2013-11-01

    A multidimensional signal processing method for a single interferometric fiber-optic gyroscope (IFOG) is proposed, to the best of our knowledge, for the first time. The proposed method, based on a novel IFOG structure with quadrature demodulation, combines a multidimensional gray model (GM) and a wavelet compression technique for noise suppression and sensitivity enhancement. In the IFOG, two series of measured rotation rates are obtained simultaneously: an in-phase component and a quadrature component. Together with the traditionally measured rate, the three measured rates are processed by the combined gray-wavelet method. Simulations show that the intensity noise and non-reciprocal phase fluctuations are effectively suppressed by this method. Experimental comparisons with a one-dimensional GM(1, 1) model show that the proposed three-dimensional method achieves much better denoising performance. This advantage is validated by the Allan variance analysis: in a low-SNR (signal-to-noise ratio) experiment, our method reduces the angle random walk (ARW) and the bias instability (BI) from 1 × 10-2 deg h-1/2 and 3 × 10-2 deg h-1 to 1 × 10-3 deg h-1/2 and 3 × 10-3 deg h-1, respectively; in a high-SNR experiment, our method reduces the ARW and the BI from 9 × 10-4 deg h-1/2 and 5 × 10-3 deg h-1 to 4 × 10-4 deg h-1/2 and 3 × 10-3 deg h-1, respectively. Further, our method increases the dimension of the state-of-the-art IFOG technique from one to three, thus obtaining higher IFOG sensitivity and stability by exploiting the increase in available information.

  2. Near-field scanning optical microscopy using polymethylmethacrylate optical fiber probes

    International Nuclear Information System (INIS)

    Chibani, H.; Dukenbayev, K.; Mensi, M.; Sekatskii, S.K.; Dietler, G.

    2010-01-01

    We report the first use of polymethylmethacrylate (PMMA) optical fiber-made probes for scanning near-field optical microscopy (SNOM). The sharp tips were prepared by chemical etching of the fibers in ethyl acetate, and the probes were prepared by proper gluing of sharpened fibers onto the tuning fork in the conditions of the double resonance (working frequency of a tuning fork coincides with the resonance frequency of dithering of the free-standing part of the fiber) reported earlier for the case of glass fibers. Quality factors of the probes in the range 2000-6000 were obtained, which enables the realization of an excellent topographical resolution including state-of-art imaging of single DNA molecules. Near-field optical performance of the microscope is illustrated by the Photon Scanning Tunneling Microscope images of fluorescent beads with a diameter of 100 nm. The preparation of these plastic fiber probes proved to be easy, needs no hazardous material and/or procedures, and typical lifetime of a probe essentially exceeds that characteristic for the glass fiber probe.

  3. Probing molecular chirality by coherent optical absorption spectra

    Energy Technology Data Exchange (ETDEWEB)

    Jia, W. Z. [Quantum Optoelectronics Laboratory, School of Physics and Technology, Southwest Jiaotong University, Chengdu 610031 (China); Wei, L. F. [Quantum Optoelectronics Laboratory, School of Physics and Technology, Southwest Jiaotong University, Chengdu 610031 (China); State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-Sen University, Guangzhou 510275 (China)

    2011-11-15

    We propose an approach to sensitively probe the chirality of molecules by measuring their coherent optical-absorption spectra. It is shown that quantum dynamics of the cyclic three-level chiral molecules driven by appropriately designed external fields is total-phase dependent. This will result in chirality-dependent absorption spectra for the probe field. As a consequence, the charality-dependent information in the spectra (such as the locations and relative heights of the characteristic absorption peaks) can be utilized to identify molecular chirality and determinate enantiomer excess (i.e., the percentages of different enantiomers). The feasibility of the proposal with chiral molecules confined in hollow-core photonic crystal fiber is also discussed.

  4. Micromachined fiber optic Fabry-Perot underwater acoustic probe

    Science.gov (United States)

    Wang, Fuyin; Shao, Zhengzheng; Hu, Zhengliang; Luo, Hong; Xie, Jiehui; Hu, Yongming

    2014-08-01

    One of the most important branches in the development trend of the traditional fiber optic physical sensor is the miniaturization of sensor structure. Miniature fiber optic sensor can realize point measurement, and then to develop sensor networks to achieve quasi-distributed or distributed sensing as well as line measurement to area monitoring, which will greatly extend the application area of fiber optic sensors. The development of MEMS technology brings a light path to address the problems brought by the procedure of sensor miniaturization. Sensors manufactured by MEMS technology possess the advantages of small volume, light weight, easy fabricated and low cost. In this paper, a fiber optic extrinsic Fabry-Perot interferometric underwater acoustic probe utilizing micromachined diaphragm collaborated with fiber optic technology and MEMS technology has been designed and implemented to actualize underwater acoustic sensing. Diaphragm with central embossment, where the embossment is used to anti-hydrostatic pressure which would largely deflect the diaphragm that induce interferometric fringe fading, has been made by double-sided etching of silicon on insulator. By bonding the acoustic-sensitive diaphragm as well as a cleaved fiber end in ferrule with an outer sleeve, an extrinsic Fabry-Perot interferometer has been constructed. The sensor has been interrogated by quadrature-point control method and tested in field-stable acoustic standing wave tube. Results have been shown that the recovered signal detected by the sensor coincided well with the corresponding transmitted signal and the sensitivity response was flat in frequency range from 10 Hz to 2kHz with the value about -154.6 dB re. 1/μPa. It has been manifest that the designed sensor could be used as an underwater acoustic probe.

  5. Double optical fibre-probe device for the diagnosis of melanocytic lesions

    Science.gov (United States)

    Cicchi, Riccardo; Cosci, Alessandro; Rossari, Susanna; De Giorgi, Vincenzo; Kapsokalyvas, Dimitrios; Massi, Daniela; Pavone, Francesco S.

    2012-06-01

    We have designed and developed an optical fiber-probe for spectroscopic measurements on human tissues. The experimental setup combines fluorescence spectroscopy and Raman spectroscopy in a multidimensional approach. Concerning fluorescence spectroscopy, the excitation is provided by two laser diodes, one emitting in the UV (378 nm) and the other emitting in the visible (445 nm). These two lasers are used to selectively excite fluorescence from NADH and FAD, which are among the brightest endogenous fluorophores in human tissues. For Raman and NIR spectroscopy, the excitation is provided by a third laser diode with 785 nm excitation wavelength. Laser light is delivered to the tissue through the central optical fiber of a fiber bundle. The surrounding 48 fibers of the bundle are used for collecting fluorescence and Raman and for delivering light to the spectrograph. Fluorescence and Raman spectra are acquired on a cooled CCD camera. The instrument has been tested on fresh human skin biopsies clinically diagnosed as malignant melanoma, melanocytic nevus, or healthy skin, finding an optimal correlation with the subsequent histological exam. In some cases our examination was not in agreement with the clinical observation, but it was with the histological exam, demonstrating that the system can potentially contribute to improve clinical diagnostic capabilities and hence reduce the number of unnecessary biopsies.

  6. On the passive probing of fiber optic quantum communication channels

    International Nuclear Information System (INIS)

    Korol'kov, A. V.; Katamadze, K. G.; Kulik, S. P.; Molotkov, S. N.

    2010-01-01

    Avalanche photodetectors based on InGaAs:P are the most sensitive and only detectors operating in the telecommunication wavelength range 1.30-1.55 μm in the fiber optic quantum cryptography systems that can operate in the single photon count mode. In contrast to the widely used silicon photodetectors for wavelengths up to 1 μm operating in a waiting mode, these detectors always operate in a gated mode. The production of an electron-hole pair in the process of the absorption of a photon and the subsequent appearance of an avalanche of carriers can be accompanied by the inverse processes of the recombination and emission of photons. Such a backward emission can present a potential serious problem for the stability of fiber optic quantum cryptography systems against passive probing. The results of analyzing the detection of backscattered radiation are reported. The probability of such an emission has been estimated.

  7. The development of formative assessment probes for optics education

    Science.gov (United States)

    Dokter, Erin F. C.; Pompea, Stephen M.; Sparks, Robert T.; Walker, Constance E.

    2010-08-01

    Research exploring students' knowledge of optics from elementary through college has revealed that many concepts can be difficult for students to grasp. This can be the case particularly with fundamental concepts, such as the nature of light, how light interacts with matter, and how light behaves in optical systems. The use of formative assessment probes (low-stakes questions posed to students before instruction or in real-time in the classroom) can inform instructors about student background knowledge, and can also be used as they progress through learning in class. By understanding what students know prior to instruction, and how well they are learning in real-time, instruction can be designed and modified in order to encourage the development of scientifically-accurate knowledge.

  8. Holography and thermalization in optical pump-probe spectroscopy

    Science.gov (United States)

    Bagrov, A.; Craps, B.; Galli, F.; Keränen, V.; Keski-Vakkuri, E.; Zaanen, J.

    2018-04-01

    Using holography, we model experiments in which a 2 +1 D strange metal is pumped by a laser pulse into a highly excited state, after which the time evolution of the optical conductivity is probed. We consider a finite-density state with mildly broken translation invariance and excite it by oscillating electric field pulses. At zero density, the optical conductivity would assume its thermalized value immediately after the pumping has ended. At finite density, pulses with significant dc components give rise to slow exponential relaxation, governed by a vector quasinormal mode. In contrast, for high-frequency pulses the amplitude of the quasinormal mode is strongly suppressed, so that the optical conductivity assumes its thermalized value effectively instantaneously. This surprising prediction may provide a stimulus for taking up the challenge to realize these experiments in the laboratory. Such experiments would test a crucial open question faced by applied holography: are its predictions artifacts of the large N limit or do they enjoy sufficient UV independence to hold at least qualitatively in real-world systems?

  9. Optical transponder DC probe [for pulsed power generator

    CERN Document Server

    Thompson, M C

    1999-01-01

    The Atlas Pulse Power, Marx Bank will produce significant electromagnetic interference potential (EMI) via its 192 spark-gaps and trigger systems (36 more spark gaps). The authors have a need to measure DC charge components to a fair degree of accuracy during charge to ensure a safe and balanced system. Isolation from elevated- deck and/or high EMI environments during DC voltage or current measurement has classically been approached using frequency modulation (FM) of an imposed carrier on an optical fiber coupled system. There are shortcomings in most systems that can generally be compensated for by various means. In their application of remote sensing, the power to run this remote probe was a central issue. As such the authors took another approach to monitor the DC charge record for the Atlas' Marx banks. (0 refs).

  10. Fiber-optic polarization diversity detection for rotary probe optical coherence tomography.

    Science.gov (United States)

    Lee, Anthony M D; Pahlevaninezhad, Hamid; Yang, Victor X D; Lam, Stephen; MacAulay, Calum; Lane, Pierre

    2014-06-15

    We report a polarization diversity detection scheme for optical coherence tomography with a new, custom, miniaturized fiber coupler with single mode (SM) fiber inputs and polarization maintaining (PM) fiber outputs. The SM fiber inputs obviate matching the optical lengths of the X and Y OCT polarization channels prior to interference and the PM fiber outputs ensure defined X and Y axes after interference. Advantages for this scheme include easier alignment, lower cost, and easier miniaturization compared to designs with free-space bulk optical components. We demonstrate the utility of the detection system to mitigate the effects of rapidly changing polarization states when imaging with rotating fiber optic probes in Intralipid suspension and during in vivo imaging of human airways.

  11. Fiber optic probe of free electron evanescent fields in the optical frequency range

    Energy Technology Data Exchange (ETDEWEB)

    So, Jin-Kyu, E-mail: js1m10@orc.soton.ac.uk; MacDonald, Kevin F. [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Zheludev, Nikolay I. [Optoelectronics Research Centre and Centre for Photonic Metamaterials, University of Southampton, Highfield, Southampton SO17 1BJ (United Kingdom); Centre for Disruptive Photonic Technologies, Nanyang Technological University, Singapore 637371 (Singapore)

    2014-05-19

    We introduce an optical fiber platform which can be used to interrogate proximity interactions between free-electron evanescent fields and photonic nanostructures at optical frequencies in a manner similar to that in which optical evanescent fields are sampled using nanoscale aperture probes in scanning near-field microscopy. Conically profiled optical fiber tips functionalized with nano-gratings are employed to couple electron evanescent fields to light via the Smith-Purcell effect. We demonstrate the interrogation of medium energy (30–50 keV) electron fields with a lateral resolution of a few micrometers via the generation and detection of visible/UV radiation in the 700–300 nm (free-space) wavelength range.

  12. Proceedings of "Optical Probes of Dynamics in Complex Environments"

    Energy Technology Data Exchange (ETDEWEB)

    Sension, R; Tokmakoff, A

    2008-04-01

    This document contains the proceedings from the symposium on Optical Probes of Dynamics in Complex Environments, which organized as part of the 235th National Meeting of the American Chemical Society in New Orleans, LA from April 6 to 10, 2008. The study of molecular dynamics in chemical reaction and biological processes using time ƒresolved spectroscopy plays an important role in our understanding of energy conversion, storage, and utilization problems. Fundamental studies of chemical reactivity, molecular rearrangements, and charge transport are broadly supported by the DOE Office of Science because of their role in the development of alternative energy sources, the understanding of biological energy conversion processes, the efficient utilization of existing energy resources, and the mitigation of reactive intermediates in radiation chemistry. In addition, time resolved spectroscopy is central to all of DOEs grand challenges for fundamental energy science. This symposium brought together leaders in the field of ultrafast spectroscopy, including experimentalists, theoretical chemists, and simulators, to discuss the most recent scientific and technological advances. DOE support for this conference was used to help young US and international scientists travel to the meeting. The latest technology in ultrafast infrared, optical, and xray spectroscopy and the scientific advances that these methods enable were covered. Particular emphasis was placed on new experimental methods used to probe molecular dynamics in liquids, solids, interfaces, nanostructured materials, and biomolecules.

  13. MEMS-based non-rotatory circumferential scanning optical probe for endoscopic optical coherence tomography

    Science.gov (United States)

    Xu, Yingshun; Singh, Janak; Siang, Teo Hui; Ramakrishna, Kotlanka; Premchandran, C. S.; Sheng, Chen Wei; Kuan, Chuah Tong; Chen, Nanguang; Olivo, Malini C.; Sheppard, Colin J. R.

    2007-07-01

    In this paper, we present a non-rotatory circumferential scanning optical probe integrated with a MEMS scanner for in vivo endoscopic optical coherence tomography (OCT). OCT is an emerging optical imaging technique that allows high resolution cross-sectional imaging of tissue microstructure. To extend its usage to endoscopic applications, a miniaturized optical probe based on Microelectromechanical Systems (MEMS) fabrication techniques is currently desired. A 3D electrothermally actuated micromirror realized using micromachining single crystal silicon (SCS) process highlights its very large angular deflection, about 45 degree, with low driving voltage for safety consideration. The micromirror is integrated with a GRIN lens into a waterproof package which is compatible with requirements for minimally invasive endoscopic procedures. To implement circumferential scanning substantially for diagnosis on certain pathological conditions, such as Barret's esophagus, the micromirror is mounted on 90 degree to optical axis of GRIN lens. 4 Bimorph actuators that are connected to the mirror on one end via supporting beams and springs are selected in this micromirror design. When actuators of the micromirror are driven by 4 channels of sinusoidal waveforms with 90 degree phase differences, beam focused by a GRIN is redirected out of the endoscope by 45 degree tilting mirror plate and achieve circumferential scanning pattern. This novel driving method making full use of very large angular deflection capability of our micromirror is totally different from previously developed or developing micromotor-like rotatory MEMS device for circumferential scanning.

  14. A stimuli-responsive smart lanthanide nanocomposite for multidimensional optical recording and encryption

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiang; Xie, Yujie; Zhang, Hao-Li; Chen, Hao; Cai, Huijuan; Liu, Weisheng; Tang, Yu [State Key Lab. of Applied Organic Chemistry, Key Lab. of Nonferrous Metal Chemistry and Resources Utilization of Gansu Province, College of Chemistry and Chemical Engineering, Lanzhou Univ. (China); Song, Bo [State Key Lab. of Fine Chemicals, School of Chemistry, Dalian Univ. of Technology, Dalian (China)

    2017-03-01

    A stimuli-responsive lanthanide-based smart nanocomposite has been fabricated by supramolecular assembly and applied as an active material in multidimensional memory materials. Conjugation of the lanthanide complexes with carbon dots provides a stimuli response that is based on the modulation of the energy level of the ligand and affords microsecond-to-nanosecond fluorescence lifetimes, giving rise to intriguing memory performance in the spatial and temporal dimension. The present study points to a new direction for the future development of multidimensional memory materials based on inorganic-organic hybrid nanosystems. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

  15. A method to control the fabrication of etched optical fiber probes with nanometric tips

    International Nuclear Information System (INIS)

    Tao, Miaomiao; Gu, Ning; Huang, Lan; Jin, Yonglong

    2010-01-01

    Optical fiber probes with small size tips have attracted much interest in the areas of biosensor and near-field scanning optical microscopy. Chemical etching is a common useful method to fabricate such probes. But it is difficult to study or determine the etching time and control the shape of the fiber during the etching. In this work, a new method combining a fiber optic spectrometer with static chemical etching has been developed to fabricate optical fiber probe nanotips, where the fiber optic spectrometer is used to measure the optical signal during the etching. By calculating and analyzing the testing data, the relationship between the apex angle and the optical signal can be obtained. Accordingly, the process of fabricating optical fibers based on the optical signal can be controlled

  16. Single molecule mapping of the optical field distribution of probes for near-field microscopy

    NARCIS (Netherlands)

    Veerman, J.A.; Garcia Parajo, M.F.; Kuipers, L.; van Hulst, N.F.

    1999-01-01

    The most difficult task in near-field scanning optical microscopy (NSOM) is to make a high quality subwavelength aperture probe, Recently we have developed high definition NSOM probes by focused ion beam (FIB) milling. These probes have a higher brightness, better polarization characteristics,

  17. Atomic quantum superposition state generation via optical probing

    DEFF Research Database (Denmark)

    Nielsen, Anne E. B.; Poulsen, Uffe Vestergaard; Negretti, Antonio

    2009-01-01

    investigate cavity enhanced probing with continuous beams of both coherent and squeezed light. The stochastic master equations used in the analysis are expressed in terms of the Hamiltonian of the probed system and the interaction between the probed system and the probe field and are thus quite generally...

  18. Optical imaging of non-fluorescent nanoparticle probes in live cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gufeng; Stender, Anthony S.; Sun, Wei; and Fang, Ning

    2009-12-17

    Precise imaging of cellular and subcellular structures and dynamic processes in live cells is crucial for fundamental research in life sciences and in medical applications. Non-fluorescent nanoparticles are an important type of optical probe used in live-cell imaging due to their photostability, large optical cross-sections, and low toxicity. Here, we provide an overview of recent developments in the optical imaging of non-fluorescent nanoparticle probes in live cells.

  19. Optical coherence tomography and optical coherence domain reflectometry for deep brain stimulation probe guidance

    Science.gov (United States)

    Jeon, Sung W.; Shure, Mark A.; Baker, Kenneth B.; Chahlavi, Ali; Hatoum, Nagi; Turbay, Massud; Rollins, Andrew M.; Rezai, Ali R.; Huang, David

    2005-04-01

    Deep Brain Stimulation (DBS) is FDA-approved for the treatment of Parkinson's disease and essential tremor. Currently, placement of DBS leads is guided through a combination of anatomical targeting and intraoperative microelectrode recordings. The physiological mapping process requires several hours, and each pass of the microelectrode into the brain increases the risk of hemorrhage. Optical Coherence Domain Reflectometry (OCDR) in combination with current methodologies could reduce surgical time and increase accuracy and safety by providing data on structures some distance ahead of the probe. For this preliminary study, we scanned a rat brain in vitro using polarization-insensitive Optical Coherence Tomography (OCT). For accurate measurement of intensity and attenuation, polarization effects arising from tissue birefringence are removed by polarization diversity detection. A fresh rat brain was sectioned along the coronal plane and immersed in a 5 mm cuvette with saline solution. OCT images from a 1294 nm light source showed depth profiles up to 2 mm. Light intensity and attenuation rate distinguished various tissue structures such as hippocampus, cortex, external capsule, internal capsule, and optic tract. Attenuation coefficient is determined by linear fitting of the single scattering regime in averaged A-scans where Beer"s law is applicable. Histology showed very good correlation with OCT images. From the preliminary study using OCT, we conclude that OCDR is a promising approach for guiding DBS probe placement.

  20. Scanning near-field optical microscopy and near-field optical probes: properties, fabrication, and control of parameters

    International Nuclear Information System (INIS)

    Dryakhlushin, V F; Veiko, V P; Voznesenskii, N B

    2007-01-01

    A brief review of modern applications of scanning near-field optical (SNO) devices in microscopy, spectroscopy, and lithography is presented in the introduction. The problem of the development of SNO probes, as the most important elements of SNO devices determining their resolution and efficiency, is discussed. Based on the works of the authors, two different methods for fabricating SNO probes by using the adiabatic tapering of an optical fibre are considered: the laser-heated mechanical drawing and chemical etching. A nondestructive optical method for controlling the nanometre aperture of SNO probes is proposed, substantiated, and tested experimentally. The method is based on the reconstruction of a near-field source with the help of a theoretical algorithm of the inverse problem from the experimental far-filed intensity distribution. Some prospects for a further refinement of the construction and technology of SNO probes are discussed. (optical microscopy)

  1. Dynamics of trapped atoms around an optical nanofiber probed through polarimetry.

    Science.gov (United States)

    Solano, Pablo; Fatemi, Fredrik K; Orozco, Luis A; Rolston, S L

    2017-06-15

    The evanescent field outside an optical nanofiber (ONF) can create optical traps for neutral atoms. We present a non-destructive method to characterize such trapping potentials. An off-resonance linearly polarized probe beam that propagates through the ONF experiences a slow axis of polarization produced by trapped atoms on opposite sides along the ONF. The transverse atomic motion is imprinted onto the probe polarization through the changing atomic index of refraction. By applying a transient impulse, we measure a time-dependent polarization rotation of the probe beam that provides both a rapid and non-destructive measurement of the optical trapping frequencies.

  2. Multidimensional high harmonic spectroscopy

    International Nuclear Information System (INIS)

    Bruner, Barry D; Soifer, Hadas; Shafir, Dror; Dudovich, Nirit; Serbinenko, Valeria; Smirnova, Olga

    2015-01-01

    High harmonic generation (HHG) has opened up a new frontier in ultrafast science where attosecond time resolution and Angstrom spatial resolution are accessible in a single measurement. However, reconstructing the dynamics under study is limited by the multiple degrees of freedom involved in strong field interactions. In this paper we describe a new class of measurement schemes for resolving attosecond dynamics, integrating perturbative nonlinear optics with strong-field physics. These approaches serve as a basis for multidimensional high harmonic spectroscopy. Specifically, we show that multidimensional high harmonic spectroscopy can measure tunnel ionization dynamics with high precision, and resolves the interference between multiple ionization channels. In addition, we show how multidimensional HHG can function as a type of lock-in amplifier measurement. Similar to multi-dimensional approaches in nonlinear optical spectroscopy that have resolved correlated femtosecond dynamics, multi-dimensional high harmonic spectroscopy reveals the underlying complex dynamics behind attosecond scale phenomena. (paper)

  3. Characterization of power induced heating and damage in fiber optic probes for near-field scanning optical microscopy

    Science.gov (United States)

    Dickenson, Nicholas E.; Erickson, Elizabeth S.; Mooren, Olivia L.; Dunn, Robert C.

    2007-05-01

    Tip-induced sample heating in near-field scanning optical microscopy (NSOM) is studied for fiber optic probes fabricated using the chemical etching technique. To characterize sample heating from etched NSOM probes, the spectra of a thermochromic polymer sample are measured as a function of probe output power, as was previously reported for pulled NSOM probes. The results reveal that sample heating increases rapidly to ˜55-60°C as output powers reach ˜50nW. At higher output powers, the sample heating remains approximately constant up to the maximum power studied of ˜450nW. The sample heating profiles measured for etched NSOM probes are consistent with those previously measured for NSOM probes fabricated using the pulling method. At high powers, both pulled and etched NSOM probes fail as the aluminum coating is damaged. For probes fabricated in our laboratory we find failure occurring at input powers of 3.4±1.7 and 20.7±6.9mW for pulled and etched probes, respectively. The larger half-cone angle for etched probes (˜15° for etched and ˜6° for pulled probes) enables more light delivery and also apparently leads to a different failure mechanism. For pulled NSOM probes, high resolution images of NSOM probes as power is increased reveal the development of stress fractures in the coating at a taper diameter of ˜6μm. These stress fractures, arising from the differential heating expansion of the dielectric and the metal coating, eventually lead to coating removal and probe failure. For etched tips, the absence of clear stress fractures and the pooled morphology of the damaged aluminum coating following failure suggest that thermal damage may cause coating failure, although other mechanisms cannot be ruled out.

  4. Confocal scanning microscopy with multiple optical probes for high speed measurements and better imaging

    Science.gov (United States)

    Chun, Wanhee; Lee, SeungWoo; Gweon, Dae-Gab

    2008-02-01

    Confocal scanning microscopy (CSM) needs a scanning mechanism because only one point information of specimen can be obtained. Therefore the speed of the confocal scanning microscopy is limited by the speed of the scanning tool. To overcome this limitation from scanning tool we propose another scanning mechanism. We make three optical probes in the specimen under confocal condition of each point. Three optical probes are moved by beam scanning mechanism with shared resonant scanning mirror (RM) and galvanometer driven mirror (GM). As each optical probe scan allocated region of the specimen, information from three points is obtained simultaneously and image acquisition time is reduced. Therefore confocal scanning microscopy with multiple optical probes is expected to have three times faster speed of the image acquisition than conventional one. And as another use, multiple optical probes to which different light wavelength is applied can scan whole same region respectively. It helps to obtain better contrast image in case of specimens having different optical characteristics for specific light wavelength. In conclusion confocal scanning microscopy with multiple optical probes is useful technique for views of image acquisition speed and image quality.

  5. Optical and electrical characterization at the nanoscale with a transparent probe of a scanning tunnelling microscope

    International Nuclear Information System (INIS)

    Sychugov, Ilya; Omi, Hiroo; Murashita, Tooru; Kobayashi, Yoshihiro

    2009-01-01

    A new type of scanning probe microscope, combining features of the scanning tunnelling microscope, the scanning tunnelling luminescence microscope with a transparent probe and the aperture scanning near-field optical microscope, is described. Proof-of-concept experiments were performed under ultrahigh vacuum conditions at varying temperature on GaAs/AlAs heterostructures.

  6. Neurosurgical hand-held optical coherence tomography (OCT) forward-viewing probe

    Science.gov (United States)

    Sun, Cuiru; Lee, Kenneth K. C.; Vuong, Barry; Cusimano, Michael; Brukson, Alexander; Mariampillai, Adrian; Standish, Beau A.; Yang, Victor X. D.

    2012-02-01

    A prototype neurosurgical hand-held optical coherence tomography (OCT) imaging probe has been developed to provide micron resolution cross-sectional images of subsurface tissue during open surgery. This new ergonomic hand-held probe has been designed based on our group's previous work on electrostatically driven optical fibers. It has been packaged into a catheter probe in the familiar form factor of the clinically accepted Bayonet shaped neurosurgical non-imaging Doppler ultrasound probes. The optical design was optimized using ZEMAX simulation. Optical properties of the probe were tested to yield an ~20 um spot size, 5 mm working distance and a 3.5 mm field of view. The scan frequency can be increased or decreased by changing the applied voltage. Typically a scan frequency of less than 60Hz is chosen to keep the applied voltage to less than 2000V. The axial resolution of the probe was ~15 um (in air) as determined by the OCT system. A custom-triggering methodology has been developed to provide continuous stable imaging, which is crucial for clinical utility. Feasibility of this probe, in combination with a 1310 nm swept source OCT system was tested and images are presented to highlight the usefulness of such a forward viewing handheld OCT imaging probe. Knowledge gained from this research will lay the foundation for developing new OCT technologies for endovascular management of cerebral aneurysms and transsphenoidal neuroendoscopic treatment of pituitary tumors.

  7. Probe-controlled soliton frequency shift in the regime of optical event horizon

    DEFF Research Database (Denmark)

    Gu, Jie; Guo, Hairun; Wang, Shaofei

    2015-01-01

    In optical analogy of the event horizon, temporal pulse collision and mutual interactions are mainly between an intense solitary wave (soliton) and a dispersive probe wave. In such a regime, here we numerically investigate the probe-controlled soliton frequency shift as well as the soliton self...

  8. Quantitative measurements in laser-induced plasmas using optical probing. Final report

    International Nuclear Information System (INIS)

    Sweeney, D.W.

    1981-01-01

    Optical probing of laser induced plasmas can be used to quantitatively reconstruct electron number densities and magnetic fields. Numerical techniques for extracting quantitative information from the experimental data are described. A computer simulation of optical probing is used to determine the quantitative information that can be reasonably extracted from real experimental interferometric systems to reconstruct electron number density distributions. An example of a reconstructed interferogram shows a steepened electron distribution due to radiation pressure effects

  9. Three-Dimensional Optical Trapping for Cell Isolation Using Tapered Fiber Probe by Dynamic Chemical Etching

    International Nuclear Information System (INIS)

    Taguchi, K; Okada, J; Nomura, Y; Tamura, K

    2012-01-01

    In this paper, chemically etched fiber probe was proposed for laser trapping and manipulation of cells. We fabricated tapered fiber probe by dynamic chemical etching technique. Three-Dimensional optical trap of a yeast cell dispersed in water solution could be formed by the fiber tip with 17deg tip. Optical forces were sufficient to move the yeast cell for trapping and manipulation. From these experimental results, it was found that our proposed tapered fiber tip was a promising tool for cell isolation.

  10. Fabrication of a novel nano-probe slide for near-field optical microscopy

    International Nuclear Information System (INIS)

    Yim, Sang-Youp; Jeang, Eun-Hee; Lee, Jae-Hoon; Park, Seung-Han; Cho, Kyu-Man

    2004-01-01

    A novel probe structure, which can act as a planar nano-probe slide for near-field microscopy, was proposed and fabricated. Sub-wavelength apertures on a Si substrate are successfully produced by means of standard photolithography techniques with properly selected masks. In particular, the anisotropic etching characteristics of Si substrate and the hardness of the Si 3 N 4 film are utilized. Probe-to-probe scanning of the fabricated near-field nano-probe slide shows sub-wavelength confinement of light and comparable throughput to the conventional optical fiber probe. We also show that the nano-probe slide can serve as a supporting base and a sub-wavelength aperture to obtain the near-field photoluminescence spectra of a limited number of CdSe nanocrystals.

  11. Combined fluorescence-Raman spectroscopy measurements with an optical fiber probe for the diagnosis of melanocytic lesions

    Science.gov (United States)

    Cosci, Alessandro; Cicchi, Riccardo; Rossari, Susanna; De Giorgi, Vincenzo; Massi, Daniela; Pavone, Francesco S.

    2012-02-01

    We have designed and developed an optical fiber-probe for spectroscopic measurements on human tissues. The experimental setup combines fluorescence spectroscopy and Raman spectroscopy in a multidimensional approach. Concerning fluorescence spectroscopy, the excitation is provided by two laser diodes, one emitting in the UV (378 nm) and the other emitting in the visible (445 nm). These two lasers are used to selectively excite fluorescence from NADH and FAD, which are among the brightest endogenous fluorophores in human tissues. For Raman and NIR spectroscopy, the excitation is provided by a third laser diode with 785 nm excitation wavelength. Laser light is delivered to the tissue through the central optical fiber of a fiber bundle. The surrounding 48 fibers of the bundle are used for collecting fluorescence and Raman and for delivering light to the spectrograph. Fluorescence and Raman spectra are acquired on a cooled CCD camera. The instrument has been tested on fresh human skin biopsies clinically diagnosed as malignant melanoma, melanocytic nevus, or healthy skin, finding an optimal correlation with the subsequent histological exam. In some cases our examination was not in agreement with the clinical observation, but it was with the histological exam, demonstrating that the system can potentially contribute to improve clinical diagnostic capabilities and hence reduce the number of unnecessary biopsies.

  12. Smart optical probes for near-infrared fluorescence imaging of Alzheimer's disease pathology

    International Nuclear Information System (INIS)

    Raymond, Scott B.; Bacskai, Brian J.; Skoch, Jesse; Hills, Ivory D.; Swager, Timothy M.; Nesterov, Evgueni E.

    2008-01-01

    Near-infrared fluorescent probes for amyloid-beta (Aβ) are an exciting option for molecular imaging in Alzheimer's disease research and may translate to clinical diagnostics. However, Aβ-targeted optical probes often suffer from poor specificity and slow clearance from the brain. We are designing smart optical probes that emit characteristic fluorescence signal only when bound to Aβ. We synthesized a family of dyes and tested Aβ-binding sensitivity with fluorescence spectroscopy and tissue-staining. Select compounds exhibited Aβ-dependent changes in fluorescence quantum yield, lifetime, and emission spectra that may be imaged microscopically or in vivo using new lifetime and spectral fluorescence imaging techniques. Smart optical probes that turn on when bound to Aβ will improve amyloid detection and may enable quantitative molecular imaging in vivo. (orig.)

  13. Measurement of gas phase characteristics using new monofiber optical probes and real time signal processing

    International Nuclear Information System (INIS)

    Cartellier, A.

    1998-01-01

    Single optical or impedance phase detection probes are able to measure gas velocities provided that their sensitive length L is accurately known. In this paper, it is shown that L can be controlled during the manufacture of optical probes. Beside, for a probe geometry in the form of a cone + a cylinder + a cone, the corresponding rise time / velocity correlation becomes weakly sensitive to uncontrollable parameter such as the angle of impact on the interface. A real time signal processing performing phase detection as well as velocity measurements is described. Since its sensitivity to the operator inputs is less than the reproducibility of measurements, it is a fairly objective tool. Qualifications achieved in air/water flows with various optical probes demonstrate that the void fraction is detected with a relative error less than 10 %. For bubbly flows, the gas flux is accurate within ±10%, but this uncertainty increases when large bubbles are present in the flow. (author)

  14. High definition aperture probes for near-field optical microscopy fabricated by focused ion beam milling

    NARCIS (Netherlands)

    Veerman, J.A.; Otter, A.M.; Kuipers, L.; van Hulst, N.F.

    1998-01-01

    We have improved the optical characteristics of aluminum-coated fiber probes used in near-field scanning optical microscopy by milling with a focused ion beam. This treatment produces a flat-end face free of aluminum grains, containing a well- defined circularly-symmetric aperture with controllable

  15. Controlling the optical bistability and multistability in a two-level pumped-probe system

    International Nuclear Information System (INIS)

    Mahmoudi, Mohammad; Sahrai, Mostafa; Masoumeh Mousavi, Seyede

    2010-01-01

    We study the behavior of the optical bistability (OB) and multistability (OM) in a two-level pumped-probe atomic system by means of a unidirectional ring cavity. We show that the optical bistability in a two-level atomic system can be controlled by adjusting the intensity of the pump field and the detuning between two fields. We find that applying the pumping field decreases the threshold of the optical bistability.

  16. Application of carbon nanotubes to topographical resolution enhancement of tapered fiber scanning near field optical microscopy probes

    Science.gov (United States)

    Huntington, S. T.; Jarvis, S. P.

    2003-05-01

    Scanning near field optical microscopy (SNOM) probes are typically tapered optical fibers with metallic coatings. The tip diameters are generally in excess of 300 nm and thus provide poor topographical resolution. Here we report on the attachment multiwalled carbon nanotubes to the probes in order to substantially enhance the topographical resolution, without adversely affecting the optical resolution.

  17. Experimental Demonstration of Multidimensional Switching Nodes for All-Optical Data Center Networks

    DEFF Research Database (Denmark)

    Kamchevska, Valerija; Medhin, Ashenafi Kiros; Da Ros, Francesco

    2016-01-01

    architecture allows for scaling in different dimensions while at the same time providing support for connections with different granularity. The ring topology reduces the number of different physical links required, leading to simplified cabling and easier link management, while optical bypass holds...

  18. Multidimensional spectrometer

    Science.gov (United States)

    Zanni, Martin Thomas; Damrauer, Niels H.

    2010-07-20

    A multidimensional spectrometer for the infrared, visible, and ultraviolet regions of the electromagnetic spectrum, and a method for making multidimensional spectroscopic measurements in the infrared, visible, and ultraviolet regions of the electromagnetic spectrum. The multidimensional spectrometer facilitates measurements of inter- and intra-molecular interactions.

  19. Movable Thomson scattering system based on optical fiber (TS-probe)

    International Nuclear Information System (INIS)

    Narihara, K.; Hayashi, H.

    2009-01-01

    This paper proposes a movable compact Thomson scattering (TS) system based on optical fibers (TS-probe). A TS-probe consists of a probe head, optical fiber, a laser-diode, polychromators and lock-in amplifiers. A laser beam optics and light collection optics are mounted rigidly on a probe head with a fixed scattering position. Laser light and scattered light are transmitted by flexible optical fibers, enabling us to move the TS-prove head freely during plasma discharge. The light signal scattered from an amplitude-modulated laser is detected against the plasma light based on the principle of the lock-in amplifier. With a modulated laser power of 300W, the scattered signal from a sheet plasma of 15 mm depth and n e -10 19 m -3 will be measured with 10% accuracy by setting the integrating time to 0.1 s. The TS-probe head is like a 1/20 model of the currently operating LHD-TS. (author)

  20. All-optical optoacoustic microscopy based on probe beam deflection technique

    OpenAIRE

    Maswadi, Saher M.; Ibey, Bennett L.; Roth, Caleb C.; Tsyboulski, Dmitri A.; Beier, Hope T.; Glickman, Randolph D.; Oraevsky, Alexander A.

    2016-01-01

    Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separa...

  1. Development of novel imaging probe for optical/acoustic radiation imaging (OARI).

    Science.gov (United States)

    Ejofodomi, O'tega A; Zderic, Vesna; Zara, Jason M

    2013-11-01

    Optical/acoustic radiation imaging (OARI) is a novel imaging modality being developed to interrogate the optical and mechanical properties of soft tissues. OARI uses acoustic radiation force to generate displacement in soft tissue. Optical images before and after the application of the force are used to generate displacement maps that provide information about the mechanical properties of the tissue under interrogation. Since the images are optical images, they also represent the optical properties of the tissue as well. In this paper, the authors present the first imaging probe that uses acoustic radiation force in conjunction with optical coherence tomography (OCT) to provide information about the optical and mechanical properties of tissues to assist in the diagnosis and staging of epithelial cancers, and in particular bladder cancer. The OARI prototype probe consisted of an OCT probe encased in a plastic sheath, a miniaturized transducer glued to a plastic holder, both of which were encased in a 10 cm stainless steel tube with an inner diameter of 10 mm. The transducer delivered an acoustic intensity of 18 W/cm(2) and the OCT probe had a spatial resolution of approximately 10-20 μm. The tube was filled with deionized water for acoustic coupling and covered by a low density polyethylene cap. The OARI probe was characterized and tested on bladder wall phantoms. The phantoms possessed Young's moduli ranging from 10.2 to 12 kPa, mass density of 1.05 g/cm(3), acoustic attenuation coefficient of 0.66 dB/cm MHz, speed of sound of 1591 m/s, and optical scattering coefficient of 1.80 mm(-1). Finite element model (FEM) theoretical simulations were performed to assess the performance of the OARI probe. The authors obtained displacements of 9.4, 8.7, and 3.4 μm for the 3%, 4%, and 5% bladder wall phantoms, respectively. This shows that the probe is capable of generating optical images, and also has the ability to generate and track displacements in tissue. This will

  2. ACADEMIC TRAINING: Probing nature with high precision; particle traps, laser spectroscopy and optical combs

    CERN Multimedia

    Françoise Benz

    2002-01-01

    17, 18, 19 June LECTURE SERIES from 11.00 to 12.00 hrs - Auditorium, bldg. 500 Probing nature with high precision; particle traps, laser spectroscopy and optical combs by G. GABRIELSE / Harvard University, USA Experiments with atomic energy scales probe nature and its symmetries with exquisite precision. Particle traps allow the manipulation of single charged particles for months at a time, allow the most accurate comparison of theory and experiment, and promise to allow better measurement of fundamental quantities like the fine structure constant. Ions and atoms can be probed with lasers that are phase locked to microwave frequency standards via optical combs, thus calibrating optical sources in terms of the official cesium second. A series of three lectures will illustrate what can be measured and discuss key techniques.  ACADEMIC TRAINING Françoise Benz Tel. 73127 francoise.benz@cern.ch

  3. Scanning probe and optical tweezer investigations of biomolecular interactions

    International Nuclear Information System (INIS)

    Rigby-Singleton, Shellie

    2002-01-01

    A complex array of intermolecular forces controls the interactions between and within biological molecules. The desire to empirically explore the fundamental forces has led to the development of several biophysical techniques. Of these, the atomic force microscope (AFM) and the optical tweezers have been employed throughout this thesis to monitor the intermolecular forces involved in biomolecular interactions. The AFM is a well-established force sensing technique capable of measuring biomolecular interactions at a single molecule level. However, its versatility has not been extrapolated to the investigation of a drug-enzyme complex. The energy landscape for the force induced dissociation of the DHFR-methotrexate complex was studied. Revealing an energy barrier to dissociation located ∼0.3 nm from the bound state. Unfortunately, the AFM has a limited range of accessible loading rates and in order to profile the complete energy landscape alternative force sensing instrumentation should be considered, for example the BFP and optical tweezers. Thus, this thesis outlines the development and construction an optical trap capable of measuring intermolecular forces between biomolecules at the single molecule level. To demonstrate the force sensing abilities of the optical set up, proof of principle measurements were performed which investigate the interactions between proteins and polymer surfaces subjected to varying degrees of argon plasma treatment. Complementary data was gained from measurements performed independently by the AFM. Changes in polymer resistance to proteins as a response to changes in polymer surface chemistry were detected utilising both AFM and optical tweezers measurements. Finally, the AFM and optical tweezers were employed as ultrasensitive biosensors. Single molecule investigations of the antibody-antigen interaction between the cardiac troponin I marker and its complementary antibody, reveals the impact therapeutic concentrations of heparin have

  4. True Tapping Mode Scanning Near-Field Optical Microscopy with Bent Glass Fiber Probes.

    Science.gov (United States)

    Smirnov, A; Yasinskii, V M; Filimonenko, D S; Rostova, E; Dietler, G; Sekatskii, S K

    2018-01-01

    In scanning near-field optical microscopy, the most popular probes are made of sharpened glass fiber attached to a quartz tuning fork (TF) and exploiting the shear force-based feedback. The use of tapping mode feedback could be preferable. Such an approach can be realized, for example, using bent fiber probes. Detailed analysis of fiber vibration modes shows that realization of truly tapping mode of the probe dithering requires an extreme caution. In case of using the second resonance mode, probes vibrate mostly in shear force mode unless the bending radius is rather small (ca. 0.3 mm) and the probe's tip is short. Otherwise, the shear force character of the dithering persists. Probes having these characteristics were prepared by irradiation of a tapered etched glass fiber with a CW CO 2 laser. These probes were attached to the TF in double resonance conditions which enables achieving significant quality factor (4000-6000) of the TF + probe system (Cherkun et al., 2006). We also show that, to achieve a truly tapping character, dithering, short, and not exceeding 3 mm lengths of a freestanding part of bent fiber probe beam should also be used in the case of nonresonant excitation.

  5. Embedded calibration system for the DIII-D Langmuir probe analog fiber optic links

    International Nuclear Information System (INIS)

    Watkins, J. G.; Rajpal, R.; Mandaliya, H.; Watkins, M.; Boivin, R. L.

    2012-01-01

    This paper describes a generally applicable technique for simultaneously measuring offset and gain of 64 analog fiber optic data links used for the DIII-D fixed Langmuir probes by embedding a reference voltage waveform in the optical transmitted signal before every tokamak shot. The calibrated data channels allow calibration of the power supply control fiber optic links as well. The array of fiber optic links and the embedded calibration system described here makes possible the use of superior modern data acquisition electronics in the control room.

  6. Peculiarities of the propagation of multidimensional extremely short optical pulses in germanene

    Energy Technology Data Exchange (ETDEWEB)

    Zhukov, Alexander V., E-mail: alex_zhukov@sutd.edu.sg [Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore (Singapore); Bouffanais, Roland [Singapore University of Technology and Design, 8 Somapah Road, 487372 Singapore (Singapore); Konobeeva, Natalia N. [Volgograd State University, 400062 Volgograd (Russian Federation); Belonenko, Mikhail B. [Laboratory of Nanotechnology, Volgograd Institute of Business, 400048 Volgograd (Russian Federation); Volgograd State University, 400062 Volgograd (Russian Federation)

    2016-09-07

    Highlights: • Established dynamics of ultra-short pulses in germanene. • Studied balance between dispersive and nonlinear effects in germanene. • Spin–orbit interaction effect onto pulse propagation. - Abstract: In this Letter, we study the propagation characteristics of both two-dimensional and three-dimensional extremely short optical pulses in germanene. A distinguishing feature of germanene—in comparison with other graphene-like structures—is the presence of a significant spin–orbit interaction. The account of this interaction has a significant impact on the evolution of extremely short pulses in such systems. Specifically, extremely short optical pulses, consisting of two electric field oscillations, cause the appearance of a tail associated with the excitation of nonlinear waves. Due to the large spin–orbit interaction in germanene, this tail behind the main pulse is much smaller in germanene-based samples as compared to graphene-based ones, thereby making germanene a preferred material for the stable propagation of pulses along the sample.

  7. Micro sized implantable ball lens-based fiber optic probe design

    Science.gov (United States)

    Cha, Jaepyeong; Kang, Jin U.

    2014-02-01

    A micro sized implantable ball lens-based fiber optic probe design is described for continuous monitoring of brain activity in freely behaving mice. A prototype uses a 500-micron ball lens and a highly flexible 350-micron-diameter fiber bundle, which are enclosed by a 21G stainless steel sheath. Several types and thickness of brain tissue, consisting of fluorescent probes such as GFP, GCaMP3 calcium indicator, are used to evaluate the performance of the imaging probe. Measured working distance is approximately 400-μm, but is long enough to detect neural activities from cortical and cerebellar tissues of mice brain.

  8. Probing DNA with micro- and nanocapillaries and optical tweezers

    International Nuclear Information System (INIS)

    Steinbock, L J; Otto, O; Skarstam, D R; Jahn, S; Chimerel, C; Gornall, J L; Keyser, U F

    2010-01-01

    We combine for the first time optical tweezer experiments with the resistive pulse technique based on capillaries. Quartz glass capillaries are pulled into a conical shape with tip diameters as small as 27 nm. Here, we discuss the translocation of λ-phage DNA which is driven by an electrophoretic force through the nanocapillary. The resulting change in ionic current indicates the folding state of single λ-phage DNA molecules. Our flow cell design allows for the straightforward incorporation of optical tweezers. We show that a DNA molecule attached to an optically trapped colloid is pulled into a capillary by electrophoretic forces. The detected electrophoretic force is in good agreement with measurements in solid-state nanopores.

  9. U-Shaped and Surface Functionalized Polymer Optical Fiber Probe for Glucose Detection.

    Science.gov (United States)

    Azkune, Mikel; Ruiz-Rubio, Leire; Aldabaldetreku, Gotzon; Arrospide, Eneko; Pérez-Álvarez, Leyre; Bikandi, Iñaki; Zubia, Joseba; Vilas-Vilela, Jose Luis

    2017-12-25

    In this work we show an optical fiber evanescent wave absorption probe for glucose detection in different physiological media. High selectivity is achieved by functionalizing the surface of an only-core poly(methyl methacrylate) (PMMA) polymer optical fiber with phenilboronic groups, and enhanced sensitivity by using a U-shaped geometry. Employing a supercontinuum light source and a high-resolution spectrometer, absorption measurements are performed in the broadband visible light spectrum. Experimental results suggest the feasibility of such a fiber probe as a low-cost and selective glucose detector.

  10. Raman Probe Based on Optically-Poled Double-Core Fiber

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara; Margulis, Walter; Rottwitt, Karsten

    2012-01-01

    A Raman probe based on an optically-poled double-core fiber. In-fiber SHG allows for Raman spectroscopy of DMSO at 532nm when illuminating the fiber with 1064nm light. The fiber structure provides independent excitation and collection paths.......A Raman probe based on an optically-poled double-core fiber. In-fiber SHG allows for Raman spectroscopy of DMSO at 532nm when illuminating the fiber with 1064nm light. The fiber structure provides independent excitation and collection paths....

  11. Dynamic characterization of silicon nanowires using a terahertz optical asymmetric demultiplexer-based pump-probe scheme

    DEFF Research Database (Denmark)

    Ji, Hua; Cleary, C. S.; Dailey, J. M.

    2012-01-01

    Dynamic phase and amplitude all-optical responses of silicon nanowires are characterized using a terahertz optical asymmetric demultiplexer (TOAD) based pump-probe scheme. Ultra-fast recovery is observed for moderate pump powers....

  12. Probing myocardium biomechanics using quantitative optical coherence elastography

    Science.gov (United States)

    Wang, Shang; Lopez, Andrew L.; Morikawa, Yuka; Tao, Ge; Li, Jiasong; Larina, Irina V.; Martin, James F.; Larin, Kirill V.

    2015-03-01

    We present a quantitative optical coherence elastographic method for noncontact assessment of the myocardium elasticity. The method is based on shear wave imaging optical coherence tomography (SWI-OCT), where a focused air-puff system is used to induce localized tissue deformation through a low-pressure short-duration air stream and a phase-sensitive OCT system is utilized to monitor the propagation of the induced tissue displacement with nanoscale sensitivity. The 1-D scanning of M-mode OCT imaging and the application of optical phase retrieval and mapping techniques enable the reconstruction and visualization of 2-D depth-resolved shear wave propagation in tissue with ultra-high frame rate. The feasibility of this method in quantitative elasticity measurement is demonstrated on tissue-mimicking phantoms with the estimated Young's modulus compared with uniaxial compression tests. We also performed pilot experiments on ex vivo mouse cardiac muscle tissues with normal and genetically altered cardiomyocytes. Our results indicate this noncontact quantitative optical coherence elastographic method can be a useful tool for the cardiac muscle research and studies.

  13. Evaluation of an optical fiber probe for in vivo measurement of the photoacoustic response of tissues

    Science.gov (United States)

    Beard, Paul C.; Mills, Timothy N.

    1995-05-01

    A miniature (1 mm diameter) all-optical photoacoustic probe for generating and detecting ultrasonic thermoelastic waves in biological media at the tip of an optical fiber has been developed. The probe provides a compact and convenient means of performing pulsed photoacoustic spectroscopy for the characterization of biological tissue. The device is based upon a transparent Fabry Perot polymer film ultrasound sensor mounted directly over the end of a multimode optical fiber. The optical fiber is used to deliver nanosecond laser pulses to the tissue producing thermoelastic waves which are then detected by the sensor. Detection sensitivities of 53 mv/MPa and a 10 kPa acoustic noise floor have been demonstrated giving excellent signal to noise ratios in a strong liquid absorber. Lower, but clearly detectable, signals in post mortem human aorta have also been observed. The performance and small physical size of the device suggest that it has the potential to perform remote in situ photoacoustic measurements in tissue.

  14. Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

    Science.gov (United States)

    Voichick, Nicholas; Topping, David J.; Griffiths, Ronald E.

    2018-03-01

    Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator-prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples) are necessary to

  15. Adapting an optical nanoantenna for high E-field probing applications to a waveguided optical waveguide (WOW)

    Science.gov (United States)

    Rindorf, Lars; Glückstad, Jesper

    2013-03-01

    In the current work we intend to use the optical nano-antenna to include various functionalities for the recently demonstrated waveguided optical waveguide (WOW) by Palima et al. (Optics Express 2012). Specifically, we intend to study a WOW with an optical nano-antenna which can block the guiding light wavelength while admitting other wavelengths of light which address certain functionalities, e.g. drug release, in the WOW. In particular, we study a bow-tie optical nano-antenna to circular dielectric waveguides in aqueous environments. It is shown with finite element computer simulations that the nanoantenna can be made to operate in a bandstop mode around its resonant wavelength where there is a very high evanescent strong electrical probing field close to the antennas, and additionally the fluorescence or Raman excitations will be be unpolluted by stray light from the WOW due to the band-stop characteristic. We give geometrical parameters necessary for realizing functioning nanoantennas.

  16. True Tapping Mode Scanning Near-Field Optical Microscopy with Bent Glass Fiber Probes

    Directory of Open Access Journals (Sweden)

    A. Smirnov

    2018-01-01

    Full Text Available In scanning near-field optical microscopy, the most popular probes are made of sharpened glass fiber attached to a quartz tuning fork (TF and exploiting the shear force-based feedback. The use of tapping mode feedback could be preferable. Such an approach can be realized, for example, using bent fiber probes. Detailed analysis of fiber vibration modes shows that realization of truly tapping mode of the probe dithering requires an extreme caution. In case of using the second resonance mode, probes vibrate mostly in shear force mode unless the bending radius is rather small (ca. 0.3 mm and the probe’s tip is short. Otherwise, the shear force character of the dithering persists. Probes having these characteristics were prepared by irradiation of a tapered etched glass fiber with a CW CO2 laser. These probes were attached to the TF in double resonance conditions which enables achieving significant quality factor (4000–6000 of the TF + probe system (Cherkun et al., 2006. We also show that, to achieve a truly tapping character, dithering, short, and not exceeding 3 mm lengths of a freestanding part of bent fiber probe beam should also be used in the case of nonresonant excitation.

  17. Amyloid Fibril-Induced Structural and Spectral Modifications in the Thioflavin-T Optical Probe

    DEFF Research Database (Denmark)

    Murugan, N. Arul; Olsen, Jógvan Magnus Haugaard; Kongsted, Jacob

    2013-01-01

    Motivated by future possibilities to design target molecules for fibrils with diagnostic or therapeutic capability related to amyloidosis diseases, we investigate in this work the dielectric nature of amyloid fibril microenvironments in different binding sites using an optical probe, thioflavin-T...

  18. Near-field optical microscopy of localized excitations on rough surfaces: influence of a probe

    DEFF Research Database (Denmark)

    Bozhevolnyi, Sergey I.

    1999-01-01

    Starting from the general principles of near-field optical microscopy. I consider the influence of a probe when being used to image localized dipolar excitations and suggest a way of evaluating the perturbation thus introduced. Using the rigorous microscopic (electric) point-dipole description, I...

  19. Near-field optical microscope using a silicon-nitride probe

    NARCIS (Netherlands)

    van Hulst, N.F.; Moers, M.H.P.; Moers, M.H.P.; Noordman, O.F.J.; Noordman, O.F.J.; Tack, R.G.; Segerink, Franciscus B.; Bölger, B.; Bölger, B.

    1993-01-01

    Operation of an alternative near-field optical microscope is presented. The microscope uses a microfabricated silicon- nitride probe with integrated cantilever, as originally developed for force microscopy. The cantilever allows routine close contact near-field imaging o­n arbitrary surfaces without

  20. A New Generation Fiber Optic Probe: Characterization of Biological Fluids, Protein Crystals and Ophthalmic Diseases

    Science.gov (United States)

    Ansari, Rafat R.; Suh, Kwang I.

    1996-01-01

    A new fiber optic probe developed for determining transport properties of sub-micron particles in fluids experiments in a microgravity environment has been applied to characterize particulate dispersions/suspensions in various challenging environments which have been hitherto impossible. The probe positioned in front of a sample delivers a low power light (few nW - 3mW) from a laser and guides the light which is back scattered by the suspended particles through a receiving optical fiber to a photo detector and to a digital correlator. The probe provides rapid determination of macromolecular diffusivities and their respective size distributions. It has been applied to characterize various biological fluids, protein crystals, and ophthalmic diseases.

  1. Tissue imaging using full field optical coherence microscopy with short multimode fiber probe

    Science.gov (United States)

    Sato, Manabu; Eto, Kai; Goto, Tetsuhiro; Kurotani, Reiko; Abe, Hiroyuki; Nishidate, Izumi

    2018-03-01

    In achieving minimally invasive accessibility to deeply located regions the size of the imaging probes is important. We demonstrated full-field optical coherence tomography (FF-OCM) using an ultrathin forward-imaging short multimode fiber (SMMF) probe of 50 μm core diameter, 125 μm diameter, and 7.4 mm length for optical communications. The axial resolution was measured to be 2.14 μm and the lateral resolution was also evaluated to be below 4.38 μm using a test pattern (TP). The spatial mode and polarization characteristics of SMMF were evaluated. Inserting SMMF to in vivo rat brain, 3D images were measured and 2D information of nerve fibers was obtained. The feasibility of an SMMF as an ultrathin forward-imaging probe in FF-OCM has been demonstrated.

  2. Probing graphene defects and estimating graphene quality with optical microscopy

    International Nuclear Information System (INIS)

    Lai, Shen; Kyu Jang, Sung; Jae Song, Young; Lee, Sungjoo

    2014-01-01

    We report a simple and accurate method for detecting graphene defects that utilizes the mild, dry annealing of graphene/Cu films in air. In contrast to previously reported techniques, our simple approach with optical microscopy can determine the density and degree of dislocation of defects in a graphene film without inducing water-related damage or functionalization. Scanning electron microscopy, confocal Raman and atomic force microscopy, and X-ray photoelectron spectroscopy analysis were performed to demonstrate that our nondestructive approach to characterizing graphene defects with optimized thermal annealing provides rapid and comprehensive determinations of graphene quality

  3. Single Molecules as Optical Probes for Structure and Dynamics

    Science.gov (United States)

    Orrit, Michel

    Single molecules and single nanoparticles are convenient links between the nanoscale world and the laboratory. We discuss the limits for their optical detection by three different methods: fluorescence, direct absorption, and photothermal detection. We briefly review some recent illustrations of qualitatively new information gathered from single-molecule signals: intermittency of the fluorescence intensity, acoustic vibrations of nanoparticles (1-100 GHz) or of extended defects in molecular crystals (0.1-1 MHz), and dynamical heterogeneity in glass-forming molecular liquids. We conclude with an outlook of future uses of single-molecule methods in physical chemistry, soft matter, and material science.

  4. Raman probes based on optically-poled double-clad fiber and coupler

    DEFF Research Database (Denmark)

    Brunetti, Anna Chiara; Margulis, Walter; Rottwitt, Karsten

    2012-01-01

    of a sample of dimethyl sulfoxide (DMSO), when illuminating the waveguide with 1064nm laser light. The Raman signal is collected in the inner cladding, from which it is retrieved with either a bulk dichroic mirror or a double-clad fiber coupler. The coupler allows for a substantial reduction of the fiber......Two fiber Raman probes are presented, one based on an optically-poled double-clad fiber and the second based on an optically-poled double-clad fiber coupler respectively. Optical poling of the core of the fiber allows for the generation of enough 532nm light to perform Raman spectroscopy...

  5. Probing many-body interactions in an optical lattice clock

    Energy Technology Data Exchange (ETDEWEB)

    Rey, A.M., E-mail: arey@jilau1.colorado.edu [JILA, NIST and University of Colorado, Department of Physics, Boulder, CO 80309 (United States); Gorshkov, A.V. [Joint Quantum Institute, NIST and University of Maryland, Department of Physics, College Park, MD 20742 (United States); Kraus, C.V. [Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck (Austria); Institute for Theoretical Physics, University of Innsbruck, A-6020 Innsbruck (Austria); Martin, M.J. [JILA, NIST and University of Colorado, Department of Physics, Boulder, CO 80309 (United States); Institute for Quantum Information and Matter, California Institute of Technology, Pasadena, CA 91125 (United States); Bishof, M.; Swallows, M.D.; Zhang, X.; Benko, C.; Ye, J. [JILA, NIST and University of Colorado, Department of Physics, Boulder, CO 80309 (United States); Lemke, N.D.; Ludlow, A.D. [National Institute of Standards and Technology, Boulder, CO 80305 (United States)

    2014-01-15

    We present a unifying theoretical framework that describes recently observed many-body effects during the interrogation of an optical lattice clock operated with thousands of fermionic alkaline earth atoms. The framework is based on a many-body master equation that accounts for the interplay between elastic and inelastic p-wave and s-wave interactions, finite temperature effects and excitation inhomogeneity during the quantum dynamics of the interrogated atoms. Solutions of the master equation in different parameter regimes are presented and compared. It is shown that a general solution can be obtained by using the so called Truncated Wigner Approximation which is applied in our case in the context of an open quantum system. We use the developed framework to model the density shift and decay of the fringes observed during Ramsey spectroscopy in the JILA {sup 87}Sr and NIST {sup 171}Yb optical lattice clocks. The developed framework opens a suitable path for dealing with a variety of strongly-correlated and driven open-quantum spin systems. -- Highlights: •Derived a theoretical framework that describes many-body effects in a lattice clock. •Validated the analysis with recent experimental measurements. •Demonstrated the importance of beyond mean field corrections in the dynamics.

  6. 3D silicon neural probe with integrated optical fibers for optogenetic modulation.

    Science.gov (United States)

    Kim, Eric G R; Tu, Hongen; Luo, Hao; Liu, Bin; Bao, Shaowen; Zhang, Jinsheng; Xu, Yong

    2015-07-21

    Optogenetics is a powerful modality for neural modulation that can be useful for a wide array of biomedical studies. Penetrating microelectrode arrays provide a means of recording neural signals with high spatial resolution. It is highly desirable to integrate optics with neural probes to allow for functional study of neural tissue by optogenetics. In this paper, we report the development of a novel 3D neural probe coupled simply and robustly to optical fibers using a hollow parylene tube structure. The device shanks are hollow tubes with rigid silicon tips, allowing the insertion and encasement of optical fibers within the shanks. The position of the fiber tip can be precisely controlled relative to the electrodes on the shank by inherent design features. Preliminary in vivo rat studies indicate that these devices are capable of optogenetic modulation simultaneously with 3D neural signal recording.

  7. Micro reflectance difference techniques: Optical probes for surface exploration

    Energy Technology Data Exchange (ETDEWEB)

    Lastras-Martinez, L.F.; Del Pozo-Zamudio, O.; Herrera-Jasso, R.; Ulloa-Castillo, N.A.; Balderas-Navarro, R.E.; Ortega-Gallegos, J.; Lastras-Martinez, A. [Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, Alvaro Obregon 64, 78000 San Luis Potosi, S.L.P. (Mexico)

    2012-06-15

    Micro reflectance difference spectroscopy ({mu}-RDS) is a promising tool for the in-situ and ex-situ characterization of semiconductors surfaces and interfaces. We discuss and compare two different approaches used to measure {mu}-RD spectra. One is based on a charge-coupled device (CCD) camera, while the other uses a laser and a XY translation stage. To show the performance of these systems, we have measured surface optical anisotropies of GaSb(001) sample on which anisotropic strains have been generated by preferential mechanical polishing along [110] and [1 anti 10] directions. The spectrometers are complementary and the selection of one of them depends on the sample to be investigated and on experimental conditions. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Glucose Sensor Using U-Shaped Optical Fiber Probe with Gold Nanoparticles and Glucose Oxidase.

    Science.gov (United States)

    Chen, Kuan-Chieh; Li, Yu-Le; Wu, Chao-Wei; Chiang, Chia-Chin

    2018-04-16

    In this study, we proposed a U-shaped optical fiber probe fabricated using a flame heating method. The probe was packaged in glass tube to reduce human factors during experimental testing of the probe as a glucose sensor. The U-shaped fiber probe was found to have high sensitivity in detecting the very small molecule. When the sensor was dipped in solutions with different refractive indexes, its wavelength or transmission loss changed. We used electrostatic self-assembly to bond gold nanoparticles and glucose oxidase (GOD) onto the sensor’s surface. The results over five cycles of the experiment showed that, as the glucose concentration increased, the refractive index of the sensor decreased and its spectrum wavelength shifted. The best wavelength sensitivity was 2.899 nm/%, and the linearity was 0.9771. The best transmission loss sensitivity was 5.101 dB/%, and the linearity was 0.9734. Therefore, the proposed U-shaped optical fiber probe with gold nanoparticles and GOD has good potential for use as a blood sugar sensor in the future.

  9. Imaging optical probe for pressurized 6200K steam-water environment

    International Nuclear Information System (INIS)

    Donaldson, M.R.; Pulfrey, R.E.; Merrill, S.K.

    1979-01-01

    An air-cooled imaging optical probe, 0.3 m long with a 25.4-mm outside diameter, has been built to provide high resolution viewing of flow regimes in a steam-water environment at 620 0 K and 15.5 MPa. The probe consists of a 3.5-mm-diameter rod lens borescope, surrounded by two coaxial coolant flow channels and two coaxial insulating dead air spaces. With air flowing through the probe at 5.7 g/s, thermal analysis shows that no part of the optical borescope will exceed 366 0 K when the probe is immersed in a 620 0 K environment. The objective lens is protected by a sapphire window which tests have shown can survive over 200 hours in 620 0 K water or steam with negligible loss of resolution and contrast. Condensation on the protective window is boiled off by electrically heating the window. Computer stress analysis, plus actual tests, shows that the probe can operate successfully with conservative safety factors

  10. SU-E-T-610: Phosphor-Based Fiber Optic Probes for Proton Beam Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Darafsheh, A; Soldner, A; Liu, H; Kassaee, A; Zhu, T; Finlay, J [Univ Pennsylvania, Philadelphia, PA (United States)

    2015-06-15

    Purpose: To investigate feasibility of using fiber optics probes with rare-earth-based phosphor tips for proton beam radiation dosimetry. We designed and fabricated a fiber probe with submillimeter resolution (<0.5 mm3) based on TbF3 phosphors and evaluated its performance for measurement of proton beam including profiles and range. Methods: The fiber optic probe with TbF3 phosphor tip, embedded in tissue-mimicking phantoms was irradiated with double scattering proton beam with energy of 180 MeV. Luminescence spectroscopy was performed by a CCD-coupled spectrograph to analyze the emission spectra of the fiber tip. In order to measure the spatial beam profile and percentage depth dose, we used singular value decomposition method to spectrally separate the phosphors ionoluminescence signal from the background Cerenkov radiation signal. Results: The spectra of the TbF3 fiber probe showed characteristic ionoluminescence emission peaks at 489, 542, 586, and 620 nm. By using singular value decomposition we found the contribution of the ionoluminescence signal to measure the percentage depth dose in phantoms and compared that with measurements performed with ion chamber. We observed quenching effect at the spread out Bragg peak region, manifested as under-responding of the signal, due to the high LET of the beam. However, the beam profiles were not dramatically affected by the quenching effect. Conclusion: We have evaluated the performance of a fiber optic probe with submillimeter resolution for proton beam dosimetry. We demonstrated feasibility of spectral separation of the Cerenkov radiation from the collected signal. Such fiber probes can be used for measurements of proton beams profile and range. The experimental apparatus and spectroscopy method developed in this work provide a robust platform for characterization of proton-irradiated nanophosphor particles for ultralow fluence photodynamic therapy or molecular imaging applications.

  11. Application of advanced optical probe instrumentation in steam generator tube bundles

    International Nuclear Information System (INIS)

    Bouchter, J.C.; Gouirand, J.M.; Haquet, J.F.; Ivars, J.F.

    1990-01-01

    The Department of Energy Transfer (DTE) of the French CEA has been developing for about 15 years optical probe techniques in order to better understand and predict nuclear components dealing with two-phase flows. More recently, in the scope of an International Program, the CEA has made an intensive use of bi-optical probes in order to very precisely investigate the distributions of void fraction and gas velocity in the secondary side of a Steam-generator mock-up operating with Freon 114 (80 degrees C, 9 x 10 5 Pa at nominal conditions). At the present time, the success of this program and the recent progress achieved in the technology of the probe, in particular to withstand higher pressures and temperatures allow us to reasonably think that this device will be soon available for industrial uses. So, this paper deals with the present state of the art of the technique within CEA and in particular it successively describes: what is required of a practical point of view when it comes to perform local measurements within tube bundles and what have been the technical choices to meet these requirements; how the bi-optical probe does operate with an emphasis on the signal processing description; how the whole device accuracy, i.e., the bi-optical probe plus its complete acquisition and signal processing chain, is determined by a calibration procedure comparing first separately then all together the different components to independent numerical and physical reference methods; typical examples of measurements of the emulsion fine structure within tube bundle subchannels as regards with void fraction, gas velocity and bubble granulometries; finally, the recent progress accomplished in terms of, higher reliability, resolution, pressure and temperature resistance

  12. Technical note: False low turbidity readings from optical probes during high suspended-sediment concentrations

    Science.gov (United States)

    Voichick, Nicholas; Topping, David; Griffiths, Ronald

    2018-01-01

    Turbidity, a measure of water clarity, is monitored for a variety of purposes including (1) to help determine whether water is safe to drink, (2) to establish background conditions of lakes and rivers and detect pollution caused by construction projects and stormwater discharge, (3) to study sediment transport in rivers and erosion in catchments, (4) to manage siltation of water reservoirs, and (5) to establish connections with aquatic biological properties, such as primary production and predator–prey interactions. Turbidity is typically measured with an optical probe that detects light scattered from particles in the water. Probes have defined upper limits of the range of turbidity that they can measure. The general assumption is that when turbidity exceeds this upper limit, the values of turbidity will be constant, i.e., the probe is pegged; however, this assumption is not necessarily valid. In rivers with limited variation in the physical properties of the suspended sediment, at lower suspended-sediment concentrations, an increase in suspended-sediment concentration will cause a linear increase in turbidity. When the suspended-sediment concentration in these rivers is high, turbidity levels can exceed the upper measurement limit of an optical probe and record a constant pegged value. However, at extremely high suspended-sediment concentrations, optical turbidity probes do not necessarily stay pegged at a constant value. Data from the Colorado River in Grand Canyon, Arizona, USA, and a laboratory experiment both demonstrate that when turbidity exceeds instrument-pegged conditions, increasing suspended-sediment concentration (and thus increasing turbidity) may cause optical probes to record decreasing false turbidity values that appear to be within the valid measurement range of the probe. Therefore, under high-turbidity conditions, other surrogate measurements of turbidity (e.g., acoustic-attenuation measurements or suspended-sediment samples

  13. Probe-pin device for optical neurotransmitter sensing in the brain

    Science.gov (United States)

    Kim, Min Hyuck; Song, Kyo D.; Yoon, Hargsoon; Park, Yeonjoon; Choi, Sang H.; Lee, Dae-Sung; Shin, Kyu-Sik; Hwang, Hak-In; Lee, Uhn

    2015-04-01

    Development of an optical neurotransmitter sensing device using nano-plasmonic probes and a micro-spectrometer for real time monitoring of neural signals in the brain is underway. Clinical application of this device technology is to provide autonomous closed-loop feedback control to a deep brain stimulation (DBS) system and enhance the accuracy and efficacy of DBS treatment. By far, we have developed an implantable probe-pin device based on localized field enhancement of surface plasmonic resonance on a nanostructured sensing domain which can amplify neurochemical signals from evoked neural activity in the brain. In this paper, we will introduce the details of design and sensing performance of a proto-typed microspectrometer and nanostructured probing devices for real time measurement of neurotransmitter concentrations.

  14. Probe-controlled soliton frequency shift in the regime of optical event horizon.

    Science.gov (United States)

    Gu, Jie; Guo, Hairun; Wang, Shaofei; Zeng, Xianglong

    2015-08-24

    In optical analogy of the event horizon, temporal pulse collision and mutual interactions are mainly between an intense solitary wave (soliton) and a dispersive probe wave. In such a regime, here we numerically investigate the probe-controlled soliton frequency shift as well as the soliton self-compression. In particular, in the dispersion landscape with multiple zero dispersion wavelengths, bi-directional soliton spectral tunneling effects is possible. Moreover, we propose a mid-infrared soliton self-compression to the generation of few-cycle ultrashort pulses, in a bulk of quadratic nonlinear crystals in contrast to optical fibers or cubic nonlinear media, which could contribute to the community with a simple and flexible method to experimental implementations.

  15. Inducing spin-dependent tunneling to probe magnetic correlations in optical lattices

    DEFF Research Database (Denmark)

    Pedersen, Kim-Georg; Andersen, Brian; Syljuåsen, Olav

    2012-01-01

    We suggest a simple experimental method for probing antiferromagnetic spin correlations of two-component Fermi gases in optical lattices. The method relies on a spin selective Raman transition to excite atoms of one spin species to their first excited vibrational mode where the tunneling is large....... The resulting difference in the tunneling dynamics of the two spin species can then be exploited, to reveal the spin correlations by measuring the number of doubly occupied lattice sites at a later time. We perform quantum Monte Carlo simulations of the spin system and solve the optical lattice dynamics...

  16. Nanospot soldering polystyrene nanoparticles with an optical fiber probe laser irradiating a metallic AFM probe based on the near-field enhancement effect.

    Science.gov (United States)

    Cui, Jianlei; Yang, Lijun; Wang, Yang; Mei, Xuesong; Wang, Wenjun; Hou, Chaojian

    2015-02-04

    With the development of nanoscience and nanotechnology for the bottom-up nanofabrication of nanostructures formed from polystyrene nanoparticles, joining technology is an essential step in the manufacturing and assembly of nanodevices and nanostructures in order to provide mechanical integration and connection. To study the nanospot welding of polystyrene nanoparticles, we propose a new nanospot-soldering method using the near-field enhancement effect of a metallic atomic force microscope (AFM) probe tip that is irradiated by an optical fiber probe laser. On the basis of our theoretical analysis of the near-field enhancement effect, we set up an experimental system for nanospot soldering; this approach is carried out by using an optical fiber probe laser to irradiate the AFM probe tip to sinter the nanoparticles, providing a promising technical approach for the application of nanosoldering in nanoscience and nanotechnology.

  17. Reciprocity theory of apertureless scanning near-field optical microscopy with point-dipole probes.

    Science.gov (United States)

    Esslinger, Moritz; Vogelgesang, Ralf

    2012-09-25

    Near-field microscopy offers the opportunity to reveal optical contrast at deep subwavelength scales. In scanning near-field optical microscopy (SNOM), the diffraction limit is overcome by a nanoscopic probe in close proximity to the sample. The interaction of the probe with the sample fields necessarily perturbs the bare sample response, and a critical issue is the interpretation of recorded signals. For a few specific SNOM configurations, individual descriptions have been modeled, but a general and intuitive framework is still lacking. Here, we give an exact formulation of the measurable signals in SNOM which is easily applicable to experimental configurations. Our results are in close analogy with the description Tersoff and Hamann have derived for the tunneling currents in scanning tunneling microscopy. For point-like scattering probe tips, such as used in apertureless SNOM, the theory simplifies dramatically to a single scalar relation. We find that the measured signal is directly proportional to the field of the coupled tip-sample system at the position of the tip. For weakly interacting probes, the model thus verifies the empirical findings that the recorded signal is proportional to the unperturbed field of the bare sample. In the more general case, it provides guidance to an intuitive and faithful interpretation of recorded images, facilitating the characterization of tip-related distortions and the evaluation of novel SNOM configurations, both for aperture-based and apertureless SNOM.

  18. Measurement Accuracy of a Mono-fiber Optical Probe in a Bubbly Flow

    Czech Academy of Sciences Publication Activity Database

    Vejražka, Jiří; Večeř, M.; Orvalho, Sandra; Sechet, Ph.; Růžička, Marek; Cartellier, A.

    2010-01-01

    Roč. 36, č. 7 (2010), s. 533-548 ISSN 0301-9322 R&D Projects: GA ČR GA104/07/1110; GA ČR GP104/06/P287; GA AV ČR(CZ) IAA200720801 Institutional research plan: CEZ:AV0Z40720504 Keywords : optical probe * bubble-fiber interaction * void fraction Subject RIV: CI - Industrial Chemistry, Chemical Engineering Impact factor: 1.772, year: 2010

  19. A Comparison of Acoustic Field Measurement by a Microphone and by an Optical Interferometric Probe

    Directory of Open Access Journals (Sweden)

    R. Bálek

    2002-01-01

    Full Text Available The objective of this work is to show that our optical method for measuring acoustic pressure is in some way superior to measurement using a microphone. Measurement of the integral acoustic pressure in the air by a laser interferometric probe is compared with measurement using a microphone. We determined the particular harmonic components in the acoustic field in the case of relatively high acoustic power in the ultrasonic frequency range.

  20. Ultrafast optical pump terahertz-probe spectroscopy of strongly correlated electron materials

    International Nuclear Information System (INIS)

    Averitt, R.D.; Taylor, Antoinette J.; Thorsmolle, V.K.; Jia, Quanxi; Lobad, A.I.; Trugman, S.A.

    2001-01-01

    We have used optical-pump far-infrared probe spectroscopy to probe the low energy electron dynamics of high temperature superconductors and colossal magnetoresistance manganites. For the superconductor YBa2Cu3O7, picosecond conductivity measurements probe the interplay between Cooper-pairs and quasiparticles. In optimally doped films, the recovery time for long-range phase-coherent pairing increases from ∼1.5 ps at 4K to ∼3.5 ps near Tc, consistent with the closing of the superconducting gap. For underdoped films, the measured recovery time is temperature independent (3.5 ps) in accordance with the presence of a pseudogap. Ultrafast picosecond measurements of optically induced changes in the absolute conductivity of La0:7M0:3MnO3 thin films (M = Ca, Sr) from 10K to ∼0.9Tc reveal a two-component relaxation. A fast, ∼2 ps, conductivity decrease arises from optically induced modification of the effective phonon temperature. The slower component, related to spin-lattice relaxation, has a lifetime that increases upon approaching Tc from below in accordance with an increasing spin specific heat. Our results indicate that for T<< Tc, the conductivity is determined by incoherent phonons while spin fluctuations dominate near Tc.

  1. Electric field measurement in microwave discharge ion thruster with electro-optic probe.

    Science.gov (United States)

    Ise, Toshiyuki; Tsukizaki, Ryudo; Togo, Hiroyoshi; Koizumi, Hiroyuki; Kuninaka, Hitoshi

    2012-12-01

    In order to understand the internal phenomena in a microwave discharge ion thruster, it is important to measure the distribution of the microwave electric field inside the discharge chamber, which is directly related to the plasma production. In this study, we proposed a novel method of measuring a microwave electric field with an electro-optic (EO) probe based on the Pockels effect. The probe, including a cooling system, contains no metal and can be accessed in the discharge chamber with less disruption to the microwave distribution. This method enables measurement of the electric field profile under ion beam acceleration. We first verified the measurement with the EO probe by a comparison with a finite-difference time domain numerical simulation of the microwave electric field in atmosphere. Second, we showed that the deviations of the reflected microwave power and the beam current were less than 8% due to inserting the EO probe into the ion thruster under ion beam acceleration. Finally, we successfully demonstrated the measurement of the electric-field profile in the ion thruster under ion beam acceleration. These measurements show that the electric field distribution in the thruster dramatically changes in the ion thruster under ion beam acceleration as the propellant mass flow rate increases. These results indicate that this new method using an EO probe can provide a useful guide for improving the propulsion of microwave discharge ion thrusters.

  2. RNA aptamer probes as optical imaging agents for the detection of amyloid plaques.

    Directory of Open Access Journals (Sweden)

    Christian T Farrar

    Full Text Available Optical imaging using multiphoton microscopy and whole body near infrared imaging has become a routine part of biomedical research. However, optical imaging methods rely on the availability of either small molecule reporters or genetically encoded fluorescent proteins, which are challenging and time consuming to develop. While directly labeled antibodies can also be used as imaging agents, antibodies are species specific, can typically not be tagged with multiple fluorescent reporters without interfering with target binding, and are bioactive, almost always eliciting a biological response and thereby influencing the process that is being studied. We examined the possibility of developing highly specific and sensitive optical imaging agents using aptamer technology. We developed a fluorescently tagged anti-Aβ RNA aptamer, β55, which binds amyloid plaques in both ex vivo human Alzheimer's disease brain tissue and in vivo APP/PS1 transgenic mice. Diffuse β55 positive halos, attributed to oligomeric Aβ, were observed surrounding the methoxy-XO4 positive plaque cores. Dot blots of synthetic Aβ aggregates provide further evidence that β55 binds both fibrillar and non-fibrillar Aβ. The high binding affinity, the ease of probe development, and the ability to incorporate multiple and multimodal imaging reporters suggest that RNA aptamers may have complementary and perhaps advantageous properties compared to conventional optical imaging probes and reporters.

  3. All-optical optoacoustic microscopy based on probe beam deflection technique

    Directory of Open Access Journals (Sweden)

    Saher M. Maswadi

    2016-09-01

    Full Text Available Optoacoustic (OA microscopy using an all-optical system based on the probe beam deflection technique (PBDT for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii high sensitivity and (iv ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22 μV/Pa and its noise equivalent pressure (NEP of 11.4 Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

  4. All-optical optoacoustic microscopy based on probe beam deflection technique.

    Science.gov (United States)

    Maswadi, Saher M; Ibey, Bennett L; Roth, Caleb C; Tsyboulski, Dmitri A; Beier, Hope T; Glickman, Randolph D; Oraevsky, Alexander A

    2016-09-01

    Optoacoustic (OA) microscopy using an all-optical system based on the probe beam deflection technique (PBDT) for detection of laser-induced acoustic signals was investigated as an alternative to conventional piezoelectric transducers. PBDT provides a number of advantages for OA microscopy including (i) efficient coupling of laser excitation energy to the samples being imaged through the probing laser beam, (ii) undistorted coupling of acoustic waves to the detector without the need for separation of the optical and acoustic paths, (iii) high sensitivity and (iv) ultrawide bandwidth. Because of the unimpeded optical path in PBDT, diffraction-limited lateral resolution can be readily achieved. The sensitivity of the current PBDT sensor of 22 μV/Pa and its noise equivalent pressure (NEP) of 11.4 Pa are comparable with these parameters of the optical micro-ring resonator and commercial piezoelectric ultrasonic transducers. Benefits of the present prototype OA microscope were demonstrated by successfully resolving micron-size details in histological sections of cardiac muscle.

  5. Waveguide analysis of heat-drawn and chemically etched probe tips for scanning near-field optical microscopy.

    Science.gov (United States)

    Moar, Peter N; Love, John D; Ladouceur, François; Cahill, Laurence W

    2006-09-01

    We analyze two basic aspects of a scanning near-field optical microscope (SNOM) probe's operation: (i) spot-size evolution of the electric field along the probe with and without a metal layer, and (ii) a modal analysis of the SNOM probe, particularly in close proximity to the aperture. A slab waveguide model is utilized to minimize the analytical complexity, yet provides useful quantitative results--including losses associated with the metal coating--which can then be used as design rules.

  6. Quantitative measurements in laser induced plasmas using optical probing. Progress report, October 1, 1977--April 30, 1978

    International Nuclear Information System (INIS)

    Sweeney, D.W.

    1978-06-01

    Optical probing of laser induced plasmas can be used to quantitatively reconstruct electron number densities and magnetic fields. Numerical techniques for extracting quantitative information from the experimental data are described and four Abel inversion codes are provided. A computer simulation of optical probing is used to determine the quantitative information that can be reasonably extracted from real experimental systems. Examples of reconstructed electron number densities from interferograms of laser plasmas show steepened electron distributions

  7. Remote Raman microimaging using an AOTF and a spatially coherent microfiber optical probe

    International Nuclear Information System (INIS)

    Trey Skinner, H.; Cooney, T.F.; Sharma, S.K.; Angel, S.M.

    1996-01-01

    A fiber-optic Raman microimaging probe is described that is suitable for acquiring high-spatial-resolution Raman images in sampling situations with no clear line of sight. A high-power near-infrared diode laser combined with an acousto-optic tunable filter and a spatially coherent optical fiber bundle allow fluorescence-free Raman images of remotely located samples to be acquired at distances up to several meters. The feasibility of this technique is demonstrated with Raman images of (1) a pellet containing a mixture of a highly scattering sample, bis-methylstyrylbenzene (BMSB), KCl, and graphite, and (2) a partially graphitized diamond. These images clearly show phase boundaries over an area of approximately 0.1 mm 2 with ∼4-μm resolution. copyright 1996 Society for Applied Spectroscopy

  8. Protein rotational dynamics investigated with a dual EPR/optical molecular probe. Spin-labeled eosin.

    Science.gov (United States)

    Cobb, C E; Hustedt, E J; Beechem, J M; Beth, A H

    1993-01-01

    An acyl spin-label derivative of 5-aminoeosin (5-SLE) was chemically synthesized and employed in studies of rotational dynamics of the free probe and of the probe when bound noncovalently to bovine serum albumin using the spectroscopic techniques of fluorescence anisotropy decay and electron paramagnetic resonance (EPR) and their long-lifetime counterparts phosphorescence anisotropy decay and saturation transfer EPR. Previous work (Beth, A. H., Cobb, C. E., and J. M. Beechem, 1992. Synthesis and characterization of a combined fluorescence, phosphorescence, and electron paramagnetic resonance probe. Society of Photo-Optical Instrumentation Engineers. Time-Resolved Laser Spectroscopy III. 504-512) has shown that the spin-label moiety only slightly altered the fluorescence and phosphorescence lifetimes and quantum yields of 5-SLE when compared with 5-SLE whose nitroxide had been reduced with ascorbate and with the diamagnetic homolog 5-acetyleosin. In the present work, we have utilized time-resolved fluorescence anisotropy decay and linear EPR spectroscopies to observe and quantitate the psec motions of 5-SLE in solution and the nsec motions of the 5-SLE-bovine serum albumin complex. Time-resolved phosphorescence anisotropy decay and saturation transfer EPR studies have been carried out to observe and quantitate the microseconds motions of the 5-SLE-albumin complex in glycerol/buffer solutions of varying viscosity. These latter studies have enabled a rigorous comparison of rotational correlation times obtained from these complementary techniques to be made with a single probe. The studies described demonstrate that it is possible to employ a single molecular probe to carry out the full range of fluorescence, phosphorescence, EPR, and saturation transfer EPR studies. It is anticipated that "dual" molecular probes of this general type will significantly enhance capabilities for extracting dynamics and structural information from macromolecules and their functional

  9. Measurement of two-dimensional bubble velocity by Using tri-fiber-optical Probe

    International Nuclear Information System (INIS)

    Yang Ruichang; Zheng Rongchuan; Zhou Fanling; Liu Ruolei

    2009-01-01

    In this study, an advanced measuring system with a tri-single-fiber-optical-probe has been developed to measure two-dimensional vapor/gas bubble velocity. The use of beam splitting devices instead of beam splitting lens simplifies the optical system, so the system becomes more compact and economic, and more easy to adjust. Corresponding to using triple-optical probe for measuring two-dimensional bubble velocity, a data processing method has been developed, including processing of bubble signals, cancelling of unrelated signals, determining of bubble velocity with cross correlation technique and so on. Using the developed two-dimensional bubble velocity measuring method, the rising velocity of air bubbles in gravitational field was measured. The measured bubble velocities were compared with the empirical correlation available. Deviation was in the range of ±30%. The bubble diameter obtained by data processing is in good accordance with that observed with a synchro-scope and a camera. This shows that the method developed here is reliable.

  10. Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts.

    Science.gov (United States)

    Katagiri, Takashi; Shibayama, Kyosuke; Iida, Takeru; Matsuura, Yuji

    2018-03-27

    A real-time gas monitoring system based on optical absorption spectroscopy is proposed for localized carbon dioxide (CO₂) measurement in respiratory tracts. In this system, a small gas cell is attached to the end of a hollow optical fiber that delivers mid-infrared light with small transmission loss. The diameters of the fiber and the gas cell are smaller than 1.2 mm so that the probe can be inserted into a working channel of common bronchoscopes. The dimensions of the gas cell are designed based on absorption spectra of CO₂ standard gases in the 4.2 μm wavelength region, which are measured using a Fourier-transform infrared spectrometer. A miniature gas cell that is comprised of a stainless-steel tube with slots for gas inlet and a micro-mirror is fabricated. A compact probing system with a quantum cascade laser (QCL) light source is built using a gas cell with a hollow optical fiber for monitoring CO₂ concentration. Experimental results using human breaths show the feasibility of the system for in-situ measurement of localized CO₂ concentration in human airways.

  11. Infrared Hollow Optical Fiber Probe for Localized Carbon Dioxide Measurement in Respiratory Tracts

    Directory of Open Access Journals (Sweden)

    Takashi Katagiri

    2018-03-01

    Full Text Available A real-time gas monitoring system based on optical absorption spectroscopy is proposed for localized carbon dioxide (CO2 measurement in respiratory tracts. In this system, a small gas cell is attached to the end of a hollow optical fiber that delivers mid-infrared light with small transmission loss. The diameters of the fiber and the gas cell are smaller than 1.2 mm so that the probe can be inserted into a working channel of common bronchoscopes. The dimensions of the gas cell are designed based on absorption spectra of CO2 standard gases in the 4.2 μm wavelength region, which are measured using a Fourier-transform infrared spectrometer. A miniature gas cell that is comprised of a stainless-steel tube with slots for gas inlet and a micro-mirror is fabricated. A compact probing system with a quantum cascade laser (QCL light source is built using a gas cell with a hollow optical fiber for monitoring CO2 concentration. Experimental results using human breaths show the feasibility of the system for in-situ measurement of localized CO2 concentration in human airways.

  12. Tapered optical fiber tip probes based on focused ion beam-milled Fabry-Perot microcavities

    Science.gov (United States)

    André, Ricardo M.; Warren-Smith, Stephen C.; Becker, Martin; Dellith, Jan; Rothhardt, Manfred; Zibaii, M. I.; Latifi, H.; Marques, Manuel B.; Bartelt, Hartmut; Frazão, Orlando

    2016-09-01

    Focused ion beam technology is combined with dynamic chemical etching to create microcavities in tapered optical fiber tips, resulting in fiber probes for temperature and refractive index sensing. Dynamic chemical etching uses hydrofluoric acid and a syringe pump to etch standard optical fibers into cone structures called tapered fiber tips where the length, shape, and cone angle can be precisely controlled. On these tips, focused ion beam is used to mill several different types of Fabry-Perot microcavities. Two main cavity types are initially compared and then combined to form a third, complex cavity structure. In the first case, a gap is milled on the tapered fiber tip which allows the external medium to penetrate the light guiding region and thus presents sensitivity to external refractive index changes. In the second, two slots that function as mirrors are milled on the tip creating a silica cavity that is only sensitive to temperature changes. Finally, both cavities are combined on a single tapered fiber tip, resulting in a multi-cavity structure capable of discriminating between temperature and refractive index variations. This dual characterization is performed with the aid of a fast Fourier transform method to separate the contributions of each cavity and thus of temperature and refractive index. Ultimately, a tapered optical fiber tip probe with sub-standard dimensions containing a multi-cavity structure is projected, fabricated, characterized and applied as a sensing element for simultaneous temperature and refractive index discrimination.

  13. A new fibre optic pulse oximeter probe for monitoring splanchnic organ arterial blood oxygen saturation.

    Science.gov (United States)

    Hickey, M; Samuels, N; Randive, N; Langford, R; Kyriacou, P A

    2012-12-01

    A new, continuous method of monitoring splanchnic organ oxygen saturation (SpO(2)) would make the early detection of inadequate tissue oxygenation feasible, reducing the risk of hypoperfusion, severe ischaemia, and, ultimately, death. In an attempt to provide such a device, a new fibre optic based reflectance pulse oximeter probe and processing system were developed followed by an in vivo evaluation of the technology on seventeen patients undergoing elective laparotomy. Photoplethysmographic (PPG) signals of good quality and high signal-to-noise ratio were obtained from the small bowel, large bowel, liver and stomach. Simultaneous peripheral PPG signals from the finger were also obtained for comparison purposes. Analysis of the amplitudes of all acquired PPG signals indicated much larger amplitudes for those signals obtained from splanchnic organs than those obtained from the finger. Estimated SpO(2) values for splanchnic organs showed good agreement with those obtained from the finger fibre optic probe and those obtained from a commercial device. These preliminary results suggest that a miniaturized 'indwelling' fibre optic sensor may be a suitable method for pre-operative and post-operative evaluation of splanchnic organ SpO(2) and their health. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  14. Dicke superradiance as nondestructive probe for the state of atoms in optical lattices

    Science.gov (United States)

    ten Brinke, Nicolai; Schützhold, Ralf

    2016-04-01

    We present a proposal for a probing scheme utilizing Dicke superradiance to obtain information about ultracold atoms in optical lattices. A probe photon is absorbed collectively by an ensemble of lattice atoms generating a Dicke state. The lattice dynamics (e.g., tunneling) affects the coherence properties of that Dicke state and thus alters the superradiant emission characteristics - which in turn provides insight into the lattice (dynamics). Comparing the Bose-Hubbard and the Fermi-Hubbard model, we find similar superradiance in the strongly interacting Mott insulator regime, but crucial differences in the weakly interacting (superfluid or metallic) phase. Furthermore, we study the possibility to detect whether a quantum phase transition between the two regimes can be considered adiabatic or a quantum quench.

  15. Pump-probe nonlinear magneto-optical rotation with frequency-modulated light

    International Nuclear Information System (INIS)

    Pustelny, S.; Gawlik, W.; Jackson Kimball, D. F.; Rochester, S. M.; Yashchuk, V. V.; Budker, D.

    2006-01-01

    Specific types of atomic coherences between Zeeman sublevels can be generated and detected using a method based on nonlinear magneto-optical rotation with frequency-modulated light. Linearly polarized, frequency-modulated light is employed to selectively generate ground-state coherences between Zeeman sublevels for which Δm=2 and Δm=4 in 85 Rb and 87 Rb atoms, and additionally Δm=6 in 85 Rb. The atomic coherences are detected with a separate, unmodulated probe light beam. Separation of the pump and probe beams enables independent investigation of the processes of creation and detection of the atomic coherences. With the present technique the transfer of the Zeeman coherences, including high-order coherences, from excited to ground state by spontaneous emission has been observed

  16. Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging of Sentinel Lymph Node and Tumor

    Science.gov (United States)

    Qin, Zhengtao

    Molecular imaging is visualizations and measurements of in vivo biological processes at the molecular or cellular level using specific imaging probes. As an emerging technology, biocompatible macromolecular or nanoparticle based targeted imaging probes have gained increasing popularities. Those complexes consist of a carrier, an imaging reporter, and a targeting ligand. The active targeting ability dramatically increases the specificity. And the multivalency effect may further reduce the dose while providing a decent signal. In this thesis, sentinel lymph node (SLN) mapping and cancer imaging are two research topics. The focus is to develop molecular imaging probes with high specificity and sensitivity, for Positron Emission Tomography (PET) and optical imaging. The objective of this thesis is to explore dextran radiopharmaceuticals and porous silicon nanoparticles based molecular imaging agents. Dextran polymers are excellent carriers to deliver imaging reporters or therapeutic agents due to its well established safety profile and oligosaccharide conjugation chemistry. There is also a wide selection of dextran polymers with different lengths. On the other hand, Silicon nanoparticles represent another class of biodegradable materials for imaging and drug delivery. The success in fluorescence lifetime imaging and enhancements of the immune activation potency was briefly discussed. Chapter 1 begins with an overview on current molecular imaging techniques and imaging probes. Chapter 2 presents a near-IR dye conjugated probe, IRDye 800CW-tilmanocept. Fluorophore density was optimized to generate the maximum brightness. It was labeled with 68Ga and 99mTc and in vivo SLN mapping was successfully performed in different animals, such as mice, rabbits, dogs and pigs. With 99mTc labeled IRDye 800CW-tilmanocept, chapter 3 introduces a two-day imaging protocol with a hand-held imager. Chapter 4 proposed a method to dual radiolabel the IRDye 800CW-tilmanocept with both 68Ga and

  17. Probing the micro-rheological properties of aerosol particles using optical tweezers

    International Nuclear Information System (INIS)

    Power, Rory M; Reid, Jonathan P

    2014-01-01

    The use of optical trapping techniques to manipulate probe particles for performing micro-rheological measurements on a surrounding fluid is well-established. Here, we review recent advances made in the use of optical trapping to probe the rheological properties of trapped particles themselves. In particular, we review observations of the continuous transition from liquid to solid-like viscosity of sub-picolitre supersaturated solution aerosol droplets using optical trapping techniques. Direct measurements of the viscosity of the particle bulk are derived from the damped oscillations in shape following coalescence of two particles, a consequence of the interplay between viscous and surface forces and the capillary driven relaxation of the approximately spheroidal composite particle. Holographic optical tweezers provide a facile method for the manipulation of arrays of particles allowing coalescence to be controllably induced between two micron-sized aerosol particles. The optical forces, while sufficiently strong to confine the composite particle, are several orders of magnitude weaker than the capillary forces driving relaxation. Light, elastically back-scattered by the particle, is recorded with sub-100 ns resolution allowing measurements of fast relaxation (low viscosity) dynamics, while the brightfield image can be used to monitor the shape relaxation extending to times in excess of 1000 s. For the slowest relaxation dynamics studied (particles with the highest viscosity) the presence and line shape of whispering gallery modes in the cavity enhanced Raman spectrum can be used to infer the relaxation time while serving the dual purpose of allowing the droplet size and refractive index to be measured with accuracies of ±0.025% and ±0.1%, respectively. The time constant for the damped relaxation can be used to infer the bulk viscosity, spanning from the dilute solution limit to a value approaching that of a glass, typically considered to be >10 12

  18. Probing the micro-rheological properties of aerosol particles using optical tweezers

    Science.gov (United States)

    Power, Rory M.; Reid, Jonathan P.

    2014-07-01

    The use of optical trapping techniques to manipulate probe particles for performing micro-rheological measurements on a surrounding fluid is well-established. Here, we review recent advances made in the use of optical trapping to probe the rheological properties of trapped particles themselves. In particular, we review observations of the continuous transition from liquid to solid-like viscosity of sub-picolitre supersaturated solution aerosol droplets using optical trapping techniques. Direct measurements of the viscosity of the particle bulk are derived from the damped oscillations in shape following coalescence of two particles, a consequence of the interplay between viscous and surface forces and the capillary driven relaxation of the approximately spheroidal composite particle. Holographic optical tweezers provide a facile method for the manipulation of arrays of particles allowing coalescence to be controllably induced between two micron-sized aerosol particles. The optical forces, while sufficiently strong to confine the composite particle, are several orders of magnitude weaker than the capillary forces driving relaxation. Light, elastically back-scattered by the particle, is recorded with sub-100 ns resolution allowing measurements of fast relaxation (low viscosity) dynamics, while the brightfield image can be used to monitor the shape relaxation extending to times in excess of 1000 s. For the slowest relaxation dynamics studied (particles with the highest viscosity) the presence and line shape of whispering gallery modes in the cavity enhanced Raman spectrum can be used to infer the relaxation time while serving the dual purpose of allowing the droplet size and refractive index to be measured with accuracies of ±0.025% and ±0.1%, respectively. The time constant for the damped relaxation can be used to infer the bulk viscosity, spanning from the dilute solution limit to a value approaching that of a glass, typically considered to be >1012 Pa s, whilst

  19. Measurement of local flow pattern in boiling R12 simulating PWR conditions with multiple optical probes

    International Nuclear Information System (INIS)

    Garnier, J.

    1998-01-01

    For a comprehensive approach of boiling crisis phenomenon in order to get more reliable predictions of critical heat flux in PWR core, a flow pattern study is under progress at CEA GRENOBLE (in a joint program with Electricite de France: EdF). The first aim is to get experimental results on flow structure in the range of thermal hydraulic parameters involved in the core of a PWR (pressure up to 16 MPa, heat flux about 1 MW/m 2 , mass velocity up to 5000 kg/s/m 2 . As critical heat flux is a local phenomenon and is the result of the flow development, the data has to be measured from the beginning of boiling until boiling crisis, and from the bulk flow until the boundary layer close to the heating walls. Therefore, these results will be useful in modeling not only boiling crisis phenomenon but also condensation in subcooled boiling, coalescence, splitting up, mass and energy transfers at interfaces, and so on. In a first step, the test section is a vertical tube 19.2 mm internal diameter with an axial uniform heat flux over a 3.5m length. The study is performed on the DEBORA loop with Freon 12 as coolant fluid. We assume that basic boiling phenomena (and the knowledge we get about them) only depend on the fluid properties by means of dimensionless parameters but not on the fluid itself. In a first part, we briefly recall that interfacial detection is the most important parameter of a flow pattern study. Therefore, the use of probes able to measure the Phase Indicator Function (P.I.F.) is necessary. A first study of flow conditions shows that the flow pattern is essentially a bubbly one with vapor particles of low diameter (about 300 clm) and high velocity (up to 7 m/s). These criteria induce that a multiple optical probe is the most appropriate tool provided we improve the technology. We detail the way to obtain probes able to detect small particles at high velocity. Each fiber is stretched to get a tip of 10 Clm with the cladding kept on 50 μm length which defines

  20. Comparative study of the endoscope-based bevelled and volume fiber-optic Raman probes for optical diagnosis of gastric dysplasia in vivo at endoscopy.

    Science.gov (United States)

    Wang, Jianfeng; Lin, Kan; Zheng, Wei; Ho, Khek Yu; Teh, Ming; Yeoh, Khay Guan; Huang, Zhiwei

    2015-11-01

    This study aims to compare the diagnostic performance of the two different endoscope-based fiber-optic Raman probe designs (i.e., bevelled and volume Raman probes) for real-time, in vivo detection of gastric dysplasia at endoscopy. To conduct the clinical comparison, a total of 1,050 in vivo tissue Raman spectra (normal: n = 864; dysplasia: n = 186) were acquired from 66 gastric patients (normal: n = 48; dysplasia: n = 18) by using bevelled Raman probe, while a total of 1,913 in vivo tissue Raman spectra (normal: n = 1,786; dysplasia: n = 127) were acquired from 98 gastric patients (normal: n = 87; dysplasia: n = 11) by using volume Raman probe. The bevelled Raman probe provides approximately twofold improvements in tissue Raman-to-autofluorescence intensity ratios as compared to the use of volume Raman probe. Partial least squares discriminant analysis together with leave-one patient-out cross-validation on in vivo tissue Raman spectra acquired yields a diagnostic accuracy of 93.0 % (sensitivity of 92.5 %; specificity of 93.1 %) for differentiating gastric dysplasia from normal gastric tissue by using the bevelled fiber-optic Raman probe, which is superior to the diagnostic performance (accuracy of 88.4 %; sensitivity of 85.8 %; specificity of 88.6 %) by using the volume Raman probe. This work demonstrates that the Raman spectroscopic technique coupled with bevelled fiber-optic Raman probe has great potential to enhance in vivo diagnosis of gastric precancer and early cancer at endoscopy. Graphical Abstract Comparison of in vivo gastric tissue Raman spectra acquired by using bevelled and volume fiber-optic Raman probes.

  1. Full-field parallel interferometry coherence probe microscope for high-speed optical metrology.

    Science.gov (United States)

    Safrani, A; Abdulhalim, I

    2015-06-01

    Parallel detection of several achromatic phase-shifted images is used to obtain a high-speed, high-resolution, full-field, optical coherence probe tomography system based on polarization interferometry. The high enface imaging speed, short coherence gate, and high lateral resolution provided by the system are exploited to determine microbump height uniformity in an integrated semiconductor chip at 50 frames per second. The technique is demonstrated using the Linnik microscope, although it can be implemented on any polarization-based interference microscopy system.

  2. Investigating the micro-rheology of the vitreous humor using an optically trapped local probe

    Science.gov (United States)

    Watts, Fiona; Ean Tan, Lay; Wilson, Clive G.; Girkin, John M.; Tassieri, Manlio; Wright, Amanda J.

    2014-01-01

    We demonstrate that an optically trapped silica bead can be used as a local probe to measure the micro-rheology of the vitreous humor. The Brownian motion of the bead was observed using a fast camera and the micro-rheology determined by analysis of the time-dependent mean-square displacement of the bead. We observed regions of the vitreous that showed different degrees of viscoelasticity, along with the homogeneous and inhomogeneous nature of different regions. The motivation behind this study is to understand the vitreous structure, in particular changes due to aging, allowing more confident prediction of pharmaceutical drug behavior and delivery within the vitreous humor.

  3. Investigating the micro-rheology of the vitreous humor using an optically trapped local probe

    International Nuclear Information System (INIS)

    Watts, Fiona; Wright, Amanda J; Tan, Lay Ean; Wilson, Clive G; Girkin, John M; Tassieri, Manlio

    2014-01-01

    We demonstrate that an optically trapped silica bead can be used as a local probe to measure the micro-rheology of the vitreous humor. The Brownian motion of the bead was observed using a fast camera and the micro-rheology determined by analysis of the time-dependent mean-square displacement of the bead. We observed regions of the vitreous that showed different degrees of viscoelasticity, along with the homogeneous and inhomogeneous nature of different regions. The motivation behind this study is to understand the vitreous structure, in particular changes due to aging, allowing more confident prediction of pharmaceutical drug behavior and delivery within the vitreous humor. (paper)

  4. Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope

    International Nuclear Information System (INIS)

    Santamaria, L.; Siller, H. R.; Garcia-Ortiz, C. E.; Cortes, R.; Coello, V.

    2016-01-01

    In this work, we present an alternative optical method to determine the probe-sample separation distance in a scanning near-field optical microscope. The experimental method is based in a Lloyd’s mirror interferometer and offers a measurement precision deviation of ∼100 nm using digital image processing and numerical analysis. The technique can also be strategically combined with the characterization of piezoelectric actuators and stability evaluation of the optical system. It also opens the possibility for the development of an automatic approximation control system valid for probe-sample distances from 5 to 500 μm.

  5. Optical method for distance and displacement measurements of the probe-sample separation in a scanning near-field optical microscope

    Energy Technology Data Exchange (ETDEWEB)

    Santamaria, L.; Siller, H. R. [Tecnológico de Monterrey, Eugenio Garza Sada 2501 Sur, Monterrey, N.L., 64849 (Mexico); Garcia-Ortiz, C. E., E-mail: cegarcia@cicese.mx [CONACYT Research Fellow – CICESE, Unidad Monterrey, Alianza Centro 504, Apodaca, NL, 66629 (Mexico); Cortes, R.; Coello, V. [CICESE, Unidad Monterrey, PIIT, Alianza Centro 504, Apodaca, NL, 66629 (Mexico)

    2016-04-15

    In this work, we present an alternative optical method to determine the probe-sample separation distance in a scanning near-field optical microscope. The experimental method is based in a Lloyd’s mirror interferometer and offers a measurement precision deviation of ∼100 nm using digital image processing and numerical analysis. The technique can also be strategically combined with the characterization of piezoelectric actuators and stability evaluation of the optical system. It also opens the possibility for the development of an automatic approximation control system valid for probe-sample distances from 5 to 500 μm.

  6. Tapered optical fibers as tools for probing magneto-optical trap characteristics

    International Nuclear Information System (INIS)

    Morrissey, Michael J.; Deasy, Kieran; Wu Yuqiang; Nic Chormaic, Sile; Chakrabarti, Shrabana

    2009-01-01

    We present a novel technique for measuring the characteristics of a magneto-optical trap (MOT) for cold atoms by monitoring the spontaneous emission from trapped atoms coupled into the guided mode of a tapered optical nanofiber. We show that the nanofiber is highly sensitive to very small numbers of atoms close to its surface. The size and shape of the MOT, determined by translating the cold atom cloud across the tapered fiber, is in excellent agreement with measurements obtained using the conventional method of fluorescence imaging using a charge coupled device camera. The coupling of atomic fluorescence into the tapered fiber also allows us to monitor the loading and lifetime of the trap. The results are compared to those achieved by focusing the MOT fluorescence onto a photodiode and it was seen that the tapered fiber gives slightly longer loading and lifetime measurements due to the sensitivity of the fiber, even when very few atoms are present.

  7. Looking inside jets: optical polarimetry as a probe of Gamma-Ray Bursts physics

    Science.gov (United States)

    Kopac, D.; Mundell, C.

    2015-07-01

    It is broadly accepted that gamma-ray bursts (GRBs) are powered by accretion of matter by black holes, formed during massive stellar collapse, which launch ultra-relativistic, collimated outflows or jets. The nature of the progenitor star, the structure of the jet, and thus the underlying mechanisms that drive the explosion and provide collimation, remain some of the key unanswered questions. To approach these problems, and in particular the role of magnetic fields in GRBs, early time-resolved polarimetry is the key, because it is the only direct probe of the magnetic fields structure. Using novel fast RINGO polarimeter developed for use on the 2-m robotic optical Liverpool Telescope, we have made the first measurements of optical linear polarization of the early optical afterglows of GRBs, finding linear percentage polarization as high as 30% and, for the first time, making time-resolved polarization measurements. I will present the past 8 years of RINGO observations, discuss how the results fit into the GRB theoretical picture, and highlight recent data, in particular high-time resolution multi-colour optical photometry performed during the prompt GRB phase, which also provides some limits on polarization.

  8. The performance of a fiber optic displacement sensor for different types of probes and targets

    International Nuclear Information System (INIS)

    Yasin, M; Harun, S W; Abdul-Rashid, H A; Kusminarto; Karyono; Ahmad, H

    2008-01-01

    A simple fiber optic displacement sensor is presented using a multimode plastic bundled fiber and the intensity modulation technique. The performance of the sensor is compared for different types of probes and targets. The probe with the largest receiving core diameter demonstrates the highest linearity range, and increasing the number of receiving cores increases the sensitivity of the sensor. With a stainless steel target and the concentric bundled fiber with 16 receiving fibers as a probe, the sensitivity of the sensor is found to be 0.0220 mV/μm over 150 to 550 μm range and – 0.0061 mV/μm over 1100 to 2000 μm range. The target with a higher reflectivity shows a higher sensitivity. The linearity range for the front slope is almost similar for all targets tested. However, for the back slope, lower reflectivity objects have a relatively higher linearity range with the highest range of 1600 μm being obtained using plastic and aluminum targets. The simplicity of the design, high degree of sensitivity, dynamic range, non-contact measurement and low cost of the fabrication make it suitable for applications in industries for position control and micro displacement measurement in the hazardous regions

  9. Optical probe for porosity defect detection on inner diameter surfaces of machined bores

    Science.gov (United States)

    Kulkarni, Ojas P.; Islam, Mohammed N.; Terry, Fred L.

    2010-12-01

    We demonstrate an optical probe for detection of porosity inside spool bores of a transmission valve body with diameters down to 5 mm. The probe consists of a graded-index relay rod that focuses a laser beam spot onto the inner surface of the bore. Detectors, placed in the specular and grazing directions with respect to the incident beam, measure the change in scattered intensity when a surface defect is encountered. Based on the scattering signatures in the two directions, the system can also validate the depth of the defect and distinguish porosity from bump-type defects coming out of the metal surface. The system can detect porosity down to a 50-μm lateral dimension and ~40 μm in depth with >3-dB contrast over the background intensity fluctuations. Porosity detection systems currently use manual inspection techniques on the plant floor, and the demonstrated probe provides a noncontact technique that can help automotive manufacturers meet high-quality standards during production.

  10. In-vivo fluorescence detection of breast cancer growth factor receptors by fiber-optic probe

    Science.gov (United States)

    Bustamante, Gilbert; Wang, Bingzhi; DeLuna, Frank; Sun, LuZhe; Ye, Jing Yong

    2018-02-01

    Breast cancer treatment options often include medications that target the overexpression of growth factor receptors, such as the proto-oncogene human epidermal growth factor receptor 2 (HER2/neu) and epidermal growth factor receptor (EGFR) to suppress the abnormal growth of cancerous cells and induce cancer regression. Although effective, certain treatments are toxic to vital organs, and demand assurance that the pursued receptor is present at the tumor before administration of the drug. This requires diagnostic tools to provide tumor molecular signatures, as well as locational information. In this study, we utilized a fiber-optic probe to characterize in vivo HER2 and EGFR overexpressed tumors through the fluorescence of targeted dyes. HER2 and EGFR antibodies were conjugated with ICG-Sulfo-OSu and Alexa Fluor 680, respectively, to tag BT474 (HER2+) and MDA-MB-468 (EGFR+) tumors. The fiber was inserted into the samples via a 30-gauge needle. Different wavelengths of a supercontinuum laser were selected to couple into the fiber and excite the corresponding fluorophores in the samples. The fluorescence from the dyes was collected through the same fiber and quantified by a time-correlated single photon counter. Fluorescence at different antibody-dye concentrations was measured for calibration. Mice with subcutaneous HER2+ and/or EGFR+ tumors received intravenous injections of the conjugates and were later probed at the tumor sites. The measured fluorescence was used to distinguish between tumor types and to calculate the concentration of the antibody-dye conjugates, which were detectable at levels as low as 40 nM. The fiber-optic probe presents a minimally invasive instrument to characterize the molecular signatures of breast cancer in vivo.

  11. Two-tint pump-probe measurements using a femtosecond laser oscillator and sharp-edged optical filters.

    Science.gov (United States)

    Kang, Kwangu; Koh, Yee Kan; Chiritescu, Catalin; Zheng, Xuan; Cahill, David G

    2008-11-01

    We describe a simple approach for rejecting unwanted scattered light in two types of time-resolved pump-probe measurements, time-domain thermoreflectance (TDTR) and time-resolved incoherent anti-Stokes Raman scattering (TRIARS). Sharp edged optical filters are used to create spectrally distinct pump and probe beams from the broad spectral output of a femtosecond Ti:sapphire laser oscillator. For TDTR, the diffusely scattered pump light is then blocked by a third optical filter. For TRIARS, depolarized scattering created by the pump is shifted in frequency by approximately 250 cm(-1) relative to the polarized scattering created by the probe; therefore, spectral features created by the pump and probe scattering can be easily distinguished.

  12. Analysis and Design of a Fiber-optic Probe for DNA Sensors Final Report CRADA No. TSB-1147-95

    Energy Technology Data Exchange (ETDEWEB)

    Molau, Nicole [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Vail, Curtis [Accu.Photonics, Inc., Ann Arbor, MI (United States)

    2018-01-24

    In 1995, a challenge in the field of genetics dealt with the acquisition of efficient DNA sequencing techniques for reading the 3 billion base-pairs that comprised the human genome. AccuPhotonics, Inc. proposed to develop and manufacture a state-of-the-art near-field scanning optical microscopy (NSOM) fiber-optic probe that was expected to increase probe efficiency by two orders of magnitude over the existing state-of-the-art and to improve resolution to 10Å. The detailed design calculation and optimization of electrical properties of the fiber-optic probe tip geometry would be performed at LLNL, using existing finite-difference time-domain (FDTD) electromagnetic (EM) codes.

  13. Probing smoking craving with a multidimensional approach: validation of the 12-item French-language version of the Questionnaire on Smoking Urges

    Directory of Open Access Journals (Sweden)

    Dethier V

    2014-08-01

    Full Text Available Vincent Dethier,1 Alexandre Heeren,1,2 Laurence Galanti,3 Pierre Philippot,1 Joël Billieux1 1Laboratory for Experimental Psychopathology, Psychological Science Research Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium; 2National Fund for Scientific Research, Brussels, Belgium; 3Department of Clinical Biology, Mont-Godinne University Hospital, Yvoir, Belgium Background: The current study examined the psychometric properties of the 12-item French-language version of the Questionnaire on Smoking Urges (QSU-12, a widely used multidimensional measure of cigarette craving. Methods: Daily smokers (n=230 completed the QSU-12, the Fägerstrom Test for Nicotine Dependence, and items about addiction-related symptoms. Additional participants (n=40 completed the QSU-12 and the Fägerstrom Test for Nicotine Dependence and were assessed for expired carbon monoxide. Results: Consistent with studies validating the English version of the scale, confirmatory factor analyses supported a two-factor solution in the French version of the scale. Good scale and subscales reliabilities were observed, and convergent validity was evidenced through relationships with dependence and addiction-related symptoms. Conclusion: The French-language version of the QSU-12 is an adequate instrument to assess the multidimensional construct of craving in both research and clinical practice. Keywords: tobacco, smoking, nicotine, craving, measurement model, psychometrics, confirmatory factor analyses, carbon monoxide, addiction

  14. Micromachined diffraction based optical microphones and intensity probes with electrostatic force feedback

    Science.gov (United States)

    Bicen, Baris

    Measuring acoustic pressure gradients is critical in many applications such as directional microphones for hearing aids and sound intensity probes. This measurement is especially challenging with decreasing microphone size, which reduces the sensitivity due to small spacing between the pressure ports. Novel, micromachined biomimetic microphone diaphragms are shown to provide high sensitivity to pressure gradients on one side of the diaphragm with low thermal mechanical noise. These structures have a dominant mode shape with see-saw like motion in the audio band, responding to pressure gradients as well as spurious higher order modes sensitive to pressure. In this dissertation, integration of a diffraction based optical detection method with these novel diaphragm structures to implement a low noise optical pressure gradient microphone is described and experimental characterization results are presented, showing 36 dBA noise level with 1mm port spacing, nearly an order of magnitude better than the current gradient microphones. The optical detection scheme also provides electrostatic actuation capability from both sides of the diaphragm separately which can be used for active force feedback. A 4-port electromechanical equivalent circuit model of this microphone with optical readout is developed to predict the overall response of the device to different acoustic and electrostatic excitations. The model includes the damping due to complex motion of air around the microphone diaphragm, and it calculates the detected optical signal on each side of the diaphragm as a combination of two separate dominant vibration modes. This equivalent circuit model is verified by experiments and used to predict the microphone response with different force feedback schemes. Single sided force feedback is used for active damping to improve the linearity and the frequency response of the microphone. Furthermore, it is shown that using two sided force feedback one can significantly suppress

  15. Optical response of a quantum dot-metal nanoparticle hybrid interacting with a weak probe field.

    Science.gov (United States)

    Kosionis, Spyridon G; Terzis, Andreas F; Sadeghi, Seyed M; Paspalakis, Emmanuel

    2013-01-30

    We study optical effects in a hybrid system composed of a semiconductor quantum dot and a spherical metal nanoparticle that interacts with a weak probe electromagnetic field. We use modified nonlinear density matrix equations for the description of the optical properties of the system and obtain a closed-form expression for the linear susceptibilities of the quantum dot, the metal nanoparticle, and the total system. We then investigate the dependence of the susceptibility on the interparticle distance as well as on the material parameters of the hybrid system. We find that the susceptibility of the quantum dot exhibits optical transparency for specific frequencies. In addition, we show that there is a range of frequencies of the applied field for which the susceptibility of the semiconductor quantum dot leads to gain. This suggests that in such a hybrid system quantum coherence can reverse the course of energy transfer, allowing flow of energy from the metallic nanoparticle to the quantum dot. We also explore the susceptibility of the metal nanoparticle and show that it is strongly influenced by the presence of the quantum dot.

  16. Optical techniques for probing the excited state dynamics of quantum dot solids

    Energy Technology Data Exchange (ETDEWEB)

    Moroz, P.; Kholmicheva, N.; Razgoniaeva, N. [Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43402 (United States); Department of Physics, Bowling Green State University, Bowling Green, OH 43402 (United States); Burchfield, D. [Department of Chemistry, Bowling Green State University, Bowling Green, OH 43402 (United States); Sharma, N.; Acharya, A. [Department of Physics, Bowling Green State University, Bowling Green, OH 43402 (United States); Zamkov, M., E-mail: zamkovm@bgsu.edu [Center for Photochemical Sciences, Bowling Green State University, Bowling Green, OH 43402 (United States); Department of Physics, Bowling Green State University, Bowling Green, OH 43402 (United States)

    2016-06-01

    Highlights: • Optical techniques represent a powerful tool for probing exciton diffusion in QD solids. • Exciton dissociation in QD solids is caused by charge tunneling to traps and other dots. • Exciton and free-carrier lifetimes are given by fast and slow components of PL decay. • Surface PL offers valuable information on the type and density of traps in QD solids. - Abstract: Quantum dot (QD) solids represent an important class of functional materials that holds strong promise for future applications in technology. Their optoelectronic properties are determined by energy diffusion processes, which character can often be inferred from the temporal and spectral analysis of the film’s photoluminescence (PL). Here, optical techniques based on PL lifetime, bulk quenching, and temperature-dependent PL will be discussed. These techniques complement the electrical conductivity measurements by mapping the flow of optically induced excitons through undepleted, contact-free films with an unprecedented temporal and spatial resolution. By correlating the QD solid morphology with the ensuing photoluminescence (PL) dynamics, these methods allow estimating important transport characteristics, including exciton and charge carrier diffusion lengths, the rate of interparticle energy transfer, carrier mobility, and the exciton diffusivity. The review will cover most popular PL-based strategies and summarize the key experimental findings resulting from these works.

  17. Probing optimal measurement configuration for optical scatterometry by the multi-objective genetic algorithm

    Science.gov (United States)

    Chen, Xiuguo; Gu, Honggang; Jiang, Hao; Zhang, Chuanwei; Liu, Shiyuan

    2018-04-01

    Measurement configuration optimization (MCO) is a ubiquitous and important issue in optical scatterometry, whose aim is to probe the optimal combination of measurement conditions, such as wavelength, incidence angle, azimuthal angle, and/or polarization directions, to achieve a higher measurement precision for a given measuring instrument. In this paper, the MCO problem is investigated and formulated as a multi-objective optimization problem, which is then solved by the multi-objective genetic algorithm (MOGA). The case study on the Mueller matrix scatterometry for the measurement of a Si grating verifies the feasibility of the MOGA in handling the MCO problem in optical scatterometry by making a comparison with the Monte Carlo simulations. Experiments performed at the achieved optimal measurement configuration also show good agreement between the measured and calculated best-fit Mueller matrix spectra. The proposed MCO method based on MOGA is expected to provide a more general and practical means to solve the MCO problem in the state-of-the-art optical scatterometry.

  18. Development of micro-optics for high-resolution IL spectroscopy with a proton microbeam probe

    International Nuclear Information System (INIS)

    Kada, Wataru; Satoh, Takahiro; Yokoyama, Akihito; Koka, Masashi; Kamiya, Tomihiro

    2014-01-01

    Confocal optics for ion luminescence (IL) was developed for the precise analysis of the chemical composition of microscopic targets with an external proton microbeam probe. Anti-reflection-coated confocal micro-lens optics with an effective focus area of approximately 800 × 800 μm was installed on the microbeam line of a single-ended accelerator. Chromatic aberrations of the confocal optics were examined at wavelengths of 300–900 nm. An electrically-cooled back-thinned charge coupled device spectrometer with a wavelength resolution of 0.5 nm was used for the microscopic spectroscopy and IL imaging of microscopic mineral targets. Simultaneous microscopic IL and micro-PIXE analysis were performed using an external 3 MeV H + microbeam with a current of less than 100 pA. A spectral resolution of 3 nm was achieved for a single IL peak which corresponded to Cr 3+ impurities in a single-crystal of aluminum oxide. The use of IL spectroscopy and imaging for aerosol targets revealed microscopic distributions of the chemical and elemental composition in the atmosphere

  19. A novel optical probe for pH sensing in gastro-esophageal apparatus

    Science.gov (United States)

    Baldini, F.; Ghini, G.; Giannetti, A.; Senesi, F.; Trono, C.

    2011-03-01

    Monitoring gastric pH for long periods, usually 24 h, may be essential in analyzing the physiological pattern of acidity, in obtaining information on changes in activity during peptic ulcer disease, and in assessing the effect of antisecretory drugs. Gastro-esophageal reflux, which causes a pH decrease in the esophagus content from pH 7 even down to pH 2, can determine esophagitis with possible strictures and Barrett's esophagus. One of the difficulties of the optical measurement of pH in the gastro-esophageal apparatus lies in the required extended working range from 1 to 8 pH units. The present paper deals with a novel optical pH sensor, using methyl red as optical pH indicator. Contrary to all acidbase indicators characterized by working ranges limited to 2-3 pH units, methyl red, after its covalent immobilization on controlled pore glass (CPG), is characterized by a wide working range which fits with the clinical requirements. The novel probe design here described is suitable for gastro-esophageal applications and allows the optimization of the performances of the CPG with the immobilised indicator. This leads to a very simple configuration characterized by a very fast response time.

  20. Sub-wavelength imaging by depolarization in a reflection near-field optical microscope using an uncoated fiber probe

    DEFF Research Database (Denmark)

    Madsen, Steen; Bozhevolnyi, Sergey I.; Hvam, Jørn Märcher

    1998-01-01

    We present a reflection scanning near-field optical microscope utilizing counter-directional light propagation in an uncoated fiber probe, cross-polarized detection and shear-force feedback. Topographical and near-field optical imaging with a scanning speed of up to 10 mu m/s and a lateral...... resolution better than 40 nm are demonstrated with a latex projection test sample. Determination of the optical resolution as well as correlation between topographical and near-field optical images are discussed. (C) 1998 Elsevier Science B.V....

  1. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    International Nuclear Information System (INIS)

    Yasuda, Nobuhiro; Fukuyama, Yoshimitsu; Osawa, Hitoshi; Kimura, Shigeru; Ito, Kiminori; Tanaka, Yoshihito; Matsunaga, Toshiyuki; Kojima, Rie; Hisada, Kazuya; Tsuchino, Akio; Birukawa, Masahiro; Yamada, Noboru; Sekiguchi, Koji; Fujiie, Kazuhiko; Kawakubo, Osamu; Takata, Masaki

    2013-01-01

    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge 2 Sb 2 Te 5 film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width (ΔE/E ∼ 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge 2 Sb 2 Te 5 phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge 2 Sb 2 Te 5 layers on laser power.

  2. Biomedical Probes Based on Inorganic Nanoparticles for Electrochemical and Optical Spectroscopy Applications

    Science.gov (United States)

    Yakoh, Abdulhadee; Pinyorospathum, Chanika; Siangproh, Weena; Chailapakul, Orawon

    2015-01-01

    Inorganic nanoparticles usually provide novel and unique physical properties as their size approaches nanometer scale dimensions. The unique physical and optical properties of nanoparticles may lead to applications in a variety of areas, including biomedical detection. Therefore, current research is now increasingly focused on the use of the high surface-to-volume ratios of nanoparticles to fabricate superb chemical- or biosensors for various detection applications. This article highlights various kinds of inorganic nanoparticles, including metal nanoparticles, magnetic nanoparticles, nanocomposites, and semiconductor nanoparticles that can be perceived as useful materials for biomedical probes and points to the outstanding results arising from their use in such probes. The progress in the use of inorganic nanoparticle-based electrochemical, colorimetric and spectrophotometric detection in recent applications, especially bioanalysis, and the main functions of inorganic nanoparticles in detection are reviewed. The article begins with a conceptual discussion of nanoparticles according to types, followed by numerous applications to analytes including biomolecules, disease markers, and pharmaceutical substances. Most of the references cited herein, dating from 2010 to 2015, generally mention one or more of the following characteristics: a low detection limit, good signal amplification and simultaneous detection capabilities. PMID:26343676

  3. Fiber-based modulated optical reflectance configuration allowing for offset pump and probe beams

    Science.gov (United States)

    Fleming, A.; Folsom, C.; Jensen, C.; Ban, H.

    2016-12-01

    A new fiber-based modulated optical reflectance configuration is developed in this work. The technique maintains the fiber-based heating laser (pump) and detection laser (probe) in close proximity at a fixed separation distance in a ceramic ferrule. The pump beam periodically heats the sample inducing thermal waves into the sample. The probe beam measures the temperature response at a known distance from the pump beam over a range of heating modulation frequencies. The thermal diffusivity of the sample may be calculated from the phase response between the input heat flux and the temperature response of a sample having a reflective surface. The unique measurement configuration is ideal for in situ measurements and has many advantages for laboratory-based systems. The design and development of the system are reported along with theoretical justification for the experimental design. The thermal diffusivities of Ge and SiC are measured and found to be within 10% of reported literature values. The diffusivity for SiO2 is measured with a relative difference of approximately 100% from the literature value when the ferrule is in contact with the sample. An additional measurement was made on the SiO2 sample with the ferrule not in contact resulting in a difference of less than 2% from the literature value. The difference in the SiO2 measurement when the ferrule is in contact with the sample is likely due to a parallel heat transfer path through the dual-fiber ferrule assembly.

  4. Bio-analytical applications of mid-infrared spectroscopy using silver halide fiber-optic probes

    International Nuclear Information System (INIS)

    Heise, H.M.; Kuepper, L.; Butvina, L.N.

    2002-01-01

    Infrared-spectroscopy has proved to be a powerful method for the study of various biomedical samples, in particular for in-vitro analysis in the clinical laboratory and for non-invasive diagnostics. In general, the analysis of biofluids such as whole blood, urine, microdialysates and bioreactor broth media takes advantage of the fact that a multitude of analytes can be quantified simultaneously and rapidly without the need for reagents. Progress in the quality of infrared silver halide fibers enabled us to construct several flexible fiber-optic probes of different geometries, which are particularly suitable for the measurement of small biosamples. Recent trends show that dry film measurements by mid-infrared spectroscopy could revolutionize analytical tools in the clinical chemistry laboratory, and an example is given. Infrared diagnostic tools show a promising potential for patients, and minimal-invasive blood glucose assays or skin tissue pathology in particular cannot be left out using mid-infrared fiber-based probes. Other applications include the measurement of skin samples including penetration studies of vitamins and constituents of cosmetic cream formulations. A further field is the micro-domain analysis of biopsy samples from bog mummified corpses, and recent results on the chemistry of dermis and hair samples are reported. Another field of application, for which results are reported, is food analysis and bio-reactor monitoring

  5. Action Potential Dynamics in Fine Axons Probed with an Axonally Targeted Optical Voltage Sensor.

    Science.gov (United States)

    Ma, Yihe; Bayguinov, Peter O; Jackson, Meyer B

    2017-01-01

    The complex and malleable conduction properties of axons determine how action potentials propagate through extensive axonal arbors to reach synaptic terminals. The excitability of axonal membranes plays a major role in neural circuit function, but because most axons are too thin for conventional electrical recording, their properties remain largely unexplored. To overcome this obstacle, we used a genetically encoded hybrid voltage sensor (hVOS) harboring an axonal targeting motif. Expressing this probe in transgenic mice enabled us to monitor voltage changes optically in two populations of axons in hippocampal slices, the large axons of dentate granule cells (mossy fibers) in the stratum lucidum of the CA3 region and the much finer axons of hilar mossy cells in the inner molecular layer of the dentate gyrus. Action potentials propagated with distinct velocities in each type of axon. Repetitive firing broadened action potentials in both populations, but at an intermediate frequency the degree of broadening differed. Repetitive firing also attenuated action potential amplitudes in both mossy cell and granule cell axons. These results indicate that the features of use-dependent action potential broadening, and possible failure, observed previously in large nerve terminals also appear in much finer unmyelinated axons. Subtle differences in the frequency dependences could influence the propagation of activity through different pathways to excite different populations of neurons. The axonally targeted hVOS probe used here opens up the diverse repertoire of neuronal processes to detailed biophysical study.

  6. Fourier transform infrared imaging and infrared fiber optic probe spectroscopy identify collagen type in connective tissues.

    Directory of Open Access Journals (Sweden)

    Arash Hanifi

    Full Text Available Hyaline cartilage and mechanically inferior fibrocartilage consisting of mixed collagen types are frequently found together in repairing articular cartilage. The present study seeks to develop methodology to identify collagen type and other tissue components using Fourier transform infrared (FTIR spectral evaluation of matrix composition in combination with multivariate analyses. FTIR spectra of the primary molecular components of repair cartilage, types I and II collagen, and aggrecan, were used to develop multivariate spectral models for discrimination of the matrix components of the tissues of interest. Infrared imaging data were collected from bovine bone, tendon, normal cartilage, meniscus and human repair cartilage tissues, and composition predicted using partial least squares analyses. Histology and immunohistochemistry results were used as standards for validation. Infrared fiber optic probe spectral data were also obtained from meniscus (a tissue with mixed collagen types to evaluate the potential of this method for identification of collagen type in a minimally-invasive clinical application. Concentration profiles of the tissue components obtained from multivariate analysis were in excellent agreement with histology and immunohistochemistry results. Bone and tendon showed a uniform distribution of predominantly type I collagen through the tissue. Normal cartilage showed a distribution of type II collagen and proteoglycan similar to the known composition, while in repair cartilage, the spectral distribution of both types I and II collagen were similar to that observed via immunohistochemistry. Using the probe, the outer and inner regions of the meniscus were shown to be primarily composed of type I and II collagen, respectively, in accordance with immunohistochemistry data. In summary, multivariate analysis of infrared spectra can indeed be used to differentiate collagen type I and type II, even in the presence of proteoglycan, in

  7. Efficient optical probes for fast surface velocimetry: multiple frequency issues for Fabry and VISAR methods

    Science.gov (United States)

    Goosman, David R.; Avara, George R.; Perry, Stephen J.

    2001-04-01

    We have in the past used several types of optical probe lenses for delivering and collecting laser light to an experiment for laser velocimetry. When the test surface was in focus, however, the collected light would fill mostly the laser fiber rather than the collection fiber(s). We have designed, developed and used for 8 years nested-lens probe assemblies that solve this problem. Our first version used a commercial AR-coated glass achromat, which we cored to remove the inner fourth of its area. The core was then reinserted with its optical center offset from that of annulus by an amount slightly less than the separation between the laser and collector fibers. The laser and collector fibers are placed in contact with each other behind the lens and have NA values of 0.11 and 0.22, respectively. Because most of the collected light now focused on the collection fiber, this system was far superior to the single lens systems, but was laborious. For the last five years we used injection-molded acrylic aspheric nested lenses, which are inexpensive in quantity and require little labor to install into a probe. Only an azimuthal rotation and positioning of the fiber plane are needed to incorporate the plastic lens into a probe. Special ray-trace codes were written and used to design the lens, and many iterations by the molder were required to develop the injection processing parameters to produce a good lens, since it was thick for its diameter. These probes have real light collection efficiencies of 75% of theoretical, work well over a wide range of distances, with collection depths of field matching theory. The lenses can take 100 watts of pulsed power many times without damage, since the lens is designed so that reflections from the lens surface do not focus within the lens. The collection fiber size is designed to work with our manybeam velocimeter facility reported in a previous Congress, where the collection NA times collection fiber size exceeds the acceptance of the

  8. Development of a Strontium Magneto-Optical Trap for Probing Casimir-Polder Potentials

    Science.gov (United States)

    Martin, Paul J.

    In recent years, cold atoms have been the centerpiece of many remarkably sensitive measurements, and much effort has been made to devise miniaturized quantum sensors and quantum information processing devices. At small distances, however, mechanical effects of the quantum vacuum begin to significantly impact the behavior of the cold-atom systems. A better understanding of how surface composition and geometry affect Casimir and Casimir-Polder potentials would benefit future engineering of small-scale devices. Unfortunately, theoretical solutions are limited and the number of experimental techniques that can accurately detect such short-range forces is relatively small. We believe the exemplary properties of atomic strontium--which have enabled unprecedented frequency metrology in optical lattice clocks--make it an ideal candidate for probing slight spectroscopic perturbations caused by vacuum fluctuations. To that end, we have constructed a magneto-optical trap for strontium to enable future study of atom-surface potentials, and the apparatus and proposed detection scheme are discussed herein. Of special note is a passively stable external-cavity diode laser we developed that is both affordable and competitive with high-end commercial options.

  9. Atomic force microscopy deep trench and sidewall imaging with an optical fiber probe

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Hui, E-mail: xiehui@hit.edu.cn; Hussain, Danish; Yang, Feng [The State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, 150080 Harbin (China); Sun, Lining [The State Key Laboratory of Robotics and Systems, Harbin Institute of Technology, 2 Yikuang, 150080 Harbin (China); Robotics and Microsystems Center, Soochow University, 215021 Suzhou (China)

    2014-12-15

    We report a method to measure critical dimensions of micro- and nanostructures using the atomic force microscope (AFM) with an optical fiber probe (OFP). This method is capable of scanning narrow and deep trenches due to the long and thin OFP tip, as well as imaging of steep sidewalls with unique profiling possibilities by laterally tilting the OFP without any modifications of the optical lever. A switch control scheme is developed to measure the sidewall angle by flexibly transferring feedback control between the Z- and Y-axis, for a serial scan of the horizontal surface (raster scan on XY-plane) and sidewall (raster scan on the YZ-plane), respectively. In experiments, a deep trench with tapered walls (243.5 μm deep) and a microhole (about 14.9 μm deep) have been imaged with the orthogonally aligned OFP, as well as a silicon sidewall (fabricated by deep reactive ion etching) has been characterized with the tilted OFP. Moreover, the sidewall angle of TGZ3 (AFM calibration grating) was accurately measured using the switchable scan method.

  10. Field programmable gate array based reconfigurable scanning probe/optical microscope.

    Science.gov (United States)

    Nowak, Derek B; Lawrence, A J; Dzegede, Zechariah K; Hiester, Justin C; Kim, Cliff; Sánchez, Erik J

    2011-10-01

    The increasing popularity of nanometrology and nanospectroscopy has pushed researchers to develop complex new analytical systems. This paper describes the development of a platform on which to build a microscopy tool that will allow for flexibility of customization to suit research needs. The novelty of the described system lies in its versatility of capabilities. So far, one version of this microscope has allowed for successful near-field and far-field fluorescence imaging with single molecule detection sensitivity. This system is easily adapted for reflection, polarization (Kerr magneto-optical (MO)), Raman, super-resolution techniques, and other novel scanning probe imaging and spectroscopic designs. While collecting a variety of forms of optical images, the system can simultaneously monitor topographic information of a sample with an integrated tuning fork based shear force system. The instrument has the ability to image at room temperature and atmospheric pressure or under liquid. The core of the design is a field programmable gate array (FPGA) data acquisition card and a single, low cost computer to control the microscope with analog control circuitry using off-the-shelf available components. A detailed description of electronics, mechanical requirements, and software algorithms as well as examples of some different forms of the microscope developed so far are discussed.

  11. MODELO MULTIDIMENSIONAL

    Directory of Open Access Journals (Sweden)

    Alexis Cedeño Trujillo

    2006-04-01

    Full Text Available

    Data Warehousing, es una tecnología para el almacenamiento de grandes volúmenes de datos en una amplia perspectiva de tiempo para el soporte a la toma de decisiones. Debido a su orientación analítica, impone un procesamiento distinto al de los sistemas operacionales y requiere de un diseño de base de datos más cercano a la visión de los usuarios finales, permitiendo que sea más fácil la recuperación de información y la navegación. Este diseño de base de datos se conoce como modelo multidimensional, este artículo, abordará sus características principales.

  12. An evanescent wave biosensor--Part I: Fluorescent signal acquisition from step-etched fiber optic probes.

    Science.gov (United States)

    Anderson, G P; Golden, J P; Ligler, F S

    1994-06-01

    A fiber-optic biosensor capable of remote continuous monitoring has recently been designed. To permit sensing at locations separate from the optoelectronic instrumentation, long optical fibers are utilized. An evanescent wave immuno-probe is prepared by removing the cladding near the distal end of the fiber and covalently attaching antibodies to the core. Probes with a radius unaltered from that of the original core inefficiently returned the signal produced upon binding the fluorescent-labelled antigen. To elucidate the limiting factors in signal acquisition, a series of fibers with increasingly reduced probe core radius was examined. The results were consistent with the V-number mismatch, the difference in mode carrying capacity between the clad and unclad fiber, being a critical factor in limiting signal coupling from the fiber probe. However, it was also delineated that conditions which conserve excitation power, such that power in the evanescent wave is optimized, must also be met to obtain a maximal signal. The threshold sensitivity for the optimal step-etched fiber probe was improved by over 20-fold in an immunoassay, although, it was demonstrated that signal acquisition decreased along the probe length, suggesting that a sensor region of uniform radius is not ideal.

  13. NONINVASIVE OPTICAL IMAGING OF STAPHYLOCOCCUS AUREUS INFECTION IN VIVO USING AN ANTIMICROBIAL PEPTIDE FRAGMENT BASED NEAR-INFRARED FLUORESCENT PROBES

    Directory of Open Access Journals (Sweden)

    CUICUI LIU

    2013-07-01

    Full Text Available The diagnosis of bacterial infections remains a major challenge in medicine. Optical imaging of bacterial infection in living animals is usually conducted with genetic reporters such as light-emitting enzymes or fluorescent proteins. However, there are many circumstances where genetic reporters are not applicable, and there is an urgent need for exogenous synthetic probes that can selectively target bacteria. Optical imaging of bacteria in vivo is much less developed than methods such as radioimaging and MRI. Furthermore near-infrared (NIR dyes with emission wavelengths in the region of 650–900 nm can propagate through two or more centimeters of tissue and may enable deeper tissue imaging if sensitive detection techniques are employed. Here we constructed an antimicrobial peptide fragment UBI29-41-based near-infrared fluorescent imaging probe. The probe is composed of UBI29-41 conjugated to a near infrared dye ICG-Der-02. UBI29-41 is a cationic antimicrobial peptide that targets the anionic surfaces of bacterial cells. The probe allows detection of Staphylococcus aureus infection (5 × 107 cells in a mouse local infection model using whole animal near-infrared fluorescence imaging. Furthermore, we demonstrate that the UBI29-41-based imaging probe can selectively accumulate within bacteria. The significantly higher accumulation in bacterial infection suggests that UBI29-41-based imaging probe may be a promising imaging agent to detect bacterial infections.

  14. The application of diode laser colorimetry coupled with fiber optic dipping probe for quantitative detection of a protein

    International Nuclear Information System (INIS)

    Kim, Sung Ho; Yoo, Jong Shin

    1996-01-01

    The in-situ, simple and inexpensive analysis of protein was achieved by the portable diode laser absorption spectrometry, which consisted of visible diode laser, photodiode, optical fiber and dipping probe. It gives comparable detection limit to the use of conventional UV/Vis spectrometer for the determination of protein by Lowry method.

  15. A novel minimally invasive dual-modality fiber optic probe for prostate cancer detection

    Science.gov (United States)

    Sharma, Vikrant

    Prostate cancer is the most common form of cancer in males, and is the second leading cause of cancer related deaths in United States. In prostate cancer diagnostics and therapy, there is a critical need for a minimally invasive tool for in vivo evaluation of prostate tissue. Such a tool finds its niche in improving TRUS (trans-rectal ultrasound) guided biopsy procedure, surgical margin assessment during radical prostatectomy, and active surveillance of patients with a certain risk levels. This work is focused on development of a fiber-based dual-modality optical device (dMOD), to differentiate prostate cancer from benign tissue, in vivo. dMOD utilizes two independent optical techniques, LRS (light reflectance spectroscopy) and AFLS (auto-fluorescence lifetime spectroscopy). LRS quantifies scattering coefficient of the tissue, as well as concentrations of major tissue chromophores like hemoglobin derivatives, β-carotene and melanin. AFLS was designed to target lifetime signatures of multiple endogenous fluorophores like flavins, porphyrins and lipo-pigments. Each of these methods was independently developed, and the two modalities were integrated using a thin (1-mm outer diameter) fiber-optic probe. Resulting dMOD probe was implemented and evaluated on animal models of prostate cancer, as well as on human prostate tissue. Application of dMOD to human breast cancer (invasive ductal carcinoma) identification was also evaluated. The results obtained reveal that both LRS and AFLS are excellent techniques to discriminate prostate cancer tissue from surrounding benign tissue in animal models. Each technique independently is capable of providing near absolute (100%) accuracy for cancer detection, indicating that either of them could be used independently without the need of implementing them together. Also, in case of human breast cancer, LRS and AFLS provided comparable accuracies to dMOD, LRS accuracy (96%) being the highest for the studied population. However, the

  16. Contrast enhancement in an optical time-domain reflectometer via self-phase modulation compensation by chirped probe pulses

    International Nuclear Information System (INIS)

    Alekseev, A E; Potapov, V T; Vdovenko, V S; Simikin, D E; Gorshkov, B G

    2016-01-01

    In the present paper we propose a novel method for optical time-domain reflectometer (OTDR)–reflectogram contrast enhancement via compensation of nonlinear distortions of propagating probe pulse, which arise due to the self-phase modulation (SPM) effect in optical fiber. The compensation is performed via preliminary frequency modulation (chirp) of the initial probe pulse according to the specific law. As a result the OTDR contrast at some distant predefined fiber point is fully restored to the value of non-distorted probe pulse at the beginning of the fiber line. As a result, the performance of the phase OTDR increases. The point of full SPM compensation could be shifted to any other point of the fiber line via preliminary frequency modulation index change. The feasibility of the proposed method is theoretically proved and experimentally demonstrated. (paper)

  17. Intravascular atherosclerotic imaging with combined fluorescence and optical coherence tomography probe based on a double-clad fiber combiner

    Science.gov (United States)

    Liang, Shanshan; Saidi, Arya; Jing, Joe; Liu, Gangjun; Li, Jiawen; Zhang, Jun; Sun, Changsen; Narula, Jagat; Chen, Zhongping

    2012-07-01

    We developed a multimodality fluorescence and optical coherence tomography probe based on a double-clad fiber (DCF) combiner. The probe is composed of a DCF combiner, grin lens, and micromotor in the distal end. An integrated swept-source optical coherence tomography and fluorescence intensity imaging system was developed based on the combined probe for the early diagnoses of atherosclerosis. This system is capable of real-time data acquisition and processing as well as image display. For fluorescence imaging, the inflammation of atherosclerosis and necrotic core formed with the annexin V-conjugated Cy5.5 were imaged. Ex vivo imaging of New Zealand white rabbit arteries demonstrated the capability of the combined system.

  18. Experimental investigation on local parameter measurement using optical probes in two-phase flow under rolling condition

    International Nuclear Information System (INIS)

    Tian Daogui; Sun Licheng; Yan Changqi; Liu Guoqiang

    2013-01-01

    In order to get more local interfacial information as well as to further comprehend the intrinsic mechanism of two-phase flow under rolling condition, a method was proposed to measure the local parameters by using optical probes under rolling condition in this paper. An experimental investigation of two-phase flow under rolling condition was conducted using the probe fabricated by the authors. It is verified that the probe method is feasible to measure the local parameters in two'-phase flow under rolling condition. The results show that the interfacial parameters distribution near wall region has a distinct periodicity due to the rolling motion. The averaged deviation of the void fraction measured by the probe from that obtained from measured pressure drop is about 8%. (authors)

  19. Fiber optic probe enabled by surface-enhanced Raman scattering for early diagnosis of potential acute rejection of kidney transplant

    Science.gov (United States)

    Chi, Jingmao; Chen, Hui; Tolias, Peter; Du, Henry

    2014-06-01

    We have explored the use of a fiber-optic probe with surface-enhanced Raman scattering (SERS) sensing modality for early, noninvasive and, rapid diagnosis of potential renal acute rejection (AR) and other renal graft dysfunction of kidney transplant patients. Multimode silica optical fiber immobilized with colloidal Ag nanoparticles at the distal end was used for SERS measurements of as-collected urine samples at 632.8 nm excitation wavelength. All patients with abnormal renal graft function (3 AR episodes and 2 graft failure episodes) who were clinically diagnosed independently show common unique SERS spectral features in the urines collected just one day after transplant. SERS-based fiber-optic probe has excellent potential to be a bedside tool for early diagnosis of kidney transplant patients for timely medical intervention of patients at high risk of transplant dysfunction.

  20. The first neural probe integrated with light source (blue laser diode) for optical stimulation and electrical recording.

    Science.gov (United States)

    Park, HyungDal; Shin, Hyun-Joon; Cho, Il-Joo; Yoon, Eui-sung; Suh, Jun-Kyo Francis; Im, Maesoon; Yoon, Euisik; Kim, Yong-Jun; Kim, Jinseok

    2011-01-01

    In this paper, we report a neural probe which can selectively stimulate target neurons optically through Si wet etched mirror surface and record extracellular neural signals in iridium oxide tetrodes. Consequently, the proposed approach provides to improve directional problem and achieve at least 150/m gap distance between stimulation and recording sites by wet etched mirror surface in V-groove. Also, we developed light source, blue laser diode (OSRAM Blue Laser Diode_PL 450), integration through simple jig for one-touch butt-coupling. Furthermore, optical power and impedance of iridium oxide tetrodes were measured as 200 μW on 5 mW from LD and 206.5 k Ω at 1 kHz and we demonstrated insertion test of probe in 0.5% agarose-gel successfully. We have successfully transmitted a light of 450 nm to optical fiber through the integrated LD using by butt-coupling method.

  1. Void fraction and flow regime determination by optical probe for boiling two-phase flow in a tube subchannel

    International Nuclear Information System (INIS)

    Cheng Huiping; Wu Hongtao; Ba Changxi; Yan Xiaoming; Huang Suyi

    1995-12-01

    In view of the need to determine void fraction and flow regime of vapor-liquid two-phase flow in the steam generator test model, domestic made optical probe was applied on a small-scale freon two-phase flow test rig. Optical probe signals were collected at a sampling rate up to 500 Hz and converted into digital form. Both the time signal, and the amplitude probability density function and FFT spectrum function calculated thereof were analysed in the time and frequency domains respectively. The threshold characterizing vapor or liquid contact with the probe tip was determined from the air-water two-phase flow pressure drop test results. Then, the boiling freon two-phase flow void fraction was determined by single threshold method, and compared with numerical heat transfer computation. Typical patterns which were revealed by the above-mentioned time signal and the functions were found corresponding to distinct flow regimes, as corroborated by visual observation. The experiment shows that the optical probe was a promising technique for two-phase flow void fraction measurement and flow regime identification (3 refs., 15 figs., 1 tab.)

  2. Ultra-compact swept-source optical coherence tomography handheld probe with motorized focus adjustment (Conference Presentation)

    Science.gov (United States)

    LaRocca, Francesco; Nankivil, Derek; Keller, Brenton; Farsiu, Sina; Izatt, Joseph A.

    2017-02-01

    Handheld optical coherence tomography (OCT) systems facilitate imaging of young children, bedridden subjects, and those with less stable fixation. Smaller and lighter OCT probes allow for more efficient imaging and reduced operator fatigue, which is critical for prolonged use in either the operating room or neonatal intensive care unit. In addition to size and weight, the imaging speed, image quality, field of view, resolution, and focus correction capability are critical parameters that determine the clinical utility of a handheld probe. Here, we describe an ultra-compact swept source (SS) OCT handheld probe weighing only 211 g (half the weight of the next lightest handheld SSOCT probe in the literature) with 20.1 µm lateral resolution, 7 µm axial resolution, 102 dB peak sensitivity, a 27° x 23° field of view, and motorized focus adjustment for refraction correction between -10 to +16 D. A 2D microelectromechanical systems (MEMS) scanner, a converging beam-at-scanner telescope configuration, and an optical design employing 6 different custom optics were used to minimize device size and weight while achieving diffraction limited performance throughout the system's field of view. Custom graphics processing unit (GPU)-accelerated software was used to provide real-time display of OCT B-scans and volumes. Retinal images were acquired from adult volunteers to demonstrate imaging performance.

  3. Probing SU(N)-symmetric orbital interactions with ytterbium Fermi gases in optical lattices

    International Nuclear Information System (INIS)

    Scazza, Francesco

    2015-01-01

    This thesis reports on the creation and investigation of interacting two-orbital quantum gases of ytterbium in optical lattices. Degenerate fermionic gases of ytterbium or other alkaline-earth-like atoms have been recently proposed as model systems for orbital phenomena in condensed matter, such as Kondo screening, heavy-Fermi behaviour and colossal magnetoresistance. Such gases are moreover expected to obey a high SU(N) symmetry, owing to their highly decoupled nuclear spin, for which the emergence of novel, exotic phases of matter has been predicted. With the two lowest (meta-) stable electronic states mimicking electrons in distinct orbitals of solid materials, the two-orbital SU(N) Hubbard model and its spin-exchange inter-orbital interactions are realised. The interactions in two-orbital degenerate mixtures of different nuclear spin states of 173 Yb are probed by addressing the transition to the metastable state in a state-independent optical lattice. The complete characterisation of the two-orbital scattering channels and the demonstration of the SU(N=6) symmetry within the experimental uncertainty are presented. Most importantly, a strong spin- exchange coupling between the two orbitals is identified and the associated exchange process is observed through the dynamic equilibration of spin imbalances between ensembles in different orbitals. These findings are enabled by the implementation of high precision spectroscopic techniques and of full coherent control of the metastable state population. The realisation of SU(N)-symmetric gases with spin-exchange interactions, the elementary building block of orbital quantum magnetism, represents an important step towards the simulation of paradigmatic many-body models, such as the Kondo lattice model.

  4. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe.

    Science.gov (United States)

    Zhu, Lei; Guo, Ning; Li, Quanzheng; Ma, Ying; Jacboson, Orit; Lee, Seulki; Choi, Hak Soo; Mansfield, James R; Niu, Gang; Chen, Xiaoyuan

    2012-01-01

    The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/(64)Cu dual-labeled cyclic RGD peptide. The integrin α(v)β(3) binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD) method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data. The dual-labeled probe (64)Cu-RGD-C(DOTA)-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp) derived from dynamic optical imaging (1.762 ± 0.020) is comparable to that from dynamic PET (1.752 ± 0.026). The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  5. Biconically Tapered Fiber Optic Probes for Rapid Label-Free Immunoassays

    Directory of Open Access Journals (Sweden)

    John Miller

    2015-04-01

    Full Text Available We report use of U-shaped biconically tapered optical fibers (BTOF as probes for label-free immunoassays. The tapered regions of the sensors were functionalized by immobilization of immunoglobulin-G (Ig-G and tested for detection of anti-IgG at concentrations of 50 ng/mL to 50 µg/mL. Antibody-antigen reaction creates a biological nanolayer modifying the waveguide structure leading to a change in the sensor signal, which allows real-time monitoring. The kinetics of the antibody (mouse Ig-G-antigen (rabbit anti-mouse IgG reactions was studied. Hydrofluoric acid treatment makes the sensitive region thinner to enhance sensitivity, which we confirmed by experiments and simulations. The limit of detection for the sensor was estimated to be less than 50 ng/mL. Utilization of the rate of the sensor peak shift within the first few minutes of the antibody-antigen reaction is proposed as a rapid protein detection method.

  6. System of laser pump and synchrotron radiation probe microdiffraction to investigate optical recording process

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, Nobuhiro; Fukuyama, Yoshimitsu; Osawa, Hitoshi [Research and Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Kimura, Shigeru [Research and Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Japan Science and Technology Agency, CREST, 5 Sanbancho, Chiyoda-ku, Tokyo 102-0075 (Japan); Ito, Kiminori; Tanaka, Yoshihito [RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Matsunaga, Toshiyuki; Kojima, Rie; Hisada, Kazuya; Tsuchino, Akio; Birukawa, Masahiro [R and D Division, Panasonic Corporation, 3-4 Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 (Japan); Yamada, Noboru [Department of Materials Science and Engineering, Kyoto University, Yoshida-honmachi, Sakyo-ku, Kyoto, Kyoto 606-8501 (Japan); Sekiguchi, Koji; Fujiie, Kazuhiko; Kawakubo, Osamu [Advanced Optical Storage Development Department, Advanced Device Technology Platform, Sony Corporation, 4-14-1 Asahi-cho, Atsugi, Kanagawa 243-0014 (Japan); Takata, Masaki [Research and Utilization Division, Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); RIKEN SPring-8 Center, RIKEN, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148 (Japan); Department of Advanced Materials Science, School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8561 (Japan)

    2013-06-15

    We have developed a system of laser-pump and synchrotron radiation probe microdiffraction to investigate the phase-change process on a nanosecond time scale of Ge{sub 2}Sb{sub 2}Te{sub 5} film embedded in multi-layer structures, which corresponds to real optical recording media. The measurements were achieved by combining (i) the pump-laser system with a pulse width of 300 ps, (ii) a highly brilliant focused microbeam with wide peak-energy width ({Delta}E/E {approx} 2%) made by focusing helical undulator radiation without monochromatization, and (iii) a precise sample rotation stage to make repetitive measurements. We successfully detected a very weak time-resolved diffraction signal by using this system from 100-nm-thick Ge{sub 2}Sb{sub 2}Te{sub 5} phase-change layers. This enabled us to find the dependence of the crystal-amorphous phase change process of the Ge{sub 2}Sb{sub 2}Te{sub 5} layers on laser power.

  7. Dy{sup 3+} ions as optical probes for studying structure of boro-tellurite glasses

    Energy Technology Data Exchange (ETDEWEB)

    Tuyen, Vu Phi, E-mail: vptuyen@gust-edu.vast.vn [Duytan University, K7/25 Quang Trung, Da Nang (Viet Nam); Graduate University of Science and Technology – VAST, 18 Hoang Quoc Viet, Hanoi (Viet Nam); Sengthong, Bounyavong; Quang, Vu Xuan [Duytan University, K7/25 Quang Trung, Da Nang (Viet Nam); Van Do, Phan [Thuyloi University, 175 Tay Son, Dong Da, Hanoi (Viet Nam); Van Tuyen, Ho; Xuan Hung, Le [Duytan University, K7/25 Quang Trung, Da Nang (Viet Nam); Thanh, Nguyen Trong [Institute of Materials Science – VAST, 18 Hoang Quoc Viet, Hanoi (Viet Nam); Nogami, Masayuki [Duytan University, K7/25 Quang Trung, Da Nang (Viet Nam); Toyota Physical and Chemical research Institute (Japan); Hayakawa, Tomokatsu [Nagoya Institute of Technology, Gokisocho Showaku, 466-8555 Nagoya, Aichiken (Japan); Huy, Bui The, E-mail: buithehuy.nt@gmail.com [Duytan University, K7/25 Quang Trung, Da Nang (Viet Nam); Department of Chemistry, Changwon National University, Changwon 641-773 (Korea, Republic of)

    2016-10-15

    Dy{sup 3+}-doped glasses with various compositions (35+x)B{sub 2}O{sub 3}+ (45−x)TeO{sub 2}+9.5ZnO+10Na{sub 2}O+0.5Dy{sub 2}O{sub 3} (x=0; 10 and 20) were prepared by a melt–quenching technique. The Dy{sup 3+} ions are used as an optical probe, of which the Judd–Ofelt parameters, the phonon-side band, and the Raman spectra were quantitatively estimated to search the change of glass structure (the change of the ratio of [BO{sub 4}] to [BO{sub 3}] units, formation of the non-bridging oxygens (NBO{sup −}), the change of [TeO{sub 3}] to [TeO{sub 4}] units) as a function of the B{sub 2}O{sub 3} content. The Ω{sub 2} and Ω{sub 6} values of Dy{sup 3+}-doped boro-tellurite samples are larger than that of Dy{sup 3+}-doped borate or tellurite sample. The CIE chromaticity color coordinates were calculated for the luminescence spectra of Dy{sup 3+} ions of the glasses with the different compositions and they were all located in the vicinity of white light center of the color coordination diagram.

  8. Measurement of characteristics of solid flow in the cyclone separators with fiber optical probe

    International Nuclear Information System (INIS)

    Li Shaohua; Li Yan; Li Jinjing; Yang Shi; Yang Hairui; Zhang Hai; Lu Junfu; Yue Guangxi

    2009-01-01

    In some applications, e.g. circulating fluidized beds (CFB), cyclones are usually operated at high solid loadings. Under high inlet solid concentration, most of the particles are collected at the wall and form a dense particle spiral band because of high separation efficiency. As a result, gas-solid reactions should occur mostly in the near-wall region. To understand the gas-solid reaction mechanism in the cyclone, an experimental study was conducted in a plexiglass CFB cold apparatus, with a riser of 0.2m I.D. and 5m high, and a standard Lapple cyclone. Fiber optical probe was used to measure the characteristics of solid flow in the cyclone, including particle velocity and volumetric solid concentration, especially in the near-wall region of the cyclone. Based on the experiment results, the combustion of carbon particles in the cyclone of a CFB boiler was estimated with group combustion theory. The calculated results show that combustion effectiveness factor ηeff of near-wall particle cloud is smaller than 1/25, which means the combustion rate of a carbon particle in the near-wall region is greatly restricted by other particles in the cloud.

  9. Probing matrix and tumor mechanics with in situ calibrated optical trap based active microrheology

    Science.gov (United States)

    Staunton, Jack Rory; Vieira, Wilfred; Tanner, Kandice; Tissue Morphodynamics Unit Team

    Aberrant extracellular matrix deposition and vascularization, concomitant with proliferation and phenotypic changes undergone by cancer cells, alter mechanical properties in the tumor microenvironment during cancer progression. Tumor mechanics conversely influence progression, and the identification of physical biomarkers promise improved diagnostic and prognostic power. Optical trap based active microrheology enables measurement of forces up to 0.5 mm within a sample, allowing interrogation of in vitro biomaterials, ex vivo tissue sections, and small organisms in vivo. We fabricated collagen I hydrogels exhibiting distinct structural properties by tuning polymerization temperature Tp, and measured their shear storage and loss moduli at frequencies 1-15k Hz at multiple amplitudes. Lower Tp gels, with larger pore size but thicker, longer fibers, were stiffer than higher Tp gels; decreasing strain increased loss moduli and decreased storage moduli at low frequencies. We subcutanously injected probes with metastatic murine melanoma cells into mice. The excised tumors displayed storage and loss moduli 40 Pa and 10 Pa at 1 Hz, increasing to 500 Pa and 1 kPa at 15 kHz, respectively.

  10. Manganese dioxide nanosheets as an optical probe for photometric determination of free chlorine

    International Nuclear Information System (INIS)

    Yu, Haili; Zheng, Lei

    2016-01-01

    We report on a colorimetric assay for free chlorine using MnO 2 nanosheets as an optical probe. In the absence of free chlorine, the addition of ascorbic acid (AA) causes the chemical dissolution of MnO 2 nanosheets via a redox reaction to result in low absorbance. However, if a solution containing free chlorine is added to the system, AA will be oxidized by free chlorine and the MnO 2 nanosheets will not longer be dissolved. Hence, the AA-induced decoloration will not take place and solution will remain yellow. Under optimized experimental conditions, there is a linear relationship between the change in absorbance at 370 nm and the concentration of free chlorine in the 0.2 to 10 μM concentration range, with an 80 nM detection limit. The detection limit for visual evaluation is 8.0 μM. The assay is fairly selective for free chlorine over common inorganic ions and small organic substances. It was applied to the determination of free chlorine in tap water using the standard addition method. (author)

  11. Carrier dynamics in silicon nanowires studied using optical-pump terahertz-probe spectroscopy

    Science.gov (United States)

    Beaudoin, Alexandre; Salem, Bassem; Baron, Thierry; Gentile, Pascal; Morris, Denis

    2014-03-01

    The advance of non-contact measurements involving pulsed terahertz radiation presents great interests for characterizing electrical properties of a large ensemble of nanowires. In this work, N-doped and undoped silicon nanowires (SiNWs) grown by chemical vapour deposition (CVD) on quartz substrate were characterized using optical-pump terahertz probe (OPTP) transmission experiments. Our results show that defects and ionized impurities introduced by N-doping the CVD-grown SiNWs tend to reduce the photoexcited carrier lifetime and degrade their conductivity properties. Capture mechanisms by the surface trap states play a key role on the photocarrier dynamics in theses small diameters' (~100 nm) SiNWs and the doping level is found to alter this dynamics. We propose convincing capture and recombination scenarios that explain our OPTP measurements. Fits of our photoconductivity data curves, from 0.5 to 2 THz, using a Drude-plasmon conductivity model allow determining photocarrier mobility values of 190 and 70 cm2/V .s, for the undoped and N-doped NWs samples, respectively.

  12. Measurement of dynamic viscoelasticity of confined lubricant by using oscillating optical fiber probe

    International Nuclear Information System (INIS)

    Itoh, S; Fukuzawa, K; Hamamoto, Y; Zhang, H

    2007-01-01

    When a liquid is confined in molecularly narrow gaps, it shows characteristic viscoelasticity such as enhanced viscosity or prolonged relaxation time. In order to investigate the dynamic viscoelasticity of the confined liquid, we developed a new shear force measuring method that uses a ball-ended optical fiber as a shearing probe. Our method can measure the shear force of 0.1 nN order with the oscillation frequency of up to 10 kHz. In addition, the gap that confines the liquid can be set at any constant value ranging from 10 μm to 0.1 nm. In this study, we measured the gap dependence of viscoelasticity of confined liquid lubricants. The gap ranged from 200 nm to a few nm. The tested lubricant was Fomblin Z03 and Zdo14000. A magnetic disk was used as the solid substrate. Oscillation frequency was set at 800 Hz. The experiment showed the viscosity of both Z03 and Zdo14000 gradually increased as the confining gap decreased. The gap width where the viscosity increase started was wider than 100 nm, which is dozens of times larger than the gyration diameter of lubricant molecules. Although Z03 and Zdo14000 have negligibly small elasticity in a bulk state, elasticity suddenly appeared at gaps less than about 8 nm with Zdo14000, and at gaps less than about 4 nm with Z03. Stronger affinity of Zdo14000 molecules to the solid substrate could cause the wider gap width of elasticity appearance

  13. Characterizing shock waves in hydrogel using high speed imaging and a fiber-optic probe hydrophone

    Science.gov (United States)

    Anderson, Phillip A.; Betney, M. R.; Doyle, H. W.; Tully, B.; Ventikos, Y.; Hawker, N. A.; Roy, Ronald A.

    2017-05-01

    The impact of a stainless steel disk-shaped projectile launched by a single-stage light gas gun is used to generate planar shock waves with amplitudes on the order of 102MPa in a hydrogel target material. These shock waves are characterized using ultra-high-speed imaging as well as a fiber-optic probe hydrophone. Although the hydrogel equation of state (EOS) is unknown, the combination of these measurements with conservation of mass and momentum allows us to calculate pressure. It is also shown that although the hydrogel behaves similarly to water, the use of a water EOS underpredicts pressure amplitudes in the hydrogel by ˜10 % at the shock front. Further, the water EOS predicts pressures approximately 2% higher than those determined by conservation laws for a given value of the shock velocity. Shot to shot repeatability is controlled to within 10%, with the shock speed and pressure increasing as a function of the velocity of the projectile at impact. Thus the projectile velocity may be used as an adequate predictor of shock conditions in future work with a restricted suite of diagnostics.

  14. Study on particle behavior in the expansion of fluidized bed using a simple optical probe. Kogaku probe wo mochiita ryudoso no bocho sonai ryushi kyodo ni kansuru kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Kato, Y; Miyamoto, M [Yamaguchi University, Yamaguchi (Japan). Faculty of Engineering; Chimura, T [Toyota Motor Co. Ltd., Tokyo (Japan); Idei, Y [Ube Industries, Ltd., Tokyo (Japan)

    1991-09-25

    In order to clarify the relationship between the heat transfer rate and the expansion bed in a group of horizontal pipes in a freeboard region (an area of the heat-transfer pipe exposed above the height of static particle bed from the beginning) in a cold model of the fluidized bed, particle behavior was measured using an optical measuring method. The light axis position was set higher than the heat-transfer as X {sub p} in a direction perpendicular from the distributor, and the static bed height was set to L {sub c}. The frequency of particles and particle lumps coming to presence between the light axes is termed V {prime}{sub p}(time-averaged dimensionless amount of the optical probe output). The V {prime}{sub p} decreases with an increase in the flow velocity, and, when the difference between the probe tip and the static bed height, X {sub p}{minus} L {sub c} is small, it shows the minimum value at a certain flow velocity and then rises again. The root mean square value of the probe output, V {prime}{sub f} increased with an increase in the flow velocity, reached its maximum, then decreased to the minimum, and rose again. The flow velocity that takes the maximum heat transfer rate can be identified from the relationship among the dimensionless amount of the maximum expansion bed height and the average expansion bed height, the dimensionless height of X {sub p} when V {prime}{sub p} and V {prime}{sub f} obtained at each X {sub p} show the extreme values, and the dimensionless height of the heat-transfer pipes when the average transfer rate takes the maximum value. 6 refs., 5 figs.

  15. Oxidation of hydrogen-passivated silicon surfaces by scanning near-field optical lithography using uncoated and aluminum-coated fiber probes

    DEFF Research Database (Denmark)

    Madsen, Steen; Bozhevolnyi, Sergey I.; Birkelund, Karen

    1997-01-01

    Optically induced oxidation of hydrogen-passivated silicon surfaces using a scanning near-field optical microscope was achieved with both uncoated and aluminum-coated fiber probes. Line scans on amorphous silicon using uncoated fiber probes display a three-peak profile after etching in potassium...... hydroxide. Numerical simulations of the electromagnetic field around the probe-sample interaction region are used to explain the experimental observations. With an aluminum-coated fiber probe, lines of 35 nm in width were transferred into the amorphous silicon layer. (C) 1997 American Institute of Physics....

  16. Heterodyne pump-probe and four-wave mixing in semiconductor optical amplifiers using balanced lock-in detection

    DEFF Research Database (Denmark)

    Borri, Paola; Langbein, Wolfgang; Mørk, Jesper

    1999-01-01

    We demonstrate a new detection scheme for pump-probe and four-wave mixing heterodyne experiments, using balanced detection and a dual-phase lock-in for spectral filtering. The technique allows the use of low repetition-rate laser systems, as is demonstrated on an InGaAsP/InP bulk optical amplifier...... at 1.53 mym. Ultrafast pump-induced changes in the amplitude and phase of the transmitted probe signal are simultaneously measured, going from small to large signal changes and with no need of an absolute phase calibration, showing the versatility and the sensitivity of this detection scheme....... The results for small perturbations are consistent with previous pump-probe experiments reported in literature. Time-resolved four-wave mixing in the absorption regime of the device is measured, and compared with numerical simulations, indicating a 100 fs dephasing time....

  17. In vivo Raman measurement of levofloxacin lactate in blood using a nanoparticle-coated optical fiber probe

    Science.gov (United States)

    Liu, Shupeng; Rong, Ming; Zhang, Heng; Chen, Na; Pang, Fufei; Chen, Zhenyi; Wang, Tingyun; Yan, Jianshe

    2016-01-01

    Monitoring drug concentrations in vivo is very useful for adjusting a drug dosage during treatment and for drug research. Specifically, cutting-edge “on-line” drug research relies on knowing how drugs are metabolized or how they interact with the blood in real-time. Thus, this study explored performing in vivo Raman measurements of the model drug levofloxacin lactate in the blood using a nanoparticle-coated optical fiber probe (optical fiber nano-probe). The results show that we were able to measure real-time changes in the blood concentration of levofloxacin lactate, suggesting that this technique could be helpful for performing drug analyses and drug monitoring in a clinical setting without repeatedly withdrawing blood from patients. PMID:27231590

  18. User oriented end-station on VUV pump-probe magneto-optical ellipsometry at ELI beamlines

    Science.gov (United States)

    Espinoza, Shirly; Neuber, Gerd; Brooks, Christopher D.; Besner, Bastian; Hashemi, Maryam; Rübhausen, Michael; Andreasson, Jakob

    2017-11-01

    A state of the art ellipsometer for user operations is being implemented at ELI Beamlines in Prague, Czech Republic. It combines three of the most promising and exotic forms of ellipsometry: VUV, pump-probe and magneto-optical ellipsometry. This new ellipsometer covers a spectral operational range from the NIR up to the VUV, with high through-put between 1 and 40 eV. The ellipsometer also allows measurements of magneto-optical spectra with a 1 kHz switchable magnetic field of up to 1.5 T across the sample combining ellipsometry and Kerr spectroscopy measurements in an unprecedented spectral range. This form of generalized ellipsometry enables users to address diagonal and off-diagonal components of the dielectric tensor within one measurement. Pump-probe measurements enable users to study the dynamic behaviour of the dielectric tensor in order to resolve the time-domain phenomena in the femto to 100 ns range.

  19. Image Processing in Optical Guidance for Autonomous Landing of Lunar Probe

    OpenAIRE

    Meng, Ding; Yun-feng, Cao; Qing-xian, Wu; Zhen, Zhang

    2008-01-01

    Because of the communication delay between earth and moon, the GNC technology of lunar probe is becoming more important than ever. Current navigation technology is not able to provide precise motion estimation for probe landing control system Computer vision offers a new approach to solve this problem. In this paper, author introduces an image process algorithm of computer vision navigation for autonomous landing of lunar probe. The purpose of the algorithm is to detect and track feature poin...

  20. Design and Investigation of Optical Properties of N-(Rhodamine-B)-Lactam-Ethylenediamine (RhB-EDA) Fluorescent Probe.

    Science.gov (United States)

    Soršak, Eva; Volmajer Valh, Julija; Korent Urek, Špela; Lobnik, Aleksandra

    2018-04-14

    This study presents chemical modification of a Rhodamine B (RhB) sensor probe by ethylenediamine (EDA), and investigation of its spectral as well as sensor properties to the various metals. The synthesised N -(Rhodamine-B)-lactam-ethylenediamine (RhB-EDA) fluorescent probe shows interesting optical sensor properties, and high sensitivity and selectivity to Ag⁺ ions among all the tested metal ions (K⁺, Mg 2+ , Cu 2+ , Ni 2+ , Fe 2+ , Pb 2+ , Na⁺, Mn 2+ , Li⁺, Al 3+ , Co 2+ , Hg 2+ , Sr 2+ , Ca 2+ , Ag⁺, Cd 2+ and Zn 2+ ), while the well-known Rhodamine B (RhB) fluorescent probe shows much less sensitivity to Ag⁺ ions, but high sensitivity to Fe 2+ ions. The novel fluorescent sensor probe RhB-EDA has the capabilities to sense Ag⁺ ions up to µM ranges by using the fluorescence quenching approach. The probe displayed a dynamic response to Ag⁺ in the range of 0.43 × 10 -3 -10 -6 M with a detection limit of 0.1 μM. The sensing system of an RhB-EDA novel fluorescent probe was optimised according to the spectral properties, effect of pH and buffer, photostability, incubation time, sensitivity, and selectivity. Since all the spectral and sensing properties were tested in green aqueous media, although many other similar sensor systems rely on organic solvent solutions, the RhB-EDA sensing probe may be a good candidate for measuring Ag⁺ ions in real-life applications.

  1. Detection of Helicobacter Pylori Genome with an Optical Biosensor Based on Hybridization of Urease Gene with a Gold Nanoparticles-Labeled Probe

    Science.gov (United States)

    Shahrashoob, M.; Mohsenifar, A.; Tabatabaei, M.; Rahmani-Cherati, T.; Mobaraki, M.; Mota, A.; Shojaei, T. R.

    2016-05-01

    A novel optics-based nanobiosensor for sensitive determination of the Helicobacter pylori genome using a gold nanoparticles (AuNPs)-labeled probe is reported. Two specific thiol-modified capture and signal probes were designed based on a single-stranded complementary DNA (cDNA) region of the urease gene. The capture probe was immobilized on AuNPs, which were previously immobilized on an APTES-activated glass, and the signal probe was conjugated to different AuNPs as well. The presence of the cDNA in the reaction mixture led to the hybridization of the AuNPs-labeled capture probe and the signal probe with the cDNA, and consequently the optical density of the reaction mixture (AuNPs) was reduced proportionally to the cDNA concentration. The limit of detection was measured at 0.5 nM.

  2. Quantitative assessment of diffuse optical tomography sensitivity to the cerebral cortex using a whole-head probe

    International Nuclear Information System (INIS)

    Perdue, Katherine L; Diamond, Solomon G; Fang Qianqian

    2012-01-01

    We quantify the variability in diffuse optical tomography (DOT) sensitivity over the cortical surface in eight young adult subjects. We use the 10/5 electroencephalography system as a basis for our whole-head optical high-density probe design. The contrast-to-noise ratio (CNR) is calculated along with the percentage of the cortex that is above a CNR = 0 dB threshold. We also quantify the effect of including vasculature on the forward model and list our assumptions that allow us to estimate light penetration depth in the head. We show that using the 10/5 system for the optical probe design allows for the measurement of 37% of the cortical surface on average, with a mean CNR in the visible region of 5.5 dB. Certain anatomical regions, such as the lateral occipital cortex, had a very high percentage above the CNR threshold, while other regions such as the cingulate cortex were not measurable. Vasculature blocked optical sensitivity over 1% of the cortex. Cortical coverage was positively correlated with intracranial volume and relative cerebrospinal fluid volume, and negatively correlated with relative scalp volume and skull volume. These contributions allow experimenters to understand how anatomical variation in a subject population may impact DOT or functional near-infrared spectroscopy measurements. (paper)

  3. Multidimensional Heat Conduction

    DEFF Research Database (Denmark)

    Rode, Carsten

    1998-01-01

    Analytical theory of multidimensional heat conduction. General heat conduction equation in three dimensions. Steay state, analytical solutions. The Laplace equation. Method of separation of variables. Principle of superposition. Shape factors. Transient, multidimensional heat conduction....

  4. Adapting an optical nanoantenna for high E-field probing applications to a waveguided optical waveguide (WOW)

    DEFF Research Database (Denmark)

    Rindorf, Lars Henning; Glückstad, Jesper

    2013-01-01

    In the current work we intend to use the optical nano-antenna to include various functionalities for the recently demonstrated waveguided optical waveguide (WOW) by Palima et al. (Optics Express 2012). Specifically, we intend to study a WOW with an optical nano-antenna which can block the guiding......-stop characteristic. We give geometrical parameters necessary for realizing functioning nanoantennas. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.......In the current work we intend to use the optical nano-antenna to include various functionalities for the recently demonstrated waveguided optical waveguide (WOW) by Palima et al. (Optics Express 2012). Specifically, we intend to study a WOW with an optical nano-antenna which can block the guiding...... light wavelength while admitting other wavelengths of light which address certain functionalities, e.g. drug release, in the WOW. In particular, we study a bow-tie optical nano-antenna to circular dielectric waveguides in aqueous environments. It is shown with finite element computer simulations...

  5. In search of the best match: probing a multi-dimensional cloud microphysical parameter space to better understand what controls cloud thermodynamic phase

    Science.gov (United States)

    Tan, Ivy; Storelvmo, Trude

    2015-04-01

    Substantial improvements have been made to the cloud microphysical schemes used in the latest generation of global climate models (GCMs), however, an outstanding weakness of these schemes lies in the arbitrariness of their tuning parameters, which are also notoriously fraught with uncertainties. Despite the growing effort in improving the cloud microphysical schemes in GCMs, most of this effort has neglected to focus on improving the ability of GCMs to accurately simulate the present-day global distribution of thermodynamic phase partitioning in mixed-phase clouds. Liquid droplets and ice crystals not only influence the Earth's radiative budget and hence climate sensitivity via their contrasting optical properties, but also through the effects of their lifetimes in the atmosphere. The current study employs NCAR's CAM5.1, and uses observations of cloud phase obtained by NASA's CALIOP lidar over a 79-month period (November 2007 to June 2014) guide the accurate simulation of the global distribution of mixed-phase clouds in 20∘ latitudinal bands at the -10∘ C, -20∘C and -30∘C isotherms, by adjusting six relevant cloud microphysical tuning parameters in the CAM5.1 via Quasi-Monte Carlo sampling. Among the parameters include those that control the Wegener-Bergeron-Findeisen (WBF) timescale for the conversion of supercooled liquid droplets to ice and snow in mixed-phase clouds, the fraction of ice nuclei that nucleate ice in the atmosphere, ice crystal sedimentation speed, and wet scavenging in stratiform and convective clouds. Using a Generalized Linear Model as a variance-based sensitivity analysis, the relative contributions of each of the six parameters are quantified to gain a better understanding of the importance of their individual and two-way interaction effects on the liquid to ice proportion in mixed-phase clouds. Thus, the methodology implemented in the current study aims to search for the combination of cloud microphysical parameters in a GCM that

  6. Optical pump-and-probe test system for thermal characterization of thin metal and phase-change films

    International Nuclear Information System (INIS)

    Watabe, Kazuo; Polynkin, Pavel; Mansuripur, Masud

    2005-01-01

    A single-shot optical pump-and-probe test system is reported. The system is designed for thermal characterization of thin-film samples that can change their phase state under the influence of a short and intense laser pulse on a subnanosecond time scale. In combination with numerical analysis, the system can be used to estimate thermal constants of thin films, such as specific heat and thermal conductivity. In-plane and out-of plane thermal conductivity can be estimated independently. The system is intended for use in research on optical data storage and material processing with pulsed laser light. The system design issues are discussed. As application examples, we report on using the system to study thermal dynamics in two different thin-film samples: a gold film on a glass substrate (a single-phase system) and the quadrilayer phase-change stack typical in optical data-storage applications

  7. Novel Fiber Optic Sensor Probe with a Pair of Highly Reflected Connectors and a Vessel of Water Absorption Material for Water Leak Detection

    Directory of Open Access Journals (Sweden)

    Tae-Sik Cho

    2012-08-01

    Full Text Available The use of a fiber optic quasi-distributed sensing technique for detecting the location and severity of water leakage is suggested. A novel fiber optic sensor probe is devised with a vessel of water absorption material called as water combination soil (WCS located between two highly reflected connectors: one is a reference connector and the other is a sensing connector. In this study, the sensing output is calculated from the reflected light signals of the two connectors. The first reflected light signal is a reference and the second is a sensing signal which is attenuated by the optical fiber bending loss due to the WCS expansion absorbing water. Also, the bending loss of each sensor probe is determined by referring to the total number of sensor probes and the total power budget of an entire system. We have investigated several probe characteristics to show the design feasibility of the novel fiber sensor probe. The effects of vessel sizes of the probes on the water detection sensitivity are studied. The largest vessel probe provides the highest sensitivity of 0.267 dB/mL, while the smallest shows relatively low sensitivity of 0.067 dB/mL, and unstable response. The sensor probe with a high output value provides a high sensitivity with various detection levels while the number of total installable sensor probes decreases.

  8. Novel fiber optic sensor probe with a pair of highly reflected connectors and a vessel of water absorption material for water leak detection.

    Science.gov (United States)

    Cho, Tae-Sik; Choi, Ki-Sun; Seo, Dae-Cheol; Kwon, Il-Bum; Lee, Jung-Ryul

    2012-01-01

    The use of a fiber optic quasi-distributed sensing technique for detecting the location and severity of water leakage is suggested. A novel fiber optic sensor probe is devised with a vessel of water absorption material called as water combination soil (WCS) located between two highly reflected connectors: one is a reference connector and the other is a sensing connector. In this study, the sensing output is calculated from the reflected light signals of the two connectors. The first reflected light signal is a reference and the second is a sensing signal which is attenuated by the optical fiber bending loss due to the WCS expansion absorbing water. Also, the bending loss of each sensor probe is determined by referring to the total number of sensor probes and the total power budget of an entire system. We have investigated several probe characteristics to show the design feasibility of the novel fiber sensor probe. The effects of vessel sizes of the probes on the water detection sensitivity are studied. The largest vessel probe provides the highest sensitivity of 0.267 dB/mL, while the smallest shows relatively low sensitivity of 0.067 dB/mL, and unstable response. The sensor probe with a high output value provides a high sensitivity with various detection levels while the number of total installable sensor probes decreases.

  9. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

    Directory of Open Access Journals (Sweden)

    Lei Zhu, Ning Guo, Quanzheng Li, Ying Ma, Orit Jacboson, Seulki Lee, Hak Soo Choi, James R. Mansfield, Gang Niu, Xiaoyuan Chen

    2012-01-01

    Full Text Available Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide.Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA-ZW-1 was characterized by cell staining and receptor binding assay. Sixty-min dynamic PET and optical imaging were acquired on a MDA-MB-435 tumor model. Singular value decomposition (SVD method was applied to compute the dynamic optical signal from the two-dimensional optical projection images. Compartment models were used to quantitatively analyze and compare the dynamic optical and PET data.Results: The dual-labeled probe 64Cu-RGD-C(DOTA-ZW-1 showed integrin specific binding in vitro and in vivo. The binding potential (Bp derived from dynamic optical imaging (1.762 ± 0.020 is comparable to that from dynamic PET (1.752 ± 0.026.Conclusion: The signal un-mixing process using SVD improved the accuracy of kinetic modeling of 2D dynamic optical data. Our results demonstrate that 2D dynamic optical imaging with SVD analysis could achieve comparable quantitative results as dynamic PET imaging in preclinical xenograft models.

  10. Method for accurate determination of dissociation constants of optical ratiometric systems: chemical probes, genetically encoded sensors, and interacting molecules.

    Science.gov (United States)

    Pomorski, Adam; Kochańczyk, Tomasz; Miłoch, Anna; Krężel, Artur

    2013-12-03

    Ratiometric chemical probes and genetically encoded sensors are of high interest for both analytical chemists and molecular biologists. Their high sensitivity toward the target ligand and ability to obtain quantitative results without a known sensor concentration have made them a very useful tool in both in vitro and in vivo assays. Although ratiometric sensors are widely used in many applications, their successful and accurate usage depends on how they are characterized in terms of sensing target molecules. The most important feature of probes and sensors besides their optical parameters is an affinity constant toward analyzed molecules. The literature shows that different analytical approaches are used to determine the stability constants, with the ratio approach being most popular. However, oversimplification and lack of attention to detail results in inaccurate determination of stability constants, which in turn affects the results obtained using these sensors. Here, we present a new method where ratio signal is calibrated for borderline values of intensities of both wavelengths, instead of borderline ratio values that generate errors in many studies. At the same time, the equation takes into account the cooperativity factor or fluorescence artifacts and therefore can be used to characterize systems with various stoichiometries and experimental conditions. Accurate determination of stability constants is demonstrated utilizing four known optical ratiometric probes and sensors, together with a discussion regarding other, currently used methods.

  11. A real-time artifact reduction algorithm based on precise threshold during short-separation optical probe insertion in neurosurgery

    Directory of Open Access Journals (Sweden)

    Weitao Li

    2017-01-01

    Full Text Available During neurosurgery, an optical probe has been used to guide the micro-electrode, which is punctured into the globus pallidus (GP to create a lesion that can relieve the cardinal symptoms. Accurate target localization is the key factor to affect the treatment. However, considering the scattering nature of the tissue, the “look ahead distance (LAD” of optical probe makes the boundary between the different tissues blurred and difficult to be distinguished, which is defined as artifact. Thus, it is highly desirable to reduce the artifact caused by LAD. In this paper, a real-time algorithm based on precise threshold was proposed to eliminate the artifact. The value of the threshold was determined by the maximum error of the measurement system during the calibration procession automatically. Then, the measured data was processed sequentially only based on the threshold and the former data. Moreover, 100μm double-fiber probe and two-layer and multi-layer phantom models were utilized to validate the precision of the algorithm. The error of the algorithm is one puncture step, which was proved in the theory and experiment. It was concluded that the present method could reduce the artifact caused by LAD and make the real boundary sharper and less blurred in real-time. It might be potentially used for the neurosurgery navigation.

  12. Development of a Novel Fiber Optic Sensor Combined with a Fluorescence Turn-on Probe for Cu (II Detection

    Directory of Open Access Journals (Sweden)

    Ma J.

    2013-04-01

    Full Text Available Existing staining-based methodology for the detection of metal ions is not well suited for real-time or in situ use. This is a significant problem, given that these ions can have a considerable impact on both human health and the environment. Thus, there is growing interest and need for simple, rapid and in-situ monitoring techniques for the purpose of detecting various target analytes (e.g. heavy metals, which is of a significant importance in many fields ranging from environmental monitoring to the study of intracellular processes. Among various sensors developed, optical fiber-optic sensors (FOS, based on fluorescence, are one class of sensors that address this goal [1]. Optical fibers are ideal for environmental sensing applications because of their ability to transmit optical signals to and from the sensing region without the use of free-space optics. In this work, we present, for the first time, a simple FOS incorporating novel fluorescence turn-on mechanism [2] that could detect Cu (II as low as 10−4 M. Traditionally, fluorescence quenching or “turn-off” was used to detect Cu (II [3]. In recent years, fluorescence “turn-on” emerges as a preferable tool. The developed fiber-optic sensor has two fiber leads and one probe head. One fiber lead includes 6 fibers for He-Ne laser excitation light delivery (e-fibers. Another fiber lead has one receiving fiber (r-fiber connected to an Ocean Optics QE65000 scientific grade spectrometer, which is interrogated by a computer via USB connection. The SpectroSuite software is used to observe and to record all spectra. The probe head combines all fibers together to form a coaxial structure with the r-fiber placed in the center. The key component in the proposed fluorescent sensing system is a probe prepared by binding a receptor containing a zwitterionic chromophore (M1, through noncovalent interactions, to the fluorescent polymer (P1 resulting in quenching its emission. The sensing mechanism

  13. Study of polarization properties of fiber-optics probes with use of a binary phase plate.

    Science.gov (United States)

    Alferov, S V; Khonina, S N; Karpeev, S V

    2014-04-01

    We conduct a theoretical and experimental study of the distribution of the electric field components in the sharp focal domain when rotating a zone plate with a π-phase jump placed in the focused beam. Comparing the theoretical and experimental results for several kinds of near-field probes, an analysis of the polarization sensitivity of different types of metal-coated aperture probes is conducted. It is demonstrated that with increasing diameter of the non-metal-coated tip part there occurs an essential redistribution of sensitivity in favor of the transverse electric field components and an increase of the probe's energy throughput.

  14. Optical diagnostic suite (schlieren, interferometry, and grid image refractometry) on OMEGA EP using a 10-ps, 263-nm probe beam.

    Science.gov (United States)

    Froula, D H; Boni, R; Bedzyk, M; Craxton, R S; Ehrne, F; Ivancic, S; Jungquist, R; Shoup, M J; Theobald, W; Weiner, D; Kugland, N L; Rushford, M C

    2012-10-01

    A 10-ps, 263-nm (4ω) laser is being built to probe plasmas produced on the OMEGA EP [J. H. Kelly, L. J. Waxer, V. Bagnoud, I. A. Begishev, J. Bromage, B. E. Kruschwitz, T. E. Kessler, S. J. Loucks, D. N. Maywar, R. L. McCrory et al., J. Phys. IV France 133, 75-80 (2006)]. A suite of optical diagnostics (schlieren, interferometry, and grid image refractometry) has been designed to diagnose and characterize a wide variety of plasmas. Light scattered by the probe beam is collected by an f/4 catadioptric telescope and a transport system is designed to image with a near-diffraction-limited resolution (~1 - μm full width at half maximum) over a 5-mm field of view to a diagnostic table. The transport system provides a contrast greater than 1 : 10(4) with respect to all wavelengths outside of the 263 ± 2 nm measurement range.

  15. Optical diagnostic suite (schlieren, interferometry, and grid image refractometry) on OMEGA EP using a 10-ps, 263-nm probe beam

    International Nuclear Information System (INIS)

    Froula, D. H.; Boni, R.; Bedzyk, M.; Craxton, R. S.; Ehrne, F.; Ivancic, S.; Jungquist, R.; Shoup, M. J.; Theobald, W.; Weiner, D.; Kugland, N. L.; Rushford, M. C.

    2012-01-01

    A 10-ps, 263-nm (4ω) laser is being built to probe plasmas produced on the OMEGA EP [J. H. Kelly, L. J. Waxer, V. Bagnoud, I. A. Begishev, J. Bromage, B. E. Kruschwitz, T. E. Kessler, S. J. Loucks, D. N. Maywar, R. L. McCrory et al., J. Phys. IV France 133, 75–80 (2006)]. A suite of optical diagnostics (schlieren, interferometry, and grid image refractometry) has been designed to diagnose and characterize a wide variety of plasmas. Light scattered by the probe beam is collected by an f/4 catadioptric telescope and a transport system is designed to image with a near-diffraction-limited resolution (∼1 −μm full width at half maximum) over a 5-mm field of view to a diagnostic table. The transport system provides a contrast greater than 1 : 10 4 with respect to all wavelengths outside of the 263 ± 2 nm measurement range.

  16. Optical diagnostic suite (schlieren, interferometry, and grid image refractometry) on OMEGA EP using a 10-ps, 263-nm probe beam

    Energy Technology Data Exchange (ETDEWEB)

    Froula, D. H.; Boni, R.; Bedzyk, M.; Craxton, R. S.; Ehrne, F.; Ivancic, S.; Jungquist, R.; Shoup, M. J.; Theobald, W.; Weiner, D. [Laboratory for Laser Energetics, University of Rochester, 250 E. River Rd., Rochester, New York 14616 (United States); Kugland, N. L.; Rushford, M. C. [Lawrence Livermore National Laboratory, University of California, P. O. Box 808, Livermore, California 94551 (United States)

    2012-10-15

    A 10-ps, 263-nm (4{omega}) laser is being built to probe plasmas produced on the OMEGA EP [J. H. Kelly, L. J. Waxer, V. Bagnoud, I. A. Begishev, J. Bromage, B. E. Kruschwitz, T. E. Kessler, S. J. Loucks, D. N. Maywar, R. L. McCrory et al., J. Phys. IV France 133, 75-80 (2006)]. A suite of optical diagnostics (schlieren, interferometry, and grid image refractometry) has been designed to diagnose and characterize a wide variety of plasmas. Light scattered by the probe beam is collected by an f/4 catadioptric telescope and a transport system is designed to image with a near-diffraction-limited resolution ({approx}1 -{mu}m full width at half maximum) over a 5-mm field of view to a diagnostic table. The transport system provides a contrast greater than 1 : 10{sup 4} with respect to all wavelengths outside of the 263 {+-} 2 nm measurement range.

  17. Multi-dimensional single-spin nano-optomechanics with a levitated nanodiamond

    Science.gov (United States)

    Neukirch, Levi P.; von Haartman, Eva; Rosenholm, Jessica M.; Nick Vamivakas, A.

    2015-10-01

    Considerable advances made in the development of nanomechanical and nano-optomechanical devices have enabled the observation of quantum effects, improved sensitivity to minute forces, and provided avenues to probe fundamental physics at the nanoscale. Concurrently, solid-state quantum emitters with optically accessible spin degrees of freedom have been pursued in applications ranging from quantum information science to nanoscale sensing. Here, we demonstrate a hybrid nano-optomechanical system composed of a nanodiamond (containing a single nitrogen-vacancy centre) that is levitated in an optical dipole trap. The mechanical state of the diamond is controlled by modulation of the optical trapping potential. We demonstrate the ability to imprint the multi-dimensional mechanical motion of the cavity-free mechanical oscillator into the nitrogen-vacancy centre fluorescence and manipulate the mechanical system's intrinsic spin. This result represents the first step towards a hybrid quantum system based on levitating nanoparticles that simultaneously engages optical, phononic and spin degrees of freedom.

  18. Magnetic field effects on spectrally resolved lifetime of on-line oxygen monitoring using magneto-optic probes

    Science.gov (United States)

    Mermut, O.; Gallant, P.; Le Bouch, N.; Leclair, S.; Noiseux, I.; Vernon, M.; Morin, J.-F.; Diamond, K.; Patterson, M. S.; Samkoe, K.; Pogue, B.

    2009-02-01

    Multimodal agents that serve as both probes for contrast and light-activated effectors of cellular processes in diseased tissue were developed. These agents were introduced into multicellular tumor spheroids (3D tissue models) and in the chorioallantoic membrane (CAM) of a chicken embryo. The luminescence decay was examined using a novel technique involving a spectrally-resolved fluorescence lifetime apparatus integrated with a weak electromagnet. A spectrallyresolved lifetime setup was used to identify magneto-optic species sensitive to magnetic field effects and distinguish from background emissions. We demonstrate that the applied magnetic fields can alter reaction rates and product distribution of some dyes detected by time- and spectrally-resolved luminescence changes. We will discuss the use of exogenous magneto-optical probes taken up in tumors to both induce phototoxicity, a process that is governed by complex and dynamically evolving mechanisms involving reactive oxygen species, and monitor treatment progress. The magnetic field enhancement, measured over a range of weak fields (0-300 mT) is correlated to oxygenation and may be used to monitor dynamic changes occurring due to oxygen consumption over the course of photodynamic therapy. Such online measurements provide the possibility to derive real-time information about response to treatment via monitoring magnetic field enhancement/suppression of the time-resolved, spectrally-resolved luminescence of the probe at the site of the treatment directly. Magnetic perturbation of lifetime can serve as a status reporter, providing optical feedback of oxygen-mediated treatments in situ and allowing for real-time adjustment of a phototherapy treatment plan.

  19. Investigation of the dynamics of a nonlinear optical response in glassy chalcogenide semiconductors by the pump–probe method

    Science.gov (United States)

    Romanova, E. A.; Kuzyutkina, Yu S.; Shiryaev, V. S.; Guizard, S.

    2018-03-01

    An analysis of the results of measurements by using the pump–probe method with a femtosecond resolution in time and computer simulation of the charge carrier kinetics have revealed two types of a nonlinear optical response in samples of chalcogenide glasses belonging to the As – S – Se system, irradiated by 50-fs laser pulses with a wavelength of 0.79 μm. The difference in the nonlinear dynamics is due to the difference in the photoexcitation character, because laser radiation can be absorbed either through bound states in the band gap or without their participation, depending on the ratio of the pump photon energy to the bandgap energy.

  20. Transverse Micro-structuring of Photonic Crystal Fibers for Industrial Sensors and Side Viewing Probes for Optical Coherence Tomography Applications

    Directory of Open Access Journals (Sweden)

    Sanjay KHER

    2010-05-01

    Full Text Available In this work, we report a simple and easily adaptable technique of lateral micro-machining of Photonic Crystal fibers (PCFs using modulated CO2-laser in conjunction with electrical arc system. The technique is controlled, convenient and precise over wide dimensions (50-250 mm. Lateral access to the holes of PCF provides additional flexibility for sensitive real time detection of gases such as green-house gases. Long period gratings are made in PCF through inscription of micro-grooves for sensitive detection of longitudinal strain. A unique and versatile PCF based probe for possible endoscopic Optical Coherence Tomography (OCT applications is reported.

  1. An inverse method for determining the interaction force between the probe and sample using scanning near-field optical microscopy

    International Nuclear Information System (INIS)

    Chang, Win-Jin; Fang, Te-Hua

    2006-01-01

    This study proposes a means for calculating the interaction force during the scanning process using a scanning near-field optical microscope (SNOM) probe. The determination of the interaction force in the scanning system is regarded as an inverse vibration problem. The conjugate gradient method is applied to treat the inverse problem using available displacement measurements. The results show that the conjugate gradient method is less sensitive to measurement errors and prior information on the functional form of quality was not required. Furthermore, the initial guesses for the interaction force can be arbitrarily chosen for the iteration process

  2. All-fiber probe for optical coherence tomography with an extended depth of focus by a high-efficient fiber-based filter

    Science.gov (United States)

    Qiu, Jianrong; Shen, Yi; Shangguan, Ziwei; Bao, Wen; Yang, Shanshan; Li, Peng; Ding, Zhihua

    2018-04-01

    Although methods have been proposed to maintain high transverse resolution over an increased depth range, it is not straightforward to scale down the bulk-optic solutions to minimized probes of optical coherence tomography (OCT). In this paper, we propose a high-efficient fiber-based filter in an all-fiber OCT probe to realize an extended depth of focus (DOF) while maintaining a high transverse resolution. Mode interference in the probe is exploited to modulate the complex field with controllable radial distribution. The principle of DOF extension by the fiber-based filter is theoretically analyzed. Numerical simulations are conducted to evaluate the performances of the designed probes. A DOF extension ratio of 2.6 over conventional Gaussian beam is obtainable in one proposed probe under a focused beam diameter of 4 . 6 μm. Coupling efficiencies of internal interfaces of the proposed probe are below -40 dB except the last probe-air interface, which can also be depressed to be -44 dB after minor modification in lengths for the filter. Length tolerance of the proposed probe is determined to be - 28 / + 20 μm, which is readily satisfied in fabrication. With the merits of extended-DOF, high-resolution, high-efficiency and easy-fabrication, the proposed probe is promising in endoscopic applications.

  3. Quasi-distributed sol-gel coated fiber optic oxygen sensing probe

    Science.gov (United States)

    Zolkapli, Maizatul; Saharudin, Suhairi; Herman, Sukreen Hana; Abdullah, Wan Fazlida Hanim

    2018-03-01

    In the field of aquaculture, optical sensor technology is beginning to provide alternatives to the conventional electrical sensor. Hence, the development and characterization of a multipoint quasi-distributed optical fiber sensor for oxygen measurement is reported. The system is based on 1 mm core diameter plastic optical fiber where sections of cladding have been removed and replaced with three metal complexes sol-gel films to form sensing points. The sensing locations utilize luminophores that have emission peaks at 385 nm, 405 nm and 465 nm which associated with each of the sensing points. Interrogation of the optical sensor system is through a fiber optic spectrometer incorporating narrow bandpass emission optical filter. The sensors showed comparable sensitivity and repeatability, as well as fast response and recovery towards oxygen.

  4. Electromagnetically induced transparency line shapes for large probe fields and optically thick media

    International Nuclear Information System (INIS)

    Pack, M. V.; Camacho, R. M.; Howell, J. C.

    2007-01-01

    We calculate the line shape and linewidths for electromagnetically induced transparency (EIT) in optically thick, Doppler broadened media (buffer gasses are also considered). In generalizing the definition of the EIT linewidth to optically thick media, we find two different linewidth definitions apply depending on whether the experiment is pulsed or continuous wave (cw). Using the cw definition for the EIT line shape we derive analytic expressions describing the linewidth as a function of optical depth. We also review the EIT line shapes in optically thin media and provide physical arguments for how the line shapes change as a function of various parameters

  5. Optical Detection of Ketoprofen by Its Electropolymerization on an Indium Tin Oxide-Coated Optical Fiber Probe.

    Science.gov (United States)

    Bogdanowicz, Robert; Niedziałkowski, Paweł; Sobaszek, Michał; Burnat, Dariusz; Białobrzeska, Wioleta; Cebula, Zofia; Sezemsky, Petr; Koba, Marcin; Stranak, Vitezslav; Ossowski, Tadeusz; Śmietana, Mateusz

    2018-04-27

    In this work an application of optical fiber sensors for real-time optical monitoring of electrochemical deposition of ketoprofen during its anodic oxidation is discussed. The sensors were fabricated by reactive magnetron sputtering of indium tin oxide (ITO) on a 2.5 cm-long core of polymer-clad silica fibers. ITO tuned in optical properties and thickness allows for achieving a lossy-mode resonance (LMR) phenomenon and it can be simultaneously applied as an electrode in an electrochemical setup. The ITO-LMR electrode allows for optical monitoring of changes occurring at the electrode during electrochemical processing. The studies have shown that the ITO-LMR sensor’s spectral response strongly depends on electrochemical modification of its surface by ketoprofen. The effect can be applied for real-time detection of ketoprofen. The obtained sensitivities reached over 1400 nm/M (nm·mg −1 ·L) and 16,400 a.u./M (a.u.·mg −1 ·L) for resonance wavelength and transmission shifts, respectively. The proposed method is a valuable alternative for the analysis of ketoprofen within the concentration range of 0.25⁻250 μg mL −1 , and allows for its determination at therapeutic and toxic levels. The proposed novel sensing approach provides a promising strategy for both optical and electrochemical detection of electrochemical modifications of ITO or its surface by various compounds.

  6. Development of Ultrasonic Modulation Probe for Fluorescence Tomography Based on Acousto-Optic Effect

    Directory of Open Access Journals (Sweden)

    Trinh Quang Duc

    2011-01-01

    Full Text Available We have developed an ultrasonic probe for fluorescence modulation to image fluorescence within biological tissues. The probe consists of a focused ultrasonic transducer mounted on actuators for mechanical fan scanning, which can be used in contact with the measuring object aiming for clinical application. The mechanical fan scanning employed in the probe has a beneficial feature of portability. As a result, fluorescent beads, which were localized with the diameter of 2 mm at 20 mm depth in a pork meat tissue, were detected with resolution of 3 mm. The system performance denotes the feasibility of development towards the final goal of ultrasonic fluorescence modulation tomography for clinical applications.

  7. A SIMULTANEOUS MULTI-PROBE DETECTION LABEL-FREE OPTICAL-RESOLUTION PHOTOACOUSTIC MICROSCOPY TECHNIQUE BASED ON MICROCAVITY TRANSDUCER

    Directory of Open Access Journals (Sweden)

    YONGBO WU

    2013-07-01

    Full Text Available We demonstrate the feasibility of simultaneous multi-probe detection for an optical-resolution photoacoustic microscopy (OR-PAM system. OR-PAM has elicited the attention of biomedical imaging researchers because of its optical absorption contrast and high spatial resolution with great imaging depth. OR-PAM allows label-free and noninvasive imaging by maximizing the optical absorption of endogenous biomolecules. However, given the inadequate absorption of some biomolecules, detection sensitivity at the same incident intensity requires improvement. In this study, a modulated continuous wave with power density less than 3 mW/cm2 (1/4 of the ANSI safety limit excited the weak photoacoustic (PA signals of biological cells. A microcavity transducer is developed based on the bulk modulus of gas five orders of magnitude lower than that of solid; air pressure variation is inversely proportional to cavity volume at the same temperature increase. Considering that a PA wave expands in various directions, detecting PA signals from different positions and adding them together can increase detection sensitivity and signal-to-noise ratio. Therefore, we employ four detectors to acquire tiny PA signals simultaneously. Experimental results show that the developed OR-PAM system allows the label-free imaging of cells with weak optical absorption.

  8. Optical probing of long-range spatial correlation and symmetry in complex biophotonic architectures on transparent insect wings

    International Nuclear Information System (INIS)

    Kumar, Pramod; Shamoon, Danish; Singh, Dhirendra P; Singh, Kamal P; Mandal, Sudip

    2015-01-01

    We experimentally probe the structural organization of complex bio-photonic architecture on transparent insect wings by a simple, non-invasive, real-time optical technique. A stable and reproducible far-field diffraction pattern in transmission was observed using collimated cw and broadband fs laser pulses. A quantitative analysis of the observed diffraction pattern unveiled long-range quasi-periodic order in the arrangement of the microstructures over mm scale. These observations agree well with the Fourier analysis of SEM images of the wing taken at various length scales. We propose a simple quantitative model based on optical diffraction by an array of non overlapping microstructures with minimal disorder which supports our experimental observations. We observed a rotation of the original diffraction profile by scanning the laser beam across the wing sample which gives direct signature of organizational symmetry in microstructure arrangements at various length scales. In addition, we report the first optical detection of reorganization in the photonic architecture on the Drosophila wings by various genetic mutations. These results have potential for the design and development of diffractive optical components for applied photonics and may open up new opportunities in biomimetic device research. (letter)

  9. Development and Optical Testing of the Camera, Hand Lens, and Microscope Probe with Scannable Laser Spectroscopy (CHAMP-SLS)

    Science.gov (United States)

    Mungas, Greg S.; Gursel, Yekta; Sepulveda, Cesar A.; Anderson, Mark; La Baw, Clayton; Johnson, Kenneth R.; Deans, Matthew; Beegle, Luther; Boynton, John

    2008-01-01

    Conducting high resolution field microscopy with coupled laser spectroscopy that can be used to selectively analyze the surface chemistry of individual pixels in a scene is an enabling capability for next generation robotic and manned spaceflight missions, civil, and military applications. In the laboratory, we use a range of imaging and surface preparation tools that provide us with in-focus images, context imaging for identifying features that we want to investigate at high magnification, and surface-optical coupling that allows us to apply optical spectroscopic analysis techniques for analyzing surface chemistry particularly at high magnifications. The camera, hand lens, and microscope probe with scannable laser spectroscopy (CHAMP-SLS) is an imaging/spectroscopy instrument capable of imaging continuously from infinity down to high resolution microscopy (resolution of approx. 1 micron/pixel in a final camera format), the closer CHAMP-SLS is placed to a feature, the higher the resultant magnification. At hand lens to microscopic magnifications, the imaged scene can be selectively interrogated with point spectroscopic techniques such as Raman spectroscopy, microscopic Laser Induced Breakdown Spectroscopy (micro-LIBS), laser ablation mass-spectrometry, Fluorescence spectroscopy, and/or Reflectance spectroscopy. This paper summarizes the optical design, development, and testing of the CHAMP-SLS optics.

  10. Handheld optical coherence tomography-reflectance confocal microscopy probe for detection of basal cell carcinoma and delineation of margins

    Science.gov (United States)

    Iftimia, Nicusor; Yélamos, Oriol; Chen, Chih-Shan J.; Maguluri, Gopi; Cordova, Miguel A.; Sahu, Aditi; Park, Jesung; Fox, William; Alessi-Fox, Christi; Rajadhyaksha, Milind

    2017-07-01

    We present a hand-held implementation and preliminary evaluation of a combined optical coherence tomography (OCT) and reflectance confocal microscopy (RCM) probe for detecting and delineating the margins of basal cell carcinomas (BCCs) in human skin in vivo. A standard OCT approach (spectrometer-based) with a central wavelength of 1310 nm and 0.11 numerical aperture (NA) was combined with a standard RCM approach (830-nm wavelength and 0.9 NA) into a common path hand-held probe. Cross-sectional OCT images and enface RCM images are simultaneously displayed, allowing for three-dimensional microscopic assessment of tumor morphology in real time. Depending on the subtype and depth of the BCC tumor and surrounding skin conditions, OCT and RCM imaging are able to complement each other, the strengths of each helping overcome the limitations of the other. Four representative cases are summarized, out of the 15 investigated in a preliminary pilot study, demonstrating how OCT and RCM imaging may be synergistically combined to more accurately detect BCCs and more completely delineate margins. Our preliminary results highlight the potential benefits of combining the two technologies within a single probe to potentially guide diagnosis as well as treatment of BCCs.

  11. An electro-optical timing diagnostic for pump-probe experiments at the free-electron laser in Hamburg FLASH

    Energy Technology Data Exchange (ETDEWEB)

    Azima, Armin

    2009-07-15

    Femtosecond pump-probe experiments have extensively been used to follow atomic and molecular motion in time. The very intense extreme ultraviolet XUV light of the Free electron LASer in Hamburg FLASH facility allows to investigate fundamental processes such as direct one or few photon inner shell ionizations. A supplementary Ti:Sapphire near infrared femtosecond laser system allows to perform two-color pump-probe experiments with FLASH involving intense laser fields of hugely different photon energies. Within this work a bunch arrival measurement system has been built, which assists these two-color pump-probe experiments to reduce the temporal jitter of FLASH and to increase the temporal resolution. The diagnostic is based upon an electro-optical detection scheme and measures the relative arrival time between the Ti:Sapphire femtosecond pulse and the electron bunch, which generates the self-amplified by stimulated emission SASE XUV pulse in the undulator section of FLASH. Key feature of the diagnostic is a 150 m long glass fiber pulse transport line, which inflicts non-linear dispersion. A dispersion control system to compensate for this higher order dispersion has been developed including the control and programming of a spatial light phase modulator. It was possible to transport a 90 fs FWHM short near infrared femtosecond laser pulse Fourier limited by the dispersion compensated glass fiber. The electro-optical signal induced by the FLASH electron bunch was generated, characterized and optimized. The signal features beside the designated bunch arrival timing capability the additional possibility to measure the longitudinal electron bunch density distribution of an arbitrary bunch of FLASH in a single shot with a temporal resolution of below 100 fs RMS. Timing and bunch analysis capabilities of the developed diagnostic have been cross-checked with other comparable diagnostics at FLASH like the transversal deflecting cavity structure named LOLA. Finally, the

  12. An electro-optical timing diagnostic for pump-probe experiments at the free-electron laser in Hamburg FLASH

    International Nuclear Information System (INIS)

    Azima, Armin

    2009-07-01

    Femtosecond pump-probe experiments have extensively been used to follow atomic and molecular motion in time. The very intense extreme ultraviolet XUV light of the Free electron LASer in Hamburg FLASH facility allows to investigate fundamental processes such as direct one or few photon inner shell ionizations. A supplementary Ti:Sapphire near infrared femtosecond laser system allows to perform two-color pump-probe experiments with FLASH involving intense laser fields of hugely different photon energies. Within this work a bunch arrival measurement system has been built, which assists these two-color pump-probe experiments to reduce the temporal jitter of FLASH and to increase the temporal resolution. The diagnostic is based upon an electro-optical detection scheme and measures the relative arrival time between the Ti:Sapphire femtosecond pulse and the electron bunch, which generates the self-amplified by stimulated emission SASE XUV pulse in the undulator section of FLASH. Key feature of the diagnostic is a 150 m long glass fiber pulse transport line, which inflicts non-linear dispersion. A dispersion control system to compensate for this higher order dispersion has been developed including the control and programming of a spatial light phase modulator. It was possible to transport a 90 fs FWHM short near infrared femtosecond laser pulse Fourier limited by the dispersion compensated glass fiber. The electro-optical signal induced by the FLASH electron bunch was generated, characterized and optimized. The signal features beside the designated bunch arrival timing capability the additional possibility to measure the longitudinal electron bunch density distribution of an arbitrary bunch of FLASH in a single shot with a temporal resolution of below 100 fs RMS. Timing and bunch analysis capabilities of the developed diagnostic have been cross-checked with other comparable diagnostics at FLASH like the transversal deflecting cavity structure named LOLA. Finally, the

  13. Probing the negative permittivity perfect lens at optical frequencies using near-field optics and single molecule detection

    NARCIS (Netherlands)

    Moerland, R.J.; van Hulst, N.F.; Gersen, H.; Kuipers, L.

    2005-01-01

    Recently, the existence of a perfect lens has been predicted, made of an artificial material that has a negative electric permittivity and a negative magnetic permeability. For optical frequencies a poormans version is predicted to exist in the sub-wavelength limit. Then, only the permittivity has

  14. Scanning Probe Optical Tweezers: a new tool to study DNA-protein interactions

    NARCIS (Netherlands)

    Huisstede, J.H.G.

    2006-01-01

    The main goal of the work described in this thesis is to construct a microscope in which OT and scanning probe microscopy (SPM) are combined, to be able to localize proteins while simultaneously controlling the tension within the DNA molecule. This apparatus enables the study of the effect of

  15. Probing the dispersion properties of 1D nanophotonic waveguides with far-field Fourier optics

    DEFF Research Database (Denmark)

    Le Thomas, N.; Jágerská, J.; Houdré, R.

    2008-01-01

    We present an advanced Fourier space imaging technique to probe guided light in nanophotonic structures with an effective numerical aperture of 2.5. This superresolution technique allows us to successfully investigate the dispersive properties of 1D nanowaveguides such as photonic crystal W1...

  16. The natural abundance of 13C with different agricultural management by NIRS with fibre optic probe technology.

    Science.gov (United States)

    Fuentes, Mariela; González-Martín, Inmaculada; Hernández-Hierro, Jose Miguel; Hidalgo, Claudia; Govaerts, Bram; Etchevers, Jorge; Sayre, Ken D; Dendooven, Luc

    2009-06-30

    In the present study the natural abundance of (13)C is quantified in agricultural soils in Mexico which have been submitted to different agronomic practices, zero and conventional tillage, retention of crop residues (with and without) and rotation of crops (wheat and maize) for 17 years, which have influenced the physical, chemical and biological characteristics of the soil. The natural abundance of C13 is quantified by near infrared spectra (NIRS) with a remote reflectance fibre optic probe, applying the probe directly to the soil samples. Discriminate partial least squares analysis of the near infrared spectra allowed to classify soils with and without residues, regardless of the type of tillage or rotation systems used with a prediction rate of 90% in the internal validation and 94% in the external validation. The NIRS calibration model using a modified partial least squares regression allowed to determine the delta(13)C in soils with or without residues, with multiple correlation coefficients 0.81 and standard error prediction 0.5 per thousand in soils with residues and 0.92 and 0.2 per thousand in soils without residues. The ratio performance deviation for the quantification of delta(13)C in soil was 2.5 in soil with residues and 3.8 without residues. This indicated that the model was adequate to determine the delta(13)C of unknown soils in the -16.2 per thousand to -20.4 per thousand range. The development of the NIR calibration permits analytic determinations of the values of delta(13)C in unknown agricultural soils in less time, employing a non-destructive method, by the application of the fibre optic probe of remote reflectance to the soil sample.

  17. Probing amyloid protein aggregation with optical superresolution methods: from the test tube to models of disease.

    Science.gov (United States)

    Kaminski, Clemens F; Kaminski Schierle, Gabriele S

    2016-10-01

    The misfolding and self-assembly of intrinsically disordered proteins into insoluble amyloid structures are central to many neurodegenerative diseases such as Alzheimer's and Parkinson's diseases. Optical imaging of this self-assembly process in vitro and in cells is revolutionizing our understanding of the molecular mechanisms behind these devastating conditions. In contrast to conventional biophysical methods, optical imaging and, in particular, optical superresolution imaging, permits the dynamic investigation of the molecular self-assembly process in vitro and in cells, at molecular-level resolution. In this article, current state-of-the-art imaging methods are reviewed and discussed in the context of research into neurodegeneration.

  18. RadSensor: Xray Detection by Direct Modulation of an Optical Probe Beam

    International Nuclear Information System (INIS)

    Lowry, M E; Bennett, C V; Vernon, S P; Bond, T; Welty, R; Behymer, E; Petersen, H; Krey, A; Stewart, R; Kobayashi, N P; Sperry, V; Stephan, P; Reinhardt, C; Simpson, S; Stratton, P; Bionta, R; McKernan, M; Ables, E; Ott, L; Bond, S; Ayers, J.; Landen, O L; Bell, P M

    2003-01-01

    We present a new x-ray detection technique based on optical measurement of the effects of x-ray absorption and electron hole pair creation in a direct band-gap semiconductor. The electron-hole pairs create a frequency dependent shift in optical refractive index and absorption. This is sensed by simultaneously directing an optical carrier beam through the same volume of semiconducting medium that has experienced an xray induced modulation in the electron-hole population. If the operating wavelength of the optical carrier beam is chosen to be close to the semiconductor band-edge, the optical carrier will be modulated significantly in phase and amplitude. This approach should be simultaneously capable of very high sensitivity and excellent temporal response, even in the difficult high-energy xray regime. At xray photon energies near 10 keV and higher, we believe that sub-picosecond temporal responses are possible with near single xray photon sensitivity. The approach also allows for the convenient and EMI robust transport of high-bandwidth information via fiber optics. Furthermore, the technology can be scaled to imaging applications. The basic physics of the detector, implementation considerations, and preliminary experimental data are presented and discussed

  19. Real time dose rate measurements with fiber optic probes based on the RL and OSL of beryllium oxide

    International Nuclear Information System (INIS)

    Teichmann, T.; Sponner, J.; Jakobi, Ch.; Henniger, J.

    2016-01-01

    This work covers the examination of fiber optical probes based on the radioluminescence and real time optically stimulated luminescence of beryllium oxide. Experiments are carried out to determine the fundamental dosimetric and temporal properties of the system and evaluate its suitability for dose rate measurements in brachytherapy and other applications using non-pulsed radiation fields. For this purpose the responses of the radioluminescence and optically stimulated luminescence signal have been investigated in the dose rate range of 20 mGy/h to 3.6 Gy/h and for doses of 1 mGy up to 6 Gy. Furthermore, a new, efficient analysis procedure, the double phase reference summing, is introduced, leading to a real time optically stimulated luminescence signal. This method allows a complete compensation of the stem effect during the measurement. In contrast to previous works, the stimulation of the 1 mm cylindrical beryllium oxide detectors is performed with a symmetric function during irradiation. The investigated dose rates range from 0.3 to 3.6 Gy/h. The real time optically stimulated luminescence signal of beryllium oxide shows a dependency on both the dose rate and the applied dose. To overcome the problem of dose dependency, further experiments using higher stimulation intensities have to follow. - Highlights: • RL and OSL measurements with BeO extended to low dose (rate) range. • A new method to obtain the real time OSL: Dual Phase Reference Summing. • Real time OSL signal shows both dose and dose rate dependency. • Real time OSL enables a complete discrimination of the stem effect.

  20. A novel optical tool for controlling and probing ultrafast surface dynamics

    International Nuclear Information System (INIS)

    Yang, Yudong

    2017-12-01

    Ultrashort pulse laser sources have been greatly developed over the past few decades. The available pulse duration has been reduced to the single-cycle pulse regime. The discovery of high harmonic generation has freed us from the limitation of the laser wavelength. Moreover, the demonstration of isolated attosecond pulse generation has indicated the advent of the attosecond science era. Attosecond pulses undoubtedly allow one to study ultrafast dynamics with unprecedented time resolution. However, physical systems with genuine attosecond time scale dynamics are rather challenging to find. Ultrafast surface charge transfer, which is an important process in photochemistry and electrochemistry, is a good candidate experimental system exhibiting attosecond electronic dynamics. Specifically, the ultrafast surface charge transfer on the c(4 x 2)S/Ru(0001) surface was previously studied and the charge transfer time inferred to be 320 as using core-hole clock spectroscopy at a synchrotron facility. In order to measure this benchmark attosecond electronic dynamics with real time-resolving methods, pump pulses centered at 160 eV and probe pulses centered at 40 eV are required. To this end, a dedicated attosecond experimental beamline including an ultrashort laser pulse source and an attosecond pulse generation and characterization setup has been designed and is being developed. The author of this thesis was responsible for the construction of the attosecond experimental beamline which will be used ultrafast surface charge transfer studies. In this thesis, a completely functional attosecond extreme ultraviolet (XUV) beamline, which includes a few-cycle laser pulse source, an attosecond pulse generation and characterization setup, is described. A commercial Ti:sapphire-based chirped-pulse amplification (CPA) laser system is the overall source of the beamline. The laser system is actively carrier-envelope phase (CEP) stabilized and the output pulse duration is ∝35 fs. The

  1. A novel optical tool for controlling and probing ultrafast surface dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yudong

    2017-12-15

    Ultrashort pulse laser sources have been greatly developed over the past few decades. The available pulse duration has been reduced to the single-cycle pulse regime. The discovery of high harmonic generation has freed us from the limitation of the laser wavelength. Moreover, the demonstration of isolated attosecond pulse generation has indicated the advent of the attosecond science era. Attosecond pulses undoubtedly allow one to study ultrafast dynamics with unprecedented time resolution. However, physical systems with genuine attosecond time scale dynamics are rather challenging to find. Ultrafast surface charge transfer, which is an important process in photochemistry and electrochemistry, is a good candidate experimental system exhibiting attosecond electronic dynamics. Specifically, the ultrafast surface charge transfer on the c(4 x 2)S/Ru(0001) surface was previously studied and the charge transfer time inferred to be 320 as using core-hole clock spectroscopy at a synchrotron facility. In order to measure this benchmark attosecond electronic dynamics with real time-resolving methods, pump pulses centered at 160 eV and probe pulses centered at 40 eV are required. To this end, a dedicated attosecond experimental beamline including an ultrashort laser pulse source and an attosecond pulse generation and characterization setup has been designed and is being developed. The author of this thesis was responsible for the construction of the attosecond experimental beamline which will be used ultrafast surface charge transfer studies. In this thesis, a completely functional attosecond extreme ultraviolet (XUV) beamline, which includes a few-cycle laser pulse source, an attosecond pulse generation and characterization setup, is described. A commercial Ti:sapphire-based chirped-pulse amplification (CPA) laser system is the overall source of the beamline. The laser system is actively carrier-envelope phase (CEP) stabilized and the output pulse duration is ∝35 fs. The

  2. Temperature-referenced high-sensitivity point-probe optical fiber chem-sensors based on cladding etched fiber Bragg gratings

    OpenAIRE

    Zhou, Kaiming; Chen, Xianfeng F.; Zhang, Lin; Bennion, Ian

    2004-01-01

    Point-probe optical fiber chem-sensors have been implemented using cladding etched fiber Bragg gratings. The sensors possess refractive index sensing capability that can be utilized to measure chemical concentrations. The Bragg wavelength shift reaches 8 nm when the index of surrounding medium changes from 1.33 to 1.44, giving maximum sensitivity more than 10 times higher than that of previously reported devices. More importantly, the dual-grating configuration of the point-probe sensors offe...

  3. SQL and Multidimensional Data

    Directory of Open Access Journals (Sweden)

    Mihaela MUNTEAN

    2006-01-01

    Full Text Available Using SQL you can manipulate multidimensional data and extract that data into a relational table. There are many PL/SQL packages that you can use directly in SQL*Plus or indirectly in Analytic Workspace Manager and OLAP Worksheet. In this article I discussed about some methods that you can use for manipulating and extracting multidimensional data.

  4. A fusion-spliced near-field optical fiber probe using photonic crystal fiber for nanoscale thermometry based on fluorescence-lifetime measurement of quantum dots.

    Science.gov (United States)

    Fujii, Takuro; Taguchi, Yoshihiro; Saiki, Toshiharu; Nagasaka, Yuji

    2011-01-01

    We have developed a novel nanoscale temperature-measurement method using fluorescence in the near-field called fluorescence near-field optics thermal nanoscopy (Fluor-NOTN). Fluor-NOTN enables the temperature distributions of nanoscale materials to be measured in vivo/in situ. The proposed method measures temperature by detecting the temperature dependent fluorescence lifetimes of Cd/Se quantum dots (QDs). For a high-sensitivity temperature measurement, the auto-fluorescence generated from a fiber probe should be reduced. In order to decrease the noise, we have fabricated a novel near-field optical-fiber probe by fusion-splicing a photonic crystal fiber (PCF) and a conventional single-mode fiber (SMF). The validity of the novel fiber probe was assessed experimentally by evaluating the auto-fluorescence spectra of the PCF. Due to the decrease of auto-fluorescence, a six- to ten-fold increase of S/N in the near-field fluorescence lifetime detection was achieved with the newly fabricated fusion-spliced near-field optical fiber probe. Additionally, the near-field fluorescence lifetime of the quantum dots was successfully measured by the fabricated fusion-spliced near-field optical fiber probe at room temperature, and was estimated to be 10.0 ns.

  5. Reconstruction of elongated bubbles fusing the information from multiple optical probes through a Bayesian inference technique

    Energy Technology Data Exchange (ETDEWEB)

    Chakraborty, Shubhankar; Das, Prasanta Kr., E-mail: pkd@mech.iitkgp.ernet.in [Department of Mechanical Engineering, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India); Roy Chaudhuri, Partha [Department of Physics, Indian Institute of Technology Kharagpur, Kharagpur 721302 (India)

    2016-07-15

    In this communication, a novel optical technique has been proposed for the reconstruction of the shape of a Taylor bubble using measurements from multiple arrays of optical sensors. The deviation of an optical beam passing through the bubble depends on the contour of bubble surface. A theoretical model of the deviation of a beam during the traverse of a Taylor bubble through it has been developed. Using this model and the time history of the deviation captured by the sensor array, the bubble shape has been reconstructed. The reconstruction has been performed using an inverse algorithm based on Bayesian inference technique and Markov chain Monte Carlo sampling algorithm. The reconstructed nose shape has been compared with the true shape, extracted through image processing of high speed images. Finally, an error analysis has been performed to pinpoint the sources of the errors.

  6. Optical probe of Heisenberg-Kitaev magnetism in α -RuCl3

    Science.gov (United States)

    Sandilands, Luke J.; Sohn, C. H.; Park, H. J.; Kim, So Yeun; Kim, K. W.; Sears, Jennifer A.; Kim, Young-June; Noh, Tae Won

    2016-11-01

    We report a temperature-dependent optical spectroscopic study of the Heisenberg-Kitaev magnet α -RuCl3 . Our measurements reveal anomalies in the optical response near the magnetic ordering temperature. At higher temperatures, we observe a redistribution of spectral weight over a broad energy range that is associated with nearest-neighbor spin-spin correlations. This finding is consistent with highly frustrated magnetic interactions and in agreement with theoretical expectations for this class of material. The optical data also reveal significant electron-hole interaction effects, including a bound excitonic state. These results demonstrate a clear coupling between charge and spin degrees of freedom and provide insight into the properties of thermally disordered Heisenberg-Kitaev magnets.

  7. Surface-Enhanced Raman Scattering Sensor on an Optical Fiber Probe Fabricated with a Femtosecond Laser

    OpenAIRE

    Ma, Xiaodong; Huo, Haibin; Wang, Wenhui; Tian, Ye; Wu, Nan; Guthy, Charles; Shen, Mengyan; Wang, Xingwei

    2010-01-01

    A novel fabrication method for surface-enhanced Raman scattering (SERS) sensors that used a fast femtosecond (fs) laser scanning process to etch uniform patterns and structures on the endface of a fused silica optical fiber, which is then coated with a thin layer of silver through thermal evaporation is presented. A high quality SERS signal was detected on the patterned surface using a Rhodamine 6G (Rh6G) solution. The uniform SERS sensor built on the tip of the optical fiber tip was small, l...

  8. SkyProbe, monitoring the absolute atmospheric transmission in the optical

    Science.gov (United States)

    Cuillandre, Jean-charles; Magnier, Eugene; Mahoney, William

    2011-03-01

    Mauna Kea is known for its pristine seeing conditions, but sky transparency can be an issue for science operations since 25% of the night are not photometric, mostly due to high-altitude cirrus. Since 2001, the original single-channel SkyProbe has gathered one exposure every minute during each observing night using a small CCD camera with a very wide field of view (35 sq. deg.) encompassing the region pointed by the telescope for science operations, and exposures long enough (40 seconds) to capture at least 100 stars of Hipparcos' Tychos catalog at high galactic latitudes (and up to 600 stars at low galactic latitudes). A key advantage of SkyProbe over direct thermal infrared imaging detection of clouds, is that it allows an accurate absolute measurement, within 5%, of the true atmospheric absorption by clouds affecting the data being gathered by the telescope's main science instrument. This system has proven crucial for decision making in the CFHT queued service observing (QSO), representing today 80% of the telescope time: science exposures taken in non-photometric conditions are automatically registered for being re-observed later on (at 1/10th of the original exposure time per pointing in the observed filters) to ensure a proper final absolute photometric calibration. The new dual color system (simultaneous B&V bands) will allow a better characterization of the sky properties atop Mauna Kea and will enable a better detection of the thinner cirrus (absorption down to 0.02 mag., i.e. 2%). SkyProbe is operated within the Elixir pipeline, a collection of tools used for handling the CFHT CCD mosaics (CFH12K and MegaCam), from data pre-processing to astrometric and photometric calibration.

  9. Wave Optical Calculation of Probe Size in Low Energy Scanning Electron Microscope

    Czech Academy of Sciences Publication Activity Database

    Radlička, Tomáš

    2015-01-01

    Roč. 21, S4 (2015), s. 212-217 ISSN 1431-9276 R&D Projects: GA MŠk(CZ) LO1212 Institutional support: RVO:68081731 Keywords : scanning electron microscope * optical calculation Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.730, year: 2015

  10. Single Molecule Detection in Living Biological Cells using Carbon Nanotube Optical Probes

    Science.gov (United States)

    Strano, Michael

    2009-03-01

    Nanoscale sensing elements offer promise for single molecule analyte detection in physically or biologically constrained environments. Molecular adsorption can be amplified via modulation of sharp singularities in the electronic density of states that arise from 1D quantum confinement [1]. Single-walled carbon nanotubes (SWNT), as single molecule optical sensors [2-3], offer unique advantages such as photostable near-infrared (n-IR) emission for prolonged detection through biological media, single-molecule sensitivity and, nearly orthogonal optical modes for signal transduction that can be used to identify distinct classes of analytes. Selective binding to the SWNT surface is difficult to engineer [4]. In this lecture, we will briefly review the immerging field of fluorescent diagnostics using band gap emission from SWNT. In recent work, we demonstrate that even a single pair of SWNT provides at least four optical modes that can be modulated to uniquely fingerprint chemical agents by the degree to which they alter either the emission band intensity or wavelength. We validate this identification method in vitro by demonstrating detection and identification of six genotoxic analytes, including chemotherapeutic drugs and reactive oxygen species (ROS), which are spectroscopically differentiated into four distinct classes. We also demonstrate single-molecule sensitivity in detecting hydrogen peroxide, one of the most common genotoxins and an important cellular signal. Finally, we employ our sensing and fingerprinting method of these analytes in real time within live 3T3 cells, demonstrating the first multiplexed optical detection from a nanoscale biosensor and the first label-free tool to optically discriminate between genotoxins. We will also discuss our recent efforts to fabricate biomedical sensors for real time detection of glucose and other important physiologically relevant analytes in-vivo. The response of embedded SWNT in a swellable hydrogel construct to

  11. Time-resolved laser-excited Shpol'skii spectrometry with a fiber-optic probe and ICCD camera

    International Nuclear Information System (INIS)

    Bystol, Adam J.; Campiglia, Andres D.; Gillispie, Gregory D.

    2000-01-01

    Improved methodology for chemical analysis via laser-excited Shpol'skii spectrometry is reported. The complications of traditional methodology for measurements at liquid nitrogen temperature are avoided by freezing the distal end of a bifurcated fiber-optic probe directly into the sample matrix. Emission wavelength-time matrices were rapidly collected by automatically incrementing the gate delay of an intensified charge-coupled device (ICCD) camera relative to the laser excitation pulse. The excitation source is a compact frequency-doubled tunable dye laser whose bandwidth (<0.03 nm) is well matched for Shpol'skii spectroscopy. Data reproducibility for quantitative analysis purposes and analytical figures of merit are demonstrated for several polycyclic aromatic hydrocarbons at 77 K. Although not attempted in this study, time-resolved excitation-emission matrices could easily be collected with this instrumental system. (c) 2000 Society for Applied Spectroscopy

  12. Comparison of NO titration and fiber optics catalytic probes for determination of neutral oxygen atom concentration in plasmas and postglows

    International Nuclear Information System (INIS)

    Mozetic, Miran; Ricard, Andre; Babic, Dusan; Poberaj, Igor; Levaton, Jacque; Monna, Virginie; Cvelbar, Uros

    2003-01-01

    A comparative study of two different absolute methods NO titration and fiber optics catalytic probe (FOCP) for determination of neutral oxygen atom density is presented. Both methods were simultaneously applied for measurements of O density in a postglow of an Ar/O 2 plasma created by a surfatron microwave generator with the frequency of 2.45 GHz an adjustable output power between 30 and 160 W. It was found that the two methods gave similar results. The advantages of FOCP were found to be as follows: it is a nondestructive method, it enables real time measuring of the O density, it does not require any toxic gas, and it is much faster than NO titration. The advantage of NO titration was found to be the ability to measure O density in a large range of dissociation of oxygen molecules

  13. Pseudo-differential CMOS analog front-end circuit for wide-bandwidth optical probe current sensor

    Science.gov (United States)

    Uekura, Takaharu; Oyanagi, Kousuke; Sonehara, Makoto; Sato, Toshiro; Miyaji, Kousuke

    2018-04-01

    In this paper, we present a pseudo-differential analog front-end (AFE) circuit for a novel optical probe current sensor (OPCS) aimed for high-frequency power electronics. It employs a regulated cascode transimpedance amplifier (RGC-TIA) to achieve a high gain and a large bandwidth without using an extremely high performance operational amplifier. The AFE circuit is designed in a 0.18 µm standard CMOS technology achieving a high transimpedance gain of 120 dB Ω and high cut off frequency of 16 MHz. The measured slew rate is 70 V/µs and the input referred current noise is 1.02 pA/\\sqrt{\\text{Hz}} . The magnetic resolution and bandwidth of OPCS are estimated to be 1.29 mTrms and 16 MHz, respectively; the bandwidth is higher than that of the reported Hall effect current sensor.

  14. Single-component supported lipid bilayers probed using broadband nonlinear optics.

    Science.gov (United States)

    Olenick, Laura L; Chase, Hilary M; Fu, Li; Zhang, Yun; McGeachy, Alicia C; Dogangun, Merve; Walter, Stephanie R; Wang, Hong-Fei; Geiger, Franz M

    2018-01-31

    Broadband SFG spectroscopy is shown to offer considerable advantages over scanning systems in terms of signal-to-noise ratios when probing well-formed single-component supported lipid bilayers formed from zwitterionic lipids with PC headgroups. The SFG spectra obtained from bilayers formed from DOPC, POPC, DLPC, DMPC, DPPC and DSPC show a common peak at ∼2980 cm -1 , which is subject to interference between the C-H and the O-H stretches from the aqueous phase, while membranes having transition temperatures above the laboratory temperature produce SFG spectra with at least two additional peaks, one at ∼2920 cm -1 and another at ∼2880 cm -1 . The results validate spectroscopic and structural data from SFG experiments utilizing asymmetric bilayers in which one leaflet differs from the other in the extent of deuteration. Differences in H 2 O-D 2 O exchange experiments reveal that the lineshapes of the broadband SFG spectra are significantly influenced by interference from OH oscillators in the aqueous phase, even when those oscillators are not probed by the incident infrared light in our broadband setup. In the absence of spectral interference from the OH stretches of the solvent, the alkyl chain terminal methyl group of the bilayer is found to be tilted at an angle of 15° to 35° from the surface normal.

  15. Coronal in vivo forward-imaging of rat brain morphology with an ultra-small optical coherence tomography fiber probe

    Science.gov (United States)

    Xie, Yijing; Bonin, Tim; Löffler, Susanne; Hüttmann, Gereon; Tronnier, Volker; Hofmann, Ulrich G.

    2013-02-01

    A well-established navigation method is one of the key conditions for successful brain surgery: it should be accurate, safe and online operable. Recent research shows that optical coherence tomography (OCT) is a potential solution for this application by providing a high resolution and small probe dimension. In this study a fiber-based spectral-domain OCT system utilizing a super-luminescent-diode with the center wavelength of 840 nm providing 14.5 μm axial resolution was used. A composite 125 μm diameter detecting probe with a gradient index (GRIN) fiber fused to a single mode fiber was employed. Signals were reconstructed into grayscale images by horizontally aligning A-scans from the same trajectory with different depths. The reconstructed images can display brain morphology along the entire trajectory. For scans of typical white matter, the signals showed a higher reflection of light intensity with lower penetration depth as well as a steeper attenuation rate compared to the scans typical for gray matter. Micro-structures such as axon bundles (70 μm) in the caudate nucleus are visible in the reconstructed images. This study explores the potential of OCT to be a navigation modality in brain surgery.

  16. Intraoperative handheld probe for 3D imaging of pediatric benign vocal fold lesions using optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Benboujja, Fouzi; Garcia, Jordan; Beaudette, Kathy; Strupler, Mathias; Hartnick, Christopher J.; Boudoux, Caroline

    2016-02-01

    Excessive and repetitive force applied on vocal fold tissue can induce benign vocal fold lesions. Children affected suffer from chronic hoarseness. In this instance, the vibratory ability of the folds, a complex layered microanatomy, becomes impaired. Histological findings have shown that lesions produce a remodeling of sup-epithelial vocal fold layers. However, our understanding of lesion features and development is still limited. Indeed, conventional imaging techniques do not allow a non-invasive assessment of sub-epithelial integrity of the vocal fold. Furthermore, it remains challenging to differentiate these sub-epithelial lesions (such as bilateral nodules, polyps and cysts) from a clinical perspective, as their outer surfaces are relatively similar. As treatment strategy differs for each lesion type, it is critical to efficiently differentiate sub-epithelial alterations involved in benign lesions. In this study, we developed an optical coherence tomography (OCT) based handheld probe suitable for pediatric laryngological imaging. The probe allows for rapid three-dimensional imaging of vocal fold lesions. The system is adapted to allow for high-resolution intra-operative imaging. We imaged 20 patients undergoing direct laryngoscopy during which we looked at different benign pediatric pathologies such as bilateral nodules, cysts and laryngeal papillomatosis and compared them to healthy tissue. We qualitatively and quantitatively characterized laryngeal pathologies and demonstrated the added advantage of using 3D OCT imaging for lesion discrimination and margin assessment. OCT evaluation of the integrity of the vocal cord could yield to a better pediatric management of laryngeal diseases.

  17. Optical diagnostic suite (schlieren, interferometry, and grid image refractometry) on OMEGA EP using a 10-ps, 263-nm probe beama)

    Science.gov (United States)

    Froula, D. H.; Boni, R.; Bedzyk, M.; Craxton, R. S.; Ehrne, F.; Ivancic, S.; Jungquist, R.; Shoup, M. J.; Theobald, W.; Weiner, D.; Kugland, N. L.; Rushford, M. C.

    2012-10-01

    A 10-ps, 263-nm (4ω) laser is being built to probe plasmas produced on the OMEGA EP [J. H. Kelly, L. J. Waxer, V. Bagnoud, I. A. Begishev, J. Bromage, B. E. Kruschwitz, T. E. Kessler, S. J. Loucks, D. N. Maywar, R. L. McCrory et al., J. Phys. IV France 133, 75-80 (2006)], 10.1051/jp4:2006133015. A suite of optical diagnostics (schlieren, interferometry, and grid image refractometry) has been designed to diagnose and characterize a wide variety of plasmas. Light scattered by the probe beam is collected by an f/4 catadioptric telescope and a transport system is designed to image with a near-diffraction-limited resolution (˜1 - μm full width at half maximum) over a 5-mm field of view to a diagnostic table. The transport system provides a contrast greater than 1 : 104 with respect to all wavelengths outside of the 263 ± 2 nm measurement range.

  18. Micro-rheology and interparticle interactions in aerosols probed with optical tweezers

    Science.gov (United States)

    Reid, Jonathan P.; Power, Rory M.; Cai, Chen; Simpson, Stephen H.

    2014-09-01

    Using optical tweezers for micro-rheological investigations of a surrounding fluid has been routinely demonstrated. In this work, we will demonstrate that rheological measurements of the bulk and surface properties of aerosol particles can be made directly using optical tweezers, providing important insights into the phase behavior of materials in confined environments and the rate of molecular diffusion in viscous phases. The use of holographic optical tweezers to manipulate aerosol particles has become standard practice in recent years, providing an invaluable tool to investigate particle dynamics, including evaporation/ condensation kinetics, chemical aging and phase transformation. When combined with non-linear Raman spectroscopy, the size and refractive index of a particle can be determined with unprecedented accuracy viscosity and surface tension of particles can be measured directly in the under-damped regime at low viscosity. In the over-damped regime, we will show that viscosity measurements can extend close to the glass transition, allowing measurements over an impressive dynamic range of 12 orders of magnitude in relaxation timescale and viscosity. Indeed, prior to the coalescence event, we will show how the Brownian trajectories of trapped particles can yield important and unique insights into the interactions of aerosol particles.

  19. Model of a Plasmonic Phase Interrogation Probe for Optical Sensing of Hemoglobin in Blood Samples

    Science.gov (United States)

    Sharma, Anuj K.

    2015-11-01

    Phase interrogation based surface plasmon resonance (SPR) biosensor is proposed for the determination of Hb concentration. Previous experimental results describing variation of refractive index of human blood with Hb concentration at different wavelengths are considered for design simulations. The biosensor design with silica substrate and gold layer is considered. The sensor's performance is closely analyzed in terms of phase sensitivity and resolution. The influence of operating wavelength on biosensor's performance for Hb measurement is critically investigated, which points to carry out the Hb measurement at a shorter wavelength as phase sensitivity and resolution increase significantly with decrease in wavelength. The results are explained in terms of suitable physical concepts such as radiation damping. Use of contamination-preventing biochemical layer ascertains the stability of measurement with the intended SPR biosensor probe. The simulation results also highlight that the resolution of Hb measurement achievable with the proposed biosensor is much higher compared with several existing methods.

  20. Optical beam transport to a remote location for low jitter pump-probe experiments with a free electron laser

    Directory of Open Access Journals (Sweden)

    P. Cinquegrana

    2014-04-01

    Full Text Available In this paper we propose a scheme that allows a strong reduction of the timing jitter between the pulses of a free electron laser (FEL and external laser pulses delivered simultaneously at the FEL experimental stations for pump-probe–type experiments. The technique, applicable to all seeding-based FEL schemes, relies on the free-space optical transport of a portion of the seed laser pulse from its optical table to the experimental stations. The results presented here demonstrate that a carefully designed laser beam transport, incorporating also a transverse beam position stabilization, allows one to keep the timing fluctuations, added by as much as 150 m of free space propagation and a number of beam folding mirrors, to less than 4 femtoseconds rms. By its nature our scheme removes the major common timing jitter sources, so the overall jitter in pump-probe measurements done in this way will be below 10 fs (with a margin to be lowered to below 5 fs, much better than the best results reported previously in the literature amounting to 33 fs rms.

  1. LASER-INDUCED MULTIDIMENSIONAL FLUORESCENCE SPECTROSCOPY IN SHPOL'SKII MATRICES WITH A FIBER OPTIC PROBE AT LIQUID HELIUM TEMPERATURE. (R828081E01)

    Science.gov (United States)

    The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Concl...

  2. Beveled fiber-optic probe couples a ball lens for improving depth-resolved fluorescence measurements of layered tissue: Monte Carlo simulations

    International Nuclear Information System (INIS)

    Jaillon, Franck; Zheng Wei; Huang Zhiwei

    2008-01-01

    In this study, we evaluate the feasibility of designing a beveled fiber-optic probe coupled with a ball lens for improving depth-resolved fluorescence measurements of epithelial tissue using Monte Carlo (MC) simulations. The results show that by using the probe configuration with a beveled tip collection fiber and a flat tip excitation fiber associated with a ball lens, discrimination of fluorescence signals generated in different tissue depths is achievable. In comparison with a flat-tip collection fiber, the use of a large bevel angled collection fiber enables a better differentiation between the shallow and deep tissue layers by changing the excitation-collection fiber separations. This work suggests that the beveled fiber-optic probe coupled with a ball lens has the potential to facilitate depth-resolved fluorescence measurements of epithelial tissues

  3. Optical properties of single semiconductor nanowires and nanowire ensembles. Probing surface physics by photoluminescence spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Pfueller, Carsten

    2011-06-27

    This thesis presents a detailed investigation of the optical properties of semiconductor nanowires (NWs) in general and single GaN NWs and GaN NW ensembles in particular by photoluminescence (PL) spectroscopy. NWs are often considered as potential building blocks for future nanometer-scaled devices. This vision is based on several attractive features that are generally ascribed to NWs. For instance, they are expected to grow virtually free of strain and defects even on substrates with a large structural mismatch. In the first part of the thesis, some of these expectations are examined using semiconductor NWs of different materials. On the basis of the temperature-dependent PL of Au- and selfassisted GaAs/(Al,Ga)As core-shell NWs, the influence of foreign catalyst particles on the optical properties of NWs is investigated. For the Au-assisted NWs, we find a thermally activated, nonradiative recombination channel, possibly related to Auatoms incorporated from the catalyst. These results indicate the limited suitability of catalyst-assisted NWs for optoelectronic applications. The effect of the substrate choice is studied by comparing the PL of ZnO NWs grown on Si, Al{sub 2}O{sub 3}, and ZnO substrates. Their virtually identical optical characteristics indicate that the synthesis of NWs may indeed overcome the constraints that limit the heteroepitaxial deposition of thin films. The major part of this thesis discusses the optical properties of GaN NWs grown on Si substrates. The investigation of the PL of single GaN NWs and GaN NW ensembles reveals the significance of their large surface-to-volume ratio. Differences in the recombination behavior of GaNNW ensembles and GaN layers are observed. First, the large surface-to-volume ratio is discussed to be responsible for the different recombination mechanisms apparent in NWs. Second, certain optical features are only found in the PL of GaN NWs, but not in that of GaN layers. An unexpected broadening of the donor

  4. Demonstration of a Fiber Optic Regression Probe in a High-Temperature Flow

    Science.gov (United States)

    Korman, Valentin; Polzin, Kurt

    2011-01-01

    The capability to provide localized, real-time monitoring of material regression rates in various applications has the potential to provide a new stream of data for development testing of various components and systems, as well as serving as a monitoring tool in flight applications. These applications include, but are not limited to, the regression of a combusting solid fuel surface, the ablation of the throat in a chemical rocket or the heat shield of an aeroshell, and the monitoring of erosion in long-life plasma thrusters. The rate of regression in the first application is very fast, while the second and third are increasingly slower. A recent fundamental sensor development effort has led to a novel regression, erosion, and ablation sensor technology (REAST). The REAST sensor allows for measurement of real-time surface erosion rates at a discrete surface location. The sensor is optical, using two different, co-located fiber-optics to perform the regression measurement. The disparate optical transmission properties of the two fiber-optics makes it possible to measure the regression rate by monitoring the relative light attenuation through the fibers. As the fibers regress along with the parent material in which they are embedded, the relative light intensities through the two fibers changes, providing a measure of the regression rate. The optical nature of the system makes it relatively easy to use in a variety of harsh, high temperature environments, and it is also unaffected by the presence of electric and magnetic fields. In addition, the sensor could be used to perform optical spectroscopy on the light emitted by a process and collected by fibers, giving localized measurements of various properties. The capability to perform an in-situ measurement of material regression rates is useful in addressing a variety of physical issues in various applications. An in-situ measurement allows for real-time data regarding the erosion rates, providing a quick method for

  5. Preparing and probing atomic Majorana fermions and topological order in optical lattices

    International Nuclear Information System (INIS)

    Kraus, C V; Diehl, S; Zoller, P; Baranov, M A

    2012-01-01

    We introduce a one-dimensional system of fermionic atoms in an optical lattice whose phase diagram includes topological states of different symmetry classes with a simple possibility to switch between them. The states and topological phase transitions between them can be identified by looking at their zero-energy edge modes which are Majorana fermions. We propose several universal methods of detecting the Majorana edge states, based on their genuine features: the zero-energy, localized character of the wave functions and the induced non-local fermionic correlations. (paper)

  6. Probing focal cortical dysplasia in formalin fixed samples using tissue optical spectroscopy

    Science.gov (United States)

    Anand, Suresh; Cicchi, Riccardo; Giordano, Flavio; Buccoliero, Anna Maria; Conti, Valerio; Guerrini, Renzo; Pavone, Francesco Saverio

    2016-03-01

    Focal cortical dysplasia (FCD) is one of most common causes of intractable epilepsy in pediatric population and these are often insensitive to anti-epileptic drugs. FCD is characterized by a disarray in localized regions of the cerebral cortex and abnormal neurons which results them to misfire with incorrect signals. Resective neurosurgery to remove or disconnect the affected parts from the rest of the brain seems to be a viable option to treat FCD. Before neurosurgery the subject could undergo imaging studies including magnetic resonance imaging (MRI) or computed tomography (CT) scans. On the downside FCD could be elusive in MRI images and may be practically invisible in CT scans. Furthermore, unnecessary removal of normal tissues is to be taken into consideration as this could lead to neurological defects. In this context, optical spectroscopy have been widely investigated as an alternative technique for the detection of abnormal tissues in different organ sites. Disease progression is accompanied by a number of architectural, biochemical and morphological changes. These variations are reflected in the spectral intensity and line shape. Here, in this proof of concept study we propose to investigate the application of tissue optical spectroscopy based on fluorescence excitation at two wavelength 378 and 445 nm coupled along with Raman spectroscopy for the detection of FCD on formalin fixed tissue specimens from pediatric subjects. For fluorescence at both the excitation wavelengths FCD showed a decreased intensity at longer wavelength when compared to normal tissues. Also, differences exist in the Raman spectral profiles of normal and FCD.

  7. Organic conjugated small molecule materials based optical probe for rapid, colorimetric and UV-vis spectral detection of phosphorylated protein in placental tissue.

    Science.gov (United States)

    Wang, Yanfang; Yang, Na; Liu, Yi

    2018-04-05

    A novel organic small molecule with D-Pi-A structure was prepared, which was found to be a promising colorimetric and ratiometric UV-vis spetral probe for detection of phosphorylated proteins with the help of tetravalent zirconium ion. Such optical probe based on chromophore WYF-1 shows a rapid response (within 10s) and high selectivity and sensitivity for phosphorylated proteins, giving distinct colorimetric and ratiometric UV-vis changes at 720 and 560nm. The detection limit for phosphorylated proteins was estimated to be 100nM. In addition, detection of phosphorylated proteins in placental tissue samples with this probe was successfully applied, which indicates that this probe holds great potential for phosphorylated proteins detection. Copyright © 2018 Elsevier B.V. All rights reserved.

  8. Development of a Fiber-Optics Microspatially Offset Raman Spectroscopy Sensor for Probing Layered Materials.

    Science.gov (United States)

    Vandenabeele, Peter; Conti, Claudia; Rousaki, Anastasia; Moens, Luc; Realini, Marco; Matousek, Pavel

    2017-09-05

    Microspatially offset Raman spectroscopy (micro-SORS) has been proposed as a valuable approach to sample molecular information from layers that are covered by a turbid (nontransparent) layer. However, when large magnifications are involved, the approach is not straightforward, as spatial constraints exist to position the laser beam and the objective lens with the external beam delivery or, with internal beam delivery, the maximum spatial offset achievable is restricted. To overcome these limitations, we propose here a prototype of a new micro-SORS sensor, which uses bare glass fibers to transfer the laser radiation to the sample and to collect the Raman signal from a spatially offset zone to the Raman spectrometer. The concept also renders itself amenable to remote delivery and to the miniaturization of the probe head which could be beneficial for special applications, e.g., where access to sample areas is restricted. The basic applicability of this approach was demonstrated by studying several layered structure systems. Apart from proving the feasibility of the technique, also, practical aspects of the use of the prototype sensor are discussed.

  9. A novel pH-sensitive polymeric fluorescent probe: Synthesis, characterization and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Chen Dongyun; Xu Qingfeng; Xia Xuewei; Ge Jianfeng [Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou, Jiangsu, 215123 (China); Lu Jianmei, E-mail: lujm@suda.edu.cn [Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou, Jiangsu, 215123 (China); Li Najun, E-mail: linajun@sina.com [Key Laboratory of Organic Synthesis of Jiangsu Province, College of Chemistry, Chemical Engineering and Material Science, Soochow University, Suzhou, Jiangsu, 215123 (China)

    2010-04-15

    A novel initiator containing proflavine derivative moiety, 3,6-dibromo-isobutyramide acridine (DIA), was synthesized and initiated the atom transfer radical polymerization (ATRP) of methyl methacrylate (MMA). A water-soluble monomer, N,N-dimethylacrylamide (DMAA) was also initiated by DIA for comparison. The obtained fluorescent polymers, PMMA-DIA and PDMAA-DIA, were characterized by {sup 1}H NMR, GPC and TGA. The emission spectra of the fluorescent polymers exhibit obvious changes in color and fluorescence intensity along with pH varied in range of 3.0-9.0. In addition, the obtained polymers present good film-forming capacity and the films also have a high quantum yield and pH response. Both oil-soluble PMMA-DIA and water-soluble PDMAA-DIA have steady optical and chemical properties by containing proflavine moiety in the main chain.

  10. Probing the dielectric response of the interfacial buffer layer in epitaxial graphene via optical spectroscopy

    Science.gov (United States)

    Hill, Heather M.; Rigosi, Albert F.; Chowdhury, Sugata; Yang, Yanfei; Nguyen, Nhan V.; Tavazza, Francesca; Elmquist, Randolph E.; Newell, David B.; Hight Walker, Angela R.

    2017-11-01

    Monolayer epitaxial graphene (EG) is a suitable candidate for a variety of electronic applications. One advantage of EG growth on the Si face of SiC is that it develops as a single crystal, as does the layer below, referred to as the interfacial buffer layer (IBL), whose properties include an electronic band gap. Although much research has been conducted to learn about the electrical properties of the IBL, not nearly as much work has been reported on the optical properties of the IBL. In this work, we combine measurements from Mueller matrix ellipsometry, differential reflectance contrast, atomic force microscopy, and Raman spectroscopy, as well as calculations from Kramers-Kronig analyses and density-functional theory, to determine the dielectric function of the IBL within the energy range of 1 eV to 8.5 eV.

  11. Optical Aptamer Probes of Fluorescent Imaging to Rapid Monitoring of Circulating Tumor Cell

    Directory of Open Access Journals (Sweden)

    Ji Yeon Hwang

    2016-11-01

    Full Text Available Fluorescence detecting of exogenous EpCAM (epithelial cell adhesion molecule or muc1 (mucin1 expression correlated to cancer metastasis using nanoparticles provides pivotal information on CTC (circulating tumor cell occurrence in a noninvasive tool. In this study, we study a new skill to detect extracellular EpCAM/muc1 using quantum dot-based aptamer beacon (QD-EpCAM/muc1 ALB (aptamer linker beacon. The QD-EpCAM/muc1 ALB was designed using QDs (quantum dots and probe. The EpCAM/muc1-targeting aptamer contains a Ep-CAM/muc1 binding sequence and BHQ1 (black hole quencher 1 or BHQ2 (black hole quencher2. In the absence of target EpCAM/muc1, the QD-EpCAM/muc1 ALB forms a partial duplex loop-like aptamer beacon and remained in quenched state because the BHQ1/2 quenches the fluorescence signal-on of the QD-EpCAM/muc1 ALB. The binding of EpCAM/muc1 of CTC to the EpCAM/muc1 binding aptamer sequence of the EpCAM/muc1-targeting oligonucleotide triggered the dissociation of the BHQ1/2 quencher and subsequent signal-on of a green/red fluorescence signal. Furthermore, acute inflammation was stimulated by trigger such as caerulein in vivo, which resulted in increased fluorescent signal of the cy5.5-EpCAM/muc1 ALB during cancer metastasis due to exogenous expression of EpCAM/muc1 in Panc02-implanted mouse model.

  12. TriPer, an optical probe tuned to the endoplasmic reticulum tracks changes in luminal H2O2.

    Science.gov (United States)

    Melo, Eduardo Pinho; Lopes, Carlos; Gollwitzer, Peter; Lortz, Stephan; Lenzen, Sigurd; Mehmeti, Ilir; Kaminski, Clemens F; Ron, David; Avezov, Edward

    2017-03-27

    The fate of hydrogen peroxide (H 2 O 2 ) in the endoplasmic reticulum (ER) has been inferred indirectly from the activity of ER-localized thiol oxidases and peroxiredoxins, in vitro, and the consequences of their genetic manipulation, in vivo. Over the years hints have suggested that glutathione, puzzlingly abundant in the ER lumen, might have a role in reducing the heavy burden of H 2 O 2 produced by the luminal enzymatic machinery for disulfide bond formation. However, limitations in existing organelle-targeted H 2 O 2 probes have rendered them inert in the thiol-oxidizing ER, precluding experimental follow-up of glutathione's role in ER H 2 O 2 metabolism. Here we report on the development of TriPer, a vital optical probe sensitive to changes in the concentration of H 2 O 2 in the thiol-oxidizing environment of the ER. Consistent with the hypothesized contribution of oxidative protein folding to H 2 O 2 production, ER-localized TriPer detected an increase in the luminal H 2 O 2 signal upon induction of pro-insulin (a disulfide-bonded protein of pancreatic β-cells), which was attenuated by the ectopic expression of catalase in the ER lumen. Interfering with glutathione production in the cytosol by buthionine sulfoximine (BSO) or enhancing its localized destruction by expression of the glutathione-degrading enzyme ChaC1 in the lumen of the ER further enhanced the luminal H 2 O 2 signal and eroded β-cell viability. A tri-cysteine system with a single peroxidatic thiol enables H 2 O 2 detection in oxidizing milieux such as that of the ER. Tracking ER H 2 O 2 in live pancreatic β-cells points to a role for glutathione in H 2 O 2 turnover.

  13. Optical afterburner for an x-ray free electron laser as a tool for pump-probe experiments

    Directory of Open Access Journals (Sweden)

    E. L. Saldin

    2010-03-01

    Full Text Available We propose a new scheme for two-color operation of an x-ray self-amplified spontaneous emission free electron laser (SASE FEL. The scheme is based on an intrinsic feature of such a device: chaotic modulations of electron beam energy and energy spread on the scale of FEL coherence length are converted into large density modulations on the same scale with the help of a dispersion section, installed behind the x-ray undulator. Powerful radiation is then generated with the help of a dedicated radiator (like an undulator that selects a narrow spectral line, or one can simply use, for instance, broadband edge radiation. A typical radiation wavelength can be as short as a FEL coherence length, and can be redshifted by increasing the dispersion section strength. In practice it means the wavelength ranges from vacuum ultraviolet to infrared. The long-wavelength radiation pulse is naturally synchronized with the x-ray pulse and can be either directly used in pump-probe experiments or cross correlated with a high-power pulse from a conventional laser system. In this way experimenters overcome jitter problems and can perform pump-probe experiments with femtosecond resolution. Additional possibilities like on-line monitoring of x-ray pulse duration (making “optical replica” of an x-ray pulse are also discussed in the paper. The proposed scheme is very simple, cheap, and robust, and therefore can be easily realized in facilities like FLASH, European XFEL, LCLS, and SCSS.

  14. High-frequency conductivity of optically excited charge carriers in hydrogenated nanocrystalline silicon investigated by spectroscopic femtosecond pump–probe reflectivity measurements

    Energy Technology Data Exchange (ETDEWEB)

    He, Wei [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom); Yurkevich, Igor V. [Aston University, Nonlinearity and Complexity Research Group, Birmingham B4 7ET (United Kingdom); Zakar, Ammar [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom); Kaplan, Andrey, E-mail: a.kaplan.1@bham.ac.uk [University of Birmingham, School of Physics and Astronomy, Birmingham B15 2TT (United Kingdom)

    2015-10-01

    We report an investigation into the high-frequency conductivity of optically excited charge carriers far from equilibrium with the lattice. The investigated samples consist of hydrogenated nanocrystalline silicon films grown on a thin film of silicon oxide on top of a silicon substrate. For the investigation, we used an optical femtosecond pump–probe setup to measure the reflectance change of a probe beam. The pump beam ranged between 580 and 820 nm, whereas the probe wavelength spanned 770 to 810 nm. The pump fluence was fixed at 0.6 mJ/cm{sup 2}. We show that at a fixed delay time of 300 fs, the conductivity of the excited electron–hole plasma is described well by a classical conductivity model of a hot charge carrier gas found at Maxwell–Boltzmann distribution, while Fermi–Dirac statics is not suitable. This is corroborated by values retrieved from pump–probe reflectance measurements of the conductivity and its dependence on the excitation wavelength and carrier temperature. The conductivity decreases monotonically as a function of the excitation wavelength, as expected for a nondegenerate charge carrier gas. - Highlights: • We study high‐frequency conductivity of excited hydrogenated nanocrystalline silicon. • Reflectance change was measured as a function of pump and probe wavelength. • Maxwell–Boltzmann transport theory was used to retrieve the conductivity. • The conductivity decreases monotonically as a function of the pump wavelength.

  15. Optical probing of quantum Hall effect of composite fermions and of the liquid-insulator transition

    International Nuclear Information System (INIS)

    Rossella, F; Bellani, V; Dionigi, F; Amado, M; Diez, E; Kowalik, K; Biasiol, G; Sorba, L

    2011-01-01

    In the photoluminescence spectra of a two-dimensional electron gas in the fractional quantum Hall regime we observe the states at filling factors ν = 4/5, 5/7, 4/11 and 3/8 as clear minima in the intensity or area emission peak. The first three states are described as interacting composite fermions in fractional quantum Hall regime. The minimum in the intensity at ν 3/8, which is not explained within this picture, can be an evidence of a suppression of the screening of the Coulomb interaction among the effective quasi-particles involved in this intriguing state. The magnetic field energy dispersion at very low temperatures is also discussed. At low field the emission follows a Landau dispersion with a screened magneto-Coulomb contribution. At intermediate fields the hidden symmetry manifests. At high field above ν = 1/3 the electrons correlate into an insulating phase, and the optical emission behaviour at the liquid-insulator transition is coherent with a charge ordering driven by Coulomb correlations.

  16. Probing the properties of nebular plasmas with optical and infrared spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Barlow, M. J. [Dept. of Physics and Astronomy, University College London, London WC1E 6BT (United Kingdom)

    2012-05-25

    A number of current developments arising from spectroscopic studies of ionized nebulae are reviewed. Until the past decade or so, such studies were generally confined to the analysis of recombination lines from hydrogen and helium, along with collisionally excited forbidden lines from second and third row elements in the periodic table. However, the advent of efficient detectors on 8m-class telescopes has enabled the detection of recombination lines from second and third row elements, along with collisionally excited lines from much less abundant species. Significant discrepancies have been found between ionic abundances derived from collisionally excited lines and those obtained for the same ions from their recombination lines. The existence of 'cold plasma' with T{sub e}{<=} 1000 K has been confirmed for a number of planetary nebulae. Optical and infrared collisionally excited ionic lines from a wide range of 'neutron-capture' elements from beyond the iron abundance peak have also been detected. There is a consequent need for new calculations and experimental measurements of the atomic data needed to interpret these observations.

  17. Structural modifications of swift heavy ion irradiated PEN probed by optical and thermal measurements

    International Nuclear Information System (INIS)

    Devgan, Kusum; Singh, Lakhwant; Samra, Kawaljeet Singh

    2013-01-01

    Highlights: • The present paper reports the effect of swift heavy ion irradiation on Polyethylene Naphthalate (PEN). • Swift heavy ion irradiation introduces structural modification and degradation of PEN at different doses. • Lower irradiation doses in PEN result in modification of structural properties and higher doses lead to complete degradation. • Strong correlation between structural, optical, and thermal properties. - Abstract: The effects of swift heavy ion irradiation on the structural characteristics of Polyethylene naphthalate (PEN) were studied. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×10 11 –3×10 12 ions cm −2 . Ion induced changes were analyzed using X-ray diffraction (XRD), Fourier transform infra red (FT-IR), UV–visible spectroscopy, thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Cross-linking was observed at lower doses resulting in modification of structural properties, however higher doses lead to the degradation of the investigated polymeric samples

  18. [INVITED] Non-intrusive optical imaging of face to probe physiological traits in Autism Spectrum Disorder

    Science.gov (United States)

    Samad, Manar D.; Bobzien, Jonna L.; Harrington, John W.; Iftekharuddin, Khan M.

    2016-03-01

    Autism Spectrum Disorders (ASD) can impair non-verbal communication including the variety and extent of facial expressions in social and interpersonal communication. These impairments may appear as differential traits in the physiology of facial muscles of an individual with ASD when compared to a typically developing individual. The differential traits in the facial expressions as shown by facial muscle-specific changes (also known as 'facial oddity' for subjects with ASD) may be measured visually. However, this mode of measurement may not discern the subtlety in facial oddity distinctive to ASD. Earlier studies have used intrusive electrophysiological sensors on the facial skin to gauge facial muscle actions from quantitative physiological data. This study demonstrates, for the first time in the literature, novel quantitative measures for facial oddity recognition using non-intrusive facial imaging sensors such as video and 3D optical cameras. An Institutional Review Board (IRB) approved that pilot study has been conducted on a group of individuals consisting of eight participants with ASD and eight typically developing participants in a control group to capture their facial images in response to visual stimuli. The proposed computational techniques and statistical analyses reveal higher mean of actions in the facial muscles of the ASD group versus the control group. The facial muscle-specific evaluation reveals intense yet asymmetric facial responses as facial oddity in participants with ASD. This finding about the facial oddity may objectively define measurable differential markers in the facial expressions of individuals with ASD.

  19. Probing insect backscatter cross section and melanization using kHz optical remote detection system

    Science.gov (United States)

    Gebru, Alem; Brydegaard, Mikkel; Rohwer, Erich; Neethling, Pieter

    2017-01-01

    A kHz optical remote sensing system is implemented to determine insect melanization features. This is done by measuring the backscatter signal in the visible and near-infrared (VIS-NIR) and short-wave infrared (SWIR) in situ. It is shown that backscatter cross section in the SWIR is insensitive to melanization and absolute melanization can be derived from the ratio of backscatter cross section of different bands (SWIR/VIS-NIR). We have shown that reflectance from insect is stronger in the SWIR as compared to NIR and VIS. This reveals that melanization plays a big role to determine backscatter cross section. One can use this feature as a tool to improve insect species and age classification. To support the findings, we illustrated melanization feature using three different insects [dead, dried specimens of snow white moth (Spilosoma genus), fox moth (Macrothylacia), and leather beetle (Odontotaenius genus)]. It is shown that reflectance from the leather beetle in the VIS and NIR is more affected by melanization as compared with snow white moth.

  20. Portable optical fiber probe-based spectroscopic scanner for rapid cancer diagnosis: a new tool for intraoperative margin assessment.

    Directory of Open Access Journals (Sweden)

    Niyom Lue

    Full Text Available There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS and intrinsic fluorescence spectroscopy (IFS, and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm over a wide field of view (10 cm × 10 cm, and both high spectral resolution (2 nm and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue. Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (<5% error. Finally, studies using human breast tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a

  1. Applied multidimensional systems theory

    CERN Document Server

    Bose, Nirmal K

    2017-01-01

    Revised and updated, this concise new edition of the pioneering book on multidimensional signal processing is ideal for a new generation of students. Multidimensional systems or m-D systems are the necessary mathematical background for modern digital image processing with applications in biomedicine, X-ray technology and satellite communications. Serving as a firm basis for graduate engineering students and researchers seeking applications in mathematical theories, this edition eschews detailed mathematical theory not useful to students. Presentation of the theory has been revised to make it more readable for students, and introduce some new topics that are emerging as multidimensional DSP topics in the interdisciplinary fields of image processing. New topics include Groebner bases, wavelets, and filter banks.

  2. Ratiometric colorimetric determination of coenzyme A using gold nanoparticles and a binuclear uranyl complex as optical probes

    International Nuclear Information System (INIS)

    Wu, Rurong; Liao, Lifu; Li, Shijun; Yang, Yanyan; Xiao, Xilin; Nie, Changming

    2016-01-01

    We describe a ratiometric colorimetric method for the determination of coenzyme A (CoA) by using gold nanoparticles (AuNPs) and bis-uranyl-bis-sulfosalophen (BUBSS) as optical probes. BUBSS is a binuclear uranyl complex and formed through the chelating reaction of two uranyl ions with bis-sulfosalophen. CoA is captured by the AuNPs via the thiol group and this leads to the formation of CoA-AuNPs. In a second step, BUBSS binds two CoA-AuNPs through a coordination reaction between the uranyl ions in BUBSS and the phosphate groups in CoA-AuNPs. This causes the CoA-AuNPs to aggregate and results in a color change from wine red to blue. A ratiometric colorimetric assay was established for CoA based on the ratiometric measurement of absorbance changes at 650 and 525 nm. Their ratio is linearly related to the concentration of CoA in the 0 to 1.2 μmol⋅L -1 range, with a 6 nmol⋅ L- 1 detection limit under optimal conditions. The method was successfully applied to the determination of CoA in spiked liver samples with recoveries between 99.4 and 102.6 %. (author)

  3. A Surface Plasmon Resonance-Based Optical Fiber Probe Fabricated with Electropolymerized Molecular Imprinting Film for Melamine Detection

    Directory of Open Access Journals (Sweden)

    Wei Li

    2018-03-01

    Full Text Available Molecularly imprinted polymer (MIP films prepared by bulk polymerization suffer from numerous deficiencies, including poor mass transfer ability and difficulty in controlling reaction rate and film thickness, which usually result in poor repeatability. However, polymer film synthesized by electropolymerization methods benefit from high reproducibility, simplicity and rapidity of preparation. In the present study, an Au film served as the refractive index-sensitive metal film to couple with the light leaked out from optical fiber core and the electrode for electropolymerizing MIP film simultaneously. The manufactured probe exhibited satisfactory sensitivity and specificity. Furthermore, the surface morphology and functional groups of the synthesized MIP film were characterized by Atomic Force Microscopy (AFM and Fourier transform infrared microspectroscopy (FTIR for further insights into the adsorption and desorption processes. Given the low cost, label-free test, simple preparation process and fast response, this method has a potential application to monitor substances in complicated real samples for out-of-lab test in the future.

  4. Multi-dimensional imaging

    CERN Document Server

    Javidi, Bahram; Andres, Pedro

    2014-01-01

    Provides a broad overview of advanced multidimensional imaging systems with contributions from leading researchers in the field Multi-dimensional Imaging takes the reader from the introductory concepts through to the latest applications of these techniques. Split into 3 parts covering 3D image capture, processing, visualization and display, using 1) a Multi-View Approach and 2.) a Holographic Approach, followed by a 3rd part addressing other 3D systems approaches, applications and signal processing for advanced 3D imaging. This book describes recent developments, as well as the prospects and

  5. Symbolic Multidimensional Scaling

    NARCIS (Netherlands)

    P.J.F. Groenen (Patrick); Y. Terada

    2015-01-01

    markdownabstract__Abstract__ Multidimensional scaling (MDS) is a technique that visualizes dissimilarities between pairs of objects as distances between points in a low dimensional space. In symbolic MDS, a dissimilarity is not just a value but can represent an interval or even a histogram. Here,

  6. Functionalization of graphene oxide nanostructures improves photoluminescence and facilitates their use as optical probes in preclinical imaging

    Science.gov (United States)

    Prabhakar, Neeraj; Näreoja, Tuomas; von Haartman, Eva; Şen Karaman, Didem; Burikov, Sergey A.; Dolenko, Tatiana A.; Deguchi, Takahiro; Mamaeva, Veronika; Hänninen, Pekka E.; Vlasov, Igor I.; Shenderova, Olga A.; Rosenholm, Jessica M.

    2015-06-01

    Recently reported photoluminescent nanographene oxides (nGOs), i.e. nanographene oxidised with a sulfuric/nitric acid mixture (SNOx method), have tuneable photoluminescence and are scalable, simple and fast to produce optical probes. This material belongs to the vast class of photoluminescent carbon nanostructures, including carbon dots, nanodiamonds (NDs), graphene quantum dots (GQDs), all of which demonstrate a variety of properties that are attractive for biomedical imaging such as low toxicity and stable photoluminescence. In this study, the nGOs were organically surface-modified with poly(ethylene glycol)-poly(ethylene imine) (PEG-PEI) copolymers tagged with folic acid as the affinity ligand for cancer cells expressing folate receptors. The functionalization enhanced both the cellular uptake and quantum efficiency of the photoluminescence as compared to non-modified nGOs. The nGOs exhibited an excitation dependent photoluminescence that facilitated their detection with a wide range of microscope configurations. The functionalized nGOs were non-toxic, they were retained in the stained cell population over a period of 8 days and they were distributed equally between daughter cells. We have evaluated their applicability in in vitro and in vivo (chicken embryo CAM) models to visualize and track migratory cancer cells. The good biocompatibility and easy detection of the functionalized nGOs suggest that they could address the limitations faced with quantum dots and organic fluorophores in long-term in vivo biomedical imaging.Recently reported photoluminescent nanographene oxides (nGOs), i.e. nanographene oxidised with a sulfuric/nitric acid mixture (SNOx method), have tuneable photoluminescence and are scalable, simple and fast to produce optical probes. This material belongs to the vast class of photoluminescent carbon nanostructures, including carbon dots, nanodiamonds (NDs), graphene quantum dots (GQDs), all of which demonstrate a variety of properties that are

  7. In vivo type 2 cannabinoid receptor-targeted tumor optical imaging using a near infrared fluorescent probe.

    Science.gov (United States)

    Zhang, Shaojuan; Shao, Pin; Bai, Mingfeng

    2013-11-20

    The type 2 cannabinoid receptor (CB2R) plays a vital role in carcinogenesis and progression and is emerging as a therapeutic target for cancers. However, the exact role of CB2R in cancer progression and therapy remains unclear. This has driven the increasing efforts to study CB2R and cancers using molecular imaging tools. In addition, many types of cancers overexpress CB2R, and the expression levels of CB2R appear to be associated with tumor aggressiveness. Such upregulation of the receptor in cancer cells provides opportunities for CB2R-targeted imaging with high contrast and for therapy with low side effects. In the present study, we report the first in vivo tumor-targeted optical imaging using a novel CB2R-targeted near-infrared probe. In vitro cell fluorescent imaging and a competitive binding assay indicated specific binding of NIR760-mbc94 to CB2R in CB2-mid delayed brain tumor (DBT) cells. NIR760-mbc94 also preferentially labeled CB2-mid DBT tumors in vivo, with a 3.7-fold tumor-to-normal contrast enhancement at 72 h postinjection, whereas the fluorescence signal from the tumors of the mice treated with NIR760 free dye was nearly at the background level at the same time point. SR144528, a CB2R competitor, significantly inhibited tumor uptake of NIR760-mbc94, indicating that NIR760-mbc94 binds to CB2R specifically. In summary, NIR760-mbc94 specifically binds to CB2R in vitro and in vivo and appears to be a promising molecular tool that may have great potential for use in diagnostic imaging of CB2R-positive cancers and therapeutic monitoring as well as in elucidating the role of CB2R in cancer progression and therapy.

  8. Numeric invariants from multidimensional persistence

    Energy Technology Data Exchange (ETDEWEB)

    Skryzalin, Jacek [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Carlsson, Gunnar [Stanford Univ., Stanford, CA (United States)

    2017-05-19

    In this paper, we analyze the space of multidimensional persistence modules from the perspectives of algebraic geometry. We first build a moduli space of a certain subclass of easily analyzed multidimensional persistence modules, which we construct specifically to capture much of the information which can be gained by using multidimensional persistence over one-dimensional persistence. We argue that the global sections of this space provide interesting numeric invariants when evaluated against our subclass of multidimensional persistence modules. Lastly, we extend these global sections to the space of all multidimensional persistence modules and discuss how the resulting numeric invariants might be used to study data.

  9. Optical probes in biology

    CERN Document Server

    Zhang, Jin; Schultz, Carsten

    2015-01-01

    Introduction and BasicsEngineering of Optimized Fluorescent Proteins: An Overview from a Cyan and FRET Perspective Lindsay Haarbosch, Joachim Goedhart, Mark A. Hink, Laura van Weeren, Daphne S. Bindels, and Theodorus W.J. GadellaFluorescent Imaging Techniques: FRET and Complementary Methods Stefan Terjung and Yury BelyaevTracking: Sensors for Tracking BiomoleculesProtein-Based Calcium Sensors Thomas Thestrup and Oliver GriesbeckMonitoring Membrane Lipids with Protein Domains Expressed in Living Cells Peter Varnai

  10. A comparative study of the enhancement of molecular emission in a spatially confined plume through optical emission spectroscopy and probe beam deflection measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Dayu; Liang, Peipei; Wu, Jiada; Xu, Ning; Ying, Zhifeng; Sun, Jian, E-mail: jsun@fudan.edu.cn

    2013-01-01

    The spatial confinement effects of shock wave on the expansion of a carbon plume induced by pulsed laser ablation of graphite in air and the enhancement of the plume emission were studied by optical emission spectroscopy and probe beam deflection measurements. A metal disk was set in the way of the ablation-generated shock wave to block and reflect the supersonically propagating shock wave. The reflected shock wave propagated backwards and confined the expanding plume. The optical emission of CN molecules was enhanced in contrast to the case without the block disk and the emission enhancement was dependent on the position of the disk. Based on the results of time-integrated and -resolved optical emission spectroscopy, and the time- and space-resolved probe beam deflection measurements, the processes occurring in the plume were discussed and the mechanisms responsible for the enhancement of molecular emission in the spatially confined plume were investigated. - Highlights: ► Spatial confinement and optical emission enhancement of carbon plume were studied. ► Ablation-generated shockwave propagating in air was reflected by a block disk. ► The effects of reflected shockwave on the emission enhancement were confirmed. ► The reflect shockwave confined the carbon plume and enhanced the plume emission.

  11. A comparative study of the enhancement of molecular emission in a spatially confined plume through optical emission spectroscopy and probe beam deflection measurements

    International Nuclear Information System (INIS)

    Ding, Dayu; Liang, Peipei; Wu, Jiada; Xu, Ning; Ying, Zhifeng; Sun, Jian

    2013-01-01

    The spatial confinement effects of shock wave on the expansion of a carbon plume induced by pulsed laser ablation of graphite in air and the enhancement of the plume emission were studied by optical emission spectroscopy and probe beam deflection measurements. A metal disk was set in the way of the ablation-generated shock wave to block and reflect the supersonically propagating shock wave. The reflected shock wave propagated backwards and confined the expanding plume. The optical emission of CN molecules was enhanced in contrast to the case without the block disk and the emission enhancement was dependent on the position of the disk. Based on the results of time-integrated and -resolved optical emission spectroscopy, and the time- and space-resolved probe beam deflection measurements, the processes occurring in the plume were discussed and the mechanisms responsible for the enhancement of molecular emission in the spatially confined plume were investigated. - Highlights: ► Spatial confinement and optical emission enhancement of carbon plume were studied. ► Ablation-generated shockwave propagating in air was reflected by a block disk. ► The effects of reflected shockwave on the emission enhancement were confirmed. ► The reflect shockwave confined the carbon plume and enhanced the plume emission

  12. Multidimensional nonlinear descriptive analysis

    CERN Document Server

    Nishisato, Shizuhiko

    2006-01-01

    Quantification of categorical, or non-numerical, data is a problem that scientists face across a wide range of disciplines. Exploring data analysis in various areas of research, such as the social sciences and biology, Multidimensional Nonlinear Descriptive Analysis presents methods for analyzing categorical data that are not necessarily sampled randomly from a normal population and often involve nonlinear relations. This reference not only provides an overview of multidimensional nonlinear descriptive analysis (MUNDA) of discrete data, it also offers new results in a variety of fields. The first part of the book covers conceptual and technical preliminaries needed to understand the data analysis in subsequent chapters. The next two parts contain applications of MUNDA to diverse data types, with each chapter devoted to one type of categorical data, a brief historical comment, and basic skills peculiar to the data types. The final part examines several problems and then concludes with suggestions for futu...

  13. Optical design for CETUS: a wide-field 1.5m aperture UV payload being studied for a NASA probe class mission study

    Science.gov (United States)

    Woodruff, Robert; Robert Woodruff, Goddard Space Flight Center, Kendrick Optical Consulting

    2018-01-01

    We are developing a NASA Headquarters selected Probe-class mission concept called the Cosmic Evolution Through UV Spectroscopy (CETUS) mission, which includes a 1.5-m aperture diameter large field-of-view (FOV) telescope optimized for UV imaging, multi-object spectroscopy, and point-source spectroscopy. The optical system includes a Three Mirror Anastigmatic (TMA) telescope that simultaneously feeds three separate scientific instruments: the near-UV (NUV) Multi-Object Spectrograph (MOS) with a next-generation Micro-Shutter Array (MSA); the two-channel camera covering the far-UV (FUV) and NUV spectrum; and the point-source spectrograph covering the FUV and NUV region with selectable R~ 40,000 echelle modes and R~ 2,000 first order modes. The optical system includes fine guidance sensors, wavefront sensing, and spectral and flat-field in-flight calibration sources. This paper will describe the current optical design of CETUS.

  14. The multidimensional nucleon structure

    Directory of Open Access Journals (Sweden)

    Pasquini Barbara

    2016-01-01

    Full Text Available We discuss different kinds of parton distributions, which allow one to obtain a multidimensional picture of the internal structure of the nucleon. We use the concept of generalized transverse momentum dependent parton distributions and Wigner distributions, which combine the features of transverse-momentum dependent parton distributions and generalized parton distributions. We show examples of these functions within a phenomenological quark model, with focus on the role of the spin-spin and spin-orbit correlations of quarks.

  15. Phase collapse and revival of a 1-mode Bose-Einstein condensate induced by an off-resonant optical probe field and superselection rules

    Science.gov (United States)

    Arruda, L. G. E.; Prataviera, G. A.; de Oliveira, M. C.

    2018-02-01

    Phase collapse and revival for Bose-Einstein condensates are nonlinear phenomena appearing due to atomic collisions. While it has been observed in a general setting involving many modes, for one-mode condensates its occurrence is forbidden by the particle number superselection rule (SSR), which arises because there is no phase reference available. We consider a single mode atomic Bose-Einstein condensate interacting with an off-resonant optical probe field. We show that the condensate phase revival time is dependent on the atom-light interaction, allowing optical control on the atomic collapse and revival dynamics. Incoherent effects over the condensate phase are included by considering a continuous photo-detection over the probe field. We consider conditioned and unconditioned photo-counting events and verify that no extra control upon the condensate is achieved by the probe photo-detection, while further inference of the atomic system statistics is allowed leading to a useful test of the SSR on particle number and its imposition on the kind of physical condensate state.

  16. Fiber-optic system for dual-modality imaging of glucose probes 18F-FDG and 6-NBDG in atherosclerotic plaques.

    Directory of Open Access Journals (Sweden)

    Raiyan T Zaman

    Full Text Available Atherosclerosis is a progressive inflammatory condition that underlies coronary artery disease (CAD-the leading cause of death in the United States. Thus, the ultimate goal of this research is to advance our understanding of human CAD by improving the characterization of metabolically active vulnerable plaques within the coronary arteries using a novel catheter-based imaging system. The aims of this study include (1 developing a novel fiber-optic imaging system with a scintillator to detect both 18F and fluorescent glucose probes, and (2 validating the system on ex vivo murine plaques.A novel design implements a flexible fiber-optic catheter consisting of both a radio-luminescence and a fluorescence imaging system to detect radionuclide 18F-fluorodeoxyglucose (18F-FDG and the fluorescent analog 6-(N-(7-Nitrobenz-2-oxa-1,3-diazol-4-ylamino-6-Deoxyglucose (6-NBDG, respectively. Murine macrophage-rich atherosclerotic carotid plaques were imaged ex vivo after intravenous delivery of 18F-FDG or 6-NBDG. Confirmatory optical imaging by IVIS-200 and autoradiography were also performed.Our fiber-optic imaging system successfully visualized both 18F-FDG and 6-NBDG probes in atherosclerotic plaques. For 18F-FDG, the ligated left carotid arteries (LCs exhibited 4.9-fold higher radioluminescence signal intensity compared to the non-ligated right carotid arteries (RCs (2.6 × 10(4 ± 1.4 × 10(3 vs. 5.4 × 10(3 ± 1.3 × 10(3 A.U., P = 0.008. Similarly, for 6-NBDG, the ligated LCs emitted 4.3-fold brighter fluorescent signals than the control RCs (1.6 × 10(2 ± 2.7 × 10(1 vs. 3.8 × 10(1 ± 5.9 A.U., P = 0.002. The higher uptake of both 18F-FDG and 6-NBDG in ligated LCs were confirmed with the IVIS-200 system. Autoradiography further verified the higher uptake of 18F-FDG by the LCs.This novel fiber-optic imaging system was sensitive to both radionuclide and fluorescent glucose probes taken up by murine atherosclerotic plaques. In addition, 6-NBDG is a

  17. Growth and decay dynamics of a stable microbubble produced at the end of a near-field scanning optical microscopy fiber probe

    International Nuclear Information System (INIS)

    Taylor, R.S.; Hnatovsky, C.

    2004-01-01

    Low power cw laser radiation coupled into a near-field scanning optical microscopy fiber probe has been used to generate a stable microbubble in water. A probe tip which was selectively chemically etched and metallized served as a microheater for the generation of the stable bubble. Bubble diameters in the range of 40-400 μm and lifetimes of over an hour have been obtained. The microbubble exhibited a linear growth phase over a period of a few seconds before reaching a maximum diameter which depended on the laser power. When the laser beam was blocked the microbubble decayed with a rate which was inversely proportional to the bubble diameter. The bubble lifetime depended on the square of the initial bubble diameter. Instabilities which transform a large stable bubble into a microjet stream of micron sized bubbles as the laser power was increased is also described

  18. Multidimensional Models of Information Need

    OpenAIRE

    Yun-jie (Calvin) Xu; Kai Huang (Joseph) Tan

    2009-01-01

    User studies in information science have recognised relevance as a multidimensional construct. An implication of multidimensional relevance is that a user's information need should be modeled by multiple data structures to represent different relevance dimensions. While the extant literature has attempted to model multiple dimensions of a user's information need, the fundamental assumption that a multidimensional model is better than a uni-dimensional model has not been addressed. This study ...

  19. Local pH Monitoring of Small Cluster of Cells using a Fiber-Optic Dual-Core Micro-Probe.

    Science.gov (United States)

    Chen, Sisi; Yang, Qingbo; Xiao, Hai; Shi, Honglan; Ma, Yinfa

    2017-03-31

    Biological studies of tissues and cells have enabled numerous discoveries, but these studies still bear potential risks of invalidation because of cell heterogeneity. Through high-accuracy techniques, recent studies have demonstrated that discrepancies do exist between the results from low-number-cell studies and cell-population-based results. Thus the urgent need to re-evaluate key principles on limited number of cells has been provoked. In this study, a novel designed dual-core fiber-optic pH micro-probe was fabricated and demonstrated for niche environment pH sensing with high spatial resolution. An organic-modified silicate (OrMoSils) sol-gel thin layer was functionalized by entrapping a pH indicator, 2', 7'-Bis (2-carbonylethyl)-5(6)-carboxyfluorescein (BCECF), on a ~70 μm sized probe tip. Good linear correlation between fluorescence ratio of I 560 nm /I 640 nm and intercellular pH values was obtained within a biological-relevant pH range from 6.20 to 7.92 (R 2 = 0.9834), and with a pH resolution of 0.035 ± 0.005 pH units. The probe's horizontal spatial resolution was demonstrated to be less than 2mm. Moreover, the probe was evaluated by measuring the localized extracellular pH changes of cultured human lung cancer cells (A549) when exposed to titanium dioxide nanoparticles (TiO 2 NPs). Results showed that the probe has superior capability for fast, local, and continual monitoring of a small cluster of cells, which provides researchers a fast and accurate technique to conduct local pH measurements for cell heterogeneity-related studies.

  20. Multidimensional sexual perfectionism.

    Science.gov (United States)

    Stoeber, Joachim; Harvey, Laura N; Almeida, Isabel; Lyons, Emma

    2013-11-01

    Perfectionism is a multidimensional personality characteristic that can affect all areas of life. This article presents the first systematic investigation of multidimensional perfectionism in the domain of sexuality exploring the unique relationships that different forms of sexual perfectionism show with positive and negative aspects of sexuality. A sample of 272 university students (52 male, 220 female) completed measures of four forms of sexual perfectionism: self-oriented, partner-oriented, partner-prescribed, and socially prescribed. In addition, they completed measures of sexual esteem, sexual self-efficacy, sexual optimism, sex life satisfaction (capturing positive aspects of sexuality) and sexual problem self-blame, sexual anxiety, sexual depression, and negative sexual perfectionism cognitions during sex (capturing negative aspects). Results showed unique patterns of relationships for the four forms of sexual perfectionism, suggesting that partner-prescribed and socially prescribed sexual perfectionism are maladaptive forms of sexual perfectionism associated with negative aspects of sexuality whereas self-oriented and partner-oriented sexual perfectionism emerged as ambivalent forms associated with positive and negative aspects.

  1. Broadband pump-probe spectroscopy with sub-10-fs resolution for probing ultrafast internal conversion and coherent phonons in carotenoids

    International Nuclear Information System (INIS)

    Polli, D.; Antognazza, M.R.; Brida, D.; Lanzani, G.; Cerullo, G.; De Silvestri, S.

    2008-01-01

    We use pump-probe spectroscopy with broadband detection to study electronic energy relaxation and coherent vibrational dynamics in carotenoids. A fast optical multichannel analyzer combined with a non-collinear optical parametric amplifier allows simultaneous acquisition of the differential transmission dynamics on the 500-700 nm wavelength range with sub-10-fs temporal resolution. The broad spectral coverage enables on the one hand a detailed study of the ultrafast bright-to-dark state internal conversion process; on the other hand, the tracking of the motion of the vibrational wavepacket launched on the ground state multidimensional potential energy surface. We present results on all-trans β-carotene and on a long-chain polyene in solution. The developed experimental setup enables the straightforward acquisition and analysis of coherent vibrational dynamics, highlighting time-frequency domain features with extreme resolution

  2. Combination probe for optically assisted ultrasonic velocity-change imaging aimed at detecting unstable blood vessel plaque

    Science.gov (United States)

    Tanigawa, Shohei; Mano, Kazune; Wada, Kenji; Matsunaka, Toshiyuki; Horinaka, Hiromichi

    2016-04-01

    Blood vessel plaque with a large lipid core is at risk of becoming thrombus and is likely to induce acute heart disease. To prevent this, it is necessary to determine not only the plaque's size but also its chemical composition. We, therefore, made the prototype of a combination probe to diagnose carotid artery plaque. It is used to differentiate propagation characteristics between light spectra and ultrasonic images. By propagating light and ultrasound along a common direction, it is possible to effectively warm the diagnosis domain. Moreover, the probe is thought to be compact and be easy to use for diagnosing human carotid artery plaque. We applied the combination probe to a carotid artery phantom with a lipid area and obtained an image of the ultrasonic velocity change in the fatty area.

  3. In vivo microvascular imaging of human oral and nasal cavities using swept-source optical coherence tomography with a single forward/side viewing probe

    Science.gov (United States)

    Choi, Woo June; Wang, Ruikang K.

    2015-03-01

    We report three-dimensional (3D) imaging of microcirculation within human cavity tissues in vivo using a high-speed swept-source optical coherence tomography (SS-OCT) at 1.3 μm with a modified probe interface. Volumetric structural OCT images of the inner tissues of oral and nasal cavities are acquired with a field of view of 2 mm x 2 mm. Two types of disposable and detachable probe attachments are devised and applied to the port of the imaging probe of OCT system, enabling forward and side imaging scans for selective and easy access to specific cavity tissue sites. Blood perfusion is mapped with OCT-based microangiography from 3D structural OCT images, in which a novel vessel extraction algorithm is used to decouple dynamic light scattering signals, due to moving blood cells, from the background scattering signals due to static tissue elements. Characteristic tissue anatomy and microvessel architectures of various cavity tissue regions of a healthy human volunteer are identified with the 3D OCT images and the corresponding 3D vascular perfusion maps at a level approaching capillary resolution. The initial finding suggests that the proposed method may be engineered into a promising tool for evaluating and monitoring tissue microcirculation and its alteration within a wide-range of cavity tissues in the patients with various pathological conditions.

  4. Shear force distance control in a scanning near-field optical microscope: in resonance excitation of the fiber probe versus out of resonance excitation

    International Nuclear Information System (INIS)

    Lapshin, D.A.; Letokhov, V.S.; Shubeita, G.T.; Sekatskii, S.K.; Dietler, G.

    2004-01-01

    The experimental results of the direct measurement of the absolute value of interaction force between the fiber probe of a scanning near-field optical microscope (SNOM) operated in shear force mode and a sample, which were performed using combined SNOM-atomic force microscope setup, are discussed for the out-of-resonance fiber probe excitation mode. We demonstrate that the value of the tapping component of the total force for this mode at typical dither amplitudes is of the order of 10 nN and thus is quite comparable with the value of this force for in resonance fiber probe excitation mode. It is also shown that for all modes this force component is essentially smaller than the usually neglected static attraction force, which is of the order of 200 nN. The true contact nature of the tip-sample interaction during the out of resonance mode is proven. From this, we conclude that such a detection mode is very promising for operation in liquids, where other modes encounter great difficulties

  5. The Effects of Heteroatoms Si and S on Tuning the Optical Properties of Rhodamine- and Fluorescein-Based Fluorescence Probes: A Theoretical Analysis.

    Science.gov (United States)

    Zhou, Panwang; Ning, Cai; Alsaedi, Ahmed; Han, Keli

    2016-10-05

    The effects of the incorporated heteroatoms Si and S on tuning the optical properties of rhodamine- and fluorescein-based fluorescence probes is investigated using DFT and time-dependent DFT with four different functionals. As previously proposed, the large redshift (90 nm) produced by a Si atom in both the absorption and emission spectra can be attributed to the σ*-π* conjugation between the σ* orbital of the Si atom and the π* orbital of the adjacent carbon atoms. However, the presence of a Si atom does not alter the fluorescence quenching mechanism of the nonfluorescent forms of the investigated compounds. For the first time, these theoretical results indicate that the n orbital of the S atom plays an important role in determining the optical properties of the nonfluorescent form of rhodamine-based fluorescence probes. It alters the fluorescence quenching mechanism by lowering the energy of the dark nπ* state, which is due to breakage of the C10-S52 bond upon photoexcitation. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Optimizing the fabrication of aluminum-coated fiber probes and their application to optical near-field lithography

    DEFF Research Database (Denmark)

    Madsen, S; Holme, NCR; Ramanujam, PS

    1998-01-01

    in terms of roughness and the presence of leaking holes in the coating. We report on how the quality of the coating depends on parameters such as deposition rate and background pressure during evaporation. We have used aluminum-coated fiber probes in lithographical studies of different materials, like side...

  7. [Intraoperative multidimensional visualization].

    Science.gov (United States)

    Sperling, J; Kauffels, A; Grade, M; Alves, F; Kühn, P; Ghadimi, B M

    2016-12-01

    Modern intraoperative techniques of visualization are increasingly being applied in general and visceral surgery. The combination of diverse techniques provides the possibility of multidimensional intraoperative visualization of specific anatomical structures. Thus, it is possible to differentiate between normal tissue and tumor tissue and therefore exactly define tumor margins. The aim of intraoperative visualization of tissue that is to be resected and tissue that should be spared is to lead to a rational balance between oncological and functional results. Moreover, these techniques help to analyze the physiology and integrity of tissues. Using these methods surgeons are able to analyze tissue perfusion and oxygenation. However, to date it is not clear to what extent these imaging techniques are relevant in the clinical routine. The present manuscript reviews the relevant modern visualization techniques focusing on intraoperative computed tomography and magnetic resonance imaging as well as augmented reality, fluorescence imaging and optoacoustic imaging.

  8. Multidimensional HAM-conditions

    DEFF Research Database (Denmark)

    Hansen, Ernst Jan de Place

    Heat, Air and Moisture (HAM) conditions, experimental data are needed. Tests were performed in the large climate simulator at SBi involving full-scale wall elements. The elements were exposed for steady-state conditions, and temperature cycles simulating April and September climate in Denmark....... The effect on the moisture and temperature conditions of the addition of a vapour barrier and an outer cladding on timber frame walls was studied. The report contains comprehensive appendices documenting the full-scale tests. The tests were performed as a part of the project 'Model for Multidimensional Heat......, Air and Moisture Conditions in Building Envelope Components' carried out as a co-project between DTU Byg and SBi....

  9. Multidimensional Databases and Data Warehousing

    CERN Document Server

    Jensen, Christian

    2010-01-01

    The present book's subject is multidimensional data models and data modeling concepts as they are applied in real data warehouses. The book aims to present the most important concepts within this subject in a precise and understandable manner. The book's coverage of fundamental concepts includes data cubes and their elements, such as dimensions, facts, and measures and their representation in a relational setting; it includes architecture-related concepts; and it includes the querying of multidimensional databases.The book also covers advanced multidimensional concepts that are considered to b

  10. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    Duvaa, Uffe; Ørngreen, Rikke; Weinkouff Mathiasen, Anne-Gitte

    2013-01-01

    Mobile probing is a method, developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time and space......). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings point...... to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face). The development...

  11. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    Duvaa, Uffe; Ørngreen, Rikke; Weinkouff, Anne-Gitte

    2012-01-01

    Mobile probing is a method, which has been developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time...... and space). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings...... point to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face...

  12. Probing the Optical Properties and Strain-Tuning of Ultrathin Mo1- xW xTe2.

    Science.gov (United States)

    Aslan, Ozgur Burak; Datye, Isha M; Mleczko, Michal J; Sze Cheung, Karen; Krylyuk, Sergiy; Bruma, Alina; Kalish, Irina; Davydov, Albert V; Pop, Eric; Heinz, Tony F

    2018-04-11

    Ultrathin transition metal dichalcogenides (TMDCs) have recently been extensively investigated to understand their electronic and optical properties. Here we study ultrathin Mo 0.91 W 0.09 Te 2 , a semiconducting alloy of MoTe 2 , using Raman, photoluminescence (PL), and optical absorption spectroscopy. Mo 0.91 W 0.09 Te 2 transitions from an indirect to a direct optical band gap in the limit of monolayer thickness, exhibiting an optical gap of 1.10 eV, very close to its MoTe 2 counterpart. We apply tensile strain, for the first time, to monolayer MoTe 2 and Mo 0.91 W 0.09 Te 2 to tune the band structure of these materials; we observe that their optical band gaps decrease by 70 meV at 2.3% uniaxial strain. The spectral widths of the PL peaks decrease with increasing strain, which we attribute to weaker exciton-phonon intervalley scattering. Strained MoTe 2 and Mo 0.91 W 0.09 Te 2 extend the range of band gaps of TMDC monolayers further into the near-infrared, an important attribute for potential applications in optoelectronics.

  13. Dynamic PET and Optical Imaging and Compartment Modeling using a Dual-labeled Cyclic RGD Peptide Probe

    OpenAIRE

    Zhu, Lei; Guo, Ning; Li, Quanzheng; Ma, Ying; Jacboson, Orit; Lee, Seulki; Choi, Hak Soo; Mansfield, James R.; Niu, Gang; Chen, Xiaoyuan

    2012-01-01

    Purpose: The aim of this study is to determine if dynamic optical imaging could provide comparable kinetic parameters to that of dynamic PET imaging by a near-infrared dye/64Cu dual-labeled cyclic RGD peptide. Methods: The integrin αvβ3 binding RGD peptide was conjugated with a macrocyclic chelator 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) for copper labeling and PET imaging and a near-infrared dye ZW-1 for optical imaging. The in vitro biological activity of RGD-C(DOTA)...

  14. Structure of multidimensional patterns

    International Nuclear Information System (INIS)

    Smith, S.P.

    1982-01-01

    The problem of describing the structure of multidimensional data is important in exploratory data analysis, statistical pattern recognition, and image processing. A data set is viewed as a collection of points embedded in a high dimensional space. The primary goal of this research is to determine if the data have any clustering structure; such a structure implies the presence of class information (categories) in the data. A statistical hypothesis is used in the decision making. To this end, data with no structure are defined as data following the uniform distribution over some compact convex set in K-dimensional space, called the sampling window. This thesis defines two new tests for uniformity along with various sampling window estimators. The first test is a volume-based test which captures density changes in the data. The second test compares a uniformly distributed sample to the data by using the minimal spanning tree (MST) of the polled samples. Sampling window estimators are provided for simple sampling windows and use the convex hull of the data as a general sampling window estimator. For both of the tests for uniformity, theoretical results are provided on their size, and study their size and power against clustered alternatives is studied. Simulation is also used to study the efficacy of the sampling window estimators

  15. Image-based overlay and alignment metrology through optically opaque media with sub-surface probe microscopy

    Science.gov (United States)

    van Es, Maarten H.; Mohtashami, Abbas; Piras, Daniele; Sadeghian, Hamed

    2018-03-01

    Nondestructive subsurface nanoimaging through optically opaque media is considered to be extremely challenging and is essential for several semiconductor metrology applications including overlay and alignment and buried void and defect characterization. The current key challenge in overlay and alignment is the measurement of targets that are covered by optically opaque layers. Moreover, with the device dimensions moving to the smaller nodes and the issue of the so-called loading effect causing offsets between between targets and product features, it is increasingly desirable to perform alignment and overlay on product features or so-called on-cell overlay, which requires higher lateral resolution than optical methods can provide. Our recently developed technique known as SubSurface Ultrasonic Resonance Force Microscopy (SSURFM) has shown the capability for high-resolution imaging of structures below a surface based on (visco-)elasticity of the constituent materials and as such is a promising technique to perform overlay and alignment with high resolution in upcoming production nodes. In this paper, we describe the developed SSURFM technique and the experimental results on imaging buried features through various layers and the ability to detect objects with resolution below 10 nm. In summary, the experimental results show that the SSURFM is a potential solution for on-cell overlay and alignment as well as detecting buried defects or voids and generally metrology through optically opaque layers.

  16. Active probing of cloud multiple scattering, optical depth, vertical thickness, and liquid water content using wide-angle imaging lidar

    Science.gov (United States)

    Love, Steven P.; Davis, Anthony B.; Rohde, Charles A.; Tellier, Larry; Ho, Cheng

    2002-09-01

    At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data on various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.

  17. Active probing of cloud multiple scattering, optical depth, vertical thickness, and liquid water content using wide-angle imaging LIDAR

    International Nuclear Information System (INIS)

    Love, Steven P.; Davis, Anthony B.; Rohde, Charles A.; Tellier, Larry L.; Ho, Cheng

    2002-01-01

    At most optical wavelengths, laser light in a cloud lidar experiment is not absorbed but merely scattered out of the beam, eventually escaping the cloud via multiple scattering. There is much information available in this light scattered far from the input beam, information ignored by traditional 'on-beam' lidar. Monitoring these off-beam returns in a fully space- and time-resolved manner is the essence of our unique instrument, Wide Angle Imaging Lidar (WAIL). In effect, WAIL produces wide-field (60-degree full-angle) 'movies' of the scattering process and records the cloud's radiative Green functions. A direct data product of WAIL is the distribution of photon path lengths resulting from multiple scattering in the cloud. Following insights from diffusion theory, we can use the measured Green functions to infer the physical thickness and optical depth of the cloud layer, and, from there, estimate the volume-averaged liquid water content. WAIL is notable in that it is applicable to optically thick clouds, a regime in which traditional lidar is reduced to ceilometry. Here we present recent WAIL data oti various clouds and discuss the extension of WAIL to full diurnal monitoring by means of an ultra-narrow magneto-optic atomic line filter for daytime measurements.

  18. Intra-Tissue Pressure Measurement in Ex Vivo Liver Undergoing Laser Ablation with Fiber-Optic Fabry-Perot Probe

    Directory of Open Access Journals (Sweden)

    Daniele Tosi

    2016-04-01

    Full Text Available We report the first-ever intra-tissue pressure measurement performed during 1064 nm laser ablation (LA of an ex vivo porcine liver. Pressure detection has been performed with a biocompatible, all-glass, temperature-insensitive Extrinsic Fabry-Perot Interferometry (EFPI miniature probe; the proposed methodology mimics in-vivo treatment. Four experiments have been performed, positioning the probe at different positions from the laser applicator tip (from 0.5 mm to 5 mm. Pressure levels increase during ablation time, and decrease with distance from applicator tip: the recorded peak parenchymal pressure levels range from 1.9 kPa to 71.6 kPa. Different pressure evolutions have been recorded, as pressure rises earlier in proximity of the tip. The present study is the first investigation of parenchymal pressure detection in liver undergoing LA: the successful detection of intra-tissue pressure may be a key asset for improving LA, as pressure levels have been correlated to scattered recurrences of tumors by different studies.

  19. Quantitative in situ monitoring of an elevated temperature reaction using a water-cooled mid-infrared fiber-optic probe.

    Science.gov (United States)

    Maclaurin, P; Crabb, N C; Wells, I; Worsfold, P J; Coombs, D

    1996-04-01

    A novel water-cooled mid-infrared fiber-optic probe is described which is heatable to 230 °C. The probe has chalcogenide fibers and a ZnSe internal reflection element and is compact and fully flexible, allowing access to a wide range of standard laboratory reaction vessels and fume cupboard arrangements. Performance is demonstrated via the in situ analysis of an acid-catalyzed esterification reaction in toluene at 110 °C, and the results are compared with those from a conventional extractive sampling loop flow cell arrangement. Particular emphasis is given to the quantitative interpretation of the spectroscopic data, using gas chromatographic reference data. Calibration data are presented for univariate and partial least squares models, with an emphasis on procedures for improving the quality of interpreparation calibration and prediction through the use of focused reference analysis regimes. Subset univariate procedures are presented that yield relative errors of spectroscopy combined with bias correction partial least squares procedures for the efficient in situ quantitative analysis of laboratory scale reactions.

  20. Reflection-mode micro-spherical fiber-optic probes for in vitro real-time and single-cell level pH sensing.

    Science.gov (United States)

    Yang, Qingbo; Wang, Hanzheng; Lan, Xinwei; Cheng, Baokai; Chen, Sisi; Shi, Honglan; Xiao, Hai; Ma, Yinfa

    2015-02-01

    pH sensing at the single-cell level without negatively affecting living cells is very important but still a remaining issue in the biomedical studies. A 70 μm reflection-mode fiber-optic micro-pH sensor was designed and fabricated by dip-coating thin layer of organically modified aerogel onto a tapered spherical probe head. A pH sensitive fluorescent dye 2', 7'-Bis (2-carbonylethyl)-5(6)-carboxyfluorescein (BCECF) was employed and covalently bonded within the aerogel networks. By tuning the alkoxide mixing ratio and adjusting hexamethyldisilazane (HMDS) priming procedure, the sensor can be optimized to have high stability and pH sensing ability. The in vitro real-time sensing capability was then demonstrated in a simple spectroscopic way, and showed linear measurement responses with a pH resolution up to an average of 0.049 pH unit within a narrow, but biological meaningful pH range of 6.12-7.81. Its novel characterizations of high spatial resolution, reflection mode operation, fast response and high stability, great linear response within biological meaningful pH range and high pH resolutions, make this novel pH probe a very cost-effective tool for chemical/biological sensing, especially within the single cell level research field.

  1. Electronic structure of ferromagnetic semiconductor Ga1-xMnxAs probed by sub-gap magneto-optical spectroscopy

    OpenAIRE

    Acbas, G.; Kim, M. -H.; Cukr, M.; Novak, V.; Scarpulla, M. A.; Dubon, O. D.; Jungwirth, T.; Sinova, Jairo; Cerne, J.

    2009-01-01

    We employ Faraday and Kerr effect spectroscopy in the infrared range to investigate the electronic structure of Ga1-xMnxAs near the Fermi energy. The band structure of this archetypical dilute-moment ferromagnetic semiconductor has been a matter of controversy, fueled partly by previous measurements of the unpolarized infrared absorption and their phenomenological impurity-band interpretation. The infrared magneto-optical effects we study arise directly from the spin-splitting of the carrier ...

  2. Probing the Diffuse Optical-IR Background with TeV Blazars Detected with the MAGIC Telescopes

    Energy Technology Data Exchange (ETDEWEB)

    Prandini, Elisa [Dipartimento di Fisica e Astronomia “G. Galilei”, University of Padova, Padua (Italy); Domínguez, Alberto [Departamento de Física Atómica, Universidad Complutense, Madrid (Spain); Fallah Ramazani, Vandad [Tuorla observatory, University of Turku, Turku (Finland); Hassan, Tarek [IFAE, The Barcelona Institute of Science and Technology, Bellaterra (Spain); Mazin, Daniel [Max Planck Institute for Physics, Munich (Germany); Institute for Cosmic Ray Research, University of Tokyo, Tokyo (Japan); Moralejo, Abelardo [IFAE, The Barcelona Institute of Science and Technology, Bellaterra (Spain); Nievas Rosillo, Mireia [Departamento de Física Atómica, Universidad Complutense, Madrid (Spain); Vanzo, Gaia; Vazquez Acosta, Monica, E-mail: prandini@pd.infn.it [Instituto de Astrofísica de Canarias, Tenerife (Spain); Departamento de Astrofisica, Universidad de La Laguna, Tenerife (Spain)

    2017-11-22

    Blazars are radio loud quasars whose jet points toward the observer. The observed emission is mostly non-thermal, dominated by the jet emission, and in some cases extends up to the very high energy gamma rays (VHE; E > 100 GeV). To date, more than 60 blazars have been detected at VHE mainly with ground-based imaging atmospheric Cherenkov telescopes (IACTs) such as MAGIC, H.E.S.S., and VERITAS. Energetic photons from a blazar may interact with the diffuse optical and IR background (the extragalactic background light, EBL) leaving an imprint on the blazar energy spectrum. This effect can be used to constrain the EBL, with basic assumptions on the intrinsic energy spectrum. Current generation of IACTs is providing valuable measurements of the EBL density and energy spectrum from optical to infrared frequencies. In this contribution, we present the latest results obtained with the data taken with the MAGIC telescopes: using 32 spectra from 12 blazars, the scale factor of the optical density predicted by the EBL model from Domínguez et al. (2011) is constrained to be 0.95 (+0.11, −0.12){sub stat} (+0.16, −0.07){sub sys}, where a value of 1 means the perfect match with the model.

  3. Probing the Diffuse Optical-IR Background with TeV Blazars Detected with the MAGIC Telescopes

    Directory of Open Access Journals (Sweden)

    Elisa Prandini

    2017-11-01

    Full Text Available Blazars are radio loud quasars whose jet points toward the observer. The observed emission is mostly non-thermal, dominated by the jet emission, and in some cases extends up to the very high energy gamma rays (VHE; E > 100 GeV. To date, more than 60 blazars have been detected at VHE mainly with ground-based imaging atmospheric Cherenkov telescopes (IACTs such as MAGIC, H.E.S.S., and VERITAS. Energetic photons from a blazar may interact with the diffuse optical and IR background (the extragalactic background light, EBL leaving an imprint on the blazar energy spectrum. This effect can be used to constrain the EBL, with basic assumptions on the intrinsic energy spectrum. Current generation of IACTs is providing valuable measurements of the EBL density and energy spectrum from optical to infrared frequencies. In this contribution, we present the latest results obtained with the data taken with the MAGIC telescopes: using 32 spectra from 12 blazars, the scale factor of the optical density predicted by the EBL model from Domínguez et al. (2011 is constrained to be 0.95 (+0.11, −0.12stat (+0.16, −0.07sys, where a value of 1 means the perfect match with the model.

  4. A disposable evanescent wave fiber optic sensor coated with a molecularly imprinted polymer as a selective fluorescence probe.

    Science.gov (United States)

    Ton, Xuan-Anh; Acha, Victor; Bonomi, Paolo; Tse Sum Bui, Bernadette; Haupt, Karsten

    2015-02-15

    We have developed a disposable evanescent wave fiber optic sensor by coating a molecularly imprinted polymer (MIP) containing a fluorescent signaling group on a 4-cm long polystyrene optical waveguide. The MIP is composed of a naphthalimide-based fluorescent monomer, which shows fluorescence enhancement upon binding with carboxyl-containing molecules. The herbicide 2,4-dichlorophenoxyacetic acid and the mycotoxin citrinin were used as model analytes. The coating of the MIP was either performed ex-situ, by dip-coating the fiber with MIP particles synthesized beforehand, or in-situ by evanescent-wave photopolymerization on the fiber. The sensing element was interrogated with a fiber-coupled spectrofluorimeter. The fiber optic sensor detects targets in the low nM range and exhibits specific and selective recognition over structural analogs and non-related carboxyl-containing molecules. This technology can be extended to other carboxyl-containing analytes, and to a broader spectrum of targets using different fluorescent monomers. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Optics

    CERN Document Server

    Mathieu, Jean Paul

    1975-01-01

    Optics, Parts 1 and 2 covers electromagnetic optics and quantum optics. The first part of the book examines the various of the important properties common to all electromagnetic radiation. This part also studies electromagnetic waves; electromagnetic optics of transparent isotropic and anisotropic media; diffraction; and two-wave and multi-wave interference. The polarization states of light, the velocity of light, and the special theory of relativity are also examined in this part. The second part is devoted to quantum optics, specifically discussing the classical molecular theory of optical p

  6. Electron charge and spin delocalization revealed in the optically probed longitudinal and transverse spin dynamics in n -GaAs

    Science.gov (United States)

    Belykh, V. V.; Kavokin, K. V.; Yakovlev, D. R.; Bayer, M.

    2017-12-01

    The evolution of the electron spin dynamics as consequence of carrier delocalization in n -type GaAs is investigated by the recently developed extended pump-probe Kerr/Faraday rotation spectroscopy. We find that isolated electrons localized on donors demonstrate a prominent difference between the longitudinal and transverse spin relaxation rates in a magnetic field, which is almost absent in the metallic phase. The inhomogeneous transverse dephasing time T2* of the spin ensemble strongly increases upon electron delocalization as a result of motional narrowing that can be induced by increasing either the donor concentration or the temperature. An unexpected relation between T2* and the longitudinal spin relaxation time T1 is found, namely, that their product is about constant, as explained by the magnetic field effect on the spin diffusion. We observe a two-stage longitudinal spin relaxation, which suggests the establishment of spin temperature in the system of exchange-coupled donor-bound electrons.

  7. A novel inter-fibre light coupling sensor probe using plastic optical fibre for ethanol concentration monitoring at initial production rate

    Science.gov (United States)

    Memon, Sanober F.; Lewis, Elfed; Pembroke, J. Tony; Chowdhry, Bhawani S.

    2017-04-01

    A novel, low cost and highly sensitive optical fibre probe sensor for concentration measurement of ethanol solvent (C2H5OH) corresponding to bio-ethanol production rate by an algae is reported. The principle of operation of the sensor is based on inter-fibre light coupling through an evanescent field interaction to couple the light between two multimode fibres mounted parallel to each other at a minimum possible separation i.e. plastic optical fibre (POF) and was characterized for real time measurement in the broadband spectrum including visible and near infra-red. The wavelength dependency of this sensor design was also investigated by post processing analysis of real time data and hence the optimum wavelength range determined. The proposed sensor has shown significant response in the range of 0.005 - 0.1 %v/v (%volume/volume or volume concentration) which depicts the high sensitivity for monitoring very minute changes in concentration corresponding refractive index changes of the solution. Numerically, sensor has shown the sensitivity of 21945 intensity counts/%v/v or 109.7 counts per every 0.0050 %v/v.

  8. Experimental and density functional theory (DFT): A dual approach to probe the key properties of creatininium L-tartrate monohydrate single crystal for nonlinear optical applications

    Science.gov (United States)

    Thirumurugan, R.; Babu, B.; Anitha, K.; Chandrasekaran, J.

    2017-12-01

    A novel organic nonlinear optical (NLO) material, creatininium L-tartrate monohydrate (CTM) was synthesized and it was grown as single crystals with optical quality. 1H and 13C NMR spectral studies were performed and molecular structure of synthesized CTM compound was confirmed. Single crystal X-ray diffraction (SXRD) analysis confirmed that CTM was crystallized in orthorhombic system with non-centrosymmetric (NCS), P212121, space group. The grown crystal exhibited admirable properties such as second harmonic generation efficiency (SHG) (1.9 times KDP), and high laser damage threshold (LDT) value of 3.7 GW cm-2. CTM crystal displayed high transparency (∼60%) in the visible and near-IR region with low cut-off wavelength at 249 nm. Photoluminescence study confirmed blue wavelength emission (∼463 nm) of grown crystal. Thermal and mechanical behaviours have been successfully analysed for grown crystals. The dielectric studies were carried out for grown crystal as a function of frequencies at different temperatures. Hirshfeld surface and fingerprint plots provided the percentage of individual interactions contributed by each atom. Moreover, density functional theory (DFT) calculations have been employed to probe the frontier molecular orbitals (FMOs) and first hyperpolarizability (β) analysis of the optimized CTM structure. These results validated CTM as a suitable NLO candidate and were discussed in this work.

  9. Reconfiguration of the multiwavelength operation of optical fiber ring lasers by the modifiable intra-cavity induced losses of an in-fiber tip probe modal Michelson interferometer

    Science.gov (United States)

    Salceda-Delgado, G.; Martinez-Rios, A.; Sierra-Hernandez, J. M.; Rodríguez-Carreón, V. C.; Toral-Acosta, D.; Selvas-Aguilar, R.; Álvarez-Tamayo, R. I.; Castillo-Guzman, A. A.; Rojas-Laguna, R.

    2018-03-01

    A straightforward and versatile method for switching from single to different multiwavelength laser emission in ring cavity fiber lasers is proposed and demonstrated experimentally. The method is based on using the changeable interference pattern from an optical fiber modal Michelson interferometer as a wavelength selective filter into the ring cavity laser. The interferometer is constructed using a bi-conical tapered fiber and a single-mode fiber segment, with these being spliced together to form an optical fiber tip probe. When the length of the single-mode fiber piece is modified, the phase difference between the interfering modes of the interferometer causes a change in the interferometer free spectral range. As a consequence, the laser intra-cavity losses lead to gain competition, which allows us to adjust the number of simultaneously generated laser lines. A multiwavelength reconfiguration of the laser from one up to a maximum of eight emission lines was obtained, with a maximum SNR of around 47 dBm.

  10. Portable laser synthesizer for high-speed multi-dimensional spectroscopy

    Science.gov (United States)

    Demos, Stavros G [Livermore, CA; Shverdin, Miroslav Y [Sunnyvale, CA; Shirk, Michael D [Brentwood, CA

    2012-05-29

    Portable, field-deployable laser synthesizer devices designed for multi-dimensional spectrometry and time-resolved and/or hyperspectral imaging include a coherent light source which simultaneously produces a very broad, energetic, discrete spectrum spanning through or within the ultraviolet, visible, and near infrared wavelengths. The light output is spectrally resolved and each wavelength is delayed with respect to each other. A probe enables light delivery to a target. For multidimensional spectroscopy applications, the probe can collect the resulting emission and deliver this radiation to a time gated spectrometer for temporal and spectral analysis.

  11. PROBING X-RAY ABSORPTION AND OPTICAL EXTINCTION IN THE INTERSTELLAR MEDIUM USING CHANDRA OBSERVATIONS OF SUPERNOVA REMNANTS

    Energy Technology Data Exchange (ETDEWEB)

    Foight, Dillon R.; Slane, Patrick O. [Smithsonian Astrophysical Observatory, 60 Garden Street, Cambridge, MA 02138 (United States); Güver, Tolga [Istanbul University, Science Faculty, Department of Astronomy and Space Sciences, Beyazıt, 34119, Istanbul (Turkey); Özel, Feryal [Department of Astronomy, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States)

    2016-07-20

    We present a comprehensive study of interstellar X-ray extinction using the extensive Chandra supernova remnant (SNR) archive and use our results to refine the empirical relation between the hydrogen column density and optical extinction. In our analysis, we make use of the large, uniform data sample to assess various systematic uncertainties in the measurement of the interstellar X-ray absorption. Specifically, we address systematic uncertainties that originate from (i) the emission models used to fit SNR spectra; (ii) the spatial variations within individual remnants; (iii) the physical conditions of the remnant such as composition, temperature, and non-equilibrium regions; and (iv) the model used for the absorption of X-rays in the interstellar medium. Using a Bayesian framework to quantify these systematic uncertainties, and combining the resulting hydrogen column density measurements with the measurements of optical extinction toward the same remnants, we find the empirical relation N {sub H} = (2.87 ± 0.12) × 10{sup 21} A {sub V} cm{sup 2}, which is significantly higher than the previous measurements.

  12. Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

    Energy Technology Data Exchange (ETDEWEB)

    Fehm, Thomas Felix; Razansky, Daniel, E-mail: dr@tum.de [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany); Faculty of Medicine, Technische Universität München, Munich (Germany); Deán-Ben, Xosé Luís [Institute for Biological and Medical Imaging (IBMI), Helmholtz Zentrum München, Neuherberg (Germany)

    2014-10-27

    Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

  13. Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

    Science.gov (United States)

    Fehm, Thomas Felix; Deán-Ben, Xosé Luís; Razansky, Daniel

    2014-10-01

    Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

  14. Four dimensional hybrid ultrasound and optoacoustic imaging via passive element optical excitation in a hand-held probe

    International Nuclear Information System (INIS)

    Fehm, Thomas Felix; Razansky, Daniel; Deán-Ben, Xosé Luís

    2014-01-01

    Ultrasonography and optoacoustic imaging share powerful advantages related to the natural aptitude for real-time image rendering with high resolution, the hand-held operation, and lack of ionizing radiation. The two methods also possess very different yet highly complementary advantages of the mechanical and optical contrast in living tissues. Nonetheless, efficient integration of these modalities remains challenging owing to the fundamental differences in the underlying physical contrast, optimal signal acquisition, and image reconstruction approaches. We report on a method for hybrid acquisition and reconstruction of three-dimensional pulse-echo ultrasound and optoacoustic images in real time based on passive ultrasound generation with an optical absorber, thus avoiding the hardware complexity of active ultrasound generation. In this way, complete hybrid datasets are generated with a single laser interrogation pulse, resulting in simultaneous rendering of ultrasound and optoacoustic images at an unprecedented rate of 10 volumetric frames per second. Performance is subsequently showcased in phantom experiments and in-vivo measurements from a healthy human volunteer, confirming general clinical applicability of the method.

  15. Single-cell adhesion probed in-situ using optical tweezers: A case study with Saccharomyces cerevisiae

    Science.gov (United States)

    Castelain, Mickaël; Rouxhet, Paul G.; Pignon, Frédéric; Magnin, Albert; Piau, Jean-Michel

    2012-06-01

    A facile method of using optical trapping to measure cell adhesion forces is presented and applied to the adhesion of Saccharomyces cerevisiae on glass, in contact with solutions of different compositions. Trapping yeast cells with optical tweezers (OT) is not perturbed by cell wall deformation or cell deviation from a spherical shape. The trapping force calibration requires correction not only for the hydrodynamic effect of the neighboring wall but also for spherical aberrations affecting the focal volume and the trap stiffness. Yeast cells trapped for up to 5 h were still able to undergo budding but showed an increase of doubling time. The proportion of adhering cells showed the expected variation according to the solution composition. The detachment force varied in the same way. This observation and the fact that the detachment stress was exerted parallel to the substrate surface point to the role of interactions involving solvated macromolecules. Both the proportion of adhering cells and the removal force showed a distribution which, in our experimental conditions, must be attributed to a heterogeneity of surface properties at the cell level or at the subcellular scale. As compared with magnetic tweezers, atomic force microscopy, and more conventional ways of studying cell adhesion (shear-flow cells), OT present several advantages that are emphasized in this paper.

  16. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Ninth Edition Optics: Ninth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommen

  17. Ultrafast supercontinuum fiber-laser based pump-probe scanning magneto-optical Kerr effect microscope for the investigation of electron spin dynamics in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution.

    Science.gov (United States)

    Henn, T; Kiessling, T; Ossau, W; Molenkamp, L W; Biermann, K; Santos, P V

    2013-12-01

    We describe a two-color pump-probe scanning magneto-optical Kerr effect microscope which we have developed to investigate electron spin phenomena in semiconductors at cryogenic temperatures with picosecond time and micrometer spatial resolution. The key innovation of our microscope is the usage of an ultrafast "white light" supercontinuum fiber-laser source which provides access to the whole visible and near-infrared spectral range. Our Kerr microscope allows for the independent selection of the excitation and detection energy while avoiding the necessity to synchronize the pulse trains of two separate picosecond laser systems. The ability to independently tune the pump and probe wavelength enables the investigation of the influence of excitation energy on the optically induced electron spin dynamics in semiconductors. We demonstrate picosecond real-space imaging of the diffusive expansion of optically excited electron spin packets in a (110) GaAs quantum well sample to illustrate the capabilities of the instrument.

  18. Evaluating dark energy probes using multidimensional dark energy parameters

    International Nuclear Information System (INIS)

    Albrecht, Andreas; Bernstein, Gary

    2007-01-01

    We investigate the value of future dark-energy experiments by modeling their ability to constrain the dark-energy equation of state. Similar work was recently reported by the Dark Energy Task Force (DETF) using a two dimensional parameterization of the equation-of-state evolution. We examine constraints in a nine-dimensional dark-energy parameterization, and find that the best experiments constrain significantly more than two dimensions in our 9D space. Consequently the impact of these experiments is substantially beyond that revealed in the DETF analysis, and the estimated cost per 'impact' drops by about a factor of 10 as one moves to the very best experiments. The DETF conclusions about the relative value of different techniques and of the importance of combining techniques are unchanged by our analysis

  19. Contributions to multidimensional quadrature formulas

    International Nuclear Information System (INIS)

    Guenther, C.

    1976-11-01

    The general objective of this paper is to construct multidimensional quadrature formulas similar to the Gaussian Quadrature Formulas in one dimension. The correspondence between these formulas and orthogonal and nonnegative polynomials is established. One part of the paper considers the construction of multidimensional quadrature formulas using only methods of algebraic geometry, on the other part it is tried to obtain results on quadrature formulas with real nodes and, if possible, with positive weights. The results include the existence of quadrature formulas, information on the number resp. on the maximum possible number of points in the formulas for given polynomial degree N and the construction of formulas. (orig.) [de

  20. Multi-Dimensional Path Queries

    DEFF Research Database (Denmark)

    Bækgaard, Lars

    1998-01-01

    to create nested path structures. We present an SQL-like query language that is based on path expressions and we show how to use it to express multi-dimensional path queries that are suited for advanced data analysis in decision support environments like data warehousing environments......We present the path-relationship model that supports multi-dimensional data modeling and querying. A path-relationship database is composed of sets of paths and sets of relationships. A path is a sequence of related elements (atoms, paths, and sets of paths). A relationship is a binary path...

  1. Multidimensional real analysis I differentiation

    CERN Document Server

    Duistermaat, J J; van Braam Houckgeest, J P

    2004-01-01

    Part one of the authors' comprehensive and innovative work on multidimensional real analysis. This book is based on extensive teaching experience at Utrecht University and gives a thorough account of differential analysis in multidimensional Euclidean space. It is an ideal preparation for students who wish to go on to more advanced study. The notation is carefully organized and all proofs are clean, complete and rigorous. The authors have taken care to pay proper attention to all aspects of the theory. In many respects this book presents an original treatment of the subject and it contains man

  2. In situ optical sequencing and structure analysis of a trinucleotide repeat genome region by localization microscopy after specific COMBO-FISH nano-probing

    Science.gov (United States)

    Stuhlmüller, M.; Schwarz-Finsterle, J.; Fey, E.; Lux, J.; Bach, M.; Cremer, C.; Hinderhofer, K.; Hausmann, M.; Hildenbrand, G.

    2015-10-01

    Trinucleotide repeat expansions (like (CGG)n) of chromatin in the genome of cell nuclei can cause neurological disorders such as for example the Fragile-X syndrome. Until now the mechanisms are not clearly understood as to how these expansions develop during cell proliferation. Therefore in situ investigations of chromatin structures on the nanoscale are required to better understand supra-molecular mechanisms on the single cell level. By super-resolution localization microscopy (Spectral Position Determination Microscopy; SPDM) in combination with nano-probing using COMBO-FISH (COMBinatorial Oligonucleotide FISH), novel insights into the nano-architecture of the genome will become possible. The native spatial structure of trinucleotide repeat expansion genome regions was analysed and optical sequencing of repetitive units was performed within 3D-conserved nuclei using SPDM after COMBO-FISH. We analysed a (CGG)n-expansion region inside the 5' untranslated region of the FMR1 gene. The number of CGG repeats for a full mutation causing the Fragile-X syndrome was found and also verified by Southern blot. The FMR1 promotor region was similarly condensed like a centromeric region whereas the arrangement of the probes labelling the expansion region seemed to indicate a loop-like nano-structure. These results for the first time demonstrate that in situ chromatin structure measurements on the nanoscale are feasible. Due to further methodological progress it will become possible to estimate the state of trinucleotide repeat mutations in detail and to determine the associated chromatin strand structural changes on the single cell level. In general, the application of the described approach to any genome region will lead to new insights into genome nano-architecture and open new avenues for understanding mechanisms and their relevance in the development of heredity diseases.

  3. Optics

    CERN Document Server

    Fincham, W H A

    2013-01-01

    Optics: Eighth Edition covers the work necessary for the specialization in such subjects as ophthalmic optics, optical instruments and lens design. The text includes topics such as the propagation and behavior of light; reflection and refraction - their laws and how different media affect them; lenses - thick and thin, cylindrical and subcylindrical; photometry; dispersion and color; interference; and polarization. Also included are topics such as diffraction and holography; the limitation of beams in optical systems and its effects; and lens systems. The book is recommended for engineering st

  4. Nonlinear optical probe of biopolymer adsorption on colloidal particle surface: poly-L-lysine on polystyrene sulfate microspheres.

    Science.gov (United States)

    Eckenrode, Heather M; Dai, Hai-Lung

    2004-10-12

    A nonlinear optical technique--second harmonic generation (SHG)--has been applied to characterize the adsorption of poly-L-lysine on micrometer size polystyrene particles, whose surface is covered with negatively charged sulfonate groups, in aqueous solutions. Adsorption behavior of the biopolymer with two chain lengths (14 and 75 amino acid units; PL14 and PL75) has been examined. Centrifugation experiments were also performed to support the adsorption measurements made using SHG. The adsorption free energies of the two polymers PL75 and PL14 are determined as -16.57 and -14.40 kcal/mol, respectively. The small difference in the adsorption free energies of the two chain lengths, however, leads to dramatic difference in the concentration needed for saturated surface coverage: nearly 50 times higher concentration is needed for the smaller polymer. Under acidic colloidal conditions, polylysine is found to adsorb in a relatively flat conformation on the surface. The surface area that each polylysine molecule occupies is nearly 1 order of magnitude larger than the size of the molecule in its extended form. The low adsorption density is likely a result from Coulombic repulsion between the positive charges on the amino acid units of PL. The measurements demonstrate the utility of SHG as an efficient and sensitive experimental approach for measuring adsorption characteristics of bio/macromolecules on colloidal particles and define surface and colloidal conditions for achieving maximum surface coverage of a widely used biopolymer. Copyright 2004 American Chemical Society

  5. Simple-structured, hydrazinecarbothioamide derivatived dual-channel optical probe for Hg{sup 2+} and Ag{sup +}

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Wei [Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Key Laboratory of Oil & Gas Fine Chemicals, Ministry of Education, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 83004 (China); Chen, Yabin [Key Laboratory of Oil & Gas Fine Chemicals, Ministry of Education, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 83004 (China); Chen, Xin [Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Xie, Zhengfeng, E-mail: xiezhf@swpu.edu.cn [Oil & Gas Field Applied Chemistry Key Laboratory of Sichuan Province, School of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu 610500 (China); Key Laboratory of Oil & Gas Fine Chemicals, Ministry of Education, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 83004 (China); Hui, Yonghai [Key Laboratory of Oil & Gas Fine Chemicals, Ministry of Education, College of Chemistry and Chemical Engineering, Xinjiang University, Urumqi 83004 (China)

    2016-06-15

    A type of simple-structured, hydrazinecarbothioamide-containing Schiff-base derivative, 2-(4-(diphenylamino)benzylidene)hydrazinecarbothioamide (M1), was synthesized through condensation reaction between 4-(diphenylamino)benzaldehyde and thiosemicarbazide. In the mixture of DMSO/H{sub 2}O (DMSO/H{sub 2}O=9:1(v:v), pH=4.5), distinct “turn-off” fluorescence alterations of M1 were observed upon the addition of Hg{sup 2+}, and the addition of Ag{sup +} induced fluorescence bathochromic shift. The detection limits of Hg{sup 2+} and Ag{sup +} reach~0.19 μM and ~0.59 μM, respectively, as evaluated by the detailed fluorescence response of M1 toward incremental target ions. The different extent of photo-induced electron transfer (PET) between M1 and these two ions might be the plausible reason for such different optical response behaviors. - Highlights: • Hydrazinecarbothioamide-containing Schiff-base derivative (M1) was synthesized. • “Turn-off” fluorescence alterations of M1 were observed upon the addition of Hg{sup 2+}. • The addition of Ag{sup +} induced fluorescence bathochromic shift of M1. • Detection limits of Hg{sup 2+} and Ag{sup +} reaches ~0.19 μM and ~0.59 μM, respectively. • Hg{sup 2+} and Ag{sup +} can be detected in independent channels by M1 thus.

  6. A Multidimensional Software Engineering Course

    Science.gov (United States)

    Barzilay, O.; Hazzan, O.; Yehudai, A.

    2009-01-01

    Software engineering (SE) is a multidimensional field that involves activities in various areas and disciplines, such as computer science, project management, and system engineering. Though modern SE curricula include designated courses that address these various subjects, an advanced summary course that synthesizes them is still missing. Such a…

  7. Multidimensional Databases and Data Warehousing

    DEFF Research Database (Denmark)

    Jensen, Christian S.; Pedersen, Torben Bach; Thomsen, Christian

    The present book's subject is multidimensional data models and data modeling concepts as they are applied in real data warehouses. The book aims to present the most important concepts within this subject in a precise and understandable manner. The book's coverage of fundamental concepts includes...

  8. Recycling Behavior: A Multidimensional Approach

    Science.gov (United States)

    Meneses, Gonzalo Diaz; Palacio, Asuncion Beerli

    2005-01-01

    This work centers on the study of consumer recycling roles to examine the sociodemographic and psychographic profile of the distribution of recycling tasks and roles within the household. With this aim in mind, an empirical work was carried out, the results of which suggest that recycling behavior is multidimensional and comprises the undertaking…

  9. Sol-gel based optical sensor for determination of Fe (II): a novel probe for iron speciation.

    Science.gov (United States)

    Samadi-Maybodi, Abdolraouf; Rezaei, Vida; Rastegarzadeh, Saadat

    2015-02-05

    A highly selective optical sensor for Fe (II) ions was developed based on entrapment of a sensitive reagent, 2,4,6-tri(2-pyridyl)-s-triazine (TPTZ), in a silica sol-gel thin film coated on a glass substrate. The thin films fabricated based on tetraethoxysilane (TEOS) as precursor, sol-gel pH∼3, water:alkoxyde ratio of 4:1 and TPTZ concentration of 0.112 mol L(-1). The influence of sol-gel parameters on sensing behavior of the fabricated sensor was also investigated. The fabricated sensor can be used for determination of Fe (II) ion with an outstanding high selectivity over a dynamic range of 5-115 ng mL(-1) and a detection limit of 1.68 ng mL(-1). It also showed reproducible results with relative standard deviation of 3.5% and 1.27% for 10 and 90 ng mL(-1) of Fe (II), respectively, along with a fast response time of ∼120 s. Total iron also was determined after reduction of Fe (III) to Fe (II) using ascorbic acid as reducing agent. Then, the concentration of Fe (III) was calculated by subtracting the concentration of Fe (II) from the total iron concentration. Interference studies showed a good selectivity for Fe (II) with trapping TPTZ into sol-gel matrix and appropriately adjusting the structure of doped sol-gel. The sensor was compared with other sensors and was applied to determine iron in different water samples with good results. Copyright © 2014 Elsevier B.V. All rights reserved.

  10. Self-excited multi-scale skin vibrations probed by optical tracking micro-motions of tracers on arms

    Science.gov (United States)

    Chen, Wei-Chia; Chen, Hsiang-Ying; Chen, Yu-Sheng; Tian, Yong; I, Lin

    2017-07-01

    The self-excited multi-scale mechanical vibrations, their sources and their mutual coupling of different regions on the forearms of supine subjects, are experimentally investigated, using a simple noncontact method, optical video microscopy, which provides 1 μm and 25 ms spatiotemporal resolutions. It is found that, in proximal regions far from the radial artery, the vibrations are the global vibrations of the entire forearm excited by remote sources, propagating through the trunk and the limb. The spectrum is mainly composed of peaks of very low frequency motion (down to 0.05 Hz), low frequency respiration modes, and heartbeat induced modes (about 1 Hz and its harmonics), standing out of the spectrum floor exhibiting power law decay. The nonlinear mode-mode coupling leads to the cascaded modulations of higher frequency modes by lower frequency modes. The nearly identical waveforms without detectable phase delays for a pair of signals along or transverse to the meridian of regions far away from the artery rule out the detectable contribution from the propagation of Qi, some kind of collective excitation which more efficiently propagates along meridians, according to the Chinese medicine theory. Around the radial artery, in addition to the global vibration, the local vibration spectrum shows very slow breathing type vibration around 0.05 Hz, and the artery pulsation induced fundamental and higher harmonics with descending intensities up to the fifth harmonics, standing out of a flat spectrum floor. All the artery pulsation modes are also modulated by respiration and the very slow vibration.

  11. Impact of Different H/D Ratio on Axial Gas Holdup Measured by Four-Tips Optical Fiber Probe in Slurry Bubble Column

    Directory of Open Access Journals (Sweden)

    Yasser Imad Abdulaziz

    2016-02-01

    Full Text Available In wide range of chemical, petrochemical and energy processes, it is not possible to manage without slurry bubble column reactors. In this investigation, time average local gas holdup was recorded for three different height to diameter (H/D ratios 3, 4 and 5 in 18" diameter slurry bubble column. Air-water-glass beads system was used with superficial velocity up to 0.24 m/s. the gas holdup was measured using 4-tips optical fiber probe technique. The results show that the axial gas holdup increases almost linearly with the superficial gas velocity in 0.08 m/s and levels off with a further increase of velocity. A comparison of the present data with those reported for other slurry bubble column having diameters larger than 18" and H/D higher than 5 indicated that there is little effect of diameter on gas holdup. Also, local section-average gas holdups increase with increasing superficial gas velocity, while the effect of solid loading are less significant than that of superficial gas velocity.

  12. Optical probes of symmetry breaking in magnetic and superconducting BaFe2(As1-xPx)2

    Science.gov (United States)

    Orenstein, Joseph

    The discovery of iron pnictide superconductors has opened promising new directions in the effort to fully understand the phenomenon of high-Tc, with a focus on the connections between superconductivity, magnetism, and electronic nematicity. The BaFe2(As1-xPx)2 (P:Ba122) system in particular has received attention because isovalent substitution of As for P generates less disorder than doping on the Fe site. The phase diagram of P:Ba122 is characterized by a line of simultaneous antiferromagnetic (AF) and tetragonal-to-orthorhombic transitions, Ts (x) , that penetrates the superconducting dome at x =0.28, just below optimal doping (xopt = 0.30). In this work, we use spatially-resolved optical polarimetry and photomodulated reflectance to detect linear birefringence and therefore breaking of 4-fold rotational (C4) symmetry. In underdoped (xTsand grows continuously with decreasing T . The birefringence is unidirectional in a large (300 μm x300 μm) field of view, suggesting that C4 breaking in this range of T is caused by residual strain that couples to a diverging nematic susceptibility. Birefringence maps just below Ts (x) show the appearance of domains, indicating the onset of spontaneous symmetry breaking to an AF ground state. Surprisingly, in samples with x>0.28, in which the low T phase is superconducting/ tetragonal rather than AF/orthorhombic, C4 breaking is observed as well, with an abrupt onset and domain formation at 55 K. We tentatively associate these features with a transition to an AF phase induced by residual strain, as previously proposed [H.-H. Kuo et al. Phys. Rev. B86, 134507 (2012)] to account for structure in resistivity vs. T. Time-resolved photomodulation allow us to follow the amplitude of the AF order with time following pulsed photoexcitation. Below Tc the AF order at first weakens , but then strengthens in response to the photoinduced weakening of superconductivity. This complex time evolution is accounted for quantitatively by a model

  13. Phosphate-based glass fiber vs. bulk glass: Change in fiber optical response to probe in vitro glass reactivity.

    Science.gov (United States)

    Massera, J; Ahmed, I; Petit, L; Aallos, V; Hupa, L

    2014-04-01

    This paper investigates the effect of fiber drawing on the thermal and structural properties as well as on the glass reactivity of a phosphate glass in tris(hydroxymethyl)aminomethane-buffered (TRIS) solution and simulated body fluid (SBF). The changes induced in the thermal properties suggest that the fiber drawing process leads to a weakening and probable re-orientation of the POP bonds. Whereas the fiber drawing did not significantly impact the release of P and Ca, an increase in the release of Na into the solution was noticed. This was probably due to small structural reorientations occurring during the fiber drawing process and to a slight diffusion of Na to the fiber surface. Both the powders from the bulk and the glass fibers formed a Ca-P surface layer when immersed in SBF and TRIS. The layer thickness was higher in the calcium and phosphate supersaturated SBF than in TRIS. This paper for the first time presents the in vitro reactivity and optical response of a phosphate-based bioactive glass (PBG) fiber when immersed in SBF. The light intensity remained constant for the first 48h after which a decrease with three distinct slopes was observed: the first decrease between 48 and 200h of immersion could be correlated to the formation of the Ca-P layer at the fiber surface. After this a faster decrease in light transmission was observed from 200 to ~425h in SBF. SEM analysis suggested that after 200h, the surface of the fiber was fully covered by a thin Ca-P layer which is likely to scatter light. For immersion times longer than ~425h, the thickness of the Ca-P layer increased and thus acted as a barrier to the dissolution process limiting further reduction in light transmission. The tracking of light transmission through the PBG fiber allowed monitoring of the fiber dissolution in vitro. These results are essential in developing new bioactive fiber sensors that can be used to monitor bioresponse in situ. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Multi-dimensional Fuzzy Euler Approximation

    Directory of Open Access Journals (Sweden)

    Yangyang Hao

    2017-05-01

    Full Text Available Multi-dimensional Fuzzy differential equations driven by multi-dimen-sional Liu process, have been intensively applied in many fields. However, we can not obtain the analytic solution of every multi-dimensional fuzzy differential equation. Then, it is necessary for us to discuss the numerical results in most situations. This paper focuses on the numerical method of multi-dimensional fuzzy differential equations. The multi-dimensional fuzzy Taylor expansion is given, based on this expansion, a numerical method which is designed for giving the solution of multi-dimensional fuzzy differential equation via multi-dimensional Euler method will be presented, and its local convergence also will be discussed.

  15. Executive Information Systems' Multidimensional Models

    Directory of Open Access Journals (Sweden)

    2007-01-01

    Full Text Available Executive Information Systems are design to improve the quality of strategic level of management in organization through a new type of technology and several techniques for extracting, transforming, processing, integrating and presenting data in such a way that the organizational knowledge filters can easily associate with this data and turn it into information for the organization. These technologies are known as Business Intelligence Tools. But in order to build analytic reports for Executive Information Systems (EIS in an organization we need to design a multidimensional model based on the business model from the organization. This paper presents some multidimensional models that can be used in EIS development and propose a new model that is suitable for strategic business requests.

  16. Lagrangian multiforms and multidimensional consistency

    Energy Technology Data Exchange (ETDEWEB)

    Lobb, Sarah; Nijhoff, Frank [Department of Applied Mathematics, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2009-10-30

    We show that well-chosen Lagrangians for a class of two-dimensional integrable lattice equations obey a closure relation when embedded in a higher dimensional lattice. On the basis of this property we formulate a Lagrangian description for such systems in terms of Lagrangian multiforms. We discuss the connection of this formalism with the notion of multidimensional consistency, and the role of the lattice from the point of view of the relevant variational principle.

  17. Cuba: Multidimensional numerical integration library

    Science.gov (United States)

    Hahn, Thomas

    2016-08-01

    The Cuba library offers four independent routines for multidimensional numerical integration: Vegas, Suave, Divonne, and Cuhre. The four algorithms work by very different methods, and can integrate vector integrands and have very similar Fortran, C/C++, and Mathematica interfaces. Their invocation is very similar, making it easy to cross-check by substituting one method by another. For further safeguarding, the output is supplemented by a chi-square probability which quantifies the reliability of the error estimate.

  18. A new cationic porphyrin derivative (TMPipEOPP with large side arm substituents: a highly selective G-quadruplex optical probe.

    Directory of Open Access Journals (Sweden)

    Li-Na Zhu

    Full Text Available The discovery of uncommon DNA structures and speculation about their potential functions in genes has brought attention to specific DNA structure recognition. G-quadruplexes are four-stranded nucleic acid structures formed by G-rich DNA (or RNA sequences. G-rich sequences with a high potential to form G-quadruplexes have been found in many important genomic regions. Porphyrin derivatives with cationic side arm substituents are important G-quadruplex-binding ligands. For example, 5,10,15,20-Tetrakis(N-methylpyridinium-4-yl-21H,23H-porphyrin (TMPyP4, interacts strongly with G-quadruplexes, but has poor selectivity for G-quadruplex versus duplex DNA. To increase the G-quadruplex recognition specificity, a new cationic porphyrin derivative, 5,10,15,20-tetra-{4-[2-(1-methyl-1-piperidinylethoxy]phenyl} porphyrin (TMPipEOPP, with large side arm substituents was synthesized, and the interactions between TMPipEOPP and different DNA structures were compared. The results show that G-quadruplexes cause large changes in the UV-Vis absorption and fluorescence spectra of TMPipEOPP, but duplex and single-stranded DNAs do not, indicating that TMPipEOPP can be developed as a highly specific optical probe for discriminating G-quadruplex from duplex and single-stranded DNA. Visual discrimination is also possible. Job plot and Scatchard analysis suggest that a complicated binding interaction occurs between TMPipEOPP and G-quadruplexes. At a low [G-quadruplex]/[TMPipEOPP] ratio, one G-quadruplex binds two TMPipEOPP molecules by end-stacking and outside binding modes. At a high [G-quadruplex]/[TMPipEOPP] ratio, two G-quadruplexes bind to one TMPipEOPP molecule in a sandwich-like end-stacking mode.

  19. A new cationic porphyrin derivative (TMPipEOPP) with large side arm substituents: a highly selective G-quadruplex optical probe.

    Science.gov (United States)

    Zhu, Li-Na; Zhao, Shu-Juan; Wu, Bin; Li, Xiao-Zeng; Kong, De-Ming

    2012-01-01

    The discovery of uncommon DNA structures and speculation about their potential functions in genes has brought attention to specific DNA structure recognition. G-quadruplexes are four-stranded nucleic acid structures formed by G-rich DNA (or RNA) sequences. G-rich sequences with a high potential to form G-quadruplexes have been found in many important genomic regions. Porphyrin derivatives with cationic side arm substituents are important G-quadruplex-binding ligands. For example, 5,10,15,20-Tetrakis(N-methylpyridinium-4-yl)-21H,23H-porphyrin (TMPyP4), interacts strongly with G-quadruplexes, but has poor selectivity for G-quadruplex versus duplex DNA. To increase the G-quadruplex recognition specificity, a new cationic porphyrin derivative, 5,10,15,20-tetra-{4-[2-(1-methyl-1-piperidinyl)ethoxy]phenyl} porphyrin (TMPipEOPP), with large side arm substituents was synthesized, and the interactions between TMPipEOPP and different DNA structures were compared. The results show that G-quadruplexes cause large changes in the UV-Vis absorption and fluorescence spectra of TMPipEOPP, but duplex and single-stranded DNAs do not, indicating that TMPipEOPP can be developed as a highly specific optical probe for discriminating G-quadruplex from duplex and single-stranded DNA. Visual discrimination is also possible. Job plot and Scatchard analysis suggest that a complicated binding interaction occurs between TMPipEOPP and G-quadruplexes. At a low [G-quadruplex]/[TMPipEOPP] ratio, one G-quadruplex binds two TMPipEOPP molecules by end-stacking and outside binding modes. At a high [G-quadruplex]/[TMPipEOPP] ratio, two G-quadruplexes bind to one TMPipEOPP molecule in a sandwich-like end-stacking mode.

  20. Measures for a multidimensional multiverse

    Science.gov (United States)

    Chung, Hyeyoun

    2015-04-01

    We explore the phenomenological implications of generalizing the causal patch and fat geodesic measures to a multidimensional multiverse, where the vacua can have differing numbers of large dimensions. We consider a simple model in which the vacua are nucleated from a D -dimensional parent spacetime through dynamical compactification of the extra dimensions, and compute the geometric contribution to the probability distribution of observations within the multiverse for each measure. We then study how the shape of this probability distribution depends on the time scales for the existence of observers, for vacuum domination, and for curvature domination (tobs,tΛ , and tc, respectively.) In this work we restrict ourselves to bubbles with positive cosmological constant, Λ . We find that in the case of the causal patch cutoff, when the bubble universes have p +1 large spatial dimensions with p ≥2 , the shape of the probability distribution is such that we obtain the coincidence of time scales tobs˜tΛ˜tc . Moreover, the size of the cosmological constant is related to the size of the landscape. However, the exact shape of the probability distribution is different in the case p =2 , compared to p ≥3 . In the case of the fat geodesic measure, the result is even more robust: the shape of the probability distribution is the same for all p ≥2 , and we once again obtain the coincidence tobs˜tΛ˜tc . These results require only very mild conditions on the prior probability of the distribution of vacua in the landscape. Our work shows that the observed double coincidence of time scales is a robust prediction even when the multiverse is generalized to be multidimensional; that this coincidence is not a consequence of our particular Universe being (3 +1 )-dimensional; and that this observable cannot be used to preferentially select one measure over another in a multidimensional multiverse.

  1. Ordinal Comparison of Multidimensional Deprivation

    DEFF Research Database (Denmark)

    Sonne-Schmidt, Christoffer Scavenius; Tarp, Finn; Østerdal, Lars Peter

    This paper develops an ordinal method of comparison of multidimensional inequality. In our model, population distribution g is more unequal than f when the distributions have common median and can be obtained from f  by one or more shifts in population density that increase inequality. For our be...... benchmark 2x2 case (i.e. the case of two binary outcome variables), we derive an empirical method for making inequality comparisons. As an illustration, we apply the model to childhood poverty in Mozambique....

  2. Probe Storage

    NARCIS (Netherlands)

    Gemelli, Marcellino; Abelmann, Leon; Engelen, Johannes Bernardus Charles; Khatib, M.G.; Koelmans, W.W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo

    2011-01-01

    This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data

  3. Cultural probes

    DEFF Research Database (Denmark)

    Madsen, Jacob Østergaard

    The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation.......The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation....

  4. Probing channel temperature profiles in Al{sub x}Ga{sub 1−x}N/GaN high electron mobility transistors on 200 mm diameter Si(111) by optical spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kyaw, L. M., E-mail: a0048661@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore); Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602 (Singapore); Bera, L. K.; Dolmanan, S. B.; Tan, H. R.; Bhat, T. N.; Tripathy, S., E-mail: tripathy-sudhiranjan@imre.a-star.edu.sg [Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology, and Research), Singapore 117602 (Singapore); Liu, Y.; Bera, M. K.; Singh, S. P.; Chor, E. F. [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117576 (Singapore)

    2014-08-18

    Using micro-Raman and photoluminescence (PL) techniques, the channel temperature profile is probed in Al{sub x}Ga{sub 1-x}N/GaN high electron mobility transistors (HEMTs) fabricated on a 200 mm diameter Si(111) substrate. In particular, RuO{sub x}-based gate is used due to the semitransparent nature to the optical excitation wavelengths, thus allowing much accurate thermal investigations underneath the gate. To determine the channel temperature profile in devices subjected to different electrical bias voltages, the GaN band-edge PL peak shift calibration with respect to temperature is used. PL analyses show a maximum channel temperature up to 435 K underneath the gate edge between gate and drain, where the estimated thermal resistance in such a HEMT structure is about 13.7 KmmW{sup −1} at a power dissipation of ∼10 W/mm. The temperature profiles from micro-Raman measurements are also addressed from the E{sub 2}-high optical phonon peak shift of GaN, and this method also probes the temperature-induced peak shifts of optical phonon from Si thus showing the nature of thermal characteristics at the AlN/Si substrate interface.

  5. Perceptual Salience and Children's Multidimensional Problem Solving

    Science.gov (United States)

    Odom, Richard D.; Corbin, David W.

    1973-01-01

    Uni- and multidimensional processing of 6- to 9-year olds was studied using recall tasks in which an array of stimuli was reconstructed to match a model array. Results indicated that both age groups were able to solve multidimensional problems, but that solution rate was retarded by the unidimensional processing of highly salient dimensions.…

  6. Multidimensional fatigue and its correlates in hospitalised advanced cancer patients.

    NARCIS (Netherlands)

    Echteld, M.A.; Passchier, J.; Teunissen, S.; Claessen, S.; Wit, R. de; Rijt, C.C.D. van der

    2007-01-01

    Although fatigue is a multidimensional concept, multidimensional fatigue is rarely investigated in hospitalised cancer patients. We determined the levels and correlates of multidimensional fatigue in 100 advanced cancer patients admitted for symptom control. Fatigue dimensions were general fatigue

  7. SUSTAINABLE DEVELOPMENT, A MULTIDIMENSIONAL CONCEPT

    Directory of Open Access Journals (Sweden)

    TEODORESCU ANA MARIA

    2015-06-01

    Full Text Available Sustainable development imposed itself as a corollary of economic term "development". Sustainable development is meant to be the summation of economic, environmental and social considerations for the present and especially for the future. The concept of sustainable development plays an important role in european and global meetings since 1972, the year it has been set for the first time. Strategies necessary to achieve the objectives of sustainable development have been developed, indicators meant to indicate the result of the implementation of policies have been created, national plans were oriented towards achieving the proposed targets. I wanted to highlight the multidimensional character of the concept of sustainable development. Thus, using specialized national and international literature, I have revealed different approaches of one pillar to the detriment of another pillar depending on the specific field. In the different concepts of sustainable development, the consensus is undoubtedly agreed on its components: economic, social, environmental. Based on this fact, the concept of sustainability has different connotations depending on the specific content of each discipline: biology, economics, sociology, environmental ethics. The multidimensional valence of sustainable development consists of three pillars ability to act together for the benefit of present and future generations. Being a multidimensional concept, importance attached to a pillar over another is directed according to the particularities of each field: in economy profit prevails, in ecology care of natural resources is the most important, the social aims improving human living conditions. The challenge of sustainable development is to combine all the economic, environmental and social benefits and the present generation to come. Ecological approach is reflected in acceptance of limited natural resources by preserving natural capital. In terms of the importance of

  8. Heuristics for Multidimensional Packing Problems

    DEFF Research Database (Denmark)

    Egeblad, Jens

    for a minimum height container required for the items. The main contributions of the thesis are three new heuristics for strip-packing and knapsack packing problems where items are both rectangular and irregular. In the two first papers we describe a heuristic for the multidimensional strip-packing problem...... that is based on a relaxed placement principle. The heuristic starts with a random overlapping placement of items and large container dimensions. From the overlapping placement overlap is reduced iteratively until a non-overlapping placement is found and a new problem is solved with a smaller container size...... of this heuristic are among the best published in the literature both for two- and three-dimensional strip-packing problems for irregular shapes. In the third paper, we introduce a heuristic for two- and three-dimensional rectangular knapsack packing problems. The two-dimensional heuristic uses the sequence pair...

  9. Applied multidimensional scaling and unfolding

    CERN Document Server

    Borg, Ingwer; Mair, Patrick

    2018-01-01

    This book introduces multidimensional scaling (MDS) and unfolding as data analysis techniques for applied researchers. MDS is used for the analysis of proximity data on a set of objects, representing the data as distances between points in a geometric space (usually of two dimensions). Unfolding is a related method that maps preference data (typically evaluative ratings of different persons on a set of objects) as distances between two sets of points (representing the persons and the objects, resp.). This second edition has been completely revised to reflect new developments and the coverage of unfolding has also been substantially expanded. Intended for applied researchers whose main interests are in using these methods as tools for building substantive theories, it discusses numerous applications (classical and recent), highlights practical issues (such as evaluating model fit), presents ways to enforce theoretical expectations for the scaling solutions, and addresses the typical mistakes that MDS/unfoldin...

  10. Mobile probes

    DEFF Research Database (Denmark)

    Ørngreen, Rikke; Jørgensen, Anna Neustrup; Noesgaard, Signe Schack

    2016-01-01

    A project investigating the effectiveness of a collection of online resources for teachers' professional development used mobile probes as a data collection method. Teachers received questions and tasks on their mobile in a dialogic manner while in their everyday context as opposed...... to in an interview. This method provided valuable insight into the contextual use, i.e. how did the online resource transfer to the work practice. However, the research team also found that mobile probes may provide the scaffolding necessary for individual and peer learning at a very local (intra-school) community...... level. This paper is an initial investigation of how the mobile probes process proved to engage teachers in their efforts to improve teaching. It also highlights some of the barriers emerging when applying mobile probes as a scaffold for learning....

  11. Minimal models of multidimensional computations.

    Directory of Open Access Journals (Sweden)

    Jeffrey D Fitzgerald

    2011-03-01

    Full Text Available The multidimensional computations performed by many biological systems are often characterized with limited information about the correlations between inputs and outputs. Given this limitation, our approach is to construct the maximum noise entropy response function of the system, leading to a closed-form and minimally biased model consistent with a given set of constraints on the input/output moments; the result is equivalent to conditional random field models from machine learning. For systems with binary outputs, such as neurons encoding sensory stimuli, the maximum noise entropy models are logistic functions whose arguments depend on the constraints. A constraint on the average output turns the binary maximum noise entropy models into minimum mutual information models, allowing for the calculation of the information content of the constraints and an information theoretic characterization of the system's computations. We use this approach to analyze the nonlinear input/output functions in macaque retina and thalamus; although these systems have been previously shown to be responsive to two input dimensions, the functional form of the response function in this reduced space had not been unambiguously identified. A second order model based on the logistic function is found to be both necessary and sufficient to accurately describe the neural responses to naturalistic stimuli, accounting for an average of 93% of the mutual information with a small number of parameters. Thus, despite the fact that the stimulus is highly non-Gaussian, the vast majority of the information in the neural responses is related to first and second order correlations. Our results suggest a principled and unbiased way to model multidimensional computations and determine the statistics of the inputs that are being encoded in the outputs.

  12. Counting probe

    International Nuclear Information System (INIS)

    Matsumoto, Haruya; Kaya, Nobuyuki; Yuasa, Kazuhiro; Hayashi, Tomoaki

    1976-01-01

    Electron counting method has been devised and experimented for the purpose of measuring electron temperature and density, the most fundamental quantities to represent plasma conditions. Electron counting is a method to count the electrons in plasma directly by equipping a probe with the secondary electron multiplier. It has three advantages of adjustable sensitivity, high sensitivity of the secondary electron multiplier, and directional property. Sensitivity adjustment is performed by changing the size of collecting hole (pin hole) on the incident front of the multiplier. The probe is usable as a direct reading thermometer of electron temperature because it requires to collect very small amount of electrons, thus it doesn't disturb the surrounding plasma, and the narrow sweep width of the probe voltage is enough. Therefore it can measure anisotropy more sensitively than a Langmuir probe, and it can be used for very low density plasma. Though many problems remain on anisotropy, computer simulation has been carried out. Also it is planned to provide a Helmholtz coil in the vacuum chamber to eliminate the effect of earth magnetic field. In practical experiments, the measurement with a Langmuir probe and an emission probe mounted to the movable structure, the comparison with the results obtained in reverse magnetic field by using a Helmholtz coil, and the measurement of ionic sound wave are scheduled. (Wakatsuki, Y.)

  13. Characterization of silver halide fiber optics and hollow silica waveguides for use in the construction of a mid-infrared attenuated total reflection fourier transform infrared (ATR FT-IR) spectroscopy probe.

    Science.gov (United States)

    Damin, Craig A; Sommer, André J

    2013-11-01

    Advances in fiber optic materials have allowed for the construction of fibers and waveguides capable of transmitting infrared radiation. An investigation of the transmission characteristics associated with two commonly used types of infrared-transmitting fibers/waveguides for prospective use in a fiber/waveguide-coupled attenuated total internal reflection (ATR) probe was performed. Characterization of silver halide polycrystalline fiber optics and hollow silica waveguides was done on the basis of the transmission of infrared light using a conventional fiber optic coupling accessory and an infrared microscope. Using the fiber optic coupling accessory, the average percent transmission for three silver halide fibers was 18.1 ± 6.1% relative to a benchtop reflection accessory. The average transmission for two hollow waveguides (HWGs) using the coupling accessory was 8.0 ± 0.3%. (Uncertainties in the relative percent transmission represent the standard deviations.) Reduced transmission observed for the HWGs was attributed to the high numerical aperture of the coupling accessory. Characterization of the fibers/waveguides using a zinc selenide lens objective on an infrared microscope indicated 24.1 ± 7.2% of the initial light input into the silver halide fibers was transmitted. Percent transmission obtained for the HWGs was 98.7 ± 0.1%. Increased transmission using the HWGs resulted from the absence or minimization of insertion and scattering losses due to the hollow air core and a better-matched numerical aperture. The effect of bending on the transmission characteristics of the fibers/waveguides was also investigated. Significant deviations in the transmission of infrared light by the solid-core silver halide fibers were observed for various bending angles. Percent transmission greater than 98% was consistently observed for the HWGs at the bending angles. The combined benefits of high percent transmission, reproducible instrument responses, and increased bending

  14. Multidimensional singular integrals and integral equations

    CERN Document Server

    Mikhlin, Solomon Grigorievich; Stark, M; Ulam, S

    1965-01-01

    Multidimensional Singular Integrals and Integral Equations presents the results of the theory of multidimensional singular integrals and of equations containing such integrals. Emphasis is on singular integrals taken over Euclidean space or in the closed manifold of Liapounov and equations containing such integrals. This volume is comprised of eight chapters and begins with an overview of some theorems on linear equations in Banach spaces, followed by a discussion on the simplest properties of multidimensional singular integrals. Subsequent chapters deal with compounding of singular integrals

  15. DNA probes

    International Nuclear Information System (INIS)

    Castelino, J.

    1992-01-01

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with 32 P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism's genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens

  16. DNA probes

    Energy Technology Data Exchange (ETDEWEB)

    Castelino, J

    1993-12-31

    The creation of DNA probes for detection of specific nucleotide segments differs from ligand detection in that it is a chemical rather than an immunological reaction. Complementary DNA or RNA is used in place of the antibody and is labelled with {sup 32}P. So far, DNA probes have been successfully employed in the diagnosis of inherited disorders, infectious diseases, and for identification of human oncogenes. The latest approach to the diagnosis of communicable and parasitic infections is based on the use of deoxyribonucleic acid (DNA) probes. The genetic information of all cells is encoded by DNA and DNA probe approach to identification of pathogens is unique because the focus of the method is the nucleic acid content of the organism rather than the products that the nucleic acid encodes. Since every properly classified species has some unique nucleotide sequences that distinguish it from every other species, each organism`s genetic composition is in essence a finger print that can be used for its identification. In addition to this specificity, DNA probes offer other advantages in that pathogens may be identified directly in clinical specimens 10 figs, 2 tabs

  17. Conductivity Probe

    Science.gov (United States)

    2008-01-01

    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  18. Multidimensionally encoded magnetic resonance imaging.

    Science.gov (United States)

    Lin, Fa-Hsuan

    2013-07-01

    Magnetic resonance imaging (MRI) typically achieves spatial encoding by measuring the projection of a q-dimensional object over q-dimensional spatial bases created by linear spatial encoding magnetic fields (SEMs). Recently, imaging strategies using nonlinear SEMs have demonstrated potential advantages for reconstructing images with higher spatiotemporal resolution and reducing peripheral nerve stimulation. In practice, nonlinear SEMs and linear SEMs can be used jointly to further improve the image reconstruction performance. Here, we propose the multidimensionally encoded (MDE) MRI to map a q-dimensional object onto a p-dimensional encoding space where p > q. MDE MRI is a theoretical framework linking imaging strategies using linear and nonlinear SEMs. Using a system of eight surface SEM coils with an eight-channel radiofrequency coil array, we demonstrate the five-dimensional MDE MRI for a two-dimensional object as a further generalization of PatLoc imaging and O-space imaging. We also present a method of optimizing spatial bases in MDE MRI. Results show that MDE MRI with a higher dimensional encoding space can reconstruct images more efficiently and with a smaller reconstruction error when the k-space sampling distribution and the number of samples are controlled. Copyright © 2012 Wiley Periodicals, Inc.

  19. Discovering Multidimensional Structure in Relational Data

    DEFF Research Database (Denmark)

    Jensen, Mikael Rune; Holmgren, Thomas; Pedersen, Torben Bach

    2004-01-01

    On-Line Analytical Processing (OLAP) systems based on multidimensional databases are essential elements of decision support. However, most existing data is stored in “ordinary” relational OLTP databases, i.e., data has to be (re-) modeled as multidimensional cubes before the advantages of OLAP to...... algorithms for discovering multidimensional schemas from relational databases. The algorithms take a wide range of available metadata into account in the discovery process, including functional and inclusion dependencies, and key and cardinality information....... tools are available. In this paper we present an approach for the automatic construction of multidimensional OLAP database schemas from existing relational OLTP databases, enabling easy OLAP design and analysis for most existing data sources. This is achieved through a set of practical and effective...

  20. Two multi-dimensional uncertainty relations

    International Nuclear Information System (INIS)

    Skala, L; Kapsa, V

    2008-01-01

    Two multi-dimensional uncertainty relations, one related to the probability density and the other one related to the probability density current, are derived and discussed. Both relations are stronger than the usual uncertainty relations for the coordinates and momentum

  1. Multidimensional artificial field embedding with spatial sensitivity

    CSIR Research Space (South Africa)

    Lunga, D

    2013-06-01

    Full Text Available Multidimensional embedding is a technique useful for characterizing spectral signature relations in hyperspectral images. However, such images consist of disjoint similar spectral classes that are spatially sensitive, thus presenting challenges...

  2. CAMS: OLAPing Multidimensional Data Streams Efficiently

    Science.gov (United States)

    Cuzzocrea, Alfredo

    In the context of data stream research, taming the multidimensionality of real-life data streams in order to efficiently support OLAP analysis/mining tasks is a critical challenge. Inspired by this fundamental motivation, in this paper we introduce CAMS (C ube-based A cquisition model for M ultidimensional S treams), a model for efficiently OLAPing multidimensional data streams. CAMS combines a set of data stream processing methodologies, namely (i) the OLAP dimension flattening process, which allows us to obtain dimensionality reduction of multidimensional data streams, and (ii) the OLAP stream aggregation scheme, which aggregates data stream readings according to an OLAP-hierarchy-based membership approach. We complete our analytical contribution by means of experimental assessment and analysis of both the efficiency and the scalability of OLAPing capabilities of CAMS on synthetic multidimensional data streams. Both analytical and experimental results clearly connote CAMS as an enabling component for next-generation Data Stream Management Systems.

  3. Depth probing of the hydride formation process in thin Pd films by combined electrochemistry and fiber optics-based in situ UV/vis spectroscopy.

    Science.gov (United States)

    Wickman, Björn; Fredriksson, Mattias; Feng, Ligang; Lindahl, Niklas; Hagberg, Johan; Langhammer, Christoph

    2015-07-15

    We demonstrate a flexible combined electrochemistry and fiber optics-based in situ UV/vis spectroscopy setup to gain insight into the depth evolution of electrochemical hydride and oxide formation in Pd films with thicknesses of 20 and 100 nm. The thicknesses of our model systems are chosen such that the films are thinner or significantly thicker than the optical skin depth of Pd to create two distinctly different situations. Low power white light is irradiated on the sample and analyzed in three different configurations; transmittance through, and, reflectance from the front and the back side of the film. The obtained optical sensitivities correspond to fractions of a monolayer of adsorbed or absorbed hydrogen (H) and oxygen (O) on Pd. Moreover, a combined simultaneous readout obtained from the different optical measurement configurations provides mechanistic insights into the depth-evolution of the studied hydrogenation and oxidation processes.

  4. Multidimensional Poverty and Child Survival in India

    Science.gov (United States)

    Mohanty, Sanjay K.

    2011-01-01

    Background Though the concept of multidimensional poverty has been acknowledged cutting across the disciplines (among economists, public health professionals, development thinkers, social scientists, policy makers and international organizations) and included in the development agenda, its measurement and application are still limited. Objectives and Methodology Using unit data from the National Family and Health Survey 3, India, this paper measures poverty in multidimensional space and examine the linkages of multidimensional poverty with child survival. The multidimensional poverty is measured in the dimension of knowledge, health and wealth and the child survival is measured with respect to infant mortality and under-five mortality. Descriptive statistics, principal component analyses and the life table methods are used in the analyses. Results The estimates of multidimensional poverty are robust and the inter-state differentials are large. While infant mortality rate and under-five mortality rate are disproportionately higher among the abject poor compared to the non-poor, there are no significant differences in child survival among educationally, economically and health poor at the national level. State pattern in child survival among the education, economical and health poor are mixed. Conclusion Use of multidimensional poverty measures help to identify abject poor who are unlikely to come out of poverty trap. The child survival is significantly lower among abject poor compared to moderate poor and non-poor. We urge to popularize the concept of multiple deprivations in research and program so as to reduce poverty and inequality in the population. PMID:22046384

  5. Multidimensional poverty and child survival in India.

    Science.gov (United States)

    Mohanty, Sanjay K

    2011-01-01

    Though the concept of multidimensional poverty has been acknowledged cutting across the disciplines (among economists, public health professionals, development thinkers, social scientists, policy makers and international organizations) and included in the development agenda, its measurement and application are still limited. OBJECTIVES AND METHODOLOGY: Using unit data from the National Family and Health Survey 3, India, this paper measures poverty in multidimensional space and examine the linkages of multidimensional poverty with child survival. The multidimensional poverty is measured in the dimension of knowledge, health and wealth and the child survival is measured with respect to infant mortality and under-five mortality. Descriptive statistics, principal component analyses and the life table methods are used in the analyses. The estimates of multidimensional poverty are robust and the inter-state differentials are large. While infant mortality rate and under-five mortality rate are disproportionately higher among the abject poor compared to the non-poor, there are no significant differences in child survival among educationally, economically and health poor at the national level. State pattern in child survival among the education, economical and health poor are mixed. Use of multidimensional poverty measures help to identify abject poor who are unlikely to come out of poverty trap. The child survival is significantly lower among abject poor compared to moderate poor and non-poor. We urge to popularize the concept of multiple deprivations in research and program so as to reduce poverty and inequality in the population.

  6. Multidimensional poverty and child survival in India.

    Directory of Open Access Journals (Sweden)

    Sanjay K Mohanty

    Full Text Available Though the concept of multidimensional poverty has been acknowledged cutting across the disciplines (among economists, public health professionals, development thinkers, social scientists, policy makers and international organizations and included in the development agenda, its measurement and application are still limited. OBJECTIVES AND METHODOLOGY: Using unit data from the National Family and Health Survey 3, India, this paper measures poverty in multidimensional space and examine the linkages of multidimensional poverty with child survival. The multidimensional poverty is measured in the dimension of knowledge, health and wealth and the child survival is measured with respect to infant mortality and under-five mortality. Descriptive statistics, principal component analyses and the life table methods are used in the analyses.The estimates of multidimensional poverty are robust and the inter-state differentials are large. While infant mortality rate and under-five mortality rate are disproportionately higher among the abject poor compared to the non-poor, there are no significant differences in child survival among educationally, economically and health poor at the national level. State pattern in child survival among the education, economical and health poor are mixed.Use of multidimensional poverty measures help to identify abject poor who are unlikely to come out of poverty trap. The child survival is significantly lower among abject poor compared to moderate poor and non-poor. We urge to popularize the concept of multiple deprivations in research and program so as to reduce poverty and inequality in the population.

  7. Probe specificity

    International Nuclear Information System (INIS)

    Laget, J.M.

    1986-11-01

    Specificity and complementarity of hadron and electron probes must be systematically developed to answer three questions currently asked in intermediate energy nuclear physics: what is nucleus structure at short distances, what is nature of short range correlations, what is three body force nature [fr

  8. Improved multidimensional semiclassical tunneling theory.

    Science.gov (United States)

    Wagner, Albert F

    2013-12-12

    We show that the analytic multidimensional semiclassical tunneling formula of Miller et al. [Miller, W. H.; Hernandez, R.; Handy, N. C.; Jayatilaka, D.; Willets, A. Chem. Phys. Lett. 1990, 172, 62] is qualitatively incorrect for deep tunneling at energies well below the top of the barrier. The origin of this deficiency is that the formula uses an effective barrier weakly related to the true energetics but correctly adjusted to reproduce the harmonic description and anharmonic corrections of the reaction path at the saddle point as determined by second order vibrational perturbation theory. We present an analytic improved semiclassical formula that correctly includes energetic information and allows a qualitatively correct representation of deep tunneling. This is done by constructing a three segment composite Eckart potential that is continuous everywhere in both value and derivative. This composite potential has an analytic barrier penetration integral from which the semiclassical action can be derived and then used to define the semiclassical tunneling probability. The middle segment of the composite potential by itself is superior to the original formula of Miller et al. because it incorporates the asymmetry of the reaction barrier produced by the known reaction exoergicity. Comparison of the semiclassical and exact quantum tunneling probability for the pure Eckart potential suggests a simple threshold multiplicative factor to the improved formula to account for quantum effects very near threshold not represented by semiclassical theory. The deep tunneling limitations of the original formula are echoed in semiclassical high-energy descriptions of bound vibrational states perpendicular to the reaction path at the saddle point. However, typically ab initio energetic information is not available to correct it. The Supporting Information contains a Fortran code, test input, and test output that implements the improved semiclassical tunneling formula.

  9. Probing plasmonic nanostructures by photons and electrons

    DEFF Research Database (Denmark)

    Kneipp, Katrin; Kneipp, Harald; Kneipp, Janina

    2015-01-01

    We discuss recent developments for studying plasmonic metal nanostructures. Exploiting photons and electrons opens up new capabilities to probe the complete plasmon spectrum including bright and dark modes and related local optical fields at subnanometer spatial resolution. This comprehensive cha...

  10. Probing nuclear structure with nucleons

    International Nuclear Information System (INIS)

    Bauge, E.

    2007-01-01

    The goal of this lecture is to show how nucleon scattering can be used to probe the structure of target nuclei, and how nucleon scattering observables can be interpreted in terms of nuclear structure using microscopic optical potentials. After a brief overview of the specificities of nucleon-nucleus scattering, and a quick reminder on scattering theory, the main part of this lecture is devoted to the construction of optical potentials in which the target nuclei structure information is folded with an effective interaction. Several examples of such microscopic optical model potentials are given. (author)

  11. Temperature-dependent and anisotropic optical response of layered Pr0.5Ca1.5MnO4 probed by spectroscopic ellipsometry

    NARCIS (Netherlands)

    Majidi, M. A.; Thoeng, E.; Gogoi, P. K.; Wendt, F.; Wang, S. H.; Santoso, I.; Asmara, T. C.; Handayani, I. P.; van Loosdrecht, P. H. M.; Nugroho, A. A.; Ruebhausen, M.; Rusydi, A.; Rübhausen, M.

    2013-01-01

    We study the temperature dependence as well as anisotropy of optical conductivity (sigma(1)) in the pseudocubic single crystal Pr0.5Ca1.5MnO4 using spectrocopic ellipsometry. Three transition temperatures are observed and can be linked to charge-orbital (T-CO/OO similar to 320 K),

  12. ‘Green’-synthesized near-infrared PbS quantum dots with silica-PEG dual-layer coating: ultrastable and biocompatible optical probes for in vivo animal imaging

    Science.gov (United States)

    Wang, D.; Qian, J.; Cai, F.; He, S.; Han, S.; Mu, Y.

    2012-06-01

    In this paper, PbS semiconductor quantum dots (QDs) with near-infrared (NIR) photoluminescence were synthesized in oleic acid and paraffin liquid mixture by using an easily handled and ‘green’ approach. Surface functionalization of the QDs was accomplished with a silica and polyethylene glycol (PEG) phospholipid dual-layer coating and the excellent chemical stability of the nanoparticles is demonstrated. We then successfully applied the ultrastable PbS QDs to in vivo sentinel lymph node (SLN) mapping of mice. Histological analyses were also carried out to ensure that the intravenously injected nanoparticles did not produce any toxicity to the organism of mice. These experimental results suggested that our ultrastable NIR PbS QDs can serve as biocompatible and efficient probes for in vivo optical bioimaging and has great potentials for disease diagnosis and clinical therapies in the future.

  13. ‘Green’-synthesized near-infrared PbS quantum dots with silica–PEG dual-layer coating: ultrastable and biocompatible optical probes for in vivo animal imaging

    International Nuclear Information System (INIS)

    Wang, D; Qian, J; Cai, F; He, S; Han, S; Mu, Y

    2012-01-01

    In this paper, PbS semiconductor quantum dots (QDs) with near-infrared (NIR) photoluminescence were synthesized in oleic acid and paraffin liquid mixture by using an easily handled and ‘green’ approach. Surface functionalization of the QDs was accomplished with a silica and polyethylene glycol (PEG) phospholipid dual-layer coating and the excellent chemical stability of the nanoparticles is demonstrated. We then successfully applied the ultrastable PbS QDs to in vivo sentinel lymph node (SLN) mapping of mice. Histological analyses were also carried out to ensure that the intravenously injected nanoparticles did not produce any toxicity to the organism of mice. These experimental results suggested that our ultrastable NIR PbS QDs can serve as biocompatible and efficient probes for in vivo optical bioimaging and has great potentials for disease diagnosis and clinical therapies in the future. (paper)

  14. Aspheric surface measurement using capacitive probes

    Science.gov (United States)

    Tao, Xin; Yuan, Daocheng; Li, Shaobo

    2017-02-01

    With the application of aspheres in optical fields, high precision and high efficiency aspheric surface metrology becomes a hot research topic. We describe a novel method of non-contact measurement of aspheric surface with capacitive probe. Taking an eccentric spherical surface as the object of study, the averaging effect of capacitive probe measurement and the influence of tilting the capacitive probe on the measurement results are investigated. By comparing measurement results from simultaneous measurement of the capacitive probe and contact probe of roundness instrument, this paper indicates the feasibility of using capacitive probes to test aspheric surface and proposes the compensation method of measurement error caused by averaging effect and the tilting of the capacitive probe.

  15. Optical tomography of tissues

    International Nuclear Information System (INIS)

    Zimnyakov, D A; Tuchin, Valerii V

    2002-01-01

    Methods of optical tomography of biological tissues are considered, which include pulse-modulation and frequency-modulation tomography, diffusion tomography with the use of cw radiation sources, optical coherent tomography, speckle-correlation tomography of nonstationary media, and optoacoustic tomography. The method for controlling the optical properties of tissues is studied from the point of view of increasing a probing depth in optical coherent tomography. The modern state and prospects of the development of optical tomography are discussed. (review)

  16. Synthesis under pressure and characterizations through optical spectroscopy of jahn-teller cations (LS Ni3+, is Co3+) as probes diluted in a perovskite matrix

    Science.gov (United States)

    Sanz-Ortiz, M. N.; Rodríguez, F.; Baranov, A.; Demazeau, G.

    2008-07-01

    The objective is to explore through optical spectroscopy and magnetic measurements the coordination and electronic structures of transition-metal ions introduced as impurities with unusual valence states in the oxide perovskite LaAlO3. The selected transition-metal ions Ni3+(3d7) and Co3+(3d6) are characterized by an electronic configuration likely leading to an orbital degenerate E state in Oh symmetry, and thus electron-lattice coupling due to the Jahn-Teller effect may induce low symmetry distortion around the impurity oxygen octahedron. We show that a sol-gel process followed by high oxygen pressure treatments yields stabilization of trivalent state in oxide perovskite. Information about the coordination, electronic structure and aggregation around the magnetic impurity was obtained from X-ray diffraction, FTIR and optical spectroscopy. Finally, evidence on the possible existence of intermediate spin state in Co3+ is under consideration.

  17. Synthesis under pressure and characterizations through optical spectroscopy of jahn-teller cations (LS Ni3+, is Co3+) as probes diluted in a perovskite matrix

    International Nuclear Information System (INIS)

    Sanz-Ortiz, M N; RodrIguez, F; Baranov, A; Demazeau, G

    2008-01-01

    The objective is to explore through optical spectroscopy and magnetic measurements the coordination and electronic structures of transition-metal ions introduced as impurities with unusual valence states in the oxide perovskite LaAlO 3 . The selected transition-metal ions Ni 3+ (3d 7 ) and Co 3+ (3d 6 ) are characterized by an electronic configuration likely leading to an orbital degenerate E state in Oh symmetry, and thus electron-lattice coupling due to the Jahn-Teller effect may induce low symmetry distortion around the impurity oxygen octahedron. We show that a sol-gel process followed by high oxygen pressure treatments yields stabilization of trivalent state in oxide perovskite. Information about the coordination, electronic structure and aggregation around the magnetic impurity was obtained from X-ray diffraction, FTIR and optical spectroscopy. Finally, evidence on the possible existence of intermediate spin state in Co 3+ is under consideration

  18. Probing magnetochirality

    Indian Academy of Sciences (India)

    field wave-vector k and the magnetic field B. However, it is independent of the state of ... there were some preliminary investigations in crystals by Portigal and Burstein .... where ω is the optical frequency, aF and aOA characterize the magnetic ...

  19. Intuitionistic fuzzy (IF) evaluations of multidimensional model

    International Nuclear Information System (INIS)

    Valova, I.

    2012-01-01

    There are different logical methods for data structuring, but no one is perfect enough. Multidimensional model-MD of data is presentation of data in a form of cube (referred also as info-cube or hypercube) with data or in form of 'star' type scheme (referred as multidimensional scheme), by use of F-structures (Facts) and set of D-structures (Dimensions), based on the notion of hierarchy of D-structures. The data, being subject of analysis in a specific multidimensional model is located in a Cartesian space, being restricted by D-structures. In fact, the data is either dispersed or 'concentrated', therefore the data cells are not distributed evenly within the respective space. The moment of occurrence of any event is difficult to be predicted and the data is concentrated as per time periods, location of performed business event, etc. To process such dispersed or concentrated data, various technical strategies are needed. The basic methods for presentation of such data should be selected. The approaches of data processing and respective calculations are connected with different options for data representation. The use of intuitionistic fuzzy evaluations (IFE) provide us new possibilities for alternative presentation and processing of data, subject of analysis in any OLAP application. The use of IFE at the evaluation of multidimensional models will result in the following advantages: analysts will dispose with more complete information for processing and analysis of respective data; benefit for the managers is that the final decisions will be more effective ones; enabling design of more functional multidimensional schemes. The purpose of this work is to apply intuitionistic fuzzy evaluations of multidimensional model of data. (authors)

  20. Thermal and optical characterization of biologically synthesized ZnS nanoparticles synthesized from an endophytic fungus Aspergillus flavus: A colorimetric probe in metal detection.

    Science.gov (United States)

    Uddandarao, Priyanka; Balakrishnan, Raj Mohan

    2017-03-15

    Nanostructured semiconductor materials are of great importance for several technological applications due to their optical and thermal properties. The design and fabrication of metal sulfide nanoparticles with tunable properties for advanced applications have drawn a great deal of attention in the field of nanotechnology. ZnS is a potential II-IV group material which is used in hetero-junction solar cells, light emitting diodes, optoelectronic devices, electro luminescent devices and photovoltaic cells. Due to their multiple applications, there is a need to elucidate their thermal and optical properties. In the present study, thermal and optical properties of biologically synthesized ZnS nanoparticles are determined in detail with Thermal Gravimetric Analysis (TGA), Derivative Thermogravimetric Analysis (DTG), Differential Scanning Calorimeter (DSC), Diffuse Reflectance Spectroscopy (DRS), Photoluminescence (PL) and Raman spectroscopy. The results reveal that ZnS NPs exhibit a very strong quantum confinement with a significant increase in their optical band gap energy. These biologically synthesized ZnS NPs contain protein residues that can selectively bind with metal ions in aqueous solutions and can exhibit an aggregation-induced color change. This phenomenon is utilized to quantitatively measure the metal concentrations of Cu 2+ and Mn 2+ in this study. Further the stability of nanoparticles for the metal sensing process is accessed by UV-Vis spectrometer, zeta potential and cyclic voltammeter. The selectivity and sensitivity of ZnS NPs indicate its potential use as a sensor for metal detection in the ecosystem. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. DESIGN NOTE: From nanometre to millimetre: a feasibility study of the combination of scanning probe microscopy and combined optical and x-ray interferometry

    Science.gov (United States)

    Yacoot, Andrew; Koenders, Ludger

    2003-09-01

    This feasibility study investigates the potential combination of an x-ray interferometer and optical interferometer as a one-dimensional long range high resolution scanning stage for an atomic force microscope (AFM) in order to overcome the problems of non-linearity associated with conventional AFMs and interferometers. Preliminary results of measurements of the uniformity of the period of a grating used as a transfer standards show variations in period at the nanometre level.

  2. Probing Hypergiant Mass Loss with Adaptive Optics Imaging and Polarimetry in the Infrared: MMT-Pol and LMIRCam Observations of IRC +10420 and VY Canis Majoris

    Science.gov (United States)

    Shenoy, Dinesh P.; Jones, Terry J.; Packham, Chris; Lopez-Rodriguez, Enrique

    2015-07-01

    We present 2-5 μm adaptive optics (AO) imaging and polarimetry of the famous hypergiant stars IRC +10420 and VY Canis Majoris. The imaging polarimetry of IRC +10420 with MMT-Pol at 2.2 μ {m} resolves nebular emission with intrinsic polarization of 30%, with a high surface brightness indicating optically thick scattering. The relatively uniform distribution of this polarized emission both radially and azimuthally around the star confirms previous studies that place the scattering dust largely in the plane of the sky. Using constraints on scattered light consistent with the polarimetry at 2.2 μ {m}, extrapolation to wavelengths in the 3-5 μm band predicts a scattered light component significantly below the nebular flux that is observed in our Large Binocular Telescope/LMIRCam 3-5 μm AO imaging. Under the assumption this excess emission is thermal, we find a color temperature of ˜500 K is required, well in excess of the emissivity-modified equilibrium temperature for typical astrophysical dust. The nebular features of VY CMa are found to be highly polarized (up to 60%) at 1.3 μm, again with optically thick scattering required to reproduce the observed surface brightness. This star’s peculiar nebular feature dubbed the “Southwest Clump” is clearly detected in the 3.1 μm polarimetry as well, which, unlike IRC +10420, is consistent with scattered light alone. The high intrinsic polarizations of both hypergiants’ nebulae are compatible with optically thick scattering for typical dust around evolved dusty stars, where the depolarizing effect of multiple scatters is mitigated by the grains’ low albedos. Observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona.

  3. Scanning optical microscope with long working distance objective

    Science.gov (United States)

    Cloutier, Sylvain G.

    2010-10-19

    A scanning optical microscope, including: a light source to generate a beam of probe light; collimation optics to substantially collimate the probe beam; a probe-result beamsplitter; a long working-distance, infinity-corrected objective; scanning means to scan a beam spot of the focused probe beam on or within a sample; relay optics; and a detector. The collimation optics are disposed in the probe beam. The probe-result beamsplitter is arranged in the optical paths of the probe beam and the resultant light from the sample. The beamsplitter reflects the probe beam into the objective and transmits resultant light. The long working-distance, infinity-corrected objective is also arranged in the optical paths of the probe beam and the resultant light. It focuses the reflected probe beam onto the sample, and collects and substantially collimates the resultant light. The relay optics are arranged to relay the transmitted resultant light from the beamsplitter to the detector.

  4. Multi-Dimensional Aggregation for Temporal Data

    DEFF Research Database (Denmark)

    Böhlen, M. H.; Gamper, J.; Jensen, Christian Søndergaard

    2006-01-01

    Business Intelligence solutions, encompassing technologies such as multi-dimensional data modeling and aggregate query processing, are being applied increasingly to non-traditional data. This paper extends multi-dimensional aggregation to apply to data with associated interval values that capture...... that the data holds for each point in the interval, as well as the case where the data holds only for the entire interval, but must be adjusted to apply to sub-intervals. The paper reports on an implementation of the new operator and on an empirical study that indicates that the operator scales to large data...

  5. Simulation of a Multidimensional Input Quantum Perceptron

    Science.gov (United States)

    Yamamoto, Alexandre Y.; Sundqvist, Kyle M.; Li, Peng; Harris, H. Rusty

    2018-06-01

    In this work, we demonstrate the improved data separation capabilities of the Multidimensional Input Quantum Perceptron (MDIQP), a fundamental cell for the construction of more complex Quantum Artificial Neural Networks (QANNs). This is done by using input controlled alterations of ancillary qubits in combination with phase estimation and learning algorithms. The MDIQP is capable of processing quantum information and classifying multidimensional data that may not be linearly separable, extending the capabilities of the classical perceptron. With this powerful component, we get much closer to the achievement of a feedforward multilayer QANN, which would be able to represent and classify arbitrary sets of data (both quantum and classical).

  6. Multi-dimensional Laplace transforms and applications

    International Nuclear Information System (INIS)

    Mughrabi, T.A.

    1988-01-01

    In this dissertation we establish new theorems for computing certain types of multidimensional Laplace transform pairs from known one-dimensional Laplace transforms. The theorems are applied to the most commonly used special functions and so we obtain many two and three dimensional Laplace transform pairs. As applications, some boundary value problems involving linear partial differential equations are solved by the use of multi-dimensional Laplace transformation. Also we establish some relations between the Laplace transformation and other integral transformation in two variables

  7. SkyProbe: Real-Time Precision Monitoring in the Optical of the Absolute Atmospheric Absorption on the Telescope Science and Calibration Fields

    Science.gov (United States)

    Cuillandre, J.-C.; Magnier, E.; Sabin, D.; Mahoney, B.

    2016-05-01

    Mauna Kea is known for its pristine seeing conditions but sky transparency can be an issue for science operations since at least 25% of the observable (i.e. open dome) nights are not photometric, an effect mostly due to high-altitude cirrus. Since 2001, the original single channel SkyProbe mounted in parallel on the Canada-France-Hawaii Telescope (CFHT) has gathered one V-band exposure every minute during each observing night using a small CCD camera offering a very wide field of view (35 sq. deg.) encompassing the region pointed by the telescope for science operations, and exposures long enough (40 seconds) to capture at least 100 stars of Hipparcos' Tycho catalog at high galactic latitudes (and up to 600 stars at low galactic latitudes). The measurement of the true atmospheric absorption is achieved within 2%, a key advantage over all-sky direct thermal infrared imaging detection of clouds. The absolute measurement of the true atmospheric absorption by clouds and particulates affecting the data being gathered by the telescope's main science instrument has proven crucial for decision making in the CFHT queued service observing (QSO) representing today all of the telescope time. Also, science exposures taken in non-photometric conditions are automatically registered for a new observation at a later date at 1/10th of the original exposure time in photometric conditions to ensure a proper final absolute photometric calibration. Photometric standards are observed only when conditions are reported as being perfectly stable by SkyProbe. The more recent dual color system (simultaneous B & V bands) will offer a better characterization of the sky properties above Mauna Kea and should enable a better detection of the thinnest cirrus (absorption down to 0.01 mag., or 1%).

  8. Probing the electronic structure of Ni–Mn–In–Si based Heusler alloys thin films using magneto-optical spectra in martensitic and austenitic phases

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, A. [Department of Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Sokolov, A., E-mail: asokol@unlserve.unl.edu [Department of Physics and Astronomy, University of Nebraska-Lincoln, Lincoln, NE 68588 (United States); Gan’shina, E.A. [Department of Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Quetz, Abdiel; Dubenko, I.S. [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Stadler, S. [Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA 70803 (United States); Ali, N. [Department of Physics, Southern Illinois University, Carbondale, IL 62901 (United States); Titov, I.S.; Rodionov, I.D. [Department of Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Lähderanta, E. [Lappeenranta University of Technology, 53851 (Finland); Zhukov, A. [Dpto. de Física de Materiales, Fac. Químicas, UPV/EHU, 20018 San Sebastian (Spain); IKERBASQUE, Basque Foundation for Science, 48011 Bilbao (Spain); Granovsky, A.B. [Department of Physics, Lomonosov Moscow State University, Moscow 119991 (Russian Federation); Sabirianov, R. [Department of Physics, University of Nebraska at Omaha, Omaha, NE 68182 (United States)

    2017-06-15

    Highlights: • Magneto-optical properties of NiMnIn thin films with a magnetostructural transition. • Comparative analysis of magnetic properties in martensitic and austenite phases. • DFT calculations of the MO Kerr effect and site-resolved DOS agree with experiment. • The electronic structure does not change significantly with Martensitic transition. - Abstract: Thin films of Ni{sub 52}Mn{sub 35−x}In{sub 11+x}Si{sub 2} were fabricated by magnetron sputtering on MgO (0 0 1) single crystal substrates. Magnetization as function of temperature for Ni{sub 52}Mn{sub 35}In{sub 11}Si{sub 2} exhibits features consistent with a magnetostructural transition (MST) from an austenitic phase to a martensitic phase, similar to the bulk material. We observed that the martensitic transformation is externally sensitive to small changes in chemical composition and stoichiometry. It has been found that thin films of Ni{sub 52}Mn{sub 34−x}In{sub 11+x}Si{sub 2} with x = 0 and 1 undergo a temperature-induced MST or remain in a stable austenitic phase, respectively. Comparison of magneto-optical transverse Kerr effect spectra obtained at 0.5–4.0 eV in the 35–300 K temperature interval reveal insignificant differences between the martensitic and austenite phases. We found that the field and temperature dependencies of the transverse Kerr effect are quite different from the magnetization behavior, which is attributed to magnetic inhomogeneity across the films. To elucidate the effects of magnetostructural phase transitions on the electronic properties, we performed density functional calculations of the magneto-optical Kerr effect.

  9. Optical Spectroscopy

    DEFF Research Database (Denmark)

    Thyrhaug, Erling

    The work presented in this thesis is broadly concerned with how complexation reactions and molecular motion can be characterized with the standard techniques in optical spectroscopy. The thesis aims to show a relatively broad range of methods for probing physico-chemical properties in fluorophore...... information about chemical equilibria, kinetics and molecular motion by monitoring changes in optical properties of the system. The five presented research projects are largely unrelated to each other both in aim and in what property is probed, however they are all connected in that they are fluorophore...... reactions by optical spectroscopy. In project 1 simple steady-state absorption and fluorescence spectroscopy is used to determine the stoichiometries and equilibrium constants in the inclusion complex formation between cyclodextrins and derivatives of the water-insoluble oligo(phenylene vinylene) in aqueous...

  10. Application of multidimensional IRT models to longitudinal data

    NARCIS (Netherlands)

    te Marvelde, J.M.; Glas, Cornelis A.W.; Van Landeghem, Georges; Van Damme, Jan

    2006-01-01

    The application of multidimensional item response theory (IRT) models to longitudinal educational surveys where students are repeatedly measured is discussed and exemplified. A marginal maximum likelihood (MML) method to estimate the parameters of a multidimensional generalized partial credit model

  11. The emergence and evolution of the multidimensional organization

    NARCIS (Netherlands)

    Strikwerda, J.; Stoelhorst, J.W.

    2009-01-01

    The article discusses multidimensional organizations and the evolution of complex organizations. The six characteristics of multidimensional organizations, disadvantages of the successful organizational structure that is categorized as a multidivisional, multi-unit or M-form, research by the

  12. Multidimensional Screening as a Pharmacology Laboratory Experience.

    Science.gov (United States)

    Malone, Marvin H.; And Others

    1979-01-01

    A multidimensional pharmacodynamic screening experiment that addresses drug interaction is included in the pharmacology-toxicology laboratory experience of pharmacy students at the University of the Pacific. The student handout with directions for the procedure is reproduced, drug compounds tested are listed, and laboratory evaluation results are…

  13. Continued validation of the Multidimensional Perfectionism Scale.

    Science.gov (United States)

    Clavin, S L; Clavin, R H; Gayton, W F; Broida, J

    1996-06-01

    Scores on the Multidimensional Perfectionism Scale have been correlated with measures of obsessive-compulsive tendencies for women, so the validity of scores on this scale for 41 men was examined. Scores on the Perfectionism Scale were significantly correlated (.47-.03) with scores on the Maudsley Obsessive-Compulsive Inventory.

  14. Multi-dimensional indoor location information model

    NARCIS (Netherlands)

    Xiong, Q.; Zhu, Q.; Zlatanova, S.; Huang, L.; Zhou, Y.; Du, Z.

    2013-01-01

    Aiming at the increasing requirements of seamless indoor and outdoor navigation and location service, a Chinese standard of Multidimensional Indoor Location Information Model is being developed, which defines ontology of indoor location. The model is complementary to 3D concepts like CityGML and

  15. Multi-dimensional quasitoeplitz Markov chains

    Directory of Open Access Journals (Sweden)

    Alexander N. Dudin

    1999-01-01

    Full Text Available This paper deals with multi-dimensional quasitoeplitz Markov chains. We establish a sufficient equilibrium condition and derive a functional matrix equation for the corresponding vector-generating function, whose solution is given algorithmically. The results are demonstrated in the form of examples and applications in queues with BMAP-input, which operate in synchronous random environment.

  16. Multidimensional human dynamics in mobile phone communications.

    Science.gov (United States)

    Quadri, Christian; Zignani, Matteo; Capra, Lorenzo; Gaito, Sabrina; Rossi, Gian Paolo

    2014-01-01

    In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages). Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process.

  17. Multidimensional stochastic approximation using locally contractive functions

    Science.gov (United States)

    Lawton, W. M.

    1975-01-01

    A Robbins-Monro type multidimensional stochastic approximation algorithm which converges in mean square and with probability one to the fixed point of a locally contractive regression function is developed. The algorithm is applied to obtain maximum likelihood estimates of the parameters for a mixture of multivariate normal distributions.

  18. Multidimensional human dynamics in mobile phone communications.

    Directory of Open Access Journals (Sweden)

    Christian Quadri

    Full Text Available In today's technology-assisted society, social interactions may be expressed through a variety of techno-communication channels, including online social networks, email and mobile phones (calls, text messages. Consequently, a clear grasp of human behavior through the diverse communication media is considered a key factor in understanding the formation of the today's information society. So far, all previous research on user communication behavior has focused on a sole communication activity. In this paper we move forward another step on this research path by performing a multidimensional study of human sociality as an expression of the use of mobile phones. The paper focuses on user temporal communication behavior in the interplay between the two complementary communication media, text messages and phone calls, that represent the bi-dimensional scenario of analysis. Our study provides a theoretical framework for analyzing multidimensional bursts as the most general burst category, that includes one-dimensional bursts as the simplest case, and offers empirical evidence of their nature by following the combined phone call/text message communication patterns of approximately one million people over three-month period. This quantitative approach enables the design of a generative model rooted in the three most significant features of the multidimensional burst - the number of dimensions, prevalence and interleaving degree - able to reproduce the main media usage attitude. The other findings of the paper include a novel multidimensional burst detection algorithm and an insight analysis of the human media selection process.

  19. MCMC estimation of multidimensional IRT models

    NARCIS (Netherlands)

    Beguin, Anton; Glas, Cornelis A.W.

    1998-01-01

    A Bayesian procedure to estimate the three-parameter normal ogive model and a generalization to a model with multidimensional ability parameters are discussed. The procedure is a generalization of a procedure by J. Albert (1992) for estimating the two-parameter normal ogive model. The procedure will

  20. Swelling-induced optical anisotropy of thermoresponsive hydrogels based on poly(2-(2-methoxyethoxy)ethyl methacrylate): deswelling kinetics probed by quantitative Mueller matrix polarimetry.

    Science.gov (United States)

    Patil, Nagaraj; Soni, Jalpa; Ghosh, Nirmalya; De, Priyadarsi

    2012-11-29

    Thermodynamically favored polymer-water interactions below the lower critical solution temperature (LCST) caused swelling-induced optical anisotropy (linear retardance) of thermoresponsive hydrogels based on poly(2-(2-methoxyethoxy)ethyl methacrylate). This was exploited to study the macroscopic deswelling kinetics quantitatively by a generalized polarimetry analysis method, based on measurement of the Mueller matrix and its subsequent inverse analysis via the polar decomposition approach. The derived medium polarization parameters, namely, linear retardance (δ), diattenuation (d), and depolarization coefficient (Δ), of the hydrogels showed interesting differences between the gels prepared by conventional free radical polymerization (FRP) and reversible addition-fragmentation chain transfer polymerization (RAFT) and also between dry and swollen state. The effect of temperature, cross-linking density, and polymerization technique employed to synthesize hydrogel on deswelling kinetics was systematically studied via conventional gravimetry and corroborated further with the corresponding Mueller matrix derived quantitative polarimetry characteristics (δ, d, and Δ). The RAFT gels exhibited higher swelling ratio and swelling-induced optical anisotropy compared to FRP gels and also deswelled faster at 30 °C. On the contrary, at 45 °C, deswelling was significantly retarded for the RAFT gels due to formation of a skin layer, which was confirmed and quantified via the enhanced diattenuation and depolarization parameters.

  1. Second- and third-harmonic generation as a local probe for nanocrystal-doped polymer materials with a suppressed optical breakdown threshold

    Science.gov (United States)

    Konorov, S. O.; Fedotov, A. B.; Ivanov, A. A.; Alfimov, M. V.; Zabotnov, S. V.; Naumov, A. N.; Sidorov-Biryukov, D. A.; Podshivalov, A. A.; Petrov, A. N.; Fornarini, L.; Carpanese, M.; Ferrante, G.; Fantoni, R.; Zheltikov, A. M.

    2003-09-01

    Second- and third-harmonic generation processes are shown to allow the detection of absorptive agglomerates of nanocrystals in transparent materials and the visualization of optical breakdown in nanocomposite materials. Correlations between laser-induced breakdown and the behavior of the second- and third-harmonic signals produced in SiC/PMMA nanocomposite films are studied. The potential of second- and third-harmonic generation for the on-line visualization of laser breakdown in nanocomposite polymer materials is revealed, with the ablative material removal being monitored by the decay of the second- and third-harmonic signals. The second and third harmonics generated around the optical breakdown threshold by 75-fs pulses of 1.25-μm Cr:forsterite laser radiation are respectively more than two and four orders of magnitude more intense than the second and third harmonics produced under identical conditions by 40-ps pulses of a Nd:YAG laser. The breakdown threshold for PMMA films doped with 10-20-nm SiC nanocrystals forming absorptive agglomerates are demonstrated to be more than an order of magnitude lower than the breakdown threshold for crystalline SiC and about an order of magnitude lower than that for nondoped PMMA films.

  2. Optical nonlinearities of colloidal InP@ZnS core-shell quantum dots probed by Z-scan and two-photon excited emission

    International Nuclear Information System (INIS)

    Wawrzynczyk, Dominika; Szeremeta, Janusz; Samoc, Marek; Nyk, Marcin

    2015-01-01

    Spectrally resolved nonlinear optical properties of colloidal InP@ZnS core-shell quantum dots of various sizes were investigated with the Z-scan technique and two-photon fluorescence excitation method using a femtosecond laser system tunable in the range from 750 nm to 1600 nm. In principle, both techniques should provide comparable results and can be interchangeably used for determination of the nonlinear optical absorption parameters, finding maximal values of the cross sections and optimizing them. We have observed slight differences between the two-photon absorption cross sections measured by the two techniques and attributed them to the presence of non-radiative paths of absorption or relaxation. The most significant value of two-photon absorption cross section σ 2 for 4.3 nm size InP@ZnS quantum dot was equal to 2200 GM, while the two-photon excitation action cross section σ 2 Φ was found to be 682 GM at 880 nm. The properties of these cadmium-free colloidal quantum dots can be potentially useful for nonlinear bioimaging

  3. Influence of probe motion on laser probe temperature in circulating blood.

    Science.gov (United States)

    Hehrlein, C; Splinter, R; Littmann, L; Tuntelder, J R; Tatsis, G P; Svenson, R H

    1991-01-01

    The purpose of this study was to evaluate the effect of probe motion on laser probe temperature in various blood flow conditions. Laser probe temperatures were measured in an in vitro blood circulation model consisting of 3.2 nm-diameter plastic tubes. A 2.0 mm-diameter metal probe attached to a 300 microns optical quartz fiber was coupled to an argon laser. Continuous wave 4 watts and 8 watts of laser power were delivered to the fiber tip corresponding to a 6.7 +/- 0.5 and 13.2 +/- 0.7 watts power setting at the laser generator. The laser probe was either moved with constant velocity or kept stationary. A thermocouple inserted in the lateral portion of the probe was used to record probe temperatures. Probe temperature changes were found with the variation of laser power, probe velocity, blood flow, and duration of laser exposure. Probe motion significantly reduced probe temperatures. After 10 seconds of 4 watts laser power the probe temperature in stagnant blood decreased from 303 +/- 18 degrees C to 113 +/- 17 degrees C (63%) by moving the probe with a velocity of 5 cm/sec. Blood flow rates of 170 ml/min further decreased the probe temperature from 113 +/- 17 degrees C to 50 +/- 8 degrees C (56%). At 8 watts of laser power a probe temperature reduction from 591 +/- 25 degrees C to 534 +/- 36 degrees C (10%) due to 5 cm/sec probe velocity was noted. Probe temperatures were reduced to 130 +/- 30 degrees C (78%) under the combined influence of 5 cm/sec probe velocity and 170 ml/min blood flow.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Micron-scale mapping of megagauss magnetic fields using optical polarimetry to probe hot electron transport in petawatt-class laser-solid interactions.

    Science.gov (United States)

    Chatterjee, Gourab; Singh, Prashant Kumar; Robinson, A P L; Blackman, D; Booth, N; Culfa, O; Dance, R J; Gizzi, L A; Gray, R J; Green, J S; Koester, P; Kumar, G Ravindra; Labate, L; Lad, Amit D; Lancaster, K L; Pasley, J; Woolsey, N C; Rajeev, P P

    2017-08-21

    The transport of hot, relativistic electrons produced by the interaction of an intense petawatt laser pulse with a solid has garnered interest due to its potential application in the development of innovative x-ray sources and ion-acceleration schemes. We report on spatially and temporally resolved measurements of megagauss magnetic fields at the rear of a 50-μm thick plastic target, irradiated by a multi-picosecond petawatt laser pulse at an incident intensity of ~10 20 W/cm 2 . The pump-probe polarimetric measurements with micron-scale spatial resolution reveal the dynamics of the magnetic fields generated by the hot electron distribution at the target rear. An annular magnetic field profile was observed ~5 ps after the interaction, indicating a relatively smooth hot electron distribution at the rear-side of the plastic target. This is contrary to previous time-integrated measurements, which infer that such targets will produce highly structured hot electron transport. We measured large-scale filamentation of the hot electron distribution at the target rear only at later time-scales of ~10 ps, resulting in a commensurate large-scale filamentation of the magnetic field profile. Three-dimensional hybrid simulations corroborate our experimental observations and demonstrate a beam-like hot electron transport at initial time-scales that may be attributed to the local resistivity profile at the target rear.

  5. Dispersible crystalline nanobundles of YPO{sub 4} and Ln (Eu, Tb)-doped YPO{sub 4}: rapid synthesis, optical properties and bio-probe applications

    Energy Technology Data Exchange (ETDEWEB)

    Majeed, Shafquat, E-mail: shafquatmajeed@gmail.com [Indian Institute of Science, Materials Research Centre (India); Bashir, Mohsin [Indian Institute of Science, Department of Molecular Reproduction, Development and Genetics (MRDG) (India); Shivashankar, S. A. [Indian Institute of Science, Materials Research Centre (India)

    2015-07-15

    Undoped and Ln{sup 3+} (Eu and Tb)-doped crystalline nanobundles of YPO{sub 4} were prepared by a facile microwave-assisted route with water as a solvent and without using any surfactant. TEM investigations reveal that the as-prepared powder consists of lenticular-shaped nanobundles (∼100 nm in diameter) made of very small nanorods with diameter less than 10 nm and length varying from 20 to 50 nm. Each nanorod in turn is single crystalline, as revealed by HRTEM imaging. The as-prepared nanobundles are easily dispersible in various solvents, especially water, without any surface functionalization, which is critical for various bio-probe applications like cell and tissue imaging. The Eu- and Tb-doped YPO{sub 4} nanobundles show good photoluminescence properties and were further evaluated for their use as fluorescent biolabels. Our results show that HeLa cells labelled with Eu- and Tb-doped YPO{sub 4} nanobundles show bright red (Eu) and green (Tb) intracellular luminescence under a confocal microscope. Concentration- and time-dependent MTT cell viability assays show that the nanobundles show low toxicity towards cells which makes them promising in bioimaging field.

  6. Multidimensional Data Model and Query Language for Informetrics.

    Science.gov (United States)

    Niemi, Timo; Hirvonen, Lasse; Jarvelin, Kalervo

    2003-01-01

    Discusses multidimensional data analysis, or online analytical processing (OLAP), which offer a single subject-oriented source for analyzing summary data based on various dimensions. Develops a conceptual/logical multidimensional model for supporting the needs of informetrics, including a multidimensional query language whose basic idea is to…

  7. Use of ultrafast dispersed pump-dump-probe and pump-repump-probe spectroscopies to explore the light-induced dynamics of peridinin in solution

    NARCIS (Netherlands)

    Papagiannakis, E.; Vengris, M.; Larsen, D.S.; van Stokkum, I.H.M.; Hiller, R.G.; van Grondelle, R.

    2006-01-01

    Optical pump-induced dynamics of the highly asymmetric carotenoid peridinin in methanol was studied by dispersed pump-probe, pump-dump-probe, and pump-repump-probe transient absorption spectroscopy in the visible region. Dispersed pump-probe measurements show that the decay of the initially excited

  8. Nine New Fluorescent Probes

    Science.gov (United States)

    Lin, Tsung-I.; Jovanovic, Misa V.; Dowben, Robert M.

    1989-06-01

    Absorption and fluorescence spectroscopic studies are reported here for nine new fluorescent probes recently synthesized in our laboratories: four pyrene derivatives with substituents of (i) 1,3-diacetoxy-6,8-dichlorosulfonyl, (ii) 1,3-dihydroxy-6,8-disodiumsulfonate, (iii) 1,3-disodiumsulfonate, and (iv) l-ethoxy-3,6,8-trisodiumsulfonate groups, and five [7-julolidino] coumarin derivatives with substituents of (v) 3-carboxylate-4-methyl, (vi) 3- methylcarboxylate, (vii) 3-acetate-4-methyl, (viii) 3-propionate-4-methyl, and (ix) 3-sulfonate-4-methyl groups. Pyrene compounds i and ii and coumarin compounds v and vi exhibit interesting absorbance and fluorescence properties: their absorption maxima are red shifted compared to the parent compound to the blue-green region, and the band width broadens considerably. All four blue-absorbing dyes fluoresce intensely in the green region, and the two pyrene compounds emit at such long wavelengths without formation of excimers. The fluorescence properties of these compounds are quite environment-sensitive: considerable spectral shifts and fluorescence intensity changes have been observed in the pH range from 3 to 10 and in a wide variety of polar and hydrophobic solvents with vastly different dielectric constants. The high extinction and fluorescence quantum yield of these probes make them ideal fluorescent labeling reagents for proteins, antibodies, nucleic acids, and cellular organelles. The pH and hydrophobicity-dependent fluorescence changes can be utilized as optical pH and/or hydrophobicity indicators for mapping environmental difference in various cellular components in a single cell. Since all nine probes absorb in the UV, but emit at different wavelengths in the visible, these two groups of compounds offer an advantage of utilizing a single monochromatic light source (e.g., a nitrogen laser) to achieve multi-wavelength detection for flow cytometry application. As a first step to explore potential application in

  9. Probe-based recording technology

    International Nuclear Information System (INIS)

    Naberhuis, Steve

    2002-01-01

    The invention of the scanning tunneling microscope (STM) prompted researchers to contemplate whether such technology could be used as the basis for the storage and retrieval of information. With magnetic data storage technology facing limits in storage density due to the thermal instability of magnetic bits, the super-paramagnetic limit, the heir-apparent for information storage at higher densities appeared to be variants of the STM or similar probe-based storage techniques such as atomic force microscopy (AFM). Among these other techniques that could provide replacement technology for magnetic storage, near-field optical scanning optical microscopy (NSOM or SNOM) has also been investigated. Another alternative probe-based storage technology called atomic resolution storage (ARS) is also currently under development. An overview of these various technologies is herein presented, with an analysis of the advantages and disadvantages inherent in each particularly with respect to reduced device dimensions. The role of micro electro mechanical systems (MEMS) is emphasized

  10. Multidimensional integral representations problems of analytic continuation

    CERN Document Server

    Kytmanov, Alexander M

    2015-01-01

    The monograph is devoted to integral representations for holomorphic functions in several complex variables, such as Bochner-Martinelli, Cauchy-Fantappiè, Koppelman, multidimensional logarithmic residue etc., and their boundary properties. The applications considered are problems of analytic continuation of functions from the boundary of a bounded domain in C^n. In contrast to the well-known Hartogs-Bochner theorem, this book investigates functions with the one-dimensional property of holomorphic extension along complex lines, and includes the problems of receiving multidimensional boundary analogs of the Morera theorem.   This book is a valuable resource for specialists in complex analysis, theoretical physics, as well as graduate and postgraduate students with an understanding of standard university courses in complex, real and functional analysis, as well as algebra and geometry.

  11. High-Speed Microscale Optical Tracking Using Digital Frequency-Domain Multiplexing.

    Science.gov (United States)

    Maclachlan, Robert A; Riviere, Cameron N

    2009-06-01

    Position-sensitive detectors (PSDs), or lateral-effect photodiodes, are commonly used for high-speed, high-resolution optical position measurement. This paper describes the instrument design for multidimensional position and orientation measurement based on the simultaneous position measurement of multiple modulated sources using frequency-domain-multiplexed (FDM) PSDs. The important advantages of this optical configuration in comparison with laser/mirror combinations are that it has a large angular measurement range and allows the use of a probe that is small in comparison with the measurement volume. We review PSD characteristics and quantitative resolution limits, consider the lock-in amplifier measurement system as a communication link, discuss the application of FDM to PSDs, and make comparisons with time-domain techniques. We consider the phase-sensitive detector as a multirate DSP problem, explore parallels with Fourier spectral estimation and filter banks, discuss how to choose the modulation frequencies and sample rates that maximize channel isolation under design constraints, and describe efficient digital implementation. We also discuss hardware design considerations, sensor calibration, probe construction and calibration, and 3-D measurement by triangulation using two sensors. As an example, we characterize the resolution, speed, and accuracy of an instrument that measures the position and orientation of a 10 mm × 5 mm probe in 5 degrees of freedom (DOF) over a 30-mm cube with 4-μm peak-to-peak resolution at 1-kHz sampling.

  12. Applications of Convex Analysis to Multidimensional Scaling

    OpenAIRE

    Jan de Leeuw

    2011-01-01

    In this paper we discuss the convergence of an algorithm for metric and nonmetric multidimensional scaling that is very similar to the C-matrix algorithm of Guttman. The paper improves some earlier results in two respects. In the first place the analysis is extended to cover general Minkovski metrics, in the second place a more elementary proof of convergence based on results of Robert is presented.

  13. Multidimensional Scaling Visualization using Parametric Similarity Indices

    OpenAIRE

    Machado, J. A. Tenreiro; Lopes, António M.; Galhano, A.M.

    2015-01-01

    In this paper, we apply multidimensional scaling (MDS) and parametric similarity indices (PSI) in the analysis of complex systems (CS). Each CS is viewed as a dynamical system, exhibiting an output time-series to be interpreted as a manifestation of its behavior. We start by adopting a sliding window to sample the original data into several consecutive time periods. Second, we define a given PSI for tracking pieces of data. We then compare the windows for different values of the parameter, an...

  14. Frost Multidimensional Perfectionism Scale: the portuguese version

    Directory of Open Access Journals (Sweden)

    Ana Paula Monteiro Amaral

    2013-01-01

    Full Text Available BACKGROUND: The Frost Multidimensional Perfectionism Scale is one of the most world widely used measures of perfectionism. OBJECTIVE: To analyze the psychometric properties of the Portuguese version of the Frost Multidimensional Perfectionism Scale. METHODS: Two hundred and seventeen (178 females students from two Portuguese Universities filled in the scale, and a subgroup (n = 166 completed a retest with a four weeks interval. RESULTS: The scale reliability was good (Cronbach alpha = .857. Corrected item-total correlations ranged from .019 to .548. The scale test-retest reliability suggested a good temporal stability with a test-retest correlation of .765. A principal component analysis with Varimax rotation was performed and based on the Scree plot, two robust factorial structures were found (four and six factors. The principal component analyses, using Monte Carlo PCA for parallel analyses confirmed the six factor solution. The concurrent validity with Hewitt and Flett MPS was high, as well as the discriminant validity of positive and negative affect (Profile of Mood Stats-POMS. DISCUSSION: The two factorial structures (of four and six dimensions of the Portuguese version of Frost Multidimensional Perfectionism Scale replicate the results from different authors, with different samples and cultures. This suggests this scale is a robust instrument to assess perfectionism, in several clinical and research settings as well as in transcultural studies.

  15. Proximal Probes Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  16. Probe Techniques. Introductory Remarks

    Energy Technology Data Exchange (ETDEWEB)

    Emeleus, K. G. [School of Physics and Applied Mathematics, Queen' s University, Belfast (United Kingdom)

    1968-04-15

    In this brief introduction to the session on probes, the history of theii development is first touched on briefly. Reference is then made to the significance of the work to be described by Medicus, for conductivity and recombination calculations, and by Lam and Su, for a wide range of medium and higher pressure plasmas. Finally, a number of other probe topics are mentioned, including multiple probes; probes in electronegative plasmas; resonance probes; probes in noisy discharges; probes as oscillation detectors; use of probes where space-charge is not negligible. (author)

  17. IVVS probe mechanical concept design

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Paolo, E-mail: paolo.rossi@enea.it; Neri, Carlo; De Collibus, Mario Ferri; Mugnaini, Giampiero; Pollastrone, Fabio; Crescenzi, Fabio

    2015-10-15

    Highlights: • ENEA designed, developed and tested a laser based In Vessel Viewing System (IVVS). • IVVS mechanical design has been revised from 2011 to 2013 to meet ITER requirements. • Main improvements are piezoceramic actuators and a step focus system. • Successful qualification activities validated the concept design for ITER environment. - Abstract: ENEA has been deeply involved in the design, development and testing of a laser based In Vessel Viewing System (IVVS) required for the inspection of ITER plasma-facing components. The IVVS probe shall be deployed into the vacuum vessel, providing high resolution images and metrology measurements to detect damages and possible erosion. ENEA already designed and manufactured an IVVS probe prototype based on a rad-hard concept and driven by commercial micro-step motors, which demonstrated satisfying viewing and metrology performances at room conditions. The probe sends a laser beam through a reflective rotating prism. By rotating the axes of the prism, the probe can scan all the environment points except those present in a shadow cone and the backscattered light signal is then processed to measure the intensity level (viewing) and the distance from the probe (metrology). During the last years, in order to meet all the ITER environmental conditions, such as high vacuum, gamma radiation lifetime dose up to 5 MGy, cumulative neutron fluence of about 2.3 × 10{sup 17} n/cm{sup 2}, temperature of 120 °C and magnetic field of 8 T, the probe mechanical design was significantly revised introducing a new actuating system based on piezo-ceramic actuators and improved with a new step focus system. The optical and mechanical schemes have been then modified and refined to meet also the geometrical constraints. The paper describes the mechanical concept design solutions adopted in order to fulfill IVVS probe functional performance requirements considering ITER working environment and geometrical constraints.

  18. EDITORIAL: Probing the nanoworld Probing the nanoworld

    Science.gov (United States)

    Miles, Mervyn

    2009-10-01

    In nanotechnology, it is the unique properties arising from nanometre-scale structures that lead not only to their technological importance but also to a better understanding of the underlying science. Over the last twenty years, material properties at the nanoscale have been dominated by the properties of carbon in the form of the C60 molecule, single- and multi-wall carbon nanotubes, nanodiamonds, and recently graphene. During this period, research published in the journal Nanotechnology has revealed the amazing mechanical properties of such materials as well as their remarkable electronic properties with the promise of new devices. Furthermore, nanoparticles, nanotubes, nanorods, and nanowires from metals and dielectrics have been characterized for their electronic, mechanical, optical, chemical and catalytic properties. Scanning probe microscopy (SPM) has become the main characterization technique and atomic force microscopy (AFM) the most frequently used SPM. Over the past twenty years, SPM techniques that were previously experimental in nature have become routine. At the same time, investigations using AFM continue to yield impressive results that demonstrate the great potential of this powerful imaging tool, particularly in close to physiological conditions. In this special issue a collaboration of researchers in Europe report the use of AFM to provide high-resolution topographical images of individual carbon nanotubes immobilized on various biological membranes, including a nuclear membrane for the first time (Lamprecht C et al 2009 Nanotechnology 20 434001). Other SPM developments such as high-speed AFM appear to be making a transition from specialist laboratories to the mainstream, and perhaps the same may be said for non-contact AFM. Looking to the future, characterisation techniques involving SPM and spectroscopy, such as tip-enhanced Raman spectroscopy, could emerge as everyday methods. In all these advanced techniques, routinely available probes will

  19. Multidimensional Models of Type Ia Supernova Nebular Spectra: Strong Emission Lines from Stripped Companion Gas Rule Out Classic Single-degenerate Systems

    Science.gov (United States)

    Botyánszki, János; Kasen, Daniel; Plewa, Tomasz

    2018-01-01

    The classic single-degenerate model for the progenitors of Type Ia supernova (SN Ia) predicts that the supernova ejecta should be enriched with solar-like abundance material stripped from the companion star. Spectroscopic observations of normal SNe Ia at late times, however, have not resulted in definite detection of hydrogen. In this Letter, we study line formation in SNe Ia at nebular times using non-LTE spectral modeling. We present, for the first time, multidimensional radiative transfer calculations of SNe Ia with stripped material mixed in the ejecta core, based on hydrodynamical simulations of ejecta–companion interaction. We find that interaction models with main-sequence companions produce significant Hα emission at late times, ruling out these types of binaries being viable progenitors of SNe Ia. We also predict significant He I line emission at optical and near-infrared wavelengths for both hydrogen-rich or helium-rich material, providing an additional observational probe of stripped ejecta. We produce models with reduced stripped masses and find a more stringent mass limit of M st ≲ 1 × 10‑4 M ⊙ of stripped companion material for SN 2011fe.

  20. System for testing optical fibers

    Science.gov (United States)

    Golob, John E. [Olathe, KS; Looney, Larry D. [Los Alamos, NM; Lyons, Peter B. [Los Alamos, NM; Nelson, Melvin A. [Santa Barbara, CA; Davies, Terence J. [Santa Barbara, CA

    1980-07-15

    A system for measuring a combination of optical transmission properties of fiber optic waveguides. A polarized light pulse probe is injected into one end of the optical fiber. Reflections from discontinuities within the fiber are unpolarized whereas reflections of the probe pulse incident to its injection remain polarized. The polarized reflections are prevented from reaching a light detector whereas reflections from the discontinuities reaches the detector.

  1. The emergence and evolution of the multidimensional organization

    OpenAIRE

    Strikwerda, J.; Stoelhorst, J.W.

    2009-01-01

    The article discusses multidimensional organizations and the evolution of complex organizations. The six characteristics of multidimensional organizations, disadvantages of the successful organizational structure that is categorized as a multidivisional, multi-unit or M-form, research by the Foundation for Management Studies which suggests that synergies across business divisions can be exploited by the M-form, a team approach to creating economic value, examples of multidimensional firms suc...

  2. An Improved Multidimensional MPA Procedure for Bidirectional Earthquake Excitations

    OpenAIRE

    Wang, Feng; Sun, Jian-Gang; Zhang, Ning

    2014-01-01

    Presently, the modal pushover analysis procedure is extended to multidimensional analysis of structures subjected to multidimensional earthquake excitations. an improved multidimensional modal pushover analysis (IMMPA) method is presented in the paper in order to estimate the response demands of structures subjected to bidirectional earthquake excitations, in which the unidirectional earthquake excitation applied on equivalent SDOF system is replaced by the direct superposition of two compone...

  3. Multidimensional Risk Management for Underground Electricity Networks

    Directory of Open Access Journals (Sweden)

    Garcez Thalles V.

    2014-08-01

    Full Text Available In the paper we consider an electricity provider company that makes decision on allocating resources on electric network maintenance. The investments decrease malfunction rate of network nodes. An accidental event (explosion, fire, etc. or a malfunctioning on underground system can have various consequences and in different perspectives, such as deaths and injuries of pedestrians, fires in nearby locations, disturbances in the flow of vehicular traffic, loss to the company image, operating and financial losses, etc. For this reason it is necessary to apply an approach of the risk management that considers the multidimensional view of the consequences. Furthermore an analysis of decision making should consider network dependencies between the nodes of the electricity distribution system. In the paper we propose the use of the simulation to assess the network effects (such as the increase of the probability of other accidental event and the occurrence of blackouts of the dependent nodes in the multidimensional risk assessment in electricity grid. The analyzed effects include node overloading due to malfunction of adjacent nodes and blackouts that take place where there is temporarily no path in the grid between the power plant and a node. The simulation results show that network effects have crucial role for decisions in the network maintenance – outcomes of decisions to repair a particular node in the network can have significant influence on performance of other nodes. However, those dependencies are non-linear. The effects of network connectivity (number of connections between nodes on its multidimensional performance assessment depend heavily on the overloading effect level. The simulation results do not depend on network type structure (random or small world – however simulation outcomes for random networks have shown higher variance compared to small-world networks.

  4. Trust and credibility: measured by multidimensional scaling

    International Nuclear Information System (INIS)

    Warg, L.E.; Bodin, L.

    1998-01-01

    Full text of publication follows: in focus of much of today's research interest in risk communication, is the fact that the communities do not trust policy and decision makers such as politicians, government or industry people. This is especially serious in the years to come when we are expecting risk issues concerning for example the nuclear industry, global warming and hazardous waste, to be even higher on the political and social agenda all over the world. Despite the research efforts devoted to trust, society needs an in depth understanding of trust for conducting successful communication regarding environmental hazards. The present abstract is about an experimental study in psychology where focus has been on the possibility to use the multidimensional scaling technique to explore the characteristics people consider to be of importance when they say that certain persons are credible. In the study, a total of 61 students of the University of Oerebro, Sweden, were required to make comparisons of the similarity between 12 well-known swedish persons from politics science, media, industry, 'TV-world' and literature (two persons at a time), regarding their credibility when making statements about risks in society. In addition, the subjects were rating the importance of 19 factors for the credibility of a source. These 61 persons comprised three groups of students: pedagogists, business economists, and chemists. There were 61 % women and 39% men and the mean age was 23 years. The results will be analyzed using multidimensional scaling technique. Differences between the three groups will be analyzed and presented as well as those between men and women. In addition, the 19 factors will be discussed and considered when trying to label the dimensions accounted for by the multidimensional scaling technique. The result from this study will contribute to our understanding of important factors behind human judgments concerning trust and credibility. It will also point to a

  5. Detecting and Tracking Nonfluorescent Nanoparticles Probes in Live Cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Gufeng; Fang, Ning

    2012-01-17

    Precisely imaging and tracking dynamic biological processes in live cells are crucial for both fundamental research in life sciences and biomedical applications. Nonfluorescent nanoparticles are emerging as important optical probes in live-cell imaging because of their excellent photostability, large optical cross sections, and low cytotoxicity. Here, we provide a review of recent development in optical imaging of nonfluorescent nanoparticle probes and their applications in dynamic tracking and biosensing in live cells. A brief discussion on cytotoxicity of nanoparticle probes is also provided.

  6. Study of probe-sample distance for biomedical spectra measurement

    Directory of Open Access Journals (Sweden)

    Li Lei

    2011-11-01

    Full Text Available Abstract Background Fiber-based optical spectroscopy has been widely used for biomedical applications. However, the effect of probe-sample distance on the collection efficiency has not been well investigated. Method In this paper, we presented a theoretical model to maximize the illumination and collection efficiency in designing fiber optic probes for biomedical spectra measurement. This model was in general applicable to probes with single or multiple fibers at an arbitrary incident angle. In order to demonstrate the theory, a fluorescence spectrometer was used to measure the fluorescence of human finger skin at various probe-sample distances. The fluorescence spectrum and the total fluorescence intensity were recorded. Results The theoretical results show that for single fiber probes, contact measurement always provides the best results. While for multi-fiber probes, there is an optimal probe distance. When a 400- μm excitation fiber is used to deliver the light to the skin and another six 400- μm fibers surrounding the excitation fiber are used to collect the fluorescence signal, the experimental results show that human finger skin has very strong fluorescence between 475 nm and 700 nm under 450 nm excitation. The fluorescence intensity is heavily dependent on the probe-sample distance and there is an optimal probe distance. Conclusions We investigated a number of probe-sample configurations and found that contact measurement could be the primary choice for single-fiber probes, but was very inefficient for multi-fiber probes. There was an optimal probe-sample distance for multi-fiber probes. By carefully choosing the probe-sample distance, the collection efficiency could be enhanced by 5-10 times. Our experiments demonstrated that the experimental results of the probe-sample distance dependence of collection efficiency in multi-fiber probes were in general agreement with our theory.

  7. Recent developments in multimodality fluorescence imaging probes

    Directory of Open Access Journals (Sweden)

    Jianhong Zhao

    2018-05-01

    Full Text Available Multimodality optical imaging probes have emerged as powerful tools that improve detection sensitivity and accuracy, important in disease diagnosis and treatment. In this review, we focus on recent developments of optical fluorescence imaging (OFI probe integration with other imaging modalities such as X-ray computed tomography (CT, magnetic resonance imaging (MRI, positron emission tomography (PET, single-photon emission computed tomography (SPECT, and photoacoustic imaging (PAI. The imaging technologies are briefly described in order to introduce the strengths and limitations of each techniques and the need for further multimodality optical imaging probe development. The emphasis of this account is placed on how design strategies are currently implemented to afford physicochemically and biologically compatible multimodality optical fluorescence imaging probes. We also present studies that overcame intrinsic disadvantages of each imaging technique by multimodality approach with improved detection sensitivity and accuracy. KEY WORDS: Optical imaging, Fluorescence, Multimodality, Near-infrared fluorescence, Nanoprobe, Computed tomography, Magnetic resonance imaging, Positron emission tomography, Single-photon emission computed tomography, Photoacoustic imaging

  8. Photometric device using optical fibers

    International Nuclear Information System (INIS)

    Boisde, Gilbert; Perez, J.-J.

    1981-02-01

    Remote measurements in radioactive environment are now possible with optical fibers. Measurement instruments developed by CEA are constitued of: - an optical probe (5 mm to 1 meter optical path length), - a photometric measurement device, - optical fiber links. 'TELEPHOT' is a photometric device for industrial installations. It is uses interferentiel filters for 2 to 5 simultaneous wave lengths. 'CRUDMETER' measures the muddiness of water. It can be equipped with a high sensitivity cell of 50 cm optical path length tested up to 250 bars. Coupling a double beam spectrophotometer to a remote optical probe, up to 1 meter optical path length, is carried out by means of an optical device using optical fibers links, eventually several hundred meter long. For these equipments special step index large core fibers, 1 to 1.5 mm in diameter, have been developed as well connectors. For industrial control and research these instruments offer new prospect thanks to optical fibers use [fr

  9. Imaging a multidimensional multichannel potential energy surface: Photodetachment of H(-)(NH3) and NH4 (.).

    Science.gov (United States)

    Hu, Qichi; Song, Hongwei; Johnson, Christopher J; Li, Jun; Guo, Hua; Continetti, Robert E

    2016-06-28

    Probes of the Born-Oppenheimer potential energy surfaces governing polyatomic molecules often rely on spectroscopy for the bound regions or collision experiments in the continuum. A combined spectroscopic and half-collision approach to image nuclear dynamics in a multidimensional and multichannel system is reported here. The Rydberg radical NH4 and the double Rydberg anion NH4 (-) represent a polyatomic system for benchmarking electronic structure and nine-dimensional quantum dynamics calculations. Photodetachment of the H(-)(NH3) ion-dipole complex and the NH4 (-) DRA probes different regions on the neutral NH4 PES. Photoelectron energy and angular distributions at photon energies of 1.17, 1.60, and 2.33 eV compare well with quantum dynamics. Photoelectron-photofragment coincidence experiments indicate dissociation of the nascent NH4 Rydberg radical occurs to H + NH3 with a peak kinetic energy of 0.13 eV, showing the ground state of NH4 to be unstable, decaying by tunneling-induced dissociation on a time scale beyond the present scope of multidimensional quantum dynamics.

  10. Multidimensional flux-limited advection schemes

    International Nuclear Information System (INIS)

    Thuburn, J.

    1996-01-01

    A general method for building multidimensional shape preserving advection schemes using flux limiters is presented. The method works for advected passive scalars in either compressible or incompressible flow and on arbitrary grids. With a minor modification it can be applied to the equation for fluid density. Schemes using the simplest form of the flux limiter can cause distortion of the advected profile, particularly sideways spreading, depending on the orientation of the flow relative to the grid. This is partly because the simple limiter is too restrictive. However, some straightforward refinements lead to a shape-preserving scheme that gives satisfactory results, with negligible grid-flow angle-dependent distortion

  11. Point Information Gain and Multidimensional Data Analysis

    Directory of Open Access Journals (Sweden)

    Renata Rychtáriková

    2016-10-01

    Full Text Available We generalize the point information gain (PIG and derived quantities, i.e., point information gain entropy (PIE and point information gain entropy density (PIED, for the case of the Rényi entropy and simulate the behavior of PIG for typical distributions. We also use these methods for the analysis of multidimensional datasets. We demonstrate the main properties of PIE/PIED spectra for the real data with the examples of several images and discuss further possible utilizations in other fields of data processing.

  12. New method for solving multidimensional scattering problem

    International Nuclear Information System (INIS)

    Melezhik, V.S.

    1991-01-01

    A new method is developed for solving the quantum mechanical problem of scattering of a particle with internal structure. The multichannel scattering problem is formulated as a system of nonlinear functional equations for the wave function and reaction matrix. The method is successfully tested for the scattering from a nonspherical potential well and a long-range nonspherical scatterer. The method is also applicable to solving the multidimensional Schroedinger equation with a discrete spectrum. As an example the known problem of a hydrogen atom in a homogeneous magnetic field is analyzed

  13. An example of multidimensional analysis: Discriminant analysis

    International Nuclear Information System (INIS)

    Lutz, P.

    1990-01-01

    Among the approaches on the data multi-dimensional analysis, lectures on the discriminant analysis including theoretical and practical aspects are presented. The discrimination problem, the analysis steps and the discrimination categories are stressed. Examples on the descriptive historical analysis, the discrimination for decision making, the demonstration and separation of the top quark are given. In the linear discriminant analysis the following subjects are discussed: Huyghens theorem, projection, discriminant variable, geometrical interpretation, case for g=2, classification method, separation of the top events. Criteria allowing the obtention of relevant results are included [fr

  14. Sub-nanosecond laser-induced structural changes in the phase change material Ge2Sb2Te5 measured by an optical pump/x-ray probe technique: Structural snapshots with a 500 ps shutter

    International Nuclear Information System (INIS)

    Fons, P.; Brewe, D.; Stern, E.; Kolobov, A.V.; Fukaya, T.; Suzuki, M.; Uruga, T.; Kawamura, N.; Takagaki, M.; Ohsawa, H.; Tanida, H.; Tominaga, J.

    2007-01-01

    Phase-change alloys are characterized by reversible switching between amorphous and crystalline phases either by laser irradiation or by an electric programming current; the resulting changes in material properties can be used for non-volatile data storage. Switching typically occurs on nanosecond or less time scales. Considering the conflicting requirements for high-speed switching, yet long term data storage integrity, a deeper understanding of the switching processes in these materials is essential for insightful application development. Although, high-speed optical pump/probe observations have been made of reflectivity changes during the Ge 2 Sb 2 Te 5 switching process, due to the nanosecond order time scales involved little is known about the corresponding changes in structure. In addition as the amorphous phase does not diffract, its structural analysis is not amenable to analysis by high-speed diffraction techniques. We have used synchrotron-based time-resolved x-ray absorption fine structure spectroscopy (XAFS), a technique equally suitable for amorphous and crystalline phases to elaborate details in structural changes in the phase-change process. We report on two experiments using high-speed pulsed lasers that serve as optical pumps to induced material changes followed by synchrotron produced x-ray burst that serve as a time resolved structural probe. The first experiment carried out at the Advanced Photon source focuses on changes due to heating in the amorphous phase. Our experimental results indicate that the maximum temperature reached during the re-amorphization process are less than the melting point indicated in the bulk phase diagram of Ge 2 Sb 2 Te 5 reaching a maximum temperature of 620 C and in addition, do not share the same bond length distribution of a true melt. These findings strongly suggest the possibility of non-thermal melting. In the second experiment, we have obtained near-edge x-ray absorption data for a Ge 2 Sb 2 Te 5 film in the

  15. Benchmarking the Multidimensional Stellar Implicit Code MUSIC

    Science.gov (United States)

    Goffrey, T.; Pratt, J.; Viallet, M.; Baraffe, I.; Popov, M. V.; Walder, R.; Folini, D.; Geroux, C.; Constantino, T.

    2017-04-01

    We present the results of a numerical benchmark study for the MUltidimensional Stellar Implicit Code (MUSIC) based on widely applicable two- and three-dimensional compressible hydrodynamics problems relevant to stellar interiors. MUSIC is an implicit large eddy simulation code that uses implicit time integration, implemented as a Jacobian-free Newton Krylov method. A physics based preconditioning technique which can be adjusted to target varying physics is used to improve the performance of the solver. The problems used for this benchmark study include the Rayleigh-Taylor and Kelvin-Helmholtz instabilities, and the decay of the Taylor-Green vortex. Additionally we show a test of hydrostatic equilibrium, in a stellar environment which is dominated by radiative effects. In this setting the flexibility of the preconditioning technique is demonstrated. This work aims to bridge the gap between the hydrodynamic test problems typically used during development of numerical methods and the complex flows of stellar interiors. A series of multidimensional tests were performed and analysed. Each of these test cases was analysed with a simple, scalar diagnostic, with the aim of enabling direct code comparisons. As the tests performed do not have analytic solutions, we verify MUSIC by comparing it to established codes including ATHENA and the PENCIL code. MUSIC is able to both reproduce behaviour from established and widely-used codes as well as results expected from theoretical predictions. This benchmarking study concludes a series of papers describing the development of the MUSIC code and provides confidence in future applications.

  16. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    Energy Technology Data Exchange (ETDEWEB)

    Fang, X.; Xia, C.; Keppens, R. [Centre for mathematical Plasma Astrophysics, Department of Mathematics, KU Leuven, B-3001 Leuven (Belgium)

    2013-07-10

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  17. Multidimensional Learner Model In Intelligent Learning System

    Science.gov (United States)

    Deliyska, B.; Rozeva, A.

    2009-11-01

    The learner model in an intelligent learning system (ILS) has to ensure the personalization (individualization) and the adaptability of e-learning in an online learner-centered environment. ILS is a distributed e-learning system whose modules can be independent and located in different nodes (servers) on the Web. This kind of e-learning is achieved through the resources of the Semantic Web and is designed and developed around a course, group of courses or specialty. An essential part of ILS is learner model database which contains structured data about learner profile and temporal status in the learning process of one or more courses. In the paper a learner model position in ILS is considered and a relational database is designed from learner's domain ontology. Multidimensional modeling agent for the source database is designed and resultant learner data cube is presented. Agent's modules are proposed with corresponding algorithms and procedures. Multidimensional (OLAP) analysis guidelines on the resultant learner module for designing dynamic learning strategy have been highlighted.

  18. Multidimensional biochemical information processing of dynamical patterns.

    Science.gov (United States)

    Hasegawa, Yoshihiko

    2018-02-01

    Cells receive signaling molecules by receptors and relay information via sensory networks so that they can respond properly depending on the type of signal. Recent studies have shown that cells can extract multidimensional information from dynamical concentration patterns of signaling molecules. We herein study how biochemical systems can process multidimensional information embedded in dynamical patterns. We model the decoding networks by linear response functions, and optimize the functions with the calculus of variations to maximize the mutual information between patterns and output. We find that, when the noise intensity is lower, decoders with different linear response functions, i.e., distinct decoders, can extract much information. However, when the noise intensity is higher, distinct decoders do not provide the maximum amount of information. This indicates that, when transmitting information by dynamical patterns, embedding information in multiple patterns is not optimal when the noise intensity is very large. Furthermore, we explore the biochemical implementations of these decoders using control theory and demonstrate that these decoders can be implemented biochemically through the modification of cascade-type networks, which are prevalent in actual signaling pathways.

  19. MULTIDIMENSIONAL MODELING OF CORONAL RAIN DYNAMICS

    International Nuclear Information System (INIS)

    Fang, X.; Xia, C.; Keppens, R.

    2013-01-01

    We present the first multidimensional, magnetohydrodynamic simulations that capture the initial formation and long-term sustainment of the enigmatic coronal rain phenomenon. We demonstrate how thermal instability can induce a spectacular display of in situ forming blob-like condensations which then start their intimate ballet on top of initially linear force-free arcades. Our magnetic arcades host a chromospheric, transition region, and coronal plasma. Following coronal rain dynamics for over 80 minutes of physical time, we collect enough statistics to quantify blob widths, lengths, velocity distributions, and other characteristics which directly match modern observational knowledge. Our virtual coronal rain displays the deformation of blobs into V-shaped features, interactions of blobs due to mostly pressure-mediated levitations, and gives the first views of blobs that evaporate in situ or are siphoned over the apex of the background arcade. Our simulations pave the way for systematic surveys of coronal rain showers in true multidimensional settings to connect parameterized heating prescriptions with rain statistics, ultimately allowing us to quantify the coronal heating input.

  20. Testlet-Based Multidimensional Adaptive Testing.

    Science.gov (United States)

    Frey, Andreas; Seitz, Nicki-Nils; Brandt, Steffen

    2016-01-01

    Multidimensional adaptive testing (MAT) is a highly efficient method for the simultaneous measurement of several latent traits. Currently, no psychometrically sound approach is available for the use of MAT in testlet-based tests. Testlets are sets of items sharing a common stimulus such as a graph or a text. They are frequently used in large operational testing programs like TOEFL, PISA, PIRLS, or NAEP. To make MAT accessible for such testing programs, we present a novel combination of MAT with a multidimensional generalization of the random effects testlet model (MAT-MTIRT). MAT-MTIRT compared to non-adaptive testing is examined for several combinations of testlet effect variances (0.0, 0.5, 1.0, and 1.5) and testlet sizes (3, 6, and 9 items) with a simulation study considering three ability dimensions with simple loading structure. MAT-MTIRT outperformed non-adaptive testing regarding the measurement precision of the ability estimates. Further, the measurement precision decreased when testlet effect variances and testlet sizes increased. The suggested combination of the MTIRT model therefore provides a solution to the substantial problems of testlet-based tests while keeping the length of the test within an acceptable range.

  1. Testlet-based Multidimensional Adaptive Testing

    Directory of Open Access Journals (Sweden)

    Andreas Frey

    2016-11-01

    Full Text Available Multidimensional adaptive testing (MAT is a highly efficient method for the simultaneous measurement of several latent traits. Currently, no psychometrically sound approach is available for the use of MAT in testlet-based tests. Testlets are sets of items sharing a common stimulus such as a graph or a text. They are frequently used in large operational testing programs like TOEFL, PISA, PIRLS, or NAEP. To make MAT accessible for such testing programs, we present a novel combination of MAT with a multidimensional generalization of the random effects testlet model (MAT-MTIRT. MAT-MTIRT compared to non-adaptive testing is examined for several combinations of testlet effect variances (0.0, 0.5, 1.0, 1.5 and testlet sizes (3 items, 6 items, 9 items with a simulation study considering three ability dimensions with simple loading structure. MAT-MTIRT outperformed non-adaptive testing regarding the measurement precision of the ability estimates. Further, the measurement precision decreased when testlet effect variances and testlet sizes increased. The suggested combination of the MTIRT model therefore provides a solution to the substantial problems of testlet-based tests while keeping the length of the test within an acceptable range.

  2. A Multidimensional Theory of Suicide.

    Science.gov (United States)

    Leenaars, Antoon A; Dieserud, Gudrun; Wenckstern, Susanne; Dyregrov, Kari; Lester, David; Lyke, Jennifer

    2018-04-05

    Theory is the foundation of science; this is true in suicidology. Over decades of studies of suicide notes, Leenaars developed a multidimensional model of suicide, with international (crosscultural) studies and independent verification. To corroborate Leenaars's theory with a psychological autopsy (PA) study, examining age and sex of the decedent, and survivor's relationship to deceased. A PA study in Norway, with 120 survivors/informants was undertaken. Leenaars' theoretical-conceptual (protocol) analysis was undertaken of the survivors' narratives and in-depth interviews combined. Substantial interjudge reliability was noted (κ = .632). Overall, there was considerable confirmatory evidence of Leenaars's intrapsychic and interpersonal factors in suicide survivors' narratives. Differences were found in the age of the decedent, but not in sex, nor in the survivor's closeness of the relationship. Older deceased people were perceived to exhibit more heightened unbearable intrapsychic pain, associated with the suicide. Leenaars's theory has corroborative verification, through the decedents' suicide notes and the survivors' narratives. However, the multidimensional model needs further testing to develop a better evidence-based way of understanding suicide.

  3. [Multidimensional family therapy: which influences, which specificities?].

    Science.gov (United States)

    Bonnaire, C; Bastard, N; Couteron, J-P; Har, A; Phan, O

    2014-10-01

    Among illegal psycho-active drugs, cannabis is the most consumed by French adolescents. Multidimensional family therapy (MDFT) is a family-based outpatient therapy which has been developed for adolescents with drug and behavioral problems. MDFT has shown its effectiveness in adolescents with substance abuse disorders (notably cannabis abuse) not only in the United States but also in Europe (International Cannabis Need of Treatment project). MDFT is a multidisciplinary approach and an evidence-based treatment, at the crossroads of developmental psychology, ecological theories and family therapy. Its psychotherapeutic techniques find its roots in a variety of approaches which include systemic family therapy and cognitive therapy. The aims of this paper are: to describe all the backgrounds of MDFT by highlighting its characteristics; to explain how structural and strategy therapies have influenced this approach; to explore the links between MDFT, brief strategic family therapy and multi systemic family therapy; and to underline the specificities of this family therapy method. The multidimensional family therapy was created on the bases of 1) the integration of multiple therapeutic techniques stemming from various family therapy theories; and 2) studies which have shown family therapy efficiency. Several trials have shown a better efficiency of MDFT compared to group treatment, cognitive-behavioral therapy and home-based treatment. Studies have also highlighted that MDFT led to superior treatment outcomes, especially among young people with severe drug use and psychiatric co-morbidities. In the field of systemic family therapies, MDFT was influenced by: 1) the structural family therapy (S. Minuchin), 2) the strategic family theory (J. Haley), and 3) the intergenerational family therapy (Bowen and Boszormenyi-Nagy). MDFT has specific aspects: MDFT therapists think in a multidimensional perspective (because an adolescent's drug abuse is a multidimensional disorder), they

  4. Mobile Game Probes

    DEFF Research Database (Denmark)

    Borup Lynggaard, Aviaja

    2006-01-01

    This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

  5. Modeling and multidimensional optimization of a tapered free electron laser

    Directory of Open Access Journals (Sweden)

    Y. Jiao

    2012-05-01

    Full Text Available Energy extraction efficiency of a free electron laser (FEL can be greatly increased using a tapered undulator and self-seeding. However, the extraction rate is limited by various effects that eventually lead to saturation of the peak intensity and power. To better understand these effects, we develop a model extending the Kroll-Morton-Rosenbluth, one-dimensional theory to include the physics of diffraction, optical guiding, and radially resolved particle trapping. The predictions of the model agree well with that of the GENESIS single-frequency numerical simulations. In particular, we discuss the evolution of the electron-radiation interaction along the tapered undulator and show that the decreasing of refractive guiding is the major cause of the efficiency reduction, particle detrapping, and then saturation of the radiation power. With this understanding, we develop a multidimensional optimization scheme based on GENESIS simulations to increase the energy extraction efficiency via an improved taper profile and variation in electron beam radius. We present optimization results for hard x-ray tapered FELs, and the dependence of the maximum extractable radiation power on various parameters of the initial electron beam, radiation field, and the undulator system. We also study the effect of the sideband growth in a tapered FEL. Such growth induces increased particle detrapping and thus decreased refractive guiding that together strongly limit the overall energy extraction efficiency.

  6. Optical Probes for Laser Induced Shocks

    Science.gov (United States)

    1992-03-01

    target by the strong water. As the shock passes the material interface, it is pressure transients. only partially transmitted. The shock pressure is...T. Swimm , J. Appl. Phys. 61, evaporated, t1137(1987). vapor flow substantially. The coupling coefficient thus de- 3 v. A. Batanov and V. B. Fedorov...Waist-Surface Distance [mm] isurface on the drilling mechanismC Positive ( negative ) To roughly estimate the total recoil momentum positions

  7. Improving personality facet scores with multidimensional computer adaptive testing

    DEFF Research Database (Denmark)

    Makransky, Guido; Mortensen, Erik Lykke; Glas, Cees A W

    2013-01-01

    personality tests contain many highly correlated facets. This article investigates the possibility of increasing the precision of the NEO PI-R facet scores by scoring items with multidimensional item response theory and by efficiently administering and scoring items with multidimensional computer adaptive...

  8. Multidimensional Computerized Adaptive Testing for Indonesia Junior High School Biology

    Science.gov (United States)

    Kuo, Bor-Chen; Daud, Muslem; Yang, Chih-Wei

    2015-01-01

    This paper describes a curriculum-based multidimensional computerized adaptive test that was developed for Indonesia junior high school Biology. In adherence to the Indonesian curriculum of different Biology dimensions, 300 items was constructed, and then tested to 2238 students. A multidimensional random coefficients multinomial logit model was…

  9. The Tunneling Method for Global Optimization in Multidimensional Scaling.

    Science.gov (United States)

    Groenen, Patrick J. F.; Heiser, Willem J.

    1996-01-01

    A tunneling method for global minimization in multidimensional scaling is introduced and adjusted for multidimensional scaling with general Minkowski distances. The method alternates a local search step with a tunneling step in which a different configuration is sought with the same STRESS implementation. (SLD)

  10. Multidimensional Physical Self-Concept of Athletes with Physical Disabilities

    Science.gov (United States)

    Shapiro, Deborah R.; Martin, Jeffrey J.

    2010-01-01

    The purposes of this investigation were first to predict reported PA (physical activity) behavior and self-esteem using a multidimensional physical self-concept model and second to describe perceptions of multidimensional physical self-concept (e.g., strength, endurance, sport competence) among athletes with physical disabilities. Athletes (N =…

  11. Multidimensional filter banks and wavelets research developments and applications

    CERN Document Server

    Levy, Bernard

    1997-01-01

    Multidimensional Filter Banks and Wavelets: Reserach Developments and Applications brings together in one place important contributions and up-to-date research results in this important area. Multidimensional Filter Banks and Wavelets: Research Developments and Applications serves as an excellent reference, providing insight into some of the most important research issues in the field.

  12. Multidimensional First-Order Dominance Comparisons of Population Wellbeing

    DEFF Research Database (Denmark)

    Siersbæk, Nikolaj; Østerdal, Lars Peter Raahave; Arndt, Thomas Channing

    2017-01-01

    This chapter conveys the concept of first-order dominance (FOD) with particular focus on applications to multidimensional population welfare comparisons. It gives an account of the fundamental equivalent definitions of FOD both in the one-dimensional and multidimensional setting, illustrated...

  13. Supervised and Unsupervised Learning of Multidimensional Acoustic Categories

    Science.gov (United States)

    Goudbeek, Martijn; Swingley, Daniel; Smits, Roel

    2009-01-01

    Learning to recognize the contrasts of a language-specific phonemic repertoire can be viewed as forming categories in a multidimensional psychophysical space. Research on the learning of distributionally defined visual categories has shown that categories defined over 1 dimension are easy to learn and that learning multidimensional categories is…

  14. Optical network democratization.

    Science.gov (United States)

    Nejabati, Reza; Peng, Shuping; Simeonidou, Dimitra

    2016-03-06

    The current Internet infrastructure is not able to support independent evolution and innovation at physical and network layer functionalities, protocols and services, while at same time supporting the increasing bandwidth demands of evolving and heterogeneous applications. This paper addresses this problem by proposing a completely democratized optical network infrastructure. It introduces the novel concepts of the optical white box and bare metal optical switch as key technology enablers for democratizing optical networks. These are programmable optical switches whose hardware is loosely connected internally and is completely separated from their control software. To alleviate their complexity, a multi-dimensional abstraction mechanism using software-defined network technology is proposed. It creates a universal model of the proposed switches without exposing their technological details. It also enables a conventional network programmer to develop network applications for control of the optical network without specific technical knowledge of the physical layer. Furthermore, a novel optical network virtualization mechanism is proposed, enabling the composition and operation of multiple coexisting and application-specific virtual optical networks sharing the same physical infrastructure. Finally, the optical white box and the abstraction mechanism are experimentally evaluated, while the virtualization mechanism is evaluated with simulation. © 2016 The Author(s).

  15. A complete set of multidimensional Bell inequalities

    International Nuclear Information System (INIS)

    Arnault, François

    2012-01-01

    We give a multidimensional generalization of the complete set of Bell-correlation inequalities given by Werner and Wolf (2001 Phys. Rev. A 64 032112) and by Zukowski and Brukner (2002 Phys. Rev. Lett. 88 210401), for the two-dimensional case. Our construction applies to the n-party, two-observable case, where each observable is d-valued. The d d n inequalities obtained involve homogeneous polynomials. They define the facets of a polytope in a complex vector space of dimension d n . We detail the inequalities obtained in the case d = 3 and, from them, we recover known inequalities. We finally explain how the violations of our inequalities by quantum mechanics can be computed and could be observed, when using unitary observables. (paper)

  16. The simulation of multidimensional multiphase flows

    International Nuclear Information System (INIS)

    Lahey, Richard T.

    2005-01-01

    This paper presents an assessment of various models which can be used for the multidimensional simulation of multiphase flows, such as may occur in nuclear reactors. In particular, a model appropriate for the direct numerical simulation (DNS) of multiphase flows and a mechanistically based, three-dimensional, four-field, turbulent, two-fluid computational multiphase fluid dynamics (CMFD) model are discussed. A two-fluid bubbly flow model, which was derived using potential flow theory, can be extended to other flow regimes, but this will normally involve ensemble-averaging the results from direct numerical simulations (DNS) of various flow regimes to provide the detailed numerical data necessary for the development of flow-regime-specific interfacial and wall closure laws

  17. Constraint theory multidimensional mathematical model management

    CERN Document Server

    Friedman, George J

    2017-01-01

    Packed with new material and research, this second edition of George Friedman’s bestselling Constraint Theory remains an invaluable reference for all engineers, mathematicians, and managers concerned with modeling. As in the first edition, this text analyzes the way Constraint Theory employs bipartite graphs and presents the process of locating the “kernel of constraint” trillions of times faster than brute-force approaches, determining model consistency and computational allowability. Unique in its abundance of topological pictures of the material, this book balances left- and right-brain perceptions to provide a thorough explanation of multidimensional mathematical models. Much of the extended material in this new edition also comes from Phan Phan’s PhD dissertation in 2011, titled “Expanding Constraint Theory to Determine Well-Posedness of Large Mathematical Models.” Praise for the first edition: "Dr. George Friedman is indisputably the father of the very powerful methods of constraint theory...

  18. Path integral approach to multidimensional quantum tunnelling

    International Nuclear Information System (INIS)

    Balantekin, A.B.; Takigawa, N.

    1985-01-01

    Path integral formulation of the coupled channel problem in the case of multidimensional quantum tunneling is presented and two-time influence functionals are introduced. The two-time influence functionals are calculated explicitly for the three simplest cases: Harmonic oscillators linearly or quadratically coupled to the translational motion and a system with finite number of equidistant energy levels linearly coupled to the translational motion. The effects of these couplings on the transmission probability are studied for two limiting cases, adiabatic case and when the internal system has a degenerate energy spectrum. The condition for the transmission probability to show a resonant structure is discussed and exemplified. Finally, the properties of the dissipation factor in the adiabatic limit and its correlation with the friction coefficient in the classically accessible region are studied

  19. Security Contents: Politico-Military or Multidimensional?

    Directory of Open Access Journals (Sweden)

    Pere Vilanova

    1997-12-01

    Full Text Available The description of security problems has dramatically changed since the end of the bipolar system, and there are difficulties in building new concepts to comprehend a new and not yet defined international system. In the bipolar world, based on the North-South and East-West axes, security was described as systemic stability built upon deterrence and the defense of the statu quo. After the end of the Cold War, a new concept of multidimensional security was formulated. It lay emphasis on political, social (economic development andinternational (peaceful international relations democracy and the rule of law, putting aside too rapidly the military dimension. Vilanova argues that what have been identified as sources of new threats –narcotrafficking, ecology, migration, terrorism and fundamentalism– are not really new. There is a need to formulate political responses to these risks factors by means of public policies and intergovernmental and supranational action.

  20. Multidimensional splines for modeling FET nonlinearities

    Energy Technology Data Exchange (ETDEWEB)

    Barby, J A

    1986-01-01

    Circuit simulators like SPICE and timing simulators like MOTIS are used extensively for critical path verification of integrated circuits. MOSFET model evaluation dominates the run time of these simulators. Changes in technology results in costly updates, since modifications require reprogramming of the functions and their derivatives. The computational cost of MOSFET models can be reduced by using multidimensional polynomial splines. Since simulators based on the Newton Raphson algorithm require the function and first derivative, quadratic splines are sufficient for this purpose. The cost of updating the MOSFET model due to technology changes is greatly reduced since splines are derived from a set of points. Crucial for convergence speed of simulators is the fact that MOSFET characteristic equations are monotonic. This must be maintained by any simulation model. The splines the author designed do maintain monotonicity.

  1. Multidimensional Scaling for Orthodontic Root Resorption

    Directory of Open Access Journals (Sweden)

    Cristina Teodora Preoteasa

    2013-01-01

    Full Text Available The paper investigates the risk factors for the severity of orthodontic root resorption. The multidimensional scaling (MDS visualization method is used to investigate the experimental data from patients who received orthodontic treatment at the Department of Orthodontics and Dentofacial Orthopedics, Faculty of Dentistry, “Carol Davila” University of Medicine and Pharmacy, during a period of 4 years. The clusters emerging in the MDS plots reveal features and properties not easily captured by classical statistical tools. The results support the adoption of MDS for tackling the dentistry information and overcoming noise embedded into the data. The method introduced in this paper is rapid, efficient, and very useful for treating the risk factors for the severity of orthodontic root resorption.

  2. Multidimensional student skills with collaborative filtering

    Science.gov (United States)

    Bergner, Yoav; Rayyan, Saif; Seaton, Daniel; Pritchard, David E.

    2013-01-01

    Despite the fact that a physics course typically culminates in one final grade for the student, many instructors and researchers believe that there are multiple skills that students acquire to achieve mastery. Assessment validation and data analysis in general may thus benefit from extension to multidimensional ability. This paper introduces an approach for model determination and dimensionality analysis using collaborative filtering (CF), which is related to factor analysis and item response theory (IRT). Model selection is guided by machine learning perspectives, seeking to maximize the accuracy in predicting which students will answer which items correctly. We apply the CF to response data for the Mechanics Baseline Test and combine the results with prior analysis using unidimensional IRT.

  3. Gender Ideologies in Europe: A Multidimensional Framework.

    Science.gov (United States)

    Grunow, Daniela; Begall, Katia; Buchler, Sandra

    2018-02-01

    The authors argue, in line with recent research, that operationalizing gender ideology as a unidimensional construct ranging from traditional to egalitarian is problematic and propose an alternative framework that takes the multidimensionality of gender ideologies into account. Using latent class analysis, they operationalize their gender ideology framework based on data from the 2008 European Values Study, of which eight European countries reflecting the spectrum of current work-family policies were selected. The authors examine the form in which gender ideologies cluster in the various countries. Five ideology profiles were identified: egalitarian, egalitarian essentialism, intensive parenting, moderate traditional, and traditional. The five ideology profiles were found in all countries, but with pronounced variation in size. Ideologies mixing gender essentialist and egalitarian views appear to have replaced traditional ideologies, even in countries offering some institutional support for gendered separate spheres.

  4. Transport stochastic multi-dimensional media

    International Nuclear Information System (INIS)

    Haran, O.; Shvarts, D.

    1996-01-01

    Many physical phenomena evolve according to known deterministic rules, but in a stochastic media in which the composition changes in space and time. Examples to such phenomena are heat transfer in turbulent atmosphere with non uniform diffraction coefficients, neutron transfer in boiling coolant of a nuclear reactor and radiation transfer through concrete shields. The results of measurements conducted upon such a media are stochastic by nature, and depend on the specific realization of the media. In the last decade there has been a considerable efforts to describe linear particle transport in one dimensional stochastic media composed of several immiscible materials. However, transport in two or three dimensional stochastic media has been rarely addressed. The important effect in multi-dimensional transport that does not appear in one dimension is the ability to bypass obstacles. The current work is an attempt to quantify this effect. (authors)

  5. Multidimensional scaling of musical time estimations.

    Science.gov (United States)

    Cocenas-Silva, Raquel; Bueno, José Lino Oliveira; Molin, Paul; Bigand, Emmanuel

    2011-06-01

    The aim of this study was to identify the psycho-musical factors that govern time evaluation in Western music from baroque, classic, romantic, and modern repertoires. The excerpts were previously found to represent variability in musical properties and to induce four main categories of emotions. 48 participants (musicians and nonmusicians) freely listened to 16 musical excerpts (lasting 20 sec. each) and grouped those that seemed to have the same duration. Then, participants associated each group of excerpts to one of a set of sine wave tones varying in duration from 16 to 24 sec. Multidimensional scaling analysis generated a two-dimensional solution for these time judgments. Musical excerpts with high arousal produced an overestimation of time, and affective valence had little influence on time perception. The duration was also overestimated when tempo and loudness were higher, and to a lesser extent, timbre density. In contrast, musical tension had little influence.

  6. Transport stochastic multi-dimensional media

    Energy Technology Data Exchange (ETDEWEB)

    Haran, O; Shvarts, D [Israel Atomic Energy Commission, Beersheba (Israel). Nuclear Research Center-Negev; Thiberger, R [Ben-Gurion Univ. of the Negev, Beersheba (Israel)

    1996-12-01

    Many physical phenomena evolve according to known deterministic rules, but in a stochastic media in which the composition changes in space and time. Examples to such phenomena are heat transfer in turbulent atmosphere with non uniform diffraction coefficients, neutron transfer in boiling coolant of a nuclear reactor and radiation transfer through concrete shields. The results of measurements conducted upon such a media are stochastic by nature, and depend on the specific realization of the media. In the last decade there has been a considerable efforts to describe linear particle transport in one dimensional stochastic media composed of several immiscible materials. However, transport in two or three dimensional stochastic media has been rarely addressed. The important effect in multi-dimensional transport that does not appear in one dimension is the ability to bypass obstacles. The current work is an attempt to quantify this effect. (authors).

  7. Multidimensional fractional Schrödinger equation

    Science.gov (United States)

    Rodrigues, M. M.; Vieira, N.

    2012-11-01

    This work is intended to investigate the multi-dimensional space-time fractional Schrödinger equation of the form (CDt0+αu)(t,x) = iħ/2m(C∇βu)(t,x), with ħ the Planck's constant divided by 2π, m is the mass and u(t,x) is a wave function of the particle. Here (CDt0+α,C∇β are operators of the Caputo fractional derivatives, where α ∈]0,1] and β ∈]1,2]. The wave function is obtained using Laplace and Fourier transforms methods and a symbolic operational form of solutions in terms of the Mittag-Leffler functions is exhibited. It is presented an expression for the wave function and for the quantum mechanical probability density. Using Banach fixed point theorem, the existence and uniqueness of solutions is studied for this kind of fractional differential equations.

  8. Multidimensional evaluation on FR cycle systems

    International Nuclear Information System (INIS)

    Nakai, Ryodai; Fujii, Sumio; Takakuma, Katsuyuki; Katoh, Atsushi; Ono, Kiyoshi; Ohtaki, Akira; Shiotani, Hiroki

    2004-01-01

    This report explains some results of the multidimensional evaluation on various fast reactor cycle system concepts from an interim report of the 2nd phase of ''Feasibility Study on Commercialized FR Cycle System''. This method is designed to give more objective and more quantitative evaluations to clarify commercialized system candidate concepts. Here we brief current evaluation method from the five viewpoints of safety, economy, environment, resource and non-proliferation, with some trial evaluation results for some cycles consist of promising technologies in reactor, core and fuel, reprocessing and fuel manufacture. Moreover, we describe FR cycle deployment scenarios which describe advantages and disadvantages of the cycles from the viewpoints of uranium resource and radioactive waste based on long-term nuclear material mass flow analyses and advantages of the deployment of FR cycle itself from the viewpoints of the comparison with alternative power supplies as well as cost and benefit. (author)

  9. Gender Ideologies in Europe: A Multidimensional Framework

    Science.gov (United States)

    Begall, Katia; Buchler, Sandra

    2018-01-01

    The authors argue, in line with recent research, that operationalizing gender ideology as a unidimensional construct ranging from traditional to egalitarian is problematic and propose an alternative framework that takes the multidimensionality of gender ideologies into account. Using latent class analysis, they operationalize their gender ideology framework based on data from the 2008 European Values Study, of which eight European countries reflecting the spectrum of current work–family policies were selected. The authors examine the form in which gender ideologies cluster in the various countries. Five ideology profiles were identified: egalitarian, egalitarian essentialism, intensive parenting, moderate traditional, and traditional. The five ideology profiles were found in all countries, but with pronounced variation in size. Ideologies mixing gender essentialist and egalitarian views appear to have replaced traditional ideologies, even in countries offering some institutional support for gendered separate spheres. PMID:29491532

  10. Intrauterine photoacoustic and ultrasound imaging probe.

    Science.gov (United States)

    Miranda, Christopher; Barkley, Joel; Smith, Barbara

    2018-04-01

    Intrauterine photoacoustic and ultrasound imaging are probe-based imaging modalities with translational potential for use in detecting endometrial diseases. This deep-tissue imaging probe design allows for the retrofitting of commercially available endometrial sampling curettes. The imaging probe presented here has a 2.92-mm diameter and approximate length of 26 cm, which allows for entry into the human endometrial cavity, making it possible to use photoacoustic imaging and high-resolution ultrasound to characterize the uterus. We demonstrate the imaging probes' ability to provide structural information of an excised pig uterus using ultrasound imaging and detect photoacoustic signals at a radial depth of 1 cm. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

  11. The necessity-concerns framework: a multidimensional theory benefits from multidimensional analysis.

    Science.gov (United States)

    Phillips, L Alison; Diefenbach, Michael A; Kronish, Ian M; Negron, Rennie M; Horowitz, Carol R

    2014-08-01

    Patients' medication-related concerns and necessity-beliefs predict adherence. Evaluation of the potentially complex interplay of these two dimensions has been limited because of methods that reduce them to a single dimension (difference scores). We use polynomial regression to assess the multidimensional effect of stroke-event survivors' medication-related concerns and necessity beliefs on their adherence to stroke-prevention medication. Survivors (n = 600) rated their concerns, necessity beliefs, and adherence to medication. Confirmatory and exploratory polynomial regression determined the best-fitting multidimensional model. As posited by the necessity-concerns framework (NCF), the greatest and lowest adherence was reported by those necessity weak concerns and strong concerns/weak Necessity-Beliefs, respectively. However, as could not be assessed using a difference-score model, patients with ambivalent beliefs were less adherent than those exhibiting indifference. Polynomial regression allows for assessment of the multidimensional nature of the NCF. Clinicians/Researchers should be aware that concerns and necessity dimensions are not polar opposites.

  12. The Necessity-Concerns-Framework: A Multidimensional Theory Benefits from Multidimensional Analysis

    Science.gov (United States)

    Phillips, L. Alison; Diefenbach, Michael; Kronish, Ian M.; Negron, Rennie M.; Horowitz, Carol R.

    2014-01-01

    Background Patients’ medication-related concerns and necessity-beliefs predict adherence. Evaluation of the potentially complex interplay of these two dimensions has been limited because of methods that reduce them to a single dimension (difference scores). Purpose We use polynomial regression to assess the multidimensional effect of stroke-event survivors’ medication-related concerns and necessity-beliefs on their adherence to stroke-prevention medication. Methods Survivors (n=600) rated their concerns, necessity-beliefs, and adherence to medication. Confirmatory and exploratory polynomial regression determined the best-fitting multidimensional model. Results As posited by the Necessity-Concerns Framework (NCF), the greatest and lowest adherence was reported by those with strong necessity-beliefs/weak concerns and strong concerns/weak necessity-beliefs, respectively. However, as could not be assessed using a difference-score model, patients with ambivalent beliefs were less adherent than those exhibiting indifference. Conclusions Polynomial regression allows for assessment of the multidimensional nature of the NCF. Clinicians/Researchers should be aware that concerns and necessity dimensions are not polar opposites. PMID:24500078

  13. Experimental studies with a stimulated Raman backscatter probe beam in laser-irradiated plasmas

    International Nuclear Information System (INIS)

    Jiang, Z.M.; Meng, S.X.; Xu, Z.Z.

    1986-01-01

    This paper reports on the optical diagnostic experiments accomplished with a stimulated Raman backscatter probe beam set up recently in the sixbeam Nd:glass laser facility for laser fusion research at the Shanghai Insitute of Optics and Fine Mechanics

  14. Probe-diverse ptychography

    Energy Technology Data Exchange (ETDEWEB)

    Peterson, I., E-mail: isaac.russellpeterson@rmit.edu.au [ARC Centre of Excellence for Coherent X-ray Science, the University of Melbourne, School of Physics, Victoria 3010 (Australia); Harder, R. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States); Robinson, I.K. [Research Complex at Harwell, Didcot, Oxfordshire OX11 0DE (United Kingdom); London Centre for Nanotechnology, University College London, London WC1H 0AH (United Kingdom)

    2016-12-15

    We propose an extension of ptychography where the target sample is scanned separately through several probes with distinct amplitude and phase profiles and a diffraction image is recorded for each probe and each sample translation. The resulting probe-diverse dataset is used to iteratively retrieve high-resolution images of the sample and all probes simultaneously. The method is shown to yield significant improvement in the reconstructed sample image compared to the image obtained using the standard single-probe ptychographic phase-retrieval scheme.

  15. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  16. Traversing probe system

    International Nuclear Information System (INIS)

    Mashburn, D.N.; Stevens, R.H.; Woodall, H.C.

    1977-01-01

    This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride. 10 claims, 6 figures

  17. Traversing probe system

    Science.gov (United States)

    Mashburn, Douglas N.; Stevens, Richard H.; Woodall, Harold C.

    1977-01-01

    This invention comprises a rotatable annular probe-positioner which carries at least one radially disposed sensing probe, such as a Pitot tube having a right-angled tip. The positioner can be coaxially and rotatably mounted within a compressor casing or the like and then actuated to orient the sensing probe as required to make measurements at selected stations in the annulus between the positioner and compressor casing. The positioner can be actuated to (a) selectively move the probe along its own axis, (b) adjust the yaw angle of the right-angled probe tip, and (c) revolve the probe about the axis common to the positioner and casing. A cam plate engages a cam-follower portion of the probe and normally rotates with the positioner. The positioner includes a first-motor-driven ring gear which effects slidable movement of the probe by rotating the positioner at a time when an external pneumatic cylinder is actuated to engage the cam plate and hold it stationary. When the pneumatic cylinder is not actuated, this ring gear can be driven to revolve the positioner and thus the probe to a desired circumferential location about the above-mentioned common axis. A second motor-driven ring gear included in the positioner can be driven to rotate the probe about its axis, thus adjusting the yaw angle of the probe tip. The positioner can be used in highly corrosive atmosphere, such as gaseous uranium hexafluoride.

  18. Electrical resistivity probes

    Science.gov (United States)

    Lee, Ki Ha; Becker, Alex; Faybishenko, Boris A.; Solbau, Ray D.

    2003-10-21

    A miniaturized electrical resistivity (ER) probe based on a known current-voltage (I-V) electrode structure, the Wenner array, is designed for local (point) measurement. A pair of voltage measuring electrodes are positioned between a pair of current carrying electrodes. The electrodes are typically about 1 cm long, separated by 1 cm, so the probe is only about 1 inch long. The electrodes are mounted to a rigid tube with electrical wires in the tube and a sand bag may be placed around the electrodes to protect the electrodes. The probes can be positioned in a borehole or on the surface. The electrodes make contact with the surrounding medium. In a dual mode system, individual probes of a plurality of spaced probes can be used to measure local resistance, i.e. point measurements, but the system can select different probes to make interval measurements between probes and between boreholes.

  19. Development of a contact probe incorporating a Bragg grating strain sensor for nano coordinate measuring machines

    International Nuclear Information System (INIS)

    Ji, H; Hsu, H-Y; Kong, L X; Wedding, A B

    2009-01-01

    This paper presents a novel optical fibre based micro contact probe system with high sensitivity and repeatability. In this optical fibre probe with a fused spherical tip, a fibre Bragg grating has been utilized as a strain sensor in the probe stem. When the probe tip contacts the surface of the part, a strain will be induced along the probe stem and will produce a Bragg wavelength shift. The contact signal can be issued once the wavelength shift signal is produced and demodulated. With the fibre grating sensor element integrated into the probe directly, the probe system shows a high sensitivity. In this work, the strain distributions along the probe stem with the probe under axial and lateral load are analysed. A simulation of the strain distribution was performed using the finite element package ANSYS 11. Performance tests using a piezoelectric transducer stage with a displacement resolution of 1.5 nm yielded a measurement resolution of 60 nm under axial loading

  20. A study of multidimensional modeling approaches for data warehouse

    Science.gov (United States)

    Yusof, Sharmila Mat; Sidi, Fatimah; Ibrahim, Hamidah; Affendey, Lilly Suriani

    2016-08-01

    Data warehouse system is used to support the process of organizational decision making. Hence, the system must extract and integrate information from heterogeneous data sources in order to uncover relevant knowledge suitable for decision making process. However, the development of data warehouse is a difficult and complex process especially in its conceptual design (multidimensional modeling). Thus, there have been various approaches proposed to overcome the difficulty. This study surveys and compares the approaches of multidimensional modeling and highlights the issues, trend and solution proposed to date. The contribution is on the state of the art of the multidimensional modeling design.