WorldWideScience

Sample records for handed material optical

  1. Optical materials

    International Nuclear Information System (INIS)

    Poker, D.B.; Ortiz, C.

    1989-01-01

    This book reports on: Diamond films, Synthesis of optical materials, Structure related optical properties, Radiation effects in optical materials, Characterization of optical materials, Deposition of optical thin films, and Optical fibers and waveguides

  2. Hand-held optical fuel pin scanner

    International Nuclear Information System (INIS)

    Kirchner, T.L.; Powers, H.G.

    1987-01-01

    A portable, hand-held apparatus is described for optically scanning indicia imprinted about a planar end face of an article having an outer wall surface, the apparatus comprising: a supporting frame; light detector means fixed to the frame for digitizing light patterns directed thereto; indexing means on the frame for engaging the planar end face and locating the end face in a preselected focal plane on the frame. The indexing means has an inner wall surface complementary to the article wall surface for disposition thereabout and terminates in an end portion beyond the planar end face. The inner wall surface has a radially inwardly extending shoulder spaced from the end portion and engageable with the planar end face; light means directed onto the preselected focal plane; optical means mounted on the frame about a central axis, the optical means being optically interposed between the indexing means and the light detector means for directing reflected light from the preselected focal plane to the light detector means and including a dove prism centrally aligned along the central axis; and means for selectively rotating the dove prism relative to the frame about the central axis to thereby rotate the image from the focal plane as transmitted to the light detector means

  3. Hands-on optics: an informal science education initiative

    Science.gov (United States)

    Johnson, Anthony M.; Pompea, Stephen M.; Arthurs, Eugene G.; Walker, Constance E.; Sparks, Robert T.

    2007-09-01

    The project is collaboration between two scientific societies, the Optical Society of America (OSA) and SPIE - The International Society for Optical Engineering and the National Optical Astronomy Observatory (NOAO). The program is designed to bring science education enrichment to thousands of underrepresented middle school students in more than ten states, including female and minority students, who typically have not been the beneficiaries of science and engineering resources and investments. HOO provides each teacher with up to six activity modules, each containing enough materials for up to 30 students to participate in 6-8 hours of hands-on optics-related activities. Sample activities, developed by education specialists at NOAO, include building kaleidoscopes and telescopes, communicating with a beam of light, and a hit-the-target laser beam challenge. Teachers engage in two days of training and, where possible, are partnered with a local optics professional (drawn from the local rosters of SPIE and OSA members) who volunteers to spend time with the teacher and students as they explore the module activities. Through these activities, students gain experience and understanding of optics principles, as well as learning the basics of inquiry, critical thinking, and problem solving skills involving optics, and how optics interfaces with other disciplines. While the modules were designed for use in informal after- school or weekend sessions, the number of venues has expanded to large and small science centers, Boys and Girls Clubs, Girl Scouts, summer camps, family workshops, and use in the classroom.

  4. Left Handed Materials: A New Paradigm in Structured Electromagnetics

    International Nuclear Information System (INIS)

    Johri, Manoj; Paudyal, Harihar

    2010-05-01

    A new paradigm has emerged exhibiting reverse electromagnetic properties. Novel composite and micro-structured materials (metamaterials) have been designed to control electromagnetic radiation. Such substances have been called as Left Handed Material (LHM) with simultaneous negative permittivity and negative permeability and negative refractive index as well. Left handed materials are of importance because of their ability to influence the behavior of electromagnetic radiation and to display properties beyond those available in naturally occurring materials. Typically these are sub-wavelength artificial structures where the dimensions are very small compared to the working wavelength. These dimensions are normally of the order of λ/10 where λ is the wavelength of electromagnetic wave propagating in the material. Emergence of this new paradigm leads to some very interesting consequences, such as, to create lenses that are not diffraction limited, cloaking, sensors (chemical, biological and individual molecule), optical and radio communication. This new development in structured electromagnetic materials has had a dramatic impact on the physics, optics and engineering communities. (author)

  5. Hand Book of Metal Material Contrast

    International Nuclear Information System (INIS)

    Park, Yeong Hui

    1989-06-01

    This book first gives descriptions of using of this hand book and contents. It tells of steel such as bar steel, section steel, and steel sheet which are steel for general structure and steel for pressure vessel, a steel pipe, carbon steel for machine structure and alloy steel, steel for special things, stainless steel, heat resisting steel, tool steel, spring steel, forging, steel casting, nonferrous metal such as aluminium and aluminium alloy, casting, list of similar steel per metal, list of steel like ASTM, AISI per number, and list of collecting standard per metal material.

  6. New organic materials for optics: optical storage and nonlinear optics

    International Nuclear Information System (INIS)

    Gan, F.

    1996-01-01

    New organic materials have received considerable attention recently, due to their easy preparation and different variety. The most application fields in optics are optical storage and nonlinear optics. In optical storage the organic dyes have been used for example, in record able and erasable compact disks (CD-R, CD-E) nonlinear optical effects, such as nonlinear optical absorption, second and third order optical absorption, second and third order optical nonlinearities, can be applied for making optical limiters, optical modulators, as well as laser second and third harmonic generations. Due to high value of optical absorption and optical nonlinearity organic materials are always used as thin films in optical integration. In this paper the new experimental results have been presented, and future development has been also discussed. (author)

  7. Fundamentals of nonlinear optical materials

    Indian Academy of Sciences (India)

    Nonlinear optics; nonlinear polarization; optical fiber communication; optical switch- ing. PACS Nos 42.65Tg; ... The importance of nonlinear optics is to understand the nonlinear behavior in the induced polarization and to ..... but much work in material development and characterization remains to be done. 16. Conclusion.

  8. Basic optics of effect materials.

    Science.gov (United States)

    Jones, Steven A

    2010-01-01

    Effect materials derive their color and effect primarily from thin-film interference. Effect materials have evolved over the decades from simple guanine crystals to the complex multilayer optical structures of today. The development of new complex effect materials requires an understanding of the optics of effect materials. Such an understanding would also benefit the cosmetic formulator as these new effect materials are introduced. The root of this understanding begins with basic optics. This paper covers the nature of light, interference of waves, thin-film interference, color from interference, and color travel.

  9. Soft material for optical storage

    International Nuclear Information System (INIS)

    Lucchetti, L.; Simoni, F.

    2000-01-01

    The aim of transforming electronic networking into optical networking is producing a major effort in studying all optical processing and as a consequence in investigating the nonlinear optical properties of materials for this purpose. In this research area soft materials like polymers and liquid crystals are more and more attractive because they are cheap and they are more easily integrated in microcircuits hardware with respect to the well-known highly nonlinear crystals. Since optical processing spans a too wide field to be treated in one single paper, the authors will focus on one specific subject within this field and give a review of the most recent advances in studying the soft-materials properties interesting for the storage of optical information. The efforts in research of new materials and techniques for optical storage are motivated by the need to store and retrieve large amounts of data with short access time and high data rate at a competitive cost

  10. Non-linear optical materials

    CERN Document Server

    Saravanan, R

    2018-01-01

    Non-linear optical materials have widespread and promising applications, but the efforts to understand the local structure, electron density distribution and bonding is still lacking. The present work explores the structural details, the electron density distribution and the local bond length distribution of some non-linear optical materials. It also gives estimation of the optical band gap, the particle size, crystallite size, and the elemental composition from UV-Visible analysis, SEM, XRD and EDS of some non-linear optical materials respectively.

  11. Dark localized structures in a cavity filled with a left-handed material

    International Nuclear Information System (INIS)

    Tlidi, Mustapha; Kockaert, Pascal; Gelens, Lendert

    2011-01-01

    We consider a nonlinear passive optical cavity filled with left-handed and right-handed materials and driven by a coherent injected beam. We assume that both left-handed and right-handed materials possess a Kerr focusing type of nonlinearity. We show that close to the zero-diffraction regime, high-order diffraction allows us to stabilize dark localized structures in this device. These structures consist of dips in the transverse profile of the intracavity field and do not exist without high-order diffraction. We analyze the snaking bifurcation diagram associated with these structures. Finally, a realistic estimation of the model parameters is provided.

  12. Advanced fabrication of optical materials

    International Nuclear Information System (INIS)

    Hed, P.P.; Blaedel, K.L.

    1986-01-01

    The fabrication of high-precision optical elements for new generations of high-power lasers requires a deterministic method of generating precision optical surfaces entailing considerably less time, skill, and money than present optical techniques. Such a process would use precision computer-controlled machinery with ongoing in situ metrology to generate precise optical surfaces. The implementation of deterministic processes requires a better understanding of the glass-grinding process, especially the control of ductile material removal. This project is intended to develop the basic knowledge needed to implement a computer-controlled optics-manufacturing methodology

  13. HANDS-ON MATERIALS AS INVITATION TO A FANTASY WORLD

    DEFF Research Database (Denmark)

    Ejersbo, Lisser Rye

    In this article I wish to introduce an innovative use of hands-on-materials, developed by Peter Müller, a Danish elementary school teacher. The hands-on material itself consists of a collection of small plastic bears in different colors and sizes, which can be used for many different purposes among...

  14. Left-handed materials in metallic magnetic granular composites

    International Nuclear Information System (INIS)

    Chui, S.T.; Lin, Z.F.; Hu, L.-B.

    2003-01-01

    There is recently interests in the 'left-handed' materials. In these materials the direction of the wave vector of electromagnetic radiation is opposite to the direction of the energy flow. We present simple arguments that suggests that magnetic composites can also be left-handed materials. However, the physics involved seems to be different from the original argument. In our argument, the imaginary part of the dielectric constant is much larger than the real part, opposite to the original argument

  15. Design and analysis of doped left-handed materials

    International Nuclear Information System (INIS)

    Zhang Hongxin; Bao Yongfang; Chen Tianming; Lü Yinghua; Wang Haixia

    2008-01-01

    We devise three sorts of doped left-handed materials (DLHMs) by introducing inductors and capacitors into the traditional left-handed material (LHM) as heterogeneous elements. Some new properties are presented through finite-difference time-domain (FDTD) simulations. On the one hand, the resonance in the traditional LHM is weakened and the original pass band is narrowed by introducing inductors. On the other hand, the original pass band of the LHM can be shifted and a new pass band can be generated by introducing capacitors. When capacitors and inductors are introduced simultaneously, the resonance of traditional LHM is somewhat weakened and the number of original pass bands as well as its bandwidth can be changed

  16. Ultrasonic grinding of optical materials

    Science.gov (United States)

    Cahill, Michael; Bechtold, Michael; Fess, Edward; Stephan, Thomas; Bechtold, Rob

    2017-10-01

    Hard ceramic optical materials such as sapphire, ALON, Spinel, PCA, or Silicon Carbide can present a significant challenge in manufacturing precision optical components due to their tough mechanical properties. These are also the same mechanical properties that make them desirable materials when used in harsh environments. Slow processing speeds, premature tool wear, and poor surface quality are common results of the tough mechanical properties of these materials. Often, as a preparatory stage for polishing, the finish of the ground surface greatly influences the polishing process and the resulting finished product. To overcome these challenges, OptiPro Systems has developed an ultrasonic assisted grinding technology, OptiSonic, which has been designed for the precision optics and ceramics industry. OptiSonic utilizes a custom tool holder designed to produce oscillations, in microns of amplitude, in line with the rotating spindle. A software package, IntelliSonic, is integral to the function of this platform. IntelliSonic can automatically characterize tooling during setup to identify and select the ideal resonant peak which to operate at. Then, while grinding, IntelliSonic continuously adjusts the output frequency for optimal grinding efficiency while in contact with the part. This helps maintain a highly consistent process under changing load conditions for a more precise surface. Utilizing a variety of instruments, tests have proven to show a reduction in force between tool and part by up to 50%, while increasing the surface quality and reducing tool wear. This paper will present the challenges associated with these materials and solutions created to overcome them.

  17. The inhalation of radioactive materials as related to hand contamination

    Energy Technology Data Exchange (ETDEWEB)

    Bailey, J.C.; Rohr, R.C.

    1953-09-15

    Tests performed to determine the hazard associated with the inhalation of radioactive materials as the result of smoking with contaminated hands indicate that for dry uranium compounds adhering to the palmar surfaces of the hands, approximately 1.0% of the material may be transferred to a cigarette, and that of this approximately 0.2% may appear in the smoke which is inhaled. Most of the contamination originally placed in a cigarette was found in the ash, and only 11% of the material was not recovered following burning; approximately half of this loss may be attributed to normal losses inherent in the analytical process, the recovery efficiency for which was found by supplementary experiments to be 95%.

  18. Optical Fiber Force Myography Sensor for Identification of Hand Postures

    Directory of Open Access Journals (Sweden)

    Eric Fujiwara

    2018-01-01

    Full Text Available A low-cost optical fiber force myography sensor for noninvasive hand posture identification is proposed. The transducers are comprised of 10 mm periodicity silica multimode fiber microbending devices mounted in PVC plates, providing 0.05 N−1 sensitivity over ~20 N range. Next, the transducers were attached to the user forearm by means of straps in order to monitor the posterior proximal radial, the anterior medial ulnar, and the posterior distal radial muscles, and the acquired FMG optical signals were correlated to the performed gestures using a 5 hidden layers, 20-neuron artificial neural network classifier with backpropagation architecture, followed by a competitive layer. The overall results for 9 postures and 6 subjects indicated a 98.4% sensitivity and 99.7% average accuracy, being comparable to the electromyographic approaches. Moreover, in contrast to the current setups, the proposed methodology allows the identification of poses characterized by different configurations of fingers and wrist joint displacements with the utilization of only 3 transducers and a simple interrogation scheme, being suitable to further applications in human-computer interfaces.

  19. Microwave left-handed composite material made of slim ferrite rods and metallic wires

    International Nuclear Information System (INIS)

    Fang, Xu; Yang, Bai; Li-Jie, Qiao; Hong-Jie, Zhao; Ji, Zhou

    2009-01-01

    This paper reports on experimental study of the microwave properties of a composite material consisting of ferrite and copper wires. It finds that the slim ferrite rods can modify the magnetic field distribution through their anisotropy, so that the ferrite's negative influence on the copper wires' plasma will be reduced. Left-handed properties are observed even in the specimen with close stuck ferrite rods and copper wires. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

  20. Perspective and potential of smart optical materials

    Science.gov (United States)

    Choi, Sang H.; Duzik, Adam J.; Kim, Hyun-Jung; Park, Yeonjoon; Kim, Jaehwan; Ko, Hyun-U.; Kim, Hyun-Chan; Yun, Sungryul; Kyung, Ki-Uk

    2017-09-01

    The increasing requirements of hyperspectral imaging optics, electro/photo-chromic materials, negative refractive index metamaterial optics, and miniaturized optical components from micro-scale to quantum-scale optics have all contributed to new features and advancements in optics technology. Development of multifunctional capable optics has pushed the boundaries of optics into new fields that require new disciplines and materials to maximize the potential benefits. The purpose of this study is to understand and show the fundamental materials and fabrication technology for field-controlled spectrally active optics (referred to as smart optics) that are essential for future industrial, scientific, military, and space applications, such as membrane optics, filters, windows for sensors and probes, telescopes, spectroscopes, cameras, light valves, light switches, and flat-panel displays. The proposed smart optics are based on the Stark and Zeeman effects in materials tailored with quantum dot arrays and thin films made from readily polarizable materials via ferroelectricity or ferromagnetism. Bound excitonic states of organic crystals are also capable of optical adaptability, tunability, and reconfigurability. To show the benefits of smart optics, this paper reviews spectral characteristics of smart optical materials and device technology. Experiments testing the quantum-confined Stark effect, arising from rare earth element doping effects in semiconductors, and applied electric field effects on spectral and refractive index are discussed. Other bulk and dopant materials were also discovered to have the same aspect of shifts in spectrum and refractive index. Other efforts focus on materials for creating field-controlled spectrally smart active optics on a selected spectral range. Surface plasmon polariton transmission of light through apertures is also discussed, along with potential applications. New breakthroughs in micro scale multiple zone plate optics as a micro

  1. Cavity nonlinear optics with layered materials

    Directory of Open Access Journals (Sweden)

    Fryett Taylor

    2017-12-01

    Full Text Available Unprecedented material compatibility and ease of integration, in addition to the unique and diverse optoelectronic properties of layered materials, have generated significant interest in their utilization in nanophotonic devices. While initial nanophotonic experiments with layered materials primarily focused on light sources, modulators, and detectors, recent efforts have included nonlinear optical devices. In this paper, we review the current state of cavity-enhanced nonlinear optics with layered materials. Along with conventional nonlinear optics related to harmonic generation, we report on emerging directions of nonlinear optics, where layered materials can potentially play a significant role.

  2. Advanced infrared optically black baffle materials

    International Nuclear Information System (INIS)

    Seals, R.D.; Egert, C.M.; Allred, D.D.

    1990-01-01

    Infrared optically black baffle surfaces are an essential component of many advanced optical systems. All internal surfaces in advanced infrared optical sensors that require stray light management to achieve resolution are of primary concern in baffle design. Current industrial materials need improvements to meet advanced optical sensor systems requirements for optical, survivability, and endurability. Baffles are required to survive and operate in potentially severe environments. Robust diffuse-absorptive black surfaces, which are thermally and mechanically stable to threats of x-ray, launch, and in-flight maneuver conditions, with specific densities to allow an acceptable weight load, handleable during assembly, cleanable, and adaptive to affordable manufacturing, are required as optical baffle materials. In this paper an overview of recently developed advanced infrared optical baffle materials, requirements, manufacturing strategies, and the Optics MODIL (Manufacturing Operations Development and Integration Laboratory) Advanced Baffle Program are discussed

  3. Optical Head-Mounted Computer Display for Education, Research, and Documentation in Hand Surgery.

    Science.gov (United States)

    Funk, Shawn; Lee, Donald H

    2016-01-01

    Intraoperative photography and capturing videos is important for the hand surgeon. Recently, optical head-mounted computer display has been introduced as a means of capturing photographs and videos. In this article, we discuss this new technology and review its potential use in hand surgery. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  4. Optical and Casimir effects in topological materials

    Science.gov (United States)

    Wilson, Justin H.

    Two major electromagnetic phenomena, magneto-optical effects and the Casimir effect, have seen much theoretical and experimental use for many years. On the other hand, recently there has been an explosion of theoretical and experimental work on so-called topological materials, and a natural question to ask is how such electromagnetic phenomena change with these novel materials. Specifically, we will consider are topological insulators and Weyl semimetals. When Dirac electrons on the surface of a topological insulator are gapped or Weyl fermions in the bulk of a Weyl semimetal appear due to time-reversal symmetry breaking, there is a resulting quantum anomalous Hall effect (2D in one case and bulk 3D in the other, respectively). For topological insulators, we investigate the role of localized in-gap states which can leave their own fingerprints on the magneto-optics and can therefore be probed. We have shown that these states resonantly contribute to the Hall conductivity and are magneto-optically active. For Weyl semimetals we investigate the Casimir force and show that with thickness, chemical potential, and magnetic field, a repulsive and tunable Casimir force can be obtained. Additionally, various values of the parameters can give various combinations of traps and antitraps. We additionally probe the topological transition called a Lifshitz transition in the band structure of a material and show that in a Casimir experiment, one can observe a non-analytic "kink'' in the Casimir force across such a transition. The material we propose is a spin-orbit coupled semiconductor with large g-factor that can be magnetically tuned through such a transition. Additionally, we propose an experiment with a two-dimensional metal where weak localization is tuned with an applied field in order to definitively test the effect of diffusive electrons on the Casimir force---an issue that is surprisingly unresolved to this day. Lastly, we show how the time-continuous coherent state

  5. Photorefractive optics materials, properties, and applications

    CERN Document Server

    Yu, Francis T S

    1999-01-01

    The advances of photorefractive optics have demonstrated many useful and practical applications, which include the development of photorefractive optic devices for computer communication needs. To name a couple significant applications: the large capacity optical memory, which can greatly improve the accessible high-speed CD-ROM and the dynamic photorefractive gratings, which can be used for all-optic switches for high-speed fiber optic networks. This book is an important reference both for technical and non-technical staffs who are interested in this field. * Covers the recent development in materials, phenomena, and applications * Includes growth, characterization, dynamic gratings, and liquid crystal PR effect * Includes applications to photonic devices such as large capacity optical memory, 3-D interconnections, and dynamic holograms * Provides the recent overall picture of current trends in photorefractive optics * Includes optical and electronic properties of the materials as applied to dynamic photoref...

  6. Bio-Optics and Bio-Inspired Optical Materials.

    Science.gov (United States)

    Tadepalli, Sirimuvva; Slocik, Joseph M; Gupta, Maneesh K; Naik, Rajesh R; Singamaneni, Srikanth

    2017-10-25

    Through the use of the limited materials palette, optimally designed micro- and nanostructures, and tightly regulated processes, nature demonstrates exquisite control of light-matter interactions at various length scales. In fact, control of light-matter interactions is an important element in the evolutionary arms race and has led to highly engineered optical materials and systems. In this review, we present a detailed summary of various optical effects found in nature with a particular emphasis on the materials and optical design aspects responsible for their optical functionality. Using several representative examples, we discuss various optical phenomena, including absorption and transparency, diffraction, interference, reflection and antireflection, scattering, light harvesting, wave guiding and lensing, camouflage, and bioluminescence, that are responsible for the unique optical properties of materials and structures found in nature and biology. Great strides in understanding the design principles adapted by nature have led to a tremendous progress in realizing biomimetic and bioinspired optical materials and photonic devices. We discuss the various micro- and nanofabrication techniques that have been employed for realizing advanced biomimetic optical structures.

  7. Hybrid sol-gel optical materials

    Science.gov (United States)

    Zeigler, John M.

    1992-01-01

    Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

  8. Electronic, magnetic, and optical materials

    CERN Document Server

    Fulay, Pradeep

    2013-01-01

    Technological aspects of ferroelectric, piezoelectric and pyroelectric materials are discussed in detail, in a way that should allow the reader to select an optimal material for a particular application. The basics of magnetostatics are described clearly, as are a wide range of magnetic properties of materials … .-Tony Harker, Department of Physics and Astronomy, University College London

  9. Hybrid materials for optics and photonics.

    Science.gov (United States)

    Lebeau, Benedicte; Innocenzi, Plinio

    2011-02-01

    The interest in organic-inorganic hybrids as materials for optics and photonics started more than 25 years ago and since then has known a continuous and strong growth. The high versatility of sol-gel processing offers a wide range of possibilities to design tailor-made materials in terms of structure, texture, functionality, properties and shape modelling. From the first hybrid material with optical functional properties that has been obtained by incorporation of an organic dye in a silica matrix, the research in the field has quickly evolved towards more sophisticated systems, such as multifunctional and/or multicomponent materials, nanoscale and self-assembled hybrids and devices for integrated optics. In the present critical review, we have focused our attention on three main research areas: passive and active optical hybrid sol-gel materials, and integrated optics. This is far from exhaustive but enough to give an overview of the huge potential of these materials in photonics and optics (254 references).

  10. Teaching Diffraction with Hands-On Optical Spectrometry

    Science.gov (United States)

    Fischer, Robert

    2012-01-01

    Although the observation of optical spectra is common practice in physics classes, students are usually limited to a passive, qualitative observation of nice colours. This paper discusses a diffraction-based spectrometer that allows students to take quantitative measurements of spectral bands. Students can build it within minutes from generic…

  11. Laser-induced damage in optical materials

    CERN Document Server

    Ristau, Detlev

    2014-01-01

    Dedicated to users and developers of high-powered systems, Laser-Induced Damage in Optical Materials focuses on the research field of laser-induced damage and explores the significant and steady growth of applications for high-power lasers in the academic, industrial, and military arenas. Written by renowned experts in the field, this book concentrates on the major topics of laser-induced damage in optical materials and most specifically addresses research in laser damage that occurs in the bulk and on the surface or the coating of optical components. It considers key issues in the field of hi

  12. Exhibition: Fibre optics, the future is at hand

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    Until 20 June, the Pont de la Machine in Geneva will host an exhibition on fibre optics, sponsored by SIG. CERN, a major user of this technology, was invited to take part with a presentation of some of its scintillating fibre detectors.   The CERN module, designed for the SIG's fibre optics exhibition. Visitors can discover a cosmic ray detector (on the right) and its oscilloscope (on the left), as well as one of the ALFA detector modules (at the back). The Services industriels genevois (SIG), who are in the process of deploying an optical fibre network in Geneva, have decided to showcase this technology with an exhibition entitled “Fibre optique – Le futur à portée de main.” The exhibition, which will be open to the public from 26 April to 20 June, is being held at the Espace ExpoSIG, at the Pont de la Machine in the centre of Geneva. “CERN’s Physics Department was approached by SIG at the start of this year to ...

  13. Optical Spectrocopy on Nanostructrured Materials

    OpenAIRE

    Xu, Chenzhi

    2015-01-01

    Solar cells are designed to transform the optical energy into electrical energy. Using solar energy is the best way for humans to solve the energy shortage problem. Dye sensitized solar cell(DSSC) has a low cost and helps people to obtain the solar energy expediently. The DSSC is based on nano structured TiO2 ; and dye molecules help the particles of TiO2 to absorb more photons. Hence DSSC has higher efficiency than SC(solar cell without dye). This thesis elaborates and analyzes the dye which...

  14. Equipment for measuring contamination of hands with radioactive material

    International Nuclear Information System (INIS)

    Erban, J.; Kleinbauer, K.; Husak, V.; Grigar, O.

    1986-01-01

    The claimed device consists of a scintillation detector mounted in a shielding case consisting of rings. The shielding case is provided with a cavity with an inlet opening lined with polyethylene foil. The cavity shape, shielding and replaceable foil guarantee minimizing the interfering effect of radiation sources in the vicinity and of contamination of the device. Gradually inserting the hand in the cavity or suitably placing the hand can locate contamination of the hand surface. The sensitivity of the device for 125 I and 99 Tc is 200-times higher than that of Geiger-Mueller counter instruments. (M.D.)

  15. Optical properties of low-dimensional materials

    CERN Document Server

    Ogawa, T

    1998-01-01

    This book surveys recent theoretical and experimental studies of optical properties of low-dimensional materials. As an extended version of Optical Properties of Low-Dimensional Materials (Volume 1, published in 1995 by World Scientific), Volume 2 covers a wide range of interesting low-dimensional materials including both inorganic and organic systems, such as disordered polymers, deformable molecular crystals, dilute magnetic semiconductors, SiGe/Si short-period superlattices, GaAs quantum wires, semiconductor microcavities, and photonic crystals. There are excellent review articles by promis

  16. DNA as an Optical Material

    Science.gov (United States)

    2011-07-01

    the electron blocking function of the DNA layer; electroluminescence occurs in either the AlQ3 (green) or NPB layer (blue) layers. Source: J. A...been observed for sev- eral fluorescent materials with different HOMO/LUMO levels, including AlQ3 (green emission) and NPB (blue emission). OLEDs

  17. Nonlinear optics of liquid crystalline materials

    International Nuclear Information System (INIS)

    Khoo, Iam Choon

    2009-01-01

    Liquid crystals occupy an important niche in nonlinear optics as a result of their unique physical and optical properties. Besides their broadband birefringence and transparency, abilities to self-assemble into various crystalline phases and to conform to various flexible forms and shapes, liquid crystals are compatible with almost all other optoelectronic materials and technology platforms. In both isotropic and ordered phases, liquid crystals possess extraordinarily large optical nonlinearities that stretch over multiple time scales. To date, almost all conceivable nonlinear optical phenomena have been observed in a very broad spectrum spanning the entire visible to infrared and beyond. In this review, we present a self-contained complete discussion of the optical nonlinearities of liquid crystals, and a thorough review of a wide range of nonlinear optical processes and phenomena enabled by these unique properties. Starting with a brief historical account of the development of nonlinear optical studies of the mesophases of liquid crystals, we then review various liquid crystalline materials and structures, and their nonlinear optical properties. Emphasis is placed on the nematic phase, which best exemplifies the dual nature of liquid crystals, although frequent references to other phases are also made. We also delve into recent work on novel structures such as photonic crystals, metamaterials and nanostructures and their special characteristics and emergent properties. The mechanisms and complex nonlocal dynamics of optical nonlinearities associated with laser induced director axis reorientation, thermal, density, and order parameter fluctuations, space charge field formation and photorefractivity are critically reviewed as a foundation for the discussions of various nonlinear optical processes detailed in this paper

  18. Support for hands-on optics immersions (Conference Presentation)

    Science.gov (United States)

    Spalding, Gabriel C.; McCann, Lowell I.

    2016-09-01

    The Advanced Laboratory Physics Association (ALPhA) is an official affiliate organization of the AAPT, supporting upper-level undergraduate instructional lab education in physics. The ALPhA Immersions program is intended to be an efficient use of an instructor's time: with expert colleague-mentors on hand they spend 2.5 days learning a key new instructional experiment (of their choice) well enough to confidently teach it to the students at their home institutions. At an ALPhA Immersion, participants work in groups of no more than three per experimental setup. Our follow-up surveys support the notion that this individualized, concentrated focus directly results in significant updating and improvement of undergraduate laboratory instruction in physics across the country. Such programs have the effect of encouraging investment, on the part of individual institutions. For example, we have disseminated ideas, training, and equipment for contemporary single-photon-based instructional labs dealing with core, contemporary issues in Quantum Mechanics. By the time this paper is presented, ALPhA will have delivered at least 420 single-photon detectors to a wide variety of educational institutions. We have also partnered with the non-profit Jonathan F. Reichert Foundation to support equipment acquisition by institutions participating in our wide variety of training programs.

  19. Optical substrate materials for synchrotron radiation beamlines

    International Nuclear Information System (INIS)

    Howells, M.R.; Paquin, R.A.

    1997-06-01

    The authors consider the materials choices available for making optical substrates for synchrotron radiation beam lines. They find that currently the optical surfaces can only be polished to the required finish in fused silica and other glasses, silicon, CVD silicon carbide, electroless nickel and 17-4 PH stainless steel. Substrates must therefore be made of one of these materials or of a metal that can be coated with electroless nickel. In the context of material choices for mirrors they explore the issues of dimensional stability, polishing, bending, cooling, and manufacturing strategy. They conclude that metals are best from an engineering and cost standpoint while the ceramics are best from a polishing standpoint. They then give discussions of specific materials as follows: silicon carbide, silicon, electroless nickel, Glidcop trademark, aluminum, precipitation-hardening stainless steel, mild steel, invar and superinvar. Finally they summarize conclusions and propose ideas for further research

  20. Advanced materials for integrated optical waveguides

    CERN Document Server

    Tong Ph D, Xingcun Colin

    2014-01-01

    This book provides a comprehensive introduction to integrated optical waveguides for information technology and data communications. Integrated coverage ranges from advanced materials, fabrication, and characterization techniques to guidelines for design and simulation. A concluding chapter offers perspectives on likely future trends and challenges. The dramatic scaling down of feature sizes has driven exponential improvements in semiconductor productivity and performance in the past several decades. However, with the potential of gigascale integration, size reduction is approaching a physical limitation due to the negative impact on resistance and inductance of metal interconnects with current copper-trace based technology. Integrated optics provides a potentially lower-cost, higher performance alternative to electronics in optical communication systems. Optical interconnects, in which light can be generated, guided, modulated, amplified, and detected, can provide greater bandwidth, lower power consumption, ...

  1. Crosslinked polyimide electro-optic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kowalczyk, T.C.; Kosc, T.Z.; Singer, K.D. [Case Western Reserve University, Department of Physics, Cleveland, Ohio 44106-7079 (United States); Beuhler, A.J.; Wargowski, D.A. [Amoco Research Center, Amoco Chemical Co., Naperville, Illinois 60566 (United States); Cahill, P.A.; Seager, C.H.; Meinhardt, M.B. [Sandia National Laboratories, Division 1811, Albuquerque, New Mexico 87185-1407 (United States); Ermer, S. [Lockheed Research and Development Division, Palo Alto, California 94304 (United States)

    1995-11-15

    We report studies of the optical and electro-optic properties of guest--host polymeric nonlinear optical materials based on aromatic, fluorinated, fully imidized, organic soluble, thermally, and photochemically crosslinkable, guest--host polyimides. We have introduced temperature stable nonlinear optical chromophores into these polyimides and studied optical losses, electric field poling, electro-optic properties, and orientational stability. We measured electro-optic coefficients of 5.5 and 12.0 pm/V for ((2,6-Bis(2-(3-(9-(ethyl)carbazolyl))ethenyl)4H-pyran-4-ylidene)propanedinitrile) (4-(Dicyanomethylene)-2-methyl-6-(p -dimethylaminostyryl)-4H-pyran) DCM-doped guest--host systems at 800 nm using a poling field of 1.3 MV/cm. Poling induced nonlinearities in single-layer films were in agreement with the oriented gas model, but were lower in three-layer films due to voltage division across the layers. {copyright} {ital 1995} {ital American} {ital Institute} {ital of} {ital Physics}.

  2. Optical Material Characterization Using Microdisk Cavities

    Science.gov (United States)

    Michael, Christopher P.

    Since Jack Kilby recorded his "Monolithic Idea" for integrated circuits in 1958, microelectronics companies have invested billions of dollars in developing the silicon material system to increase performance and reduce cost. For decades, the industry has made Moore's Law, concerning cost and transistor density, a self-fulfilling prophecy by integrating technical and material requirements vertically down their supply chains and horizontally across competitors in the market. At recent technology nodes, the unacceptable scaling behavior of copper interconnects has become a major design constraint by increasing latency and power consumption---more than 50% of the power consumed by high speed processors is dissipated by intrachip communications. Optical networks at the chip scale are a potential low-power high-bandwidth replacement for conventional global interconnects, but the lack of efficient on-chip optical sources has remained an outstanding problem despite significant advances in silicon optoelectronics. Many material systems are being researched, but there is no ideal candidate even though the established infrastructure strongly favors a CMOS-compatible solution. This thesis focuses on assessing the optical properties of materials using microdisk cavities with the intention to advance processing techniques and materials relevant to silicon photonics. Low-loss microdisk resonators are chosen because of their simplicity and long optical path lengths. A localized photonic probe is developed and characterized that employs a tapered optical-fiber waveguide, and it is utilized in practical demonstrations to test tightly arranged devices and to help prototype new fabrication methods. A case study in AlxGa1-xAs illustrates how the optical scattering and absorption losses can be obtained from the cavity-waveguide transmission. Finally, single-crystal Er2O3 epitaxially grown on silicon is analyzed in detail as a potential CMOS-compatable gain medium due to its high Er3

  3. Nonlinear Optics with 2D Layered Materials.

    Science.gov (United States)

    Autere, Anton; Jussila, Henri; Dai, Yunyun; Wang, Yadong; Lipsanen, Harri; Sun, Zhipei

    2018-03-25

    2D layered materials (2DLMs) are a subject of intense research for a wide variety of applications (e.g., electronics, photonics, and optoelectronics) due to their unique physical properties. Most recently, increasing research efforts on 2DLMs are projected toward the nonlinear optical properties of 2DLMs, which are not only fascinating from the fundamental science point of view but also intriguing for various potential applications. Here, the current state of the art in the field of nonlinear optics based on 2DLMs and their hybrid structures (e.g., mixed-dimensional heterostructures, plasmonic structures, and silicon/fiber integrated structures) is reviewed. Several potential perspectives and possible future research directions of these promising nanomaterials for nonlinear optics are also presented. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Extrusion-mixing compared with hand-mixing of polyether impression materials?

    Science.gov (United States)

    McMahon, Caroline; Kinsella, Daniel; Fleming, Garry J P

    2010-12-01

    The hypotheses tested were two-fold (a) whether altering the base:catalyst ratio influences working time, elastic recovery and strain in compression properties of a hand-mixed polyether impression material and (b) whether an extrusion-mixed polyether impression material would have a significant advantage over a hand-mixed polyether impression material mixed to the optimum base:catalyst ratio. The polyether was hand-mixed at the optimum (manufacturers recommended) base:catalyst ratios (7:1) and further groups were made by increasing or decreasing the catalyst length by 25%. Additionally specimens were also made from an extrusion-mixed polyether impression material and compared with the optimum hand-mixed base:catalyst ratio. A penetrometer assembly was used to measure the working time (n=5). Five cylindrical specimens for each hand-mixed and extrusion mixed group investigated were employed for elastic recovery and strain in compression testing. Hand-mixing polyether impression materials with 25% more catalyst than that recommended significantly decreased the working time while hand-mixing with 25% less catalyst than that recommended significantly increased the strain in compression. The extrusion-mixed polyether impression material provided similar working time, elastic recovery and strain in compression to the hand-mixed polyether mixed at the optimum base:catalyst ratio.

  5. Materials for Nonlinear Optics Chemical Perspectives

    Science.gov (United States)

    1991-01-01

    potassium iodide for 15 h at reflux. The benzaldehyde product was then allowed to react with diethyl(4-nitrobenzyl)phosphonate in the presence of ...photocrosslinking of NLO-inactive polyacrylate monomers. Recent advances in optical technology have created great interest in the construction of second-order...might be potassium niobate.) Because of this, the value of finding an "improved" material can be accurately gauged in a relative sense, and compared to

  6. "Optics 4 every1", the hands-on optics outreach program of the Universidad Autonoma de Nuevo Leon

    Science.gov (United States)

    Viera-González, Perla M.; Sánchez-Guerrero, Guillermo E.

    2016-09-01

    The Fisica Pato2 (Physics 4 every1) outreach group started as a need of hands-on activities and active Science demonstrations in the education for kids, teenagers and basic education teachers in Nuevo Leffon maintaining a main objective of spread the word about the importance of Optics and Photonics; for accomplish this objective, since November 2013 several outreach events are organized every year by the group. The program Optics 4 every1 is supported by the Facultad de Ciencias Fisico Matematicas of the Universidad Autonoma de Nuevo Leon and the International Society for Optics and Photonics and consist in quick hands-on activities and Optics demonstrations designed for teach basic optical phenomena related with light and its application in everyday life. During 2015, with the purpose of celebrate the International Year of Light 2015, the outreach group was involved in 13 different events and reached more than 8,000 people. The present work explains the activities done and the outcome obtained with this program.

  7. Optical thin films and coatings from materials to applications

    CERN Document Server

    Flory, Francois

    2013-01-01

    Optical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. This book provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas.$bOptical coatings, including mirrors, anti-reflection coatings, beam splitters, and filters, are an integral part of most modern optical systems. Optical thin films and coatings provides an overview of thin film materials, the properties, design and manufacture of optical coatings and their use across a variety of application areas. Part one explores the design and manufacture of optical coatings. Part two highlights unconventional features of optical thin films including scattering properties of random structures in thin films, optical properties of thin film materials at short wavelengths, thermal properties and colour effects. Part three focusses on novel materials for optical thin films and coatings...

  8. Shape Memory Polymers: A Joint Chemical and Materials Engineering Hands-On Experience

    Science.gov (United States)

    Seif, Mujan; Beck, Matthew

    2018-01-01

    Hands-on experiences are excellent tools for increasing retention of first year engineering students. They also encourage interdisciplinary collaboration, a critical skill for modern engineers. In this paper, we describe and evaluate a joint Chemical and Materials Engineering hands-on lab that explores cross-linking and glass transition in…

  9. Relevant optical properties for direct restorative materials.

    Science.gov (United States)

    Pecho, Oscar E; Ghinea, Razvan; do Amaral, Erika A Navarro; Cardona, Juan C; Della Bona, Alvaro; Pérez, María M

    2016-05-01

    To evaluate relevant optical properties of esthetic direct restorative materials focusing on whitened and translucent shades. Enamel (E), body (B), dentin (D), translucent (T) and whitened (Wh) shades for E (WhE) and B (WhB) from a restorative system (Filtek Supreme XTE, 3M ESPE) were evaluated. Samples (1 mm thick) were prepared. Spectral reflectance (R%) and color coordinates (L*, a*, b*, C* and h°) were measured against black and white backgrounds, using a spectroradiometer, in a viewing booth, with CIE D65 illuminant and d/0° geometry. Scattering (S) and absorption (K) coefficients and transmittance (T%) were calculated using Kubelka-Munk's equations. Translucency (TP) and opalescence (OP) parameters and whiteness index (W*) were obtained from differences of CIELAB color coordinates. R%, S, K and T% curves from all shades were compared using VAF (Variance Accounting For) coefficient with Cauchy-Schwarz inequality. Color coordinates and optical parameters were statistically analyzed using one-way ANOVA, Tukey's test with Bonferroni correction (α=0.0007). Spectral behavior of R% and S were different for T shades. In addition, T shades showed the lowest R%, S and K values, as well as the highest T%, TP an OP values. In most cases, WhB shades showed different color and optical properties (including TP and W*) than their corresponding B shades. WhE shades showed similar mean W* values and higher mean T% and TP values than E shades. When using whitened or translucent composites, the final color is influenced not only by the intraoral background but also by the color and optical properties of multilayers used in the esthetic restoration. Copyright © 2016 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

  10. Optical coherence tomography, In vivo human hand explorer, optical coherence microscope

    CSIR Research Space (South Africa)

    Jonathan, E

    2008-07-01

    Full Text Available The hand palm is an important human body part primarily for physical manipulation of the environment. For example, palmar hyperhidriotics report a low quality of life due to excessive palmar sweating disrupting normal palm use. As a body part...

  11. Optical dynamic deformation measurements at translucent materials.

    Science.gov (United States)

    Philipp, Katrin; Koukourakis, Nektarios; Kuschmierz, Robert; Leithold, Christoph; Fischer, Andreas; Czarske, Jürgen

    2015-02-15

    Due to their high stiffness-to-weight ratio, glass fiber-reinforced polymers are an attractive material for rotors, e.g., in the aerospace industry. A fundamental understanding of the material behavior requires non-contact, in-situ dynamic deformation measurements. The high surface speeds and particularly the translucence of the material limit the usability of conventional optical measurement techniques. We demonstrate that the laser Doppler distance sensor provides a powerful and reliable tool for monitoring radial expansion at fast rotating translucent materials. We find that backscattering in material volume does not lead to secondary signals as surface scattering results in degradation of the measurement volume inside the translucent medium. This ensures that the acquired signal contains information of the rotor surface only, as long as the sample surface is rough enough. Dynamic deformation measurements of fast-rotating fiber-reinforced polymer composite rotors with surface speeds of more than 300 m/s underline the potential of the laser Doppler sensor.

  12. 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.

  13. Gen-2 Hand-Held Optical Imager towards Cancer Imaging: Reflectance and Transillumination Phantom Studies

    Directory of Open Access Journals (Sweden)

    Anuradha Godavarty

    2012-02-01

    Full Text Available Hand-held near-infrared (NIR optical imagers are developed by various researchers towards non-invasive clinical breast imaging. Unlike these existing imagers that can perform only reflectance imaging, a generation-2 (Gen-2 hand-held optical imager has been recently developed to perform both reflectance and transillumination imaging. The unique forked design of the hand-held probe head(s allows for reflectance imaging (as in ultrasound and transillumination or compressed imaging (as in X-ray mammography. Phantom studies were performed to demonstrate two-dimensional (2D target detection via reflectance and transillumination imaging at various target depths (1–5 cm deep and using simultaneous multiple point illumination approach. It was observed that 0.45 cc targets were detected up to 5 cm deep during transillumination, but limited to 2.5 cm deep during reflectance imaging. Additionally, implementing appropriate data post-processing techniques along with a polynomial fitting approach, to plot 2D surface contours of the detected signal, yields distinct target detectability and localization. The ability of the gen-2 imager to perform both reflectance and transillumination imaging allows its direct comparison to ultrasound and X-ray mammography results, respectively, in future clinical breast imaging studies.

  14. Optical bistability and multistability in polaritonic materials doped with nanoparticles

    International Nuclear Information System (INIS)

    Wang, Zhiping; Yu, Benli

    2014-01-01

    We investigate the optical bistability and multistability in polaritonic materials doped with nanoparticles inside an optical ring cavity. It is found that the optical bistability and multistability can be easily controlled by adjusting the corresponding parameters of the system properly. The effect of the dipole–dipole interaction has also been included in the formulation, which leads to interesting phenomena. Our scheme opens up the possibility of controling the optical bistability and multistability in polaritonic materials doped with nanoparticles. (letter)

  15. Readability of the Most Commonly Accessed Online Patient Education Materials Pertaining to Pathology of the Hand.

    Science.gov (United States)

    Akinleye, Sheriff D; Garofolo-Gonzalez, Garret; Montuori, Michael; Culbertson, Maya Deza; Hashem, Jennifer; Edelstein, David Marc

    2017-08-01

    The American Medical Association (AMA) and National Institutes of Health (NIH) recommend that patient education materials be written at no higher than a sixth-grade reading level. We examined 100 online educational materials for the 10 hand conditions most commonly treated by hand surgeons, as reported by the American Society for Surgery of the Hand. The listed conditions were carpal tunnel syndrome, basal joint arthritis of the thumb, de Quervain syndrome, Dupuytren's contracture, ganglion cysts, hand fractures, trigger finger, extensor tendon injuries, flexor tendon injuries, and mallet finger. Following a Google search for each condition, we analyzed the 10 most visited websites for each disorder utilizing the Flesch-Kincaid formula. The average grade reading level of the 100 websites studied was 9.49 with a reading ease of 53.03 ("fairly difficult high school"). Only 29% of the websites were at or below the national average of an eighth-grade reading level. Carpal tunnel syndrome had the highest average grade reading level at 10.32 (standard deviation: 1.52), whereas hand fractures had the lowest at 8.14 (2.03). Every hand condition in this study had an average readability at or above the ninth-grade reading level. The most frequently accessed materials for common maladies of the hand exceed both the readability limits recommended by the AMA and NIH, and the average reading ability of most US adults. Therefore, the most commonly accessed websites pertaining to hand pathology may not be comprehended by the audience for which it is intended.

  16. Readability of Patient Education Materials in Hand Surgery and Health Literacy Best Practices for Improvement.

    Science.gov (United States)

    Hadden, Kristie; Prince, Latrina Y; Schnaekel, Asa; Couch, Cory G; Stephenson, John M; Wyrick, Theresa O

    2016-08-01

    This study aimed to update a portion of a 2008 study of patient education materials from the American Society for Surgery of the Hand Web site with new readability results, to compare the results to health literacy best practices, and to make recommendations to the field for improvement. A sample of 77 patient education documents were downloaded from the American Society for Surgery of the Hand Web site, handcare.org, and assessed for readability using 4 readability tools. Mean readability grade-level scores were derived. Best practices for plain language for written health materials were compiled from 3 government agency sources. The mean readability of the 77 patient education documents in the study was 9.3 grade level. This reading level is reduced from the previous study in 2008 in which the overall mean was 10.6; however, the current sample grade level still exceeds recommended readability according to best practices. Despite a small body of literature on the readability of patient education materials related to hand surgery and other orthopedic issues over the last 7 years, readability was not dramatically improved in our current sample. Using health literacy as a framework, improvements in hand surgery patient education may result in better understanding and better outcomes for patients seeing hand surgeons. Improved understanding of patient education materials related to hand surgery may improve preventable negative outcomes that are clinically significant as well as contribute to improved quality of life for patients. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  17. Smart Materials for Electromagnetic and Optical Applications

    Science.gov (United States)

    Ramesh, Prashanth

    dissertation demonstrates GaN as a candidate material well suited for novel microelectromechanical systems. The potential of GaN for MEMS is demonstrated via the design, analysis, fabrication, testing and characterization of an optical microswitch device actuated by piezoelectric and electrostrictive means. The piezoelectric and electrostrictive properties of GaN and its differences from common piezoelectrics are discussed before elaborating on the device configuration used to implement the microswitch device. Next, the development of two recent fabrication technologies, Photoelectrochemical etch and Bias-enabled Dark Electrochemical etch, used to realize the 3-dimensional device structure in GaN are described in detail. Finally, an ultra-low-cost, laser-based, non-contact approach to test and characterize the microswitch device is described, followed by the device testing results.

  18. The Hands-On Optics Project: a demonstration of module 3-magnificent magnifications

    Science.gov (United States)

    Pompea, Stephen M.; Sparks, Robert T.; Walker, Constance E.

    2014-07-01

    The Hands-On Optics project offers an example of a set of instructional modules that foster active prolonged engagement. Developed by SPIE, OSA, and NOAO through funding from the U.S. National Science Foundation, the modules were originally designed for afterschool settings and museums. However, because they were based on national standards in mathematics, science, and technology, they were easily adapted for use in classrooms. The philosophy and implementation strategies of the six modules will be described as well as lessons learned in training educators. The modules were implementing with the help of optics industry professionals who served as expert volunteers to assist educators. A key element of the modules was that they were developed around an understanding of optics misconceptions and used culminating activities in each module as a form of authentic assessment. Thus student achievement could be measured by evaluating the actual product created by each student in applying key concepts, tools, and applications together at the end of each module. The program used a progression of disciplinary core concepts to build an integrated sequence and crosscutting ideas and practices to infuse the principles of the modern electro-optical field into the modules. Whenever possible, students were encouraged to experiment and to create, and to pursue inquiry-based approaches. The result was a program that had high appeal to regular as well as gifted students.

  19. The Quest for the Ultimate Nonlinear Optical Material

    Science.gov (United States)

    Dagenais, M.

    1990-10-01

    The following sections are included: * Introduction * From Infancy to the Real World * Highly Efficient Nonlinear Optical Materials for Switching and Processing * The Era of Pragmatism * Conclusion * References

  20. Inconsistent-handed advantage in episodic memory extends to paragraph-level materials.

    Science.gov (United States)

    Prichard, Eric C; Christman, Stephen D

    2017-09-01

    Past research using handedness as a proxy for functional access to the right hemisphere demonstrates that individuals who are mixed/inconsistently handed outperform strong/consistently handed individuals when performing episodic recall tasks. However, research has generally been restricted to stimuli presented in a list format. In the present paper, we present two studies in which participants were presented with paragraph-level material and then asked to recall material from the passages. The first study was based on a classic study looking at retroactive interference with prose materials. The second was modelled on a classic experiment looking at perspective taking and the content of memory. In both studies, the classic effects were replicated and the general finding that mixed/inconsistent-handers outperform strong/consistent-handers was replicated. This suggests that considering degree of handedness may be an empirically useful means of reducing error variance in paradigms looking at memory for prose level material.

  1. Providing open-access online materials and hands-on sessions for GIS exercises

    Science.gov (United States)

    Oguchi, T.; Yamauchi, H.; Hayakawa, Y. S.

    2017-12-01

    Researchers of GIS (Geographical Information Systems/Sciences) in Japan have collaborated to provide materials for GIS lecture classes in universities for the last 20 years. The major outcomes include 1) a GIS core curriculum, 2) a GIS "body of knowledge" explaining the details of the curriculum, 3) a series of PowerPoint presentations, and 4) a comprehensive GIS textbook. However, materials for GIS exercises at university classes using GIS software have been limited in Japan. Therefore, we launched a project to provide such materials which will be available online and accessible by anybody. The materials cover broad basic aspects of GIS including geoscientific applications such as terrain analysis using digital elevation models. The materials utilize public-domain and open-source software packages such as QGIS and GRASS. The data used are also freely available ones such as those from the Geospatial Information Authority of Japan. The use of the GitHub platform to distribute the materials allow easier online interactions by both material producers and users. Selected sets of the materials have been utilized for hands-on activities including both official university classes and public instructions. We have been updating the materials based on the opinions of people who took the hands-on courses for better GIS education. The current materials are in Japanese, but we plan to translate some of them into English.

  2. Optical band gaps of organic semiconductor materials

    Science.gov (United States)

    Costa, José C. S.; Taveira, Ricardo J. S.; Lima, Carlos F. R. A. C.; Mendes, Adélio; Santos, Luís M. N. B. F.

    2016-08-01

    UV-Vis can be used as an easy and forthright technique to accurately estimate the band gap energy of organic π-conjugated materials, widely used as thin films/composites in organic and hybrid electronic devices such as OLEDs, OPVs and OFETs. The electronic and optical properties, including HOMO-LUMO energy gaps of π-conjugated systems were evaluated by UV-Vis spectroscopy in CHCl3 solution for a large number of relevant π-conjugated systems: tris-8-hydroxyquinolinatos (Alq3, Gaq3, Inq3, Al(qNO2)3, Al(qCl)3, Al(qBr)3, In(qNO2)3, In(qCl)3 and In(qBr)3); triphenylamine derivatives (DDP, p-TTP, TPB, TPD, TDAB, m-MTDAB, NPB, α-NPD); oligoacenes (naphthalene, anthracene, tetracene and rubrene); oligothiophenes (α-2T, β-2T, α-3T, β-3T, α-4T and α-5T). Additionally, some electronic properties were also explored by quantum chemical calculations. The experimental UV-Vis data are in accordance with the DFT predictions and indicate that the band gap energies of the OSCs dissolved in CHCl3 solution are consistent with the values presented for thin films.

  3. Optical coatings material aspects in theory and practice

    CERN Document Server

    Stenzel, Olaf

    2014-01-01

    Optical coatings, i.e. multilayer stacks composed from a certain number of thin individual layers, are an essential part of any optical system necessary to tailor the properties of the optical surfaces. Hereby, the performance of any optical coating is defined by a well-balanced interplay between the properties of the individual coating materials and the geometrical parameters (such as film thickness) which define their arrangement. In all scientific books dealing with the performance of optical coatings, the main focus is on optimizing the geometrical coating parameters, particularly the number of individual layers and their thickness. At the same time, much less attention is paid to another degree of freedom in coating design, namely the possibility to tailor optical material properties to an optimum relevant for the required specification. This book, on the contrary, concentrates on the material aside of the problem. After a comprehensive review of the basics of thin film theory, traditional optical coatin...

  4. Optical properties of two-dimensional charge density wave materials

    Science.gov (United States)

    Sayers, Charles; Karbassi, Sara; Friedemann, Sven; da Como, Enrico

    Titanium diselenide (TiSe2) is a member of the layered transition metal dichalcogenide (TMD) materials. It exhibits unusual chiral charge ordering below 190 K after undergoing an initial phase transition to a commensurate (2 x 2 x 2) charge density wave (CDW) at 200 K which is enhanced further in the monolayer. Recently, the first evidence of chirality in a CDW system was discovered in this material by scanning tunneling microscopy and time-resolved reflectivity experiments, where separate left and right handed charge-ordered domains were found to exist within a single sample. We have prepared single crystals of 1T-TiSe2 using iodine vapour transport, and confirmed their quality by x-ray analysis and charge transport measurements. Using a combination of polarised optical spectroscopy techniques in the mid to far infrared (4 to 700 meV photon energy), we have measured an anisotropy relating to the CDW gap. We discuss the results on the basis of chiral domains with different handedness and the nature of the CDW transition.

  5. Wave Propagation From Electrons to Photonic Crystals and Left-Handed Materials

    CERN Document Server

    Markos, Peter

    2010-01-01

    This textbook offers the first unified treatment of wave propagation in electronic and electromagnetic systems and introduces readers to the essentials of the transfer matrix method, a powerful analytical tool that can be used to model and study an array of problems pertaining to wave propagation in electrons and photons. It is aimed at graduate and advanced undergraduate students in physics, materials science, electrical and computer engineering, and mathematics, and is ideal for researchers in photonic crystals, negative index materials, left-handed materials, plasmonics, nonlinear effects,

  6. In Situ Identification of Mineral Resources with an X-Ray-Optical "Hands-Lens" Instrument

    Science.gov (United States)

    Marshall, J.; Koppel, L.; Bratton, C.; Metzger, E.; Hecht, M.

    1999-09-01

    The recognition of material resources on a planetary surface requires exploration strategies not dissimilar to those employed by early field geologists who searched for ore deposits primarily from surface clues. In order to determine the location of mineral ores or other materials, it will be necessary to characterize host terranes at regional or subregional scales. This requires geographically broad surveys in which statistically significant numbers of samples are rapidly scanned from a roving platform. To enable broad-scale, yet power-conservative planetary-surface exploration, we are developing an instrument that combines x-ray diffractometry (XRD), x-ray fluorescence spectrometry (XRF), and optical capabilities; the instrument can be deployed at the end of a rover's robotic arm, without the need for sample capture or preparation. The instrument provides XRD data for identification of mineral species and lithological types; diffractometry of minerals is conducted by ascertaining the characteristic lattice parameters or "d-spacings" of mineral compounds. D-spacings of 1.4 to 25 angstroms can be determined to include the large molecular structures of hydrated minerals such as clays. The XRF data will identify elements ranging from carbon (Atomic Number = 6) to elements as heavy as barium (Atomic Number = 56). While a sample is being x-rayed, the instrument simultaneously acquires an optical image of the sample surface at magnifications from lx to at least 50x (200x being feasible, depending on the sample surface). We believe that imaging the sample is extremely important as corroborative sample-identification data (the need for this capability having been illustrated by the experience of the Pathfinder rover). Very few geologists would rely on instrument data for sample identification without having seen the sample. Visual inspection provides critical recognition data such as texture, crystallinity, granularity, porosity, vesicularity, color, lustre, opacity, and

  7. Handbook of the Properties of Optical Materials

    Science.gov (United States)

    1984-01-01

    EFFECTIVE MASS - - MOBILITY - - A-2 ARSEWIC SELENIOE (As2 Se3 ) OPTICAL PROPERTIES TRANSMISSION RANGE: 9 - 11n Optical Absorption Coefficient = 0.079...of 55 KRS-5 as a function of wavelength. A-2120 ZINC SELENIOE ZnSe 0 STRUCTURE CRYSTALLINE SYMMETRY = Cubic, 43m LATTICE CONSTANTS (A) = a = 5.667

  8. Scientific Applications of Optical Instruments to Materials Research

    Science.gov (United States)

    Witherow, William K.

    1997-01-01

    Microgravity is a unique environment for materials and biotechnology processing. Microgravity minimizes or eliminates some of the effects that occur in one g. This can lead to the production of new materials or crystal structures. It is important to understand the processes that create these new materials. Thus, experiments are designed so that optical data collection can take place during the formation of the material. This presentation will discuss scientific application of optical instruments at MSFC. These instruments include a near-field scanning optical microscope, a miniaturized holographic system, and a phase-shifting interferometer.

  9. The hand-hold polarization-sensitive spectral domain optical coherence and its applications

    Science.gov (United States)

    Liu, Hao; Gao, Wanrong

    2017-08-01

    The polarization-sensitive spectral domain optical coherence tomography (PSOCT) has the advantages of being able to measure the polarization properties of samples, such as phase-retardation, diattenuation, depolarization, and optical axis orientation, providing a contrast to identify the diseased area and normal area in tissues in PSOCT images. Conventionally, the sample arm of PSOCT is fixed on the stage where biomedical tissues or models is placed, and the OCT images is acquired by scanning with a galvanometer-based mirror. To be applied in the practical diagnosis, a promising way is to design a hand-held device. To this end, it is required that probe is assembled with a small volume to allow for comprehensively imaging large tissues areas at a microscopic scale, and is available to move on different samples to be acquired quickly with negligible motion artifacts. Meanwhile, the probe should be manufactured wih well stability to avoid system jitter error while it is used to detect the biological tissues in vivo. In this work, a design of a hand-hold fiber-based PSOCT is described. The device is of the size of 10 cm (length) × 8 cm (width) × 6 cm (height). Both the axial resolution and the imaging depth of the system are measured and were approximately 7 μm and 2.5 mm in air, respectively, which are in good agreement with the theoretical predictions. The A-scan rate of the system is 70 kHz. The structure is compact and all the components are fixed on the shell to reduce the motion artifact, resulting in a great stability on measuring the tissues in vivo. The cross sectional images of ex vivo chicken breast, ex vivo pork cartilage and in vivo forearm skin of human wolunteer are presented to demonstrate the capability of the system.

  10. The Weather-Beaten Dorsal Hand Clinical Rating, Shadow Casting Optical Profilometry, and Skin Capacitance Mapping

    Directory of Open Access Journals (Sweden)

    Marie Delvenne

    2013-01-01

    Full Text Available Laypeople commonly perceive some skin xerosis and withering (roughness changes during winter on some parts of the body, particularly on the dorsal hands. The aim of the study was to assess the withered skin surface changes occurring during the four seasons. A total of 47 menopausal women completed the study. A group of 31 volunteers were on hormone replacement therapy (HRT and 16 were out of HRT. Skin xerosis and scaliness were rated clinically. In addition, skin whitening was assessed by computerized shadow casting optical profilometry and by skin capacitance mapping. The volunteers were not using topical creams and over-the-counter products on their hands. Marked changes, recorded over the successive seasons, corresponded to patchy heterogeneous stratum corneum hydration and heterogeneous skin surface roughness changing over seasons; they likely resulted from changes in the environmental temperature and atmosphere moisture. The severity of the changes revealed by clinical inspection was not supported by similar directions of fluctuations in the instrumental assessments. This seemingly contradiction was in fact due to different levels of scale observation. The clinical centimetric scale and the instrumental inframillimetric scale possibly provide distinct aspects of a given biological impact.

  11. Hand-Held Sunphotometers for High School Student Construction and Measuring Aerosol Optical Thickness

    Science.gov (United States)

    Almonor, Linda; Baldwin, C.; Craig, R.; Johnson, L. P.

    2000-01-01

    Science education is taking the teaching of science from a traditional (lecture) approach to a multidimensional sense-making approach which allows teachers to support students by providing exploratory experiences. Using projects is one way of providing students with opportunities to observe and participate in sense-making activity. We created a learning environment that fostered inquiry-based learning. Students were engaged in a variety of Inquiry activities that enabled them to work in cooperative planning teams where respect for each other was encouraged and their ability to grasp, transform and transfer information was enhanced. Summer, 1998: An air pollution workshop was conducted for high school students in the Medgar Evers College/Middle College High School Liberty Partnership Summer Program. Students learned the basics of meteorology: structure and composition of the atmosphere and the processes that cause weather. The highlight of this workshop was the building of hand-held sunphotometers, which measure the intensity of the sunlight striking the Earth. Summer, 1999: high school students conducted a research project which measured the mass and size of ambient particulates and enhanced our ability to observe through land based measurements changes in the optical depth of ambient aerosols over Brooklyn. Students used hand held Sunphotometers to collect data over a two week period and entered it into the NASA GISS database by way of the internet.

  12. Optical improvement for laser material processing

    Energy Technology Data Exchange (ETDEWEB)

    Bosman, J.; De Keijzer, M.A.; De Kok, C.J.G.M. [ECN Engineering and Services, Petten (Netherlands); Molenaar, R.; Kettelarij, H.

    2010-05-15

    The use of laser technology enables flexibility and new concepts for example solar cell production but also optical moulds. The reason why laser technology is used in these cases is not the laser system itself but the ability to tailor this type of energy to the demands of the production processes. To ensure the full potential of the laser technology it can be improved by adding optical elements like polarizer, cameras, lenses and sensors. Two of these extra optical elements are presented here. First laser pulse energy attenuation. This is used to increase the controllability of laser processes. And second a new camera optic that enables integrated alignment with respect to features on the product. This last option enables marking on existing features and automated compensation of scanner drift. These camera systems can be used for micro welding of polymers and repair of existing markings in moulds.

  13. Light scattering in porous materials: Geometrical optics and stereological approach

    International Nuclear Information System (INIS)

    Malinka, Aleksey V.

    2014-01-01

    Porous material has been considered from the point of view of stereology (geometrical statistics), as a two-phase random mixture of solid material and air. Considered are the materials having the refractive index with the real part that differs notably from unit and the imaginary part much less than unit. Light scattering in such materials has been described using geometrical optics. These two – the geometrical optics laws and the stereological approach – allow one to obtain the inherent optical properties of such a porous material, which are basic in the radiative transfer theory: the photon survival probability, the scattering phase function, and the polarization properties (Mueller matrix). In this work these characteristics are expressed through the refractive index of the material and the random chord length distribution. The obtained results are compared with the traditional approach, modeling the porous material as a pack of particles of different shapes. - Highlights: • Porous material has been considered from the point of view of stereology. • Properties of a two-phase random mixture of solid material and air are considered. • Light scattering in such materials has been described using geometrical optics. • The inherent optical properties of such a porous material have been obtained

  14. Overlapping illusions by transformation optics without any negative refraction material

    Science.gov (United States)

    Sun, Fei; He, Sailing

    2016-01-01

    A novel method to achieve an overlapping illusion without any negative refraction index material is introduced with the help of the optic-null medium (ONM) designed by an extremely stretching spatial transformation. Unlike the previous methods to achieve such an optical illusion by transformation optics (TO), our method can achieve a power combination and reshape the radiation pattern at the same time. Unlike the overlapping illusion with some negative refraction index material, our method is not sensitive to the loss of the materials. Other advantages over existing methods are discussed. Numerical simulations are given to verify the performance of the proposed devices.

  15. Structurally integrated fiber optic damage assessment system for composite materials.

    Science.gov (United States)

    Measures, R M; Glossop, N D; Lymer, J; Leblanc, M; West, J; Dubois, S; Tsaw, W; Tennyson, R C

    1989-07-01

    Progress toward the development of a fiber optic damage assessment system for composite materials is reported. This system, based on the fracture of embedded optical fibers, has been characterized with respect to the orientation and location of the optical fibers in the composite. Together with a special treatment, these parameters have been tailored to yield a system capable of detecting the threshold of damage for various impacted Kevlar/epoxy panels. The technique has been extended to measure the growth of a damage region which could arise from either impact, manufacturing flaws, or static overloading. The mechanism of optical fiber fracture has also been investigated. In addition, the influence of embedded optical fibers on the tensile and compressive strength of the composite material has been studied. Image enhanced backlighting has been shown to be a powerful and convenient method of assessing internal damage to translucent composite materials.

  16. [Influence of promotional material on hand hygiene in the safety culture of a tertiary hospital].

    Science.gov (United States)

    Molina-Cabrillana, J; Dorta-Hung, M E; Otero Sanz, L; Henández Vera, J R; Martín-Rodríguez, M M; García de Carlos, P

    2016-06-01

    In order to increase safety culture about hand hygiene by means of messages and reminders about its importance in preventing nosocomial infections, we developed a new set of materials in the Complejo Hospitalario Universitario Insular Materno-Infantil of Las Palmas, Gran Canaria, constitued by two centres with 450 beds each and acredited for medical internal residents training. We hired a well-known caricaturist, who adapted the messages to the local way of speaking, by using characters that used to appear in his artwork in the local newspaper. Also, we continued to work with other graphic design professionals. We monitored adherence and consumption of products for hand rubbing. We noted an increase in both indicators in the following months after the implementation of this strategy. Moreover, we revised the infrastructures for hand hygiene, and were able to demonstrate improvements in most of the patient care areas. The material was well accepted by professionals, patients and visitors. No other interventions were made, so we think improvements can be attributable to this strategy in our setting. Copyright © 2016 SECA. Published by Elsevier Espana. All rights reserved.

  17. Theory-inspired development of organic electro-optic materials

    Energy Technology Data Exchange (ETDEWEB)

    Dalton, Larry R., E-mail: dalton@chem.washington.ed [Department of Chemistry, Bagley Hall 202D, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States); Department of Electrical Engineering, Bagley Hall 202D, Box 351700, University of Washington, Seattle, Washington 98195-1700 (United States)

    2009-11-30

    Real-time, time-dependent density functional theory (RTTDDFT) and pseudo-atomistic Monte Carlo-molecular dynamics (PAMCMD) calculations have been used in a correlated manner to achieve quantitative definition of structure/function relationships necessary for the optimization of electro-optic activity in organic materials. Utilizing theoretical guidance, electro-optic coefficients (at telecommunication wavelengths) have been increased to 500 pm/V while keeping optical loss to less than 2 dB/cm. RTTDDFT affords the advantage of permitting explicit treatment of time-dependent electric fields, both applied fields and internal fields. This modification has permitted the quantitative simulation of the variation of linear and nonlinear optical properties of chromophores and the electro-optic activity of materials with optical frequency and dielectric permittivity. PAMCMD statistical mechanical calculations have proven an effective means of treating the full range of spatially-anisotropic intermolecular electrostatic interactions that play critical roles in defining the degree of noncentrosymmetric order that is achieved by electric field poling of organic electro-optic materials near their glass transition temperatures. New techniques have been developed for the experimental characterization of poling-induced acentric order including a modification of variable angle polarization absorption spectroscopy (VAPAS) permitting a meaningful correlation of theoretical and experimental data related to poling-induced order for a variety of complex organic electro-optic materials.

  18. Theory-inspired development of organic electro-optic materials

    International Nuclear Information System (INIS)

    Dalton, Larry R.

    2009-01-01

    Real-time, time-dependent density functional theory (RTTDDFT) and pseudo-atomistic Monte Carlo-molecular dynamics (PAMCMD) calculations have been used in a correlated manner to achieve quantitative definition of structure/function relationships necessary for the optimization of electro-optic activity in organic materials. Utilizing theoretical guidance, electro-optic coefficients (at telecommunication wavelengths) have been increased to 500 pm/V while keeping optical loss to less than 2 dB/cm. RTTDDFT affords the advantage of permitting explicit treatment of time-dependent electric fields, both applied fields and internal fields. This modification has permitted the quantitative simulation of the variation of linear and nonlinear optical properties of chromophores and the electro-optic activity of materials with optical frequency and dielectric permittivity. PAMCMD statistical mechanical calculations have proven an effective means of treating the full range of spatially-anisotropic intermolecular electrostatic interactions that play critical roles in defining the degree of noncentrosymmetric order that is achieved by electric field poling of organic electro-optic materials near their glass transition temperatures. New techniques have been developed for the experimental characterization of poling-induced acentric order including a modification of variable angle polarization absorption spectroscopy (VAPAS) permitting a meaningful correlation of theoretical and experimental data related to poling-induced order for a variety of complex organic electro-optic materials.

  19. Phosphorus-based compounds for EUV multilayer optics materials

    NARCIS (Netherlands)

    Medvedev, Viacheslav; Yakshin, Andrey; van de Kruijs, Robbert Wilhelmus Elisabeth; Bijkerk, Frederik

    2015-01-01

    We have evaluated the prospects of phosphorus-based compounds in extreme ultraviolet multilayer optics. Boron phosphide (BP) is suggested to be used as a spacer material in reflective multilayer optics operating just above the L-photoabsorption edge of P (λ ≈9.2 nm). Mo, Ag, Ru, Rh, and Pd were

  20. Optical Coherence Tomography for Material Characterization

    NARCIS (Netherlands)

    Liu, P.

    2014-01-01

    Optical coherence tomography (OCT) is a non-invasive, contactless and high resolution imaging method, which allows the reconstruction of two or three dimensional depth-resolved images in turbid media. In the past 20 years, OCT has been extensively developed in the field of biomedical diagnostics,

  1. Spectroscopic properties of rare earths in optical materials

    CERN Document Server

    Parisi, Jürgen; Osgood, R; Warlimont, Hans; Liu, Guokui; Jacquier, Bernard

    2005-01-01

    Aimed at researchers and graduate students, this book provides up-to-date information for understanding electronic interactions that impact the optical properties of rare earth ions in solids. Its goal is to establish a connection between fundamental principles and the materials properties of rare-earth activated luminescent and laser optical materials. The theoretical survey and introduction to spectroscopic properties include electronic energy level structure, intensities of optical transitions, ion-phonon interactions, line broadening, and energy transfer and up-conversion. An important aspect of the book lies in its deep and detailed discussions on materials properties and the potential of new applications such as optical storage, information processing, nanophotonics, and molecular probes that have been identified in recent experimental studies. This volume will be a valuable reference book on advanced topics of rare earth spectroscopy and materials science.

  2. New directions for ion beam processing of optical materials

    Energy Technology Data Exchange (ETDEWEB)

    White, C W; Budai, J D; Zhu, J G; Withrow, S P [Oak Ridge National Lab., TN (United States)

    1997-03-01

    Recent developments in the use of ion implantation to modify the properties of optical materials are summarized. The use of ion implantation to form nanocrystal and quantum dots is emphasized. (author)

  3. Pulsed x-ray induced attenuation measurements of single mode optical fibers and coupler materials

    International Nuclear Information System (INIS)

    Johan, A.; Charre, P.

    1994-01-01

    Pulsed X-ray induced transient radiation attenuation measurements of single mode optical fibers have been performed versus total dose, light wavelength, optical power and fiber coil diameter in order to determine the behavior of parameters sensitive to ionizing radiation. The results did not show any photobleaching phenomenon and the attenuation was found independent of the spool diameter. As expected, transient attenuation was lower for higher wave-lengths. The recovery took place in the millisecond range and was independent of total dose, light wavelength and optical power. In optical modules and devices a large range of behaviors was observed according to coupler material i.e., Corning coupler showed a small peak attenuation that remained more than one day later; on the other hand LiTaO 3 material experienced an order of magnitude higher peak attenuation and a recovery in the millisecond range. For applications with optical fibers and integrated optics devices the authors showed that in many cases the optical fiber (length above 100 m) is the most sensitive device in a transient ionizing radiation field

  4. Hand motion modeling for psychology analysis in job interview using optical flow-history motion image: OF-HMI

    Science.gov (United States)

    Khalifa, Intissar; Ejbali, Ridha; Zaied, Mourad

    2018-04-01

    To survive the competition, companies always think about having the best employees. The selection is depended on the answers to the questions of the interviewer and the behavior of the candidate during the interview session. The study of this behavior is always based on a psychological analysis of the movements accompanying the answers and discussions. Few techniques are proposed until today to analyze automatically candidate's non verbal behavior. This paper is a part of a work psychology recognition system; it concentrates in spontaneous hand gesture which is very significant in interviews according to psychologists. We propose motion history representation of hand based on an hybrid approach that merges optical flow and history motion images. The optical flow technique is used firstly to detect hand motions in each frame of a video sequence. Secondly, we use the history motion images (HMI) to accumulate the output of the optical flow in order to have finally a good representation of the hand`s local movement in a global temporal template.

  5. Broadband optical characterization of material properties

    DEFF Research Database (Denmark)

    Nielsen, Otto Højager Attermann

    the applicability of optical techniques for this purpose, the fermentation of milk into yogurt has been used as a model system. Studies have been conducted on commercially available products, but also of on-line measurement of the fermentation process. The second process is from the aquaculture industry...... reports on the design and operation of the different measurement techniques together with the necessary theoretical background for the industrial applications. For the purpose of milk fermentation this work has demonstrated that the reduced scattering properties of milk change significantly throughout...... the fermentation process. It has also been shown that the optical inspection methods sense changes to structural properties before any are detected by traditional mechanical rheology. Finally, the developed hyperspectral imaging system was used to quantify the content of astaxanthin in fish feed, and performed...

  6. The chemistry and physics of nonlinear optical materials

    International Nuclear Information System (INIS)

    Velsko, S.P.; Eimerl, D.

    1989-01-01

    Recent efforts to engineer new nonlinear optical materials with specific desired characteristics has engendered a need for a theoretical description of optical properties which is readily accessible to chemists, yet correctly treats the essential physics of dielectric response. This paper describes a simple empirical molecular orbital model which gives useful insights into the relationship between chemical composition, crystalline structure, and optical susceptibilities. The authors compare the probabilities of finding new harmonic generators in various chemical classes. Rigorous bounds on the magnitudes of linear and nonlinear optical coefficients and their anisotropies are also discussed

  7. Studies of imaging characteristics for a slab of a lossy left-handed material

    International Nuclear Information System (INIS)

    Shen Linfang; He Sailing

    2003-01-01

    The characteristics of an imaging system formed by a slab of a lossy left-handed material (LHM) are studied. The transfer function of the LHM imaging system is written in an appropriate product form with each term having a clear physical interpretation. A tiny loss of the LHM may suppress the transmission of evanescent waves through the LHM slab and this is explained physically. An analytical expression for the resolution of the imaging system is derived. It is shown that it is impossible to make a subwavelength imaging by using a realistic LHM imaging system unless the LHM slab is much thinner than the wavelength

  8. Traditional and emerging materials for optical metasurfaces

    Directory of Open Access Journals (Sweden)

    Zhu Alexander Y.

    2017-03-01

    Full Text Available One of the most promising and vibrant research areas in nanotechnology has been the field of metasurfaces. These are two dimensional representations of metaatoms, or artificial interfaces designed to possess specialized electromagnetic properties which do not occur in nature, for specific applications. In this article, we present a brief review of metasurfaces from a materials perspective, and examine how the choice of different materials impact functionalities ranging from operating bandwidth to efficiencies. We place particular emphasis on emerging and non-traditional materials for metasurfaces such as high index dielectrics, topological insulators and digital metamaterials, and the potentially transformative role they could play in shaping further advances in the field.

  9. Rational design of organic electro-optic materials

    CERN Document Server

    Dalton, L R

    2003-01-01

    Quantum mechanical calculations are used to optimize the molecular first hyperpolarizability of organic chromophores and statistical mechanical calculations are used to optimize the translation of molecular hyperpolarizability to macroscopic electro-optic activity (to values of greater than 100 pm V sup - sup 1 at telecommunications wavelengths). Macroscopic material architectures are implemented exploiting new concepts in nanoscale architectural engineering. Multi-chromophore-containing dendrimers and dendronized polymers not only permit optimization of electro-optic activity but also of auxiliary properties including optical loss (both absorption and scattering), thermal and photochemical stability and processability. New reactive ion etching and photolithographic techniques permit the fabrication of three-dimensional optical circuitry and the integration of that circuitry with semiconductor very-large-scale integration electronics and silica fibre optics. Electro-optic devices have been fabricated exploiti...

  10. Optical identification using imperfections in 2D materials

    Science.gov (United States)

    Cao, Yameng; Robson, Alexander J.; Alharbi, Abdullah; Roberts, Jonathan; Woodhead, Christopher S.; Noori, Yasir J.; Bernardo-Gavito, Ramón; Shahrjerdi, Davood; Roedig, Utz; Fal'ko, Vladimir I.; Young, Robert J.

    2017-12-01

    The ability to uniquely identify an object or device is important for authentication. Imperfections, locked into structures during fabrication, can be used to provide a fingerprint that is challenging to reproduce. In this paper, we propose a simple optical technique to read unique information from nanometer-scale defects in 2D materials. Imperfections created during crystal growth or fabrication lead to spatial variations in the bandgap of 2D materials that can be characterized through photoluminescence measurements. We show a simple setup involving an angle-adjustable transmission filter, simple optics and a CCD camera can capture spatially-dependent photoluminescence to produce complex maps of unique information from 2D monolayers. Atomic force microscopy is used to verify the origin of the optical signature measured, demonstrating that it results from nanometer-scale imperfections. This solution to optical identification with 2D materials could be employed as a robust security measure to prevent counterfeiting.

  11. An electromagnetically actuated fiber optic switch using magnetized ferromagnetic materials

    Science.gov (United States)

    Pandojirao-S, Praveen; Dhaubanjar, Naresh; Phuyal, Pratibha C.; Chiao, Mu; Chiao, J.-C.

    2008-03-01

    This paper presents the design, fabrication and testing of a fiber optic switch actuated electromagnetically. The ferromagnetic gel coated optical fiber is actuated using external electromagnetic fields. The ferromagnetic gel consists of ferromagnetic powders dispersed in epoxy. The fabrication utilizes a simple cost-effective coating setup. A direct fiberto-fiber alignment eliminates the need for complementary optical parts and the displacement of fiber switches the laser coupling. The magnetic characteristics of magnetized ferromagnetic materials are performed using alternating gradient magnetometer and the magnetic hysteresis curves are measured for different ferromagnetic materials including iron, cobalt, and nickel. Optical fiber switches with various fiber lengths are actuated and their static and dynamic responses for the same volume of ferromagnetic gel are summarized. The highest displacement is 1.345 mm with an input current of 260mA. In this paper, the performance of fiber switches with various coating materials is presented.

  12. Progress in nano-electro optics characterization of nano-optical materials and optical near-field interactions

    CERN Document Server

    Ohtsu, Motoichi

    2005-01-01

    This volume focuses on the characterization of nano-optical materials and optical-near field interactions. It begins with the techniques for characterizing the magneto-optical Kerr effect and continues with methods to determine structural and optical properties in high-quality quantum wires with high spatial uniformity. Further topics include: near-field luminescence mapping in InGaN/GaN single quantum well structures in order to interpret the recombination mechanism in InGaN-based nano-structures; and theoretical treatment of the optical near field and optical near-field interactions, providing the basis for investigating the signal transport and associated dissipation in nano-optical devices. Taken as a whole, this overview will be a valuable resource for engineers and scientists working in the field of nano-electro-optics.

  13. Materials and integration schemes for above-IC integrated optics

    NARCIS (Netherlands)

    Schmitz, Jurriaan; Rangarajan, B.; Kovalgin, Alexeij Y.

    2014-01-01

    A study is presented on silicon oxynitride material for waveguides and germanium-silicon alloys for p-i-n diodes. The materials are manufactured at low, CMOS-backend compatible temperatures, targeting the integration of optical functions on top of CMOS chips. Low-temperature germanium-silicon

  14. Security enhancement of hand geometry scanners using optical blood flow detection

    Science.gov (United States)

    Crihalmeanu, Musat C.; Jerabek, Mark A.; Meehan, Kathleen

    2004-08-01

    In today's security conscious society the efficiency of biometric systems has an increasing tendency to replace the classic but less effective keys and passwords. Hand geometry readers are popular biometrics used for acces control and time and attendance applications. One of their weaknesses is vulnerability to spoofing using fake hands (latex, play-doh or dead-hands). The object of this paper is to design a feature to be added to the hand geometry scanner in order to detect vitality in the hand, reducing the possibilities for spoofing. This paper demonstrates how the hand reader was successfully spoofed and shows the implementation of the vitality detection feature through an inexpensive but efficient electronic design. The method used for detection is photo-plethysmography. The Reflectance Sensor built is of original conception. After amplifying, filtering and processing the sensor's signal, a message is shown via an LCD display, concerning the liveness of the hand and the pulse rate.

  15. Integration of Magneto-Optical Materials for Novel Optical Devices & Magnetophotonic Crystals, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — This work proposes to capitalize on our Phase I success in monolithically integrating magneto-optic and magnetic materials with semiconductor platforms in order to...

  16. Metal Oxide Nanostructured Materials for Optical and Energy Applications

    OpenAIRE

    Moore, Michael Christopher

    2013-01-01

    With a rapidly growing population, dwindling resources, and increasing environmental pressures, the need for sustainable technological solutions becomes more urgent. Metal oxides make up much of the earth's crust and are typically inexpensive materials, but poor electrical and optical properties prevent them from being useful for most semiconductor applications. Recent breakthroughs in chemistry and materials science allow for the growth of high-quality materials with nanometer-scale features...

  17. Strained silicon as a new electro-optic material

    DEFF Research Database (Denmark)

    Jacobsen, Rune Shim; Andersen, Karin Nordström; Borel, Peter Ingo

    2006-01-01

    For decades, silicon has been the material of choice for mass fabrication of electronics. This is in contrast to photonics, where passive optical components in silicon have only recently been realized1, 2. The slow progress within silicon optoelectronics, where electronic and optical...... functionalities can be integrated into monolithic components based on the versatile silicon platform, is due to the limited active optical properties of silicon3. Recently, however, a continuous-wave Raman silicon laser was demonstrated4; if an effective modulator could also be realized in silicon, data...... processing and transmission could potentially be performed by all-silicon electronic and optical components. Here we have discovered that a significant linear electro-optic effect is induced in silicon by breaking the crystal symmetry. The symmetry is broken by depositing a straining layer on top...

  18. Theory of absorption integrated optical sensor of gaseous materials

    Science.gov (United States)

    Egorov, A. A.

    2010-10-01

    The eigen and noneigen (leaky) modes of a three-layer planar integrated optical waveguide are described. The dispersion relation of a three-layer planar waveguide and other dependences are derived, and the cutoff conditions are analyzed. The diagram of propagation constants of the guided and radiation modes of an irregular asymmetric three-layer waveguide and the dependence of the electric field amplitudes of radiation modes of substrate on vertical coordinate in a tantalum integrated optical waveguide are presented. The operating principles of an absorption integrated optical waveguide sensor are investigated. The dependences of sensitivity of an integrated optical waveguide sensor on the sensory cell length, the coupling efficiency of the laser radiation into the waveguide, the absorption cross-section of the studied material, and the level of additive statistical noise are investigated. Some of the prospective areas of application of integrated-optical waveguide sensors are outlined.

  19. Study of PMMA materials for a digital optical module

    Science.gov (United States)

    Spina, Roberto; Tricarico, Luigi; Berardi, Vincenzo; De Rosa, Gianfranca; Ruggeri, Alan C.; Mastrorilli, Piero

    2018-05-01

    This work illustrates the material characterization to realize of a prototypal polymeric cover of a Digital Optical Module for the Hyper-Kamiokande neutrino experiment. The cover was made of a high transmittance poly-methyl methacrylate (PMMA), used as a glass substitute. The main objective of the present research is to investigate the structural and optical properties of PMMA, evaluating the respect of the project specification.

  20. Introducing Magneto-Optical Functions into Soft Materials

    Science.gov (United States)

    2017-05-03

    including organic and bio materials by using magnetic nanomaterials. This final report includes the successful developments of magneto-optical... successful developments of magneto-optical properties in both organic and bio magnetic nanocomposites during the project period of three years...proteins on the photoluminescence of nanodiamond. J. Appl . Phys. 2011, 109 (3), 034704. 7, Xu, H.; Hung, C.E.; Cheng, C.L.; Hu, B., Magneto-electric

  1. Analytical solution for wave propagation through a graded index interface between a right-handed and a left-handed material.

    Science.gov (United States)

    Dalarsson, Mariana; Tassin, Philippe

    2009-04-13

    We have investigated the transmission and reflection properties of structures incorporating left-handed materials with graded index of refraction. We present an exact analytical solution to Helmholtz' equation for a graded index profile changing according to a hyperbolic tangent function along the propagation direction. We derive expressions for the field intensity along the graded index structure, and we show excellent agreement between the analytical solution and the corresponding results obtained by accurate numerical simulations. Our model straightforwardly allows for arbitrary spectral dispersion.

  2. Analytical solution for wave propagation through a graded index interface between a right-handed and a left-handed material

    OpenAIRE

    Dalarsson, Mariana; Tassin, Philippe

    2012-01-01

    We have investigated the transmission and reflection properties of structures incorporating left-handed materials with graded index of refraction. We present an exact analytical solution to Helmholtz' equation for a graded index profile changing according to a hyperbolic tangent function along the propagation direction. We derive expressions for the field intensity along the graded index structure, and we show excellent agreement between the analytical solution and the corresponding results o...

  3. Nonlinear Optics: Materials, Fundamentals, and Applications. Postdeadline papers

    Science.gov (United States)

    1992-08-01

    The Nonlinear Optics: Materials, Fundamentals, and Applications conference was held on 17-21 Aug. 1992. The following topics were addressed: subpicosecond time resolved four-wave mixing spectroscopy in heteroepitaxial ZnSe thin layers; anisotropic two-photon transition in GaAs/AlGaAs multiple quantum well waveguides; two picosecond, narrow-band, tunable, optical parametric systems using BBO and LBO; second generation in an optically active liquid: experimental observation of a fourth-order optical nonlinearity due to molecular chirality; optical image recognition system implemented with a 3-D memory disk; phase-matched second-harmonic generation in waveguides of polymeric Langmuir-Blodgett films; fluence dependent dynamics observed in the resonant third-order optical response of C60 and C70 films; temporal modulation of spatial optical solitons: a variational approach; measurements of light-scattering noise during two-wave mixing in a Kerr medium; excess noise introduced by beam propagation through an atomic vapor; an approach to all-optical switching based on second-order nonlinearities; multilayer, nonlinear ARROW waveguides for surface emitted sum-frequency mixing; energy scaling of SBS phase conjugate mirrors to 4J; vector versus scalar theory for the double phase conjugate mirror; cross-talk and error probability in counter-beam lambda-multiplexed digital holograms; and modal growth of SHG in doped silica thin film waveguides.

  4. Radiation-induced attenuation in integrated optical materials

    International Nuclear Information System (INIS)

    Evans, B.D.

    1989-01-01

    This paper reports that three materials commonly employed in opto-electronic integrated circuits evaluated for radiation-induced optical attenuation in the range 300 nm to 3000 nm. These include optically clear epoxy and crystalline lithium niobate after Co-60 exposure and crystalline tellurium dioxide after mixed gamma/fast-neutron exposure. In all these materials, however, induced loss was restricted to shorter wavelengths; attenuation induced at the telecommunications windows near 850, 1300 and 1550 nm was <0.1 dB/cm

  5. Active material, optical mode and cavity impact on nanoscale electro-optic modulation performance

    Science.gov (United States)

    Amin, Rubab; Suer, Can; Ma, Zhizhen; Sarpkaya, Ibrahim; Khurgin, Jacob B.; Agarwal, Ritesh; Sorger, Volker J.

    2017-10-01

    Electro-optic modulation is a key function in optical data communication and possible future optical compute engines. The performance of modulators intricately depends on the interaction between the actively modulated material and the propagating waveguide mode. While a variety of high-performance modulators have been demonstrated, no comprehensive picture of what factors are most responsible for high performance has emerged so far. Here we report the first systematic and comprehensive analytical and computational investigation for high-performance compact on-chip electro-optic modulators by considering emerging active materials, model considerations and cavity feedback at the nanoscale. We discover that the delicate interplay between the material characteristics and the optical mode properties plays a key role in defining the modulator performance. Based on physical tradeoffs between index modulation, loss, optical confinement factors and slow-light effects, we find that there exist combinations of bias, material and optical mode that yield efficient phase or amplitude modulation with acceptable insertion loss. Furthermore, we show how material properties in the epsilon near zero regime enable reduction of length by as much as by 15 times. Lastly, we introduce and apply a cavity-based electro-optic modulator figure of merit, Δλ/Δα, relating obtainable resonance tuning via phase shifting relative to the incurred losses due to the fundamental Kramers-Kronig relations suggesting optimized device operating regions with optimized modulation-to-loss tradeoffs. This work paves the way for a holistic design rule of electro-optic modulators for high-density on-chip integration.

  6. Kuznetsov-Ma waves train generation in a left-handed material

    Science.gov (United States)

    Atangana, Jacques; Giscard Onana Essama, Bedel; Biya-Motto, Frederick; Mokhtari, Bouchra; Cherkaoui Eddeqaqi, Noureddine; Crépin Kofane, Timoléon

    2015-03-01

    We analyze the behavior of an electromagnetic wave which propagates in a left-handed material. Second-order dispersion and cubic-quintic nonlinearities are considered. This behavior of an electromagnetic wave is modeled by a nonlinear Schrödinger equation which is solved by collective coordinates theory in order to characterize the light pulse intensity profile. More so, a specific frequency range has been outlined where electromagnetic wave behavior will be investigated. The perfect combination of second-order dispersion and cubic nonlinearity leads to a robust soliton. When the quintic nonlinearity comes into play, it provokes strong and long internal perturbations which lead to Benjamin-Feir instability. This phenomenon, also called modulational instability, induces appearance of a Kuznetsov-Ma waves train. We numerically verify the validity of Kuznetsov-Ma theory by presenting physical conditions which lead to Kuznetsov-Ma waves train generation. Thereafter, some properties of such waves train are also verified.

  7. Spin Hall effect of a light beam in left-handed materials

    International Nuclear Information System (INIS)

    Luo Hailu; Wen Shuangchun; Shu Weixing; Tang Zhixiang; Zou Yanhong; Fan Dianyuan

    2009-01-01

    We establish a general propagation model to describe the spin Hall effect of light beam in left-handed materials (LHMs). A spin-dependent shift of the beam centroid perpendicular to the refractive index gradient for the light beam through an air-LHM interface is demonstrated. For a certain circularly polarized component, whether the transverse shift is positive or negative depends on the magnitude of the refractive index gradient. Very surprisingly, the spin Hall effect in the LHM is unreversed, although the sign of refractive index gradient is reversed. The physics underlying this counterintuitive effect is that the spin angular momentum of photons is unreversed. Further, we reveal that the angular shift in the LHM is reversed due to the negative diffraction. These findings provide alternative evidence for that the linear momentum of photons is reversed, while the spin angular momentum is unreversed in the LHM.

  8. Low losses left-handed materials with optimized electric and magnetic resonance

    Science.gov (United States)

    Zhou, Xin; Liu, Yahong; Zhao, Xiaopeng

    2010-03-01

    We propose that the losses in left-handed materials (LHMs) can be significantly affected by changing the coupling relationship between electric and magnetic resonance. A double bowknot shaped structure (DBS) is used to construct the LHMs. And the magnetic resonance of the DBS, which resonated in the case of lower and higher frequencies than the electric resonant dip, is studied in simulation and experiment by tailoring the structural parameters. The case of magnetic resonance located at low electric resonance frequencies band is confirmed to have relatively low losses. Using full wave simulation of prism shaped structure composed of DBS unit cells, we prove the negative refraction behavior in such a frame. This study can serve as a guide for designing other similar metal-dielectric-metal (MDM) in low losses at terahertz or higher frequencies.

  9. Optical characteristics of novel bulk and nanoengineered laser host materials

    Science.gov (United States)

    Prasad, Narasimha S.; Sova, Stacey; Kelly, Lisa; Bevan, Talon; Arnold, Bradley; Cooper, Christopher; Choa, Fow-Sen; Singh, N. B.

    2018-02-01

    The hexagonal apatite single crystals have been investigated for their applications as laser host materials. Czochralksi and flux growth methods have been utilized to obtain single crystals. For low temperature processing (useful properties as laser hosts and bone materials. Calcium lanthanum silicate (Nd-doped) and lanthanum aluminate material systems were studied in detail. Nanoengineered calcium and lanthanum based silicates were synthesized by a solution method and their optical and morphological characteristics were compared with Czochralski grown bulk hydroxyapatite single crystals. Materials were evaluated by absorbance, fluorescence and Raman characteristics. Neodymium, iron and chromium doped crystals grown by a solution method showed weak but similar optical properties to that of Czochralski grown single crystals.

  10. Rational design of organic electro-optic materials

    International Nuclear Information System (INIS)

    Dalton, L R

    2003-01-01

    Quantum mechanical calculations are used to optimize the molecular first hyperpolarizability of organic chromophores and statistical mechanical calculations are used to optimize the translation of molecular hyperpolarizability to macroscopic electro-optic activity (to values of greater than 100 pm V -1 at telecommunications wavelengths). Macroscopic material architectures are implemented exploiting new concepts in nanoscale architectural engineering. Multi-chromophore-containing dendrimers and dendronized polymers not only permit optimization of electro-optic activity but also of auxiliary properties including optical loss (both absorption and scattering), thermal and photochemical stability and processability. New reactive ion etching and photolithographic techniques permit the fabrication of three-dimensional optical circuitry and the integration of that circuitry with semiconductor very-large-scale integration electronics and silica fibre optics. Electro-optic devices have been fabricated exploiting stripline, cascaded prism and microresonator device structures. Sub-1 V drive voltages and operational bandwidths of greater than 100 GHz have been demonstrated. Both single-and double-ring microresonators have been fabricated for applications such as active wavelength division multiplexing. Free spectral range values of 1 THz and per channel modulation bandwidths of 15 GHz have been realized permitting single-chip data rates of 500 Gb s -1 . Other demonstrated devices include phased array radar, optical gyroscopes, acoustic spectrum analysers, ultrafast analog/digital converters and ultrahigh bandwidth signal generators. (topical review)

  11. 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.

  12. Quantitative optical mapping of two-dimensional materials

    DEFF Research Database (Denmark)

    Jessen, Bjarke S.; Whelan, Patrick R.; Mackenzie, David M. A.

    2018-01-01

    The pace of two-dimensional materials (2DM) research has been greatly accelerated by the ability to identify exfoliated thicknesses down to a monolayer from their optical contrast. Since this process requires time-consuming and error-prone manual assignment to avoid false-positives from image...

  13. Optical techniques for solid-state materials characterization

    CERN Document Server

    Prasankumar, Rohit P

    2016-01-01

    This book has comprehensively covered the essential optical approaches needed for solid-state materials characterization. Written by experts in the field, this will be a great reference for students, engineers, and scientists.-Professor Yoke Khin Yap, Michigan Technical University.

  14. Second NATO Workshop on Passive Infrared Optical Materials and Coatings

    Science.gov (United States)

    1987-12-01

    sponsor, NATO AC/243 ( Panel III tion is sprayed through a furnace at RSG 2). This is an abridged version of about 1000*C. A 7-hour operation yields the...strength, generate high-quality optical surfaces Cl, of the monocrystalline material is 4 162 MPa at a load increase rate of 18 MPa due to removal of water

  15. The use of polyurethane foam as an antimicrobial dressing material in hand surgery

    Directory of Open Access Journals (Sweden)

    Nebil Yesiloglu

    2015-12-01

    Full Text Available Polyurethane foam is generally used in negative pressure-assisted wound closure therapy. It provides an antimicrobial environment around the wound, while reducing the rate of skin maceration. The authors used polyurethane foam in routine hand dressings after hand surgery operations that were performed for both congenital and acquired purposes. [Hand Microsurg 2015; 4(3.000: 91-92

  16. Structural and optical properties of electro-optic material. Sputtered (Ba,Sr)TiO3

    International Nuclear Information System (INIS)

    Suzuki, Masato; Xu, Zhimou; Tanushi, Yuichiro; Yokoyama, Shin

    2006-01-01

    In order to develop a novel ring resonator optical switch, we have studied the structural and optical properties of the electro-optic material (Ba,Sr)TiO 3 (BST) deposited by RF sputtering on a SiO 2 cladding layer (1.0 μm). The crystallinity of the BST films is evaluated by X-ray diffraction and the optical propagation loss of the waveguides is measured using a He-Ne laser. As a result, it is found that there is a strong relationship between the optical propagation loss and crystallinity of the sputtered film. It is suggested that the propagating light is influenced by the crystal property, for example, the grain size and density of the polycrystalline BST film. (author)

  17. Evaluation of material dispersion using a nanosecond optical pulse radiator.

    Science.gov (United States)

    Horiguchi, M; Ohmori, Y; Miya, T

    1979-07-01

    To study the material dispersion effects on graded-index fibers, a method for measuring the material dispersion in optical glass fibers has been developed. Nanosecond pulses in the 0.5-1.7-microm region are generated by a nanosecond optical pulse radiator and grating monochromator. These pulses are injected into a GeO(2)-P(2)0(5)-doped silica graded-index fiber. Relative time delay changes between different wavelengths are used to determine material dispersion, core glass refractive index, material group index, and optimum profile parameter of the graded-index fiber. From the measured data, the optimum profile parameter on the GeO(2)-P(2)O(5)-doped silica graded-index fiber could be estimated to be 1.88 at 1.27 microm of the material dispersion free wavelength region and 1.82 at 1.55 microm of the lowest-loss wavelength region in silica-based optical fiber waveguides.

  18. Space optical materials and space qualification of optics; Proceedings of the Meeting, Orlando, FL, Mar. 30, 31, 1989

    Science.gov (United States)

    Hale, Robert R.

    1989-10-01

    The present conference on space optical materials discusses current metals and nonmetals-related processing R&D efforts, investigations of space optical effects, and the spaceborne qualification of optical components and systems. Attention is given to CVD SiC for optical applications, optical materials for space-based lasers, the high-efficiency acoustooptic and optoelectronic crystalline material Tl3AsSe3, HIPed Be for low-scatter cryogenic optics, durable solar-reflective surfacing for Be optics, thermal effects on Be mirrors, contamination effects on optical surfaces in the monolayer regime, and IR background signature survey experiment results. Also discussed are the contamination-control program for the EUE instrument, an optical multipass radiation system for the heating of levitated samples, optical sample-position sensing for electrostatic levitation, and the qualification of space lighting systems.

  19. Comparison of a digital and an optical analogue hand-held refractometer for the measurement of canine urine specific gravity.

    Science.gov (United States)

    Paris, J K; Bennett, A D; Dodkin, S J; Gunn-Moore, D A

    2012-05-05

    Urine specific gravity (USG) is used clinically as a measure of urine concentration, and is routinely assessed by refractometry. A comparison between optical analogue and digital refractometers for evaluation of canine urine has not been reported. The aim of this study was to compare a digital and an optical analogue hand-held refractometer for the measurement of canine USG, and to assess correlation with urine osmolality. Prospective study. Free-catch urine samples were collected from 285 hospitalised adult dogs, and paired USG readings were obtained with a digital and an optical analogue refractometer. In 50 dogs, urine osmolality was also measured using a freezing point depression osmometer. There was a small but statistically significant difference between the two refractometers (P<0.001), with the optical analogue refractometer reading higher than the digital refractometer (mean difference 0.0006, sd 0.0012). Paired refractometer measurements varied by <0.002 in 91.5 per cent of cases. The optical analogue and digital refractometer readings showed excellent correlation with osmolality (r=0.980 and r=0.977, respectively, P<0.001 in both cases). Despite statistical significance, the difference between the two refractometers is unlikely to be clinically significant. Both instruments provide an accurate assessment of USG in dogs.

  20. Extravasation of radiographic contrast material and compartment syndrome in the hand: a case report

    Directory of Open Access Journals (Sweden)

    Torrededia Laura

    2011-02-01

    Full Text Available Abstract Radiocontrast agents are a type of medical contrast material used to improve the visibility of internal bodily structures in X-ray based imaging techniques such as computed tomography (CT or radiography. Radiocontrast agents are typically iodine or barium compounds. Extravasation of contrast is a possible complication of imaging studies performed with contrasts. Most extravasations cause minimal swelling or erythema, however, skin necrosis, ulceration and compartment syndrome may occur with extravasation of large volumes of contrast. A case report is presented in which significant extravasation of contrast was caused while injecting the contrast intravenously into the back of the hand of a 50 year old patient during computed tomography. The patient was undergoing chemotherapy. The patient developed a compartment syndrome and a fasciotomy was required. Treatment options are outlined and emphasis is made on prevention of this iatrogenic complication. Some of the preventive measures to avoid these complications include use of non-ionic contrast (low osmolarity, careful choice of the site of intravenous administration, and close monitoring of the patient during injection of contrast to minimize or prevent extravasation injuries. Clear information to patients and prompt recognition of the complication can allow for other non-surgical treatment options than the one required in this case.

  1. P-polarized surface waves in a slab waveguide with left-handed material for sensing applications

    International Nuclear Information System (INIS)

    Taya, Sofyan A.

    2015-01-01

    In this paper, surface waves excited at the interface between left-handed and right-handed materials are employed for sensing applications. The propagation of p-polarized (TM) surface waves in a three-layer slab waveguide structure with air core layer as an analyte and anisotropic left-handed materials as claddings is investigated for detection of any changes in the refractive index of the analyte. The dispersion equations and the sensitivity of the effective refractive index to any change in the air layer index are derived, plotted, and discussed in details. The field profile is also explored. It is found that the sensitivity of the proposed surface wave sensor is almost independent of the wavelength of the propagating wave. A considerable sensitivity improvement can be obtained with the increase of transverse components of the left-handed material permittivity. - Highlights: • P-polarized surface waves in a three-layer slab waveguide are employed for sensing applications. • The structure contains air core layer as an analyte and anisotropic left-handed material in the claddings. • The sensitivity is found to be almost independent of the wavelength of the propagating wave. • Unusual sensitivity enhancement is observed as the transverse components of the LHM permittivity increase. • The asymmetric waveguide structure exhibits much higher sensitivity compared to the symmetric one

  2. Systematic development of new thermoluminescence and optically stimulated luminescence materials

    Energy Technology Data Exchange (ETDEWEB)

    Yukihara, E.G., E-mail: eduardo.yukihara@okstate.edu [Physics Department, 145 Physical Sciences II, Oklahoma State University, Stillwater, OK 74078 (United States); Milliken, E.D.; Oliveira, L.C. [Physics Department, 145 Physical Sciences II, Oklahoma State University, Stillwater, OK 74078 (United States); Orante-Barron, V.R. [Departamento de Investigacion en Polimeros y Materiales, Universidad de Sonora, Hermosillo, Sonora 83000, Mexico (Mexico); Jacobsohn, L.G. [Center for Optical Materials Science and Engineering Technologies (COMSET), and School of Materials Science and Engineering, Clemson University, Clemson, SC (United States); Blair, M.W. [Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2013-01-15

    This paper presents an overview of a systematic study to develop new thermoluminescence (TL) and optically stimulated luminescence (OSL) materials using solution combustion synthesis (SCS) for applications such as personal OSL dosimetry, 2D dose mapping, and temperature sensing. A discussion on the material requirements for these applications is included. We present X-ray diffraction (XRD) data on single phase materials obtained with SCS, as well as radioluminescence (RL), TL and OSL data of lanthanide-doped materials. The results demonstrate the possibility of producing TL and OSL materials with sensitivity similar to or approaching those of commercial TL and OSL materials used in dosimetry (e.g., LiF:Mg,Ti and Al{sub 2}O{sub 3}:C) using SCS. The results also show that the luminescence properties can be improved by Li co-doping and annealing. The presence of an atypical TL background and anomalous fading are discussed and deserve attention in future investigations. We hope that these preliminary results on the use of SCS for production of TL and OSL materials are helpful to guide future efforts towards the development of new luminescence materials for different applications. - Highlights: Black-Right-Pointing-Pointer TL and OSL material produced with sensitivity similar to commercial materials. Black-Right-Pointing-Pointer Luminescence properties improved by Li co-doping and annealing. Black-Right-Pointing-Pointer The presence of atypical TL background and anomalous fading observed.

  3. Reconfigurable optical manipulation by phase change material waveguides.

    Science.gov (United States)

    Zhang, Tianhang; Mei, Shengtao; Wang, Qian; Liu, Hong; Lim, Chwee Teck; Teng, Jinghua

    2017-05-25

    Optical manipulation by dielectric waveguides enables the transportation of particles and biomolecules beyond diffraction limits. However, traditional dielectric waveguides could only transport objects in the forward direction which does not fulfill the requirements of the next generation lab-on-chip system where the integrated manipulation system should be much more flexible and multifunctional. In this work, bidirectional transportation of objects on the nanoscale is demonstrated on a rectangular waveguide made of the phase change material Ge 2 Sb 2 Te 5 (GST) by numerical simulations. Either continuous pushing forces or pulling forces are generated on the trapped particles when the GST is in the amorphous or crystalline phase. With the technique of a femtosecond laser induced phase transition on the GST, we further proposed a reconfigurable optical trap array on the same waveguide. This work demonstrates GST waveguide's potential of achieving multifunctional manipulation of multiple objects on the nanoscale with plausible optical setups.

  4. Inkjet Printing of Functional Materials for Optical and Photonic Applications

    Science.gov (United States)

    Alamán, Jorge; Alicante, Raquel; Peña, Jose Ignacio; Sánchez-Somolinos, Carlos

    2016-01-01

    Inkjet printing, traditionally used in graphics, has been widely investigated as a valuable tool in the preparation of functional surfaces and devices. This review focuses on the use of inkjet printing technology for the manufacturing of different optical elements and photonic devices. The presented overview mainly surveys work done in the fabrication of micro-optical components such as microlenses, waveguides and integrated lasers; the manufacturing of large area light emitting diodes displays, liquid crystal displays and solar cells; as well as the preparation of liquid crystal and colloidal crystal based photonic devices working as lasers or optical sensors. Special emphasis is placed on reviewing the materials employed as well as in the relevance of inkjet in the manufacturing of the different devices showing in each of the revised technologies, main achievements, applications and challenges. PMID:28774032

  5. Inkjet Printing of Functional Materials for Optical and Photonic Applications

    Directory of Open Access Journals (Sweden)

    Jorge Alamán

    2016-11-01

    Full Text Available Inkjet printing, traditionally used in graphics, has been widely investigated as a valuable tool in the preparation of functional surfaces and devices. This review focuses on the use of inkjet printing technology for the manufacturing of different optical elements and photonic devices. The presented overview mainly surveys work done in the fabrication of micro-optical components such as microlenses, waveguides and integrated lasers; the manufacturing of large area light emitting diodes displays, liquid crystal displays and solar cells; as well as the preparation of liquid crystal and colloidal crystal based photonic devices working as lasers or optical sensors. Special emphasis is placed on reviewing the materials employed as well as in the relevance of inkjet in the manufacturing of the different devices showing in each of the revised technologies, main achievements, applications and challenges.

  6. Diffused holographic information storage and retrieval using photorefractive optical materials

    Science.gov (United States)

    McMillen, Deanna Kay

    Holography offers a tremendous opportunity for dense information storage, theoretically one bit per cubic wavelength of material volume, with rapid retrieval, of up to thousands of pages of information simultaneously. However, many factors prevent the theoretical storage limit from being reached, including dynamic range problems and imperfections in recording materials. This research explores new ways of moving closer to practical holographic information storage and retrieval by altering the recording materials, in this case, photorefractive crystals, and by increasing the current storage capacity while improving the information retrieved. As an experimental example of the techniques developed, the information retrieved is the correlation peak from an optical recognition architecture, but the materials and methods developed are applicable to many other holographic information storage systems. Optical correlators can potentially solve any signal or image recognition problem. Military surveillance, fingerprint identification for law enforcement or employee identification, and video games are but a few examples of applications. A major obstacle keeping optical correlators from being universally accepted is the lack of a high quality, thick (high capacity) holographic recording material that operates with red or infrared wavelengths which are available from inexpensive diode lasers. This research addresses the problems from two positions: find a better material for use with diode lasers, and reduce the requirements placed on the material while maintaining an efficient and effective system. This research found that the solutions are new dopants introduced into photorefractive lithium niobate to improve wavelength sensitivities and the use of a novel inexpensive diffuser that reduces the dynamic range and optical element quality requirements (which reduces the cost) while improving performance. A uniquely doped set of 12 lithium niobate crystals was specified and

  7. Surface finish and subsurface damage in polycrystalline optical materials

    Science.gov (United States)

    Shafrir, Shai Negev

    We measure and describe surface microstructure and subsurface damage (SSD) induced by microgrinding of hard metals and hard ceramics used in optical applications. We examine grinding of ceramic materials with bonded abrasives, and, specifically, deterministic microgrinding (DMG). DMG, at fixed nominal infeed rate and with bound diamond abrasive tools, is the preferred technique for optical fabrication of ceramic materials. In DMG material removal is by microcracking. DMG provides cost effective high manufacturing rates, while attaining higher strength and performance, i.e., low level of subsurface damage (SSD). A wide range of heterogeneous materials of interest to the optics industry were studied in this work. These materials include: A binderless tungsten carbide, nonmagnetic Ni-based tungsten carbides, magnetic Co-based tungsten carbides, and, in addition, other hard optical ceramics, such as aluminum oxynitride (Al23O27N5/ALON), polycrystalline alumina (Al2O3/PCA), and chemical vapor deposited (CVD) silicon carbide (Si4C/SiC). These materials are all commercially available. We demonstrate that spots taken with magnetorheological finishing (MRF) platforms can be used for estimating SSD depth induced by the grinding process. Surface morphology was characterized using various microscopy techniques, such as: contact interferometer, noncontact white light interferometer, light microscopy, scanning electron microscopy (SEM), and atomic force microscopy (AFM). The evolution of surface roughness with the amount of material removed by the MRF process, as measured within the spot deepest point of penetration, can be divided into two stages. In the first stage the induced damaged layer and associated SSD from microgrinding are removed, reaching a low surface roughness value. In the second stage we observe interaction between the MRF process and the material's microstructure as MRF exposes the subsurface without introducing new damage. Line scans taken parallel to the MR

  8. Studies on thin film materials on acrylics for optical applications

    Indian Academy of Sciences (India)

    Unknown

    single layer films of MgF2 and SiO2 have good optical transmittance ... increased from 76°C to 108°C during a period of 12 min of deposition. ... the film to PMMA substrate is also good. The difference ... We tried a 4-layer coating of design, consisting of Sub. .... Coating Materials brochure of E Merck, Germany 1998 and of.

  9. Optical Sensors for Biomolecules Using Nanoporous Sol-Gel Materials

    Science.gov (United States)

    Fang, Jonathan; Zhou, Jing C.; Lan, Esther H.; Dunn, Bruce; Gillman, Patricia L.; Smith, Scott M.

    2004-01-01

    An important consideration for space missions to Mars is the ability to detect biosignatures. Solid-state sensing elements for optical detection of biological entities are possible using sol-gel based biologically active materials. We have used these materials as optical sensing elements in a variety of bioassays, including immunoassays and enzyme assays. By immobilizing an appropriate biomolecule in the sol-gel sensing element, we have successfully detected analytes such as amino acids and hormones. In the case of the amino acid glutamate, the enzyme glutamate dehydrogenase was the immobilized molecule, whereas in the case of the hormone cortisol, an anti-cortisol antibody was immobilized in the sensing element. In this previous work with immobilized enzymes and antibodies, excellent sensitivity and specificity were demonstrated in a variety of formats including bulk materials, thin films and fibers. We believe that the sol-gel approach is an attractive platform for bioastronautics sensing applications because of the ability to detect a wide range of entities such as amino acids, fatty acids, hopanes, porphyrins, etc. The sol-gel approach produces an optically transparent 3D silica matrix that forms around the biomolecule of interest, thus stabilizing its structure and functionality while allowing for optical detection. This encapsulation process protects the biomolecule and leads to a more "rugged" sensor. The nanoporous structure of the sol-gel matrix allows diffusion of small target molecules but keeps larger, biomolecules immobilized in the pores. We are currently developing these biologically active sol-gel materials into small portable devices for on-orbit cortisol detection

  10. THz - ToF Optical Layer Analysis (OLA) to determine optical properties of dielectric materials

    Science.gov (United States)

    Spranger, Holger; Beckmann, Jörg

    2017-02-01

    Electromagnetic waves with frequencies between 0.1 and 10 THz are described as THz-radiation (T-ray). The ability to penetrate dielectric materials makes T-rays attractive to reveal discontinuities in polymer and ceramic materials. THz-Time Domain Spectroscopy Systems (THz-TDS) are available on the market today which operates with THz-pulses transmitted and received by optically pumped semiconductor antennas. In THz-TDS the travelling time (ToF) and shape of the pulse is changed if it interacts with the dielectric material and its inherent discontinuities. A tomogram of the object under the test can be reconstructed from time of flight diffraction (ToFD) scans if a synthetic focusing aperture (SAFT) algorithm is applied. The knowledge of the base materials shape and optical properties is essential for a proper reconstruction result. To obtain these properties a model is assumed which describes the device under the test as multilayer structure composed of thin layers with different dielectric characteristics. The Optical Layer Analysis (OLA) is able to fulfill these requirements. A short description why the optical properties are crucial for meaningful SAFT reconstruction results will be given first. Afterwards the OLA will be derived and applied on representative samples to discuss and evaluate its benefits and limits.

  11. OPTICAL-ELECTRONIC SYSTEM FOR EXPRESS ANALYSIS OF ORE DRESSABILITY FOR MINERAL RAW MATERIALS BY OPTICAL METHOD

    Directory of Open Access Journals (Sweden)

    A. A. Alekhin

    2013-05-01

    Full Text Available The article deals with creation results of experimental prototype of optical-electronic complex, designed to assess ore dressability of mineral raw materials by optical sorting method.

  12. Magneto optical properties of silver doped magnetic nanocomposite material

    Directory of Open Access Journals (Sweden)

    N. Abirami

    2017-11-01

    Full Text Available Magnetic composite materials challenge traditional materials in broad applications such as transformer, sensors and electrical motors. In this work by studying the permittivity and permeability spectra of silver doped magnetic nanocomposite system, the variation of the effective refractive index with frequency is investigated for different filling factor. It is found that the value of resonance frequency decrease with filling factor. The polariton dispersion of the system is also studied. This study of the nanocomposite system can be exploited in designing modern optical devices.PACS: 75.50-y, 71.36.+c, 78.67.Sc, 78.20.Ci. Keywords: Permittivity, Permeability, Nanocomposite system, Polariton

  13. Optical coherence tomography based 1D to 6D eye-in-hand calibration

    DEFF Research Database (Denmark)

    Antoni, Sven Thomas; Otte, Christoph; Savarimuthu, Thiusius Rajeeth

    2017-01-01

    and based on this introduce pivot+d, a new 1D to 6D eye-in-hand calibration. We provide detailed results on the convergence and accuracy of our method and use translational and rotational ground truth to show that our methods allow for submillimeter positioning accuracy of an OCT beam with a robot.......e., it can be easily integrated with instruments. However, to use OCT for intra-operative guidance its spatial alignment needs to be established. Hence, we consider eye-in-hand calibration between the 1D OCT imaging and a 6D robotic position system. We present a method to perform pivot calibration for OCT....... For pivot calibration we observe a mean translational error of 0.5161 ± 0.4549 mm while pivot+d shows 0.3772 ± 0.2383 mm. Additionally, pivot+d improves rotation detection by about 8° when compared to pivot calibration....

  14. Optics and optronics in university courses for officers of the Federal Armed Forces - special curricula and hands-on lessons vs. academic requirements

    Science.gov (United States)

    Hahlweg, Cornelius; Rothe, Hendrik

    2016-09-01

    For more than two decades lessons in optics, digital image processing and optronics are compulsory optional subjects and as such integral parts of the courses in mechanical engineering at the University of the Federal Armed Forces in Hamburg. They are provided by the Chair for Measurement and Information Technology. Historically, the curricula started as typical basic lessons in optics and digital image processing and related sensors. Practical sessions originally concentrated on image processing procedures in Pascal, C and later Matlab. They evolved into a broad portfolio of practical hands-on lessons in lab and field, including high-tech and especially military equipment, but also homemaker style primitive experiments, of which the paper will give a methodical overview. A special topic - as always with optics in education - is the introduction to the various levels of abstraction in conjunction with the highly complex and wide-ranging matter squeezed into only two trimesters - instead of semesters at civil universities - for an audience being subject to strains from both study and duty. The talk will be accompanied by striking multi-media material, which will be also part of the multi-media attachment of the paper.

  15. Optical Force Sensor for the DEXMART Hand Twisted String Actuation System

    Directory of Open Access Journals (Sweden)

    Gianluca PALLI

    2013-01-01

    Full Text Available In this paper, the force sensor developed for the twisted string actuation system of the DEXMART Hand is described. The proposed solution makes use of optoelectronic components for measuring the deformation of the properly designed motor module structure caused by the force applied to the tendon transmission system. The paper reports the working principle, the calibration and the characterization of the sensor in terms of sensitivity, repeatability, full-scale and Signal-to-Noise ratio.

  16. Computational Modeling of Ultrafast Pulse Propagation in Nonlinear Optical Materials

    Science.gov (United States)

    Goorjian, Peter M.; Agrawal, Govind P.; Kwak, Dochan (Technical Monitor)

    1996-01-01

    There is an emerging technology of photonic (or optoelectronic) integrated circuits (PICs or OEICs). In PICs, optical and electronic components are grown together on the same chip. rib build such devices and subsystems, one needs to model the entire chip. Accurate computer modeling of electromagnetic wave propagation in semiconductors is necessary for the successful development of PICs. More specifically, these computer codes would enable the modeling of such devices, including their subsystems, such as semiconductor lasers and semiconductor amplifiers in which there is femtosecond pulse propagation. Here, the computer simulations are made by solving the full vector, nonlinear, Maxwell's equations, coupled with the semiconductor Bloch equations, without any approximations. The carrier is retained in the description of the optical pulse, (i.e. the envelope approximation is not made in the Maxwell's equations), and the rotating wave approximation is not made in the Bloch equations. These coupled equations are solved to simulate the propagation of femtosecond optical pulses in semiconductor materials. The simulations describe the dynamics of the optical pulses, as well as the interband and intraband.

  17. [The neuroprotective effect of erigeron breviscapus (vant) hand-mazz on retinal ganglion cells after optic nerve crush injury].

    Science.gov (United States)

    Jiang, Bing; Jiang, You-qin

    2003-08-01

    To investigate whether a Chinese herbal medicine, erigeron breviscapus (vant) hand-mazz (EBHM), can protect the retinal ganglion cells (RGC) damaged by calibrated optic nerve crush injury. Forty-two Sprague-Dawley rats were randomly divided into two groups. Calibrated optic nerve crush injury model was induced in the right eyes by a special designed optic nerve clip. The left eyes served as a control. All 42 rats were randomly divided into 2 groups. Group A consisted of the rats with calibrated optic nerve crush injury and group B consisted of rats with calibrated optic nerve crush injury treated with EBHM. In group B, EBHM solution was given once after the crush injury. According to the time interval between the optic nerve crush and the sacrifice, both groups A and B were further divided into three subgroups (day 4, day 14 and day 21). Therefore, there were 7 rats in each subgroup. Three days before sacrifice, 3% fast blue was injected into superior colliculi bilaterally. The eyes were enucleated after the rat was sacrificed, and flat mounts of the retina from both eyes were prepared on a slide and observed under a fluorescence microscope. Four photos with 400 x magnification were taken from each of the four quadrants of the retina 1 mm away from the optic disc. The labeled RGC were counted by a computerized image analyzer. The labeled RGC rate was used for statistical analysis (the labeled RGC rate = number of RGC in injured eye/control eye x 100%). In group A, the labeled RGC rate was (77.79 +/- 7.11)%, (63.76 +/- 3.79)% and (54.66 +/- 4.75)% on day 4, day 14 and day 21, respectively. In group B, the labeled RGC rate was (80.13 +/- 12.03)%, (78.17 +/- 9.19)% and (83.59 +/- 12.61)% on day 4, day 14 and day 21, respectively. In group B, which was treated with EBHM after injury, the labeled RGC rate was significantly higher than that of group A on day 14 and day 21. In the experimental optic nerve crush model in rats, EBHM therapy can increase the survival rate of

  18. Understanding and control of optical performance from ceramic materials

    International Nuclear Information System (INIS)

    Barbour, J.C.; Knapp, J.A.; Potter, B.G.; Jennison, D.R.; Verdozzi, C.A.; Follstaedt, D.M.; Bendale, R.D.; Simmons, J.H.

    1998-06-01

    This report summarizes a two-year Laboratory-Directed Research and Development (LDRD) program to gain understanding and control of the important parameters which govern the optical performance of rare-earth (RE) doped ceramics. This LDRD developed the capability to determine stable atomic arrangements in RE doped alumina using local density functional theory, and to model the luminescence from RE-doped alumina using molecular dynamic simulations combined with crystal-field calculations. Local structural features for different phases of alumina were examined experimentally by comparing their photoluminescence spectra and the atomic arrangement of the amorphous phase was determined to be similar to that of the gamma phase. The luminescence lifetimes were correlated to these differences in the local structure. The design of both high and low-phonon energy host materials was demonstrated through the growth of Er-doped aluminum oxide and lanthanum oxide. Multicomponent structures of rare-earth doped telluride glass in an alumina and silica matrix were also prepared. Finally, the optical performance of Er-doped alumina was determined as a function of hydrogen content in the host matrix. This LDRD is the groundwork for future experimentation to understand the effects of ionizing radiation on the optical properties of RE-doped ceramic materials used in space and other radiation environments

  19. Extreme Spectroscopy: In situ nuclear materials behavior from optical data

    Energy Technology Data Exchange (ETDEWEB)

    Guimbretiere, G.; Canizares, A.; Raimboux, N.; Omnee, R.; Duval, F.; Ammar, M.R.; Simon, P. [CNRS - UPR3079 CEMHTI, Universite d' Orleans, 45071Orleans cedex 2 (France); Desgranges, L.; Mohun, R. [CEA, DEN, DEC, F-13108 Saint-Paul-Lez-Durance (France); Jegou, C.; Magnin, M. [CEA/DTCD/SECM/LMPA, Marcoule 30207 Bagnols Sur Ceze (France); Clavier, N.; Dacheux, N. [ICSM-UMR5257 CEA/CNRS/UM2/ENSCM, Marcoule, BP17171, 30207 Bagnols sur Ceze (France)

    2015-07-01

    In the nuclear industry, materials are regularly exposed to high temperature or/and irradiation and a better knowledge and understanding of their behavior under such extreme conditions is a key-point for improvements and further developments. Nowadays, Raman spectroscopy begins to be well known as a promising technique in the post mortem and remote characterization of nuclear materials exposed to extreme conditions. On this topic, at ANIMMA 2013 conference, we have presented some results about its implementation in the study of model or real nuclear fuel. However, the strength of Raman spectroscopy as in situ characterization tool is mainly its ability to be implemented remotely through optical fibers. Aware of this, implementation of other optical techniques can be considered in order to gain information not only on the structural dynamics of materials but also on the electronic charge carrier populations. In this paper, we propose to present our last advances in Raman characterization of nuclear materials and enlarge to the in situ use of complementary optical spectroscopies. Emphasis will be made on the information that can be gained to the behavior of the model fuel depleted UO{sub 2} under extreme conditions of high temperature and ionic irradiation: - In Situ Raman identification of the radiolysis alteration products of UO{sub 2} in contact with water under ionic irradiation. - In Situ Raman recording of the damaged dynamic of UO{sub 2} under inert atmosphere. - In Situ Raman and photo-luminescence study of virgin and damaged UO2 at high temperature. - In Situ study of electronic charge carriers' behavior in U{sub x}Th{sub 1-x}O{sub 2} solid solutions by mean of Iono- and Thermo- luminescence under and post- ionic irradiation. (authors)

  20. New Class of Wide Energy Gap Benzotriimidazole Optical Materials

    Directory of Open Access Journals (Sweden)

    Jianmin Shi

    2017-10-01

    Full Text Available A new class of wide energy gap benzotriimidazole materials have been synthesized by a two-step condensation reaction. All of the benzotriimidazole compounds have π-π* absorption bands in the range of 250–400 nm. The photoluminescence (PL quantum efficiency of each benzotriimidazole depends strongly on the presence of electron withdrawing groups. PL quantum efficiencies of benzotriimidazoles without electron withdrawing groups were less than desirable (40–43%, while molecules with electron withdrawing groups displayed much stronger PL with efficiencies in the range of 73–75%. The electron withdrawing groups shift the emission to a longer wavelength, towards a more “true blue” color. This new class of benzotriimidazole optical materials could be used as electron-injecting and electron-transporting blue luminescence materials for potential organic light-emitting diode (OLED applications.

  1. Mechanical characterization of composite materials by optical techniques: A review

    Science.gov (United States)

    Bruno, Luigi

    2018-05-01

    The present review provides an overview of work published in recent years dealing with the mechanical characterization of composite materials performed by optical techniques. The paper emphasizes the strengths derived from the employment of full-field methods when the strain field of an anisotropic material must be evaluated. This is framed in contrast to the use of conventional measurement techniques, which provide single values of the measured quantities unable to offer thorough descriptions of deformation distribution. The review outlines the intensity and articulation of work in this research field to date and its ongoing importance not only in the academy, but also in industrial sectors where composite materials represent a strategic resource for development.

  2. Enhanced optical limiting effects of graphene materials in polyimide

    International Nuclear Information System (INIS)

    Gan, Yao; Feng, Miao; Zhan, Hongbing

    2014-01-01

    Three different graphene nanostructure suspensions of graphene oxide nanosheets (GONSs), graphene oxide nanoribbons (GONRs), and graphene oxide quantum dots (GOQDs) are prepared and characterized. Using a typical two-step method, the GONSs, GONRs, and GOQDs are incorporated into a polyimide (PI) matrix to synthesize graphene/PI composite films, whose nonlinear optical (NLO) and optical limiting (OL) properties are investigated at 532 nm in the nanosecond regime. The GONR suspension exhibits superior NLO and OL effects compared with those of GONSs and GOQDs because of its stronger nonlinear scattering and excited-state absorption. The graphene/PI composite films exhibit NLO and OL performance superior to that of their corresponding suspensions, which is attributed primarily to a combination of nonlinear mechanisms, charge transfer between graphene materials and PI, and the matrix effect

  3. Cryogenic Q-factor measurement of optical substrate materials

    Energy Technology Data Exchange (ETDEWEB)

    Nietzsche, S; Nawrodt, R; Zimmer, A; Thuerk, M; Vodel, W; Seidel, P [Institut fuer Festkoerperphysik, Friedrich-Schiller-Universitaet Jena, Helmholtzweg 5, 07743 Jena (Germany)

    2006-03-02

    Upcoming generations of interferometric gravitational wave detectors are likely to be operated at cryogenic temperatures because one of the sensitivity limiting factors of the present generation is the thermal noise of optical components (e.g. end mirrors, cavity couplers, beam splitters). The main contributions to this noise are due to the substrate, the optical coating, and the suspension. The thermal noise can be reduced by cooling to cryogenic temperatures. In addition the overall mechanical quality factor should preferable increase at low temperatures. The experimental details of a new cryogenic apparatus for investigations of the temperature dependency of the Q-factor of several substrate materials in the range of 5 to 300 K are presented. To perform a ring down recording an electrostatic mode excitation of the samples and an interferometric read-out of the amplitude of the vibrations was used.

  4. Optical properties of (nanometer MCM-41)-(malachite green) composite materials

    International Nuclear Information System (INIS)

    Li Xiaodong; Zhai Qingzhou; Zou Mingqiang

    2010-01-01

    Nanosized materials loaded with organic dyes are of interest with respect to novel optical applications. The optical properties of malachite green (MG) in MCM-41 are considerably influenced by the limited nanoporous channels of nanometer MCM-41. Nanometer MCM-41 was synthesized by tetraethyl orthosilicate (TEOS) as the source of silica and cetyltrimethylammonium bromide (CTMAB) as the template. The liquid-phase grafting method has been employed for incorporation of the malachite green molecules into the channels of nanometer MCM-41. A comparative study has been carried out on the adsorption of the malachite green into modified MCM-41 and unmodified MCM-41. The modified MCM-41 was synthesized using a silylation reagent, trimethychlorosilane (TMSCl), which functionalized the surface of nanometer MCM-41 for proper host-guest interaction. The prepared (nanometer MCM-41)-MG samples have been studied by powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, low-temperature nitrogen adsorption-desorption technique at 77 K, Raman spectra and luminescence studies. In the prepared (nanometer MCM-41)-MG composite materials, the frameworks of the host molecular sieve were kept intact and the MG located inside the pores of MCM-41. Compared with the MG, it is found that the prepared composite materials perform a considerable luminescence. The excitation and emission spectra of MG in both modified MCM-41 and unmodified MCM-41 were examined to explore the structural effects on the optical properties of MG. The results of luminescence spectra indicated that the MG molecules existed in monomer form within MCM-41. However, the luminescent intensity of MG incorporated in the modified MCM-41 are higher than that of MG encapsulated in unmodified MCM-41, which may be due to the anchored methyl groups on the channels of the nanometer MCM-41 and the strong host-guest interactions. The steric effect from the pore size of the host materials is significant. Raman

  5. HoloHands: games console interface for controlling holographic optical manipulation

    Science.gov (United States)

    McDonald, C.; McPherson, M.; McDougall, C.; McGloin, D.

    2013-03-01

    The increasing number of applications for holographic manipulation techniques has sparked the development of more accessible control interfaces. Here, we describe a holographic optical tweezers experiment which is controlled by gestures that are detected by a Microsoft Kinect. We demonstrate that this technique can be used to calibrate the tweezers using the Stokes drag method and compare this to automated calibrations. We also show that multiple particle manipulation can be handled. This is a promising new line of research for gesture-based control which could find applications in a wide variety of experimental situations.

  6. HoloHands: games console interface for controlling holographic optical manipulation

    International Nuclear Information System (INIS)

    McDonald, C; McPherson, M; McDougall, C; McGloin, D

    2013-01-01

    The increasing number of applications for holographic manipulation techniques has sparked the development of more accessible control interfaces. Here, we describe a holographic optical tweezers experiment which is controlled by gestures that are detected by a Microsoft Kinect. We demonstrate that this technique can be used to calibrate the tweezers using the Stokes drag method and compare this to automated calibrations. We also show that multiple particle manipulation can be handled. This is a promising new line of research for gesture-based control which could find applications in a wide variety of experimental situations. (paper)

  7. Fast linear solver for radiative transport equation with multiple right hand sides in diffuse optical tomography

    International Nuclear Information System (INIS)

    Jia, Jingfei; Kim, Hyun K.; Hielscher, Andreas H.

    2015-01-01

    It is well known that radiative transfer equation (RTE) provides more accurate tomographic results than its diffusion approximation (DA). However, RTE-based tomographic reconstruction codes have limited applicability in practice due to their high computational cost. In this article, we propose a new efficient method for solving the RTE forward problem with multiple light sources in an all-at-once manner instead of solving it for each source separately. To this end, we introduce here a novel linear solver called block biconjugate gradient stabilized method (block BiCGStab) that makes full use of the shared information between different right hand sides to accelerate solution convergence. Two parallelized block BiCGStab methods are proposed for additional acceleration under limited threads situation. We evaluate the performance of this algorithm with numerical simulation studies involving the Delta–Eddington approximation to the scattering phase function. The results show that the single threading block RTE solver proposed here reduces computation time by a factor of 1.5–3 as compared to the traditional sequential solution method and the parallel block solver by a factor of 1.5 as compared to the traditional parallel sequential method. This block linear solver is, moreover, independent of discretization schemes and preconditioners used; thus further acceleration and higher accuracy can be expected when combined with other existing discretization schemes or preconditioners. - Highlights: • We solve the multiple-right-hand-side problem in DOT with a block BiCGStab method. • We examine the CPU times of the block solver and the traditional sequential solver. • The block solver is faster than the sequential solver by a factor of 1.5–3.0. • Multi-threading block solvers give additional speedup under limited threads situation.

  8. Optical response of the FXG solution to different phantom materials

    International Nuclear Information System (INIS)

    Cavinato, C.C.; Sakuraba, R.K.; Cruz, J.C.; Campos, L.L.

    2011-01-01

    The purpose of this work is to evaluate the performance of the Fricke xylenol gel (FXG) solution developed at IPEN, prepared with 270 Bloom gelatine (made in Brazil), for clinical electron beams to the reference depth, using different phantom materials. The colour change, optical absorption spectra, intra and inter-batches reproducibility, dose-response, lower detection limit, energy and dose rate dependent response and response uniformity were studied. The excellent results obtained indicate the viability of employing this solution in 2D spectrophotometric dosimetry (could be extended to 3D MRI dosimetry) to be applied in quality assurance for clinical radiotherapy treatment planning of superficial tumours being treated with clinical electron beams.

  9. Structure/property relationships in non-linear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Cole, J M [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); [Durham Univ. (United Kingdom); Howard, J A.K. [Durham Univ. (United Kingdom); McIntyre, G J [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France)

    1997-04-01

    The application of neutrons to the study of structure/property relationships in organic non-linear optical materials (NLOs) is described. In particular, charge-transfer effects and intermolecular interactions are investigated. Charge-transfer effects are studied by charge-density analysis and an example of one such investigation is given. The study of intermolecular interactions concentrates on the effects of hydrogen-bonding and an example is given of two structurally similar molecules with very disparate NLO properties, as a result of different types of hydrogen-bonding. (author). 3 refs.

  10. Measurement of optical coupling between adjacent bi-material microcantilevers.

    Science.gov (United States)

    Canetta, Carlo; Narayanaswamy, Arvind

    2013-10-01

    Low thermal conductance bi-material microcantilevers are fabricated with a pad area near the free end to accommodate a focused laser spot. A pair of such cantilevers are proposed as a configuration for measuring thermal conductance of a nanostructure suspended between the two. We determine the resolution of such a device by measuring the stray conductance it would detect in the absence of any nanostructure. Stray conductance, primarily due to optical coupling, is measured for cantilevers with varying pad size and found to be as low as 0.05 nW K(-1), with cantilevers with larger pad size yielding the smallest stray conductance.

  11. Helmholtz solitons in power-law optical materials

    International Nuclear Information System (INIS)

    Christian, J. M.; McDonald, G. S.; Potton, R. J.; Chamorro-Posada, P.

    2007-01-01

    A nonlinear Helmholtz equation for optical materials with regimes of power-law type of nonlinearity is proposed. This model captures the evolution of broad beams at any angle with respect to the reference direction in a wide range of media, including some semiconductors, doped glasses, and liquid crystals. Exact analytical soliton solutions are presented for a generic nonlinearity, within which known Kerr solitons comprise a subset. Three general conservation laws are also reported. Analysis and numerical simulations examine the stability of the Helmholtz power-law solitons. A propagation feature, associated with spatial solitons in power-law media, constituting a class of oscillatory solution, is identified

  12. Optical and electrical phenomena in dielectric materials under irradiation

    CERN Document Server

    Plaksin, O A; Stepanov, P A; Demenkov, P V; Chernov, V M; Krutskikh, A O

    2002-01-01

    Optical and acoustic properties of the materials based on Al sub 2 O sub 3 , SiO sub 2 and BN under 8 MeV proton irradiation (<10 sup 4 Gy/s) have been measured. Electric charge partitioning has been shown to result in charging the microscopic regions in the bulk of the dielectrics under irradiation, which is due to different mobility of free electrons and holes (sapphire), concentration inhomogeneity in the system of charge carrier traps (alumina), or thermodynamic instability of the homogeneous distribution of the filled traps (silica glasses). Prevalent charge carrier recombination in the grain boundaries causes re-crystallization of pyrolytic boron nitride under irradiation, which shows up as simultaneous decrease of the intensity of radiation-induced luminescence (RIL) of the centres in the grain boundaries and the BN. The local charging results in optical inhomogeneity of the silica glasses which is sustained by the optical loss spectra of the irradiated glasses, features of kinetics of bleaching, RI...

  13. Solitonic guides in photopolymerizable materials for optical devices

    Science.gov (United States)

    Dorkenoo, Kokou D.; Cregut, Olivier; Fort, Alain

    2003-11-01

    These last twenty years, advanced studies in integrated optics have demonstrated the capacity to elaborate optical circuits in planar substrates. Most of the optical integrated devices are realized on glass substrate and the guide areas are usually obtained by photolithography techniques. We present here a new approach based on the use of compounds photopolymerizable in the visible range. The conditions of self written channel creation by solitonic propagation inside the bulk of the photopolymerizable formulation are analyzed. Waveguides can be self-written in photopolymerizable materials1,2 due to the dependence of their refractive index on intensity and duration of the active light. This process results from the competition between the diffraction of the incident Gaussian beam and the photopolymerization which tends to increase the refractive index where light intensity is the highest. By controlling the difference between the refractive index values of the polymerized and non polymerized zones, the beam can be self-trapped along the propagation axis giving rise to a waveguide over distances as large as 10 cm without any broadening. Such permanent waveguides can be structured by inscription of gratings and doped with a dye in a plastic cell leading to the elaboration of a completely plastic laser.

  14. (Bio)hybrid materials based on optically active particles

    Science.gov (United States)

    Reitzig, Manuela; Härtling, Thomas; Opitz, Jörg

    2014-03-01

    In this contribution we provide an overview of current investigations on optically active particles (nanodiamonds, upconversion phospors) for biohybrid and sensing applications. Due to their outstanding properties nanodiamonds gain attention in various application elds such as microelectronics, optical monitoring, medicine, and biotechnology. Beyond the typical diamond properties such as high thermal conductivity and extreme hardness, the carbon surface and its various functional groups enable diverse chemical and biological surface functionalization. At Fraunhofer IKTS-MD we develop a customization of material surfaces via integration of chemically modi ed nanodiamonds at variable surfaces, e.g bone implants and pipelines. For the rst purpose, nanodiamonds are covalently modi ed at their surface with amino or phosphate functionalities that are known to increase adhesion to bone or titanium alloys. The second type of surface is approached via mechanical implementation into coatings. Besides nanodiamonds, we also investigate the properties of upconversion phosphors. In our contribution we show how upconversion phosphors are used to verify sterilization processes via a change of optical properties due to sterilizing electron beam exposure.

  15. Materials and Reliability Handbook for Semiconductor Optical and Electron Devices

    CERN Document Server

    Pearton, Stephen

    2013-01-01

    Materials and Reliability Handbook for Semiconductor Optical and Electron Devices provides comprehensive coverage of reliability procedures and approaches for electron and photonic devices. These include lasers and high speed electronics used in cell phones, satellites, data transmission systems and displays. Lifetime predictions for compound semiconductor devices are notoriously inaccurate due to the absence of standard protocols. Manufacturers have relied on extrapolation back to room temperature of accelerated testing at elevated temperature. This technique fails for scaled, high current density devices. Device failure is driven by electric field or current mechanisms or low activation energy processes that are masked by other mechanisms at high temperature. The Handbook addresses reliability engineering for III-V devices, including materials and electrical characterization, reliability testing, and electronic characterization. These are used to develop new simulation technologies for device operation and ...

  16. New Optical Sensing Materials for Application in Marine Research

    Science.gov (United States)

    Borisov, S.; Klimant, I.

    2012-04-01

    Optical chemosensors are versatile analytical tools which find application in numerous fields of science and technology. They proved to be a promising alternative to electrochemical methods and are applied increasingly often in marine research. However, not all state-of-the- art optical chemosensors are suitable for these demanding applications since they do not fully fulfil the requirements of high luminescence brightness, high chemical- and photochemical stability or their spectral properties are not adequate. Therefore, development of new advanced sensing materials is still of utmost importance. Here we present a set of novel optical sensing materials recently developed in the Institute of Analytical Chemistry and Food Chemistry which are optimized for marine applications. Particularly, we present new NIR indicators and sensors for oxygen and pH which feature high brightness and low level of autofluorescence. The oxygen sensors rely on highly photostable metal complexes of benzoporphyrins and azabenzoporphyrins and enable several important applications such as simultaneous monitoring of oxygen and chlorophyll or ultra-fast oxygen monitoring (Eddy correlation). We also developed ulta-sensitive oxygen optodes which enable monitoring in nM range and are primary designed for investigation of oxygen minimum zones. The dynamic range of our new NIR pH indicators based on aza-BODIPY dyes is optimized for the marine environment. A highly sensitive NIR luminescent phosphor (chromium(III) doped yttrium aluminium borate) can be used for non-invasive temperature measurements. Notably, the oxygen, pH sensors and temperature sensors are fully compatible with the commercially available fiber-optic readers (Firesting from PyroScience). An optical CO2 sensor for marine applications employs novel diketopyrrolopyrrol indicators and enables ratiometric imaging using a CCD camera. Oxygen, pH and temperature sensors suitable for lifetime and ratiometric imaging of analytes

  17. Designing Plasmonic Materials and Optical Metasurfaces for Light Manipulation and Optical Sensing

    Science.gov (United States)

    Chen, Wenxiang

    Metamaterials are artificial materials designed to create optical properties that do not exist in nature. They are assemblies of subwavelength structures that are tailored in size, shape, composition, and orientation to realize the desired property. Metamaterials are promising for applications in diverse areas: optical filters, lenses, holography, sensors, photodetectors, photovoltaics, photocatalysts, medical devices, and many more, because of their excellent abilities in bending, absorbing, enhancing and blocking light. However, the practical use of metamaterials is challenged by the lack of plasmonic materials with proper permittivity for different applications and the slow and expensive fabrication methods available to pattern sub-wavelength structures. We have also only touched the surface in exploring the innovative uses of metamaterials to solve world problems. In this thesis, we study the fundamental optical properties of metamaterial building blocks by designing material permittivity. We continuously tune the interparticle distance in colloidal Au nanocrystal (NC) solids via the partial ligand exchange process. Then we combine top-down nanoimprint lithography with bottom-up assembly of colloidal NCs to develop a large-area, low-cost fabrication method for subwavelength nanostructures. Via this method, we fabricate and characterize nano-antenna arrays of different sizes and demonstrate metasurface quarter wave-plates of different bandwidth, and compare their performances with simulation results. We also integrate the metasurfaces with chemically- and mechanically-responsive polymers for strong-signal sensing. In the first design, we combine ultrathin plasmonic nanorods with hydrogel to fabricate optical moisture sensors for agricultural use. In the second application, we design mechanically tunable Au grating resonances on a polydimethylsiloxane (PDMS) substrate. The dimensions of Au grating are carefully engineered to achieve a hybridized, ultrasharp, and

  18. Cherenkov radiation by an electron bunch that moves in a vacuum above a left-handed material

    International Nuclear Information System (INIS)

    Averkov, Yu.O.; Yakovenko, V.M.

    2005-01-01

    Cherenkov radiation by a nonrelativistic electron bunch that moves above an interface of a vacuum-left-handed material has been investigated theoretically. The electron density of the bunch is described by a Gauss distribution. Cherenkov radiation for the frequency range where the refractive index is negative is shown to lead to simultaneous excitation of both bulk and surface electromagnetic waves over one and the same frequency range. In this case the wave vector magnitude in the plane of the interface of surface electromagnetic waves is larger than the corresponding wave vector magnitude of bulk electromagnetic waves. The energy flows in a left-handed material have been calculated. The spectral density and the radiation pattern have been investigated

  19. Laser-matter structuration of optical and biological materials

    Energy Technology Data Exchange (ETDEWEB)

    Hallo, L., E-mail: hallo@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Mezel, C., E-mail: candice.mezel@cea.fr [CELIA, Universite Bordeaux 1 (France); CEA Le Ripault, 37260 Monts (France); Guillemot, F., E-mail: fabien.guillemot@inserm.fr [UMR 577 INSERM, Universite Bordeaux 2 (France); Chimier, B., E-mail: chimier@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Bourgeade, A., E-mail: antoine.bourgeade@cea.fr [CEA-CESTA, Le Barp (France); Regan, C., E-mail: regan@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Duchateau, G., E-mail: duchateau@celia.u-bordeaux1.fr [CELIA, Universite Bordeaux 1 (France); Souquet, A., E-mail: agnes.souquet@inserm.fr [UMR 577 INSERM, Universite Bordeaux 2 (France); Hebert, D., E-mail: david.hebert@cea.fr [CEA-CESTA, Le Barp (France)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer In this study we model nanomaterial structuring. Black-Right-Pointing-Pointer The laser energy deposition is discussed first. Black-Right-Pointing-Pointer Full and approximate models are discussed. Black-Right-Pointing-Pointer Dynamic material response is addressed via hydrodynamics. Black-Right-Pointing-Pointer Sild effects are accounted for - Abstract: Interaction of ultrafast laser, i.e. from the femtosecond (fs) to the nanosecond (ns) regime, with initially transparent matter may produce very high energy density hot spots in the bulk as well as at the material surface, depending on focusing conditions. In the fs regime, absorption is due to ionisation of the dielectric, which enables absorption process to begin, and then hydrodynamic to take place. In the ns regime both absorption and hydrodynamic are coupled to each other, which complexifies considerably the comprehension but matter structuration looks similar. A numerical tool including solution of 3D Maxwell equations and a rate equation for free electrons is first compared to some available simple models of laser energy absorption. Then, subsequent material deformation, i.e. structuration, is determined by solving hydrodynamic equations, including or not solid behaviour. We show that nature of the final structures strongly depends on the amount of deposited energy and on the shape of the absorption zone. Then we address some problems related to laser-matter structuration of optical and biological materials in the fs, ps and ns regimes.

  20. Three-dimensional evaluation of effectiveness of hand and rotary instrumentation for retreatment of canals filled with different materials.

    Science.gov (United States)

    Hammad, Mohammad; Qualtrough, Alison; Silikas, Nick

    2008-11-01

    The aim of this study was to measure the remaining filling volume of different obturation materials from root-filled extracted teeth by using 2 removal techniques. Eighty single-rooted teeth were collected and decoronated, and the root canal was prepared by using the ProTaper nickel-titanium rotary files. The teeth were randomly allocated into 4 groups, and each group was obturated by using a different material. Group 1 was filled with gutta-percha and TubliSeal sealer, group 2 was filled with EndoRez points and EndoRez sealer, group 3 was filled with RealSeal points and RealSeal sealer, and Group 4 was filled with a gutta-percha point and GuttaFlow sealer. Teeth were scanned with a micro-computed tomography scan, and then root fillings were removed by using ProTaper retreatment files or hand K-files. Teeth were scanned again, and volume measurements were carried out with micro-computed tomography software. Statistical analysis showed significant differences between the 2 removal techniques for gutta-percha and for both techniques between gutta-percha and the other groups. The present study showed that all tested filling materials were not completely removed during retreatment by using hand or rotary files. Gutta-percha was more efficiently removed by using hand K-files.

  1. 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.

  2. 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.

  3. 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.

  4. Photonic band gap materials: towards an all-optical transistor

    Science.gov (United States)

    Florescu, Marian

    2002-05-01

    The transmission of information as optical signals encoded on light waves traveling through optical fibers and optical networks is increasingly moving to shorter and shorter distance scales. In the near future, optical networking is poised to supersede conventional transmission over electric wires and electronic networks for computer-to-computer communications, chip-to-chip communications, and even on-chip communications. The ever-increasing demand for faster and more reliable devices to process the optical signals offers new opportunities in developing all-optical signal processing systems (systems in which one optical signal controls another, thereby adding "intelligence" to the optical networks). All-optical switches, two-state and many-state all-optical memories, all-optical limiters, all-optical discriminators and all-optical transistors are only a few of the many devices proposed during the last two decades. The "all-optical" label is commonly used to distinguish the devices that do not involve dissipative electronic transport and require essentially no electrical communication of information. The all-optical transistor action was first observed in the context of optical bistability [1] and consists in a strong differential gain regime, in which, for small variations in the input intensity, the output intensity has a very strong variation. This analog operation is for all-optical input what transistor action is for electrical inputs.

  5. Fiber Optic Thermal Health Monitoring of Aerospace Structures and Materials

    Science.gov (United States)

    Wu, Meng-Chou; Winfree, William P.; Allison, Sidney G.

    2009-01-01

    A new technique is presented for thermographic detection of flaws in materials and structures by performing temperature measurements with fiber Bragg gratings. Individual optical fibers with multiple Bragg gratings employed as surface temperature sensors were bonded to the surfaces of structures with subsurface defects or thickness variations. Both during and following the application of a thermal heat flux to the surface, the individual Bragg grating sensors measured the temporal and spatial temperature variations. The investigated structures included a 10-ply composite specimen with subsurface delaminations of various sizes and depths. The data obtained from grating sensors were further analyzed with thermal modeling to reveal particular characteristics of the interested areas. These results were found to be consistent with those from conventional thermography techniques. Limitations of the technique were investigated using both experimental and numerical simulation techniques. Methods for performing in-situ structural health monitoring are discussed.

  6. Integrated optoelectronic materials and circuits for optical interconnects

    International Nuclear Information System (INIS)

    Hutcheson, L.D.

    1988-01-01

    Conventional interconnect and switching technology is rapidly becoming a critical issue in the realization of systems using high speed silicon and GaAs based technologies. In recent years clock speeds and on-chip density for VLSI/VHSIC technology has made packaging these high speed chips extremely difficult. A strong case can be made for using optical interconnects for on-chip/on-wafer, chip-to-chip and board-to-board high speed communications. GaAs integrated optoelectronic circuits (IOC's) are being developed in a number of laboratories for performing Input/Output functions at all levels. In this paper integrated optoelectronic materials, electronics and optoelectronic devices are presented. IOC's are examined from the standpoint of what it takes to fabricate the devices and what performance can be expected

  7. Interstellar material in front of chi ophiuchi. I. Optical observations

    International Nuclear Information System (INIS)

    Frisch, P.C.

    1979-01-01

    Optical observations of the interstellar material in front of chi Oph are discussed. The main interstellar cloud is made up of several regions with velocities between -6 and -12 km s -1 (heliocentric). Both CH and CH + are found within this feature, but with central velocities which differ by 2 km s -1 . Another cloud, with a velocity of -26 km s -1 , contains relatively strong Ca + lines. It has a ratio between Ca + and Na 0 column densities that is appropriate for ''high-velocity'' clouds. Calcium, iron, and sodium column densities are used to estimate an average electron density for the line of sight as well as for each cloud. The abundances of CH and CH + , and the absence of CN, are analyzed in terms of current theories about their origin

  8. Hands on what? The relative effectiveness of physical versus virtual materials in an engineering design project by middle school children

    Science.gov (United States)

    Klahr, David; Triona, Lara M.; Williams, Cameron

    2007-01-01

    Hands-on activities play an important, but controversial, role in early science education. In this study we attempt to clarify some of the issues surrounding the controversy by calling attention to distinctions between: (a) type of instruction (direct or discovery); (b) type of knowledge to be acquired (domain-general or domain-specific); and (c) type of materials that are used (physical or virtual). We then describe an empirical study that investigates the relative effectiveness of the physical-virtual dimension. In the present study, seventh and eighth grade students assembled and tested mousetrap cars with the goal of designing a car that would go the farthest. Children were assigned to four different conditions, depending on whether they manipulated physical or virtual materials, and whether they had a fixed number of cars they could construct or a fixed amount of time in which to construct them. All four conditions were equally effective in producing significant gains in learners' knowledge about causal factors, in their ability to design optimal cars, and in their confidence in their knowledge. Girls' performance, knowledge, and effort were equal to boys' in all conditions, but girls' confidence remained below boys' throughout. Given the fact that, on several different measures, children were able to learn as well with virtual as with physical materials, the inherent pragmatic advantages of virtual materials in science may make them the preferred instructional medium in many hands-on contexts.

  9. Robotic Hand

    Science.gov (United States)

    1993-01-01

    The Omni-Hand was developed by Ross-Hime Designs, Inc. for Marshall Space Flight Center (MSFC) under a Small Business Innovation Research (SBIR) contract. The multiple digit hand has an opposable thumb and a flexible wrist. Electric muscles called Minnacs power wrist joints and the interchangeable digits. Two hands have been delivered to NASA for evaluation for potential use on space missions and the unit is commercially available for applications like hazardous materials handling and manufacturing automation. Previous SBIR contracts resulted in the Omni-Wrist and Omni-Wrist II robotic systems, which are commercially available for spray painting, sealing, ultrasonic testing, as well as other uses.

  10. Calculated efficiencies of three-material low stress coatings for diffractive x-ray transmission optics

    International Nuclear Information System (INIS)

    Kubec, Adam; Braun, Stefan; Gawlitza, Peter; Menzel, Maik; Leson, Andreas

    2016-01-01

    Diffractive X-ray optical elements made by thin film coating techniques such as multilayer Laue lenses (MLL) and multilayer zone plates (MZP) are promising approaches to achieve resolutions in hard X-ray microscopy applications of less than 10 nm. The challenge is to make a lens with a large numerical aperture on the one hand and a decent working distance on the other hand. One of the limiting factors with the coated structures is the internal stress in the films, which can lead to significant bending of the substrate and various types of unwanted diffraction effects. Several approaches have been discussed to overcome this challenge. One of these is a three-material combination such as Mo/MoSi_2/Si, where four single layers per period are deposited. Mo and Si represent the absorber and spacer in this case while MoSi_2 forms a diffusion barrier; in addition the thicknesses of absorber and spacer are chosen to minimize residual stress of the overall coating. Here the diffraction efficiency as well as the profile of the beam in the focal plane are discussed in order to find a tradeoff between lowest residual stress and best diffraction properties.

  11. Synthesis & Studies of New Non-Destructive Read-Out Materials for Optical Storage and Optical Switches

    National Research Council Canada - National Science Library

    Rentzepis, Peter M

    2005-01-01

    .... The optical, chemical and spectroscopic properties of this non-destructive write/read/erase computer memory material have been studied This organic storage system consists of two different molecular...

  12. Integrated optical detection of autonomous capillary microfluidic immunoassays:a hand-held point-of-care prototype.

    Science.gov (United States)

    Novo, P; Chu, V; Conde, J P

    2014-07-15

    The miniaturization of biosensors using microfluidics has potential in enabling the development of point-of-care devices, with the added advantages of reduced time and cost of analysis with limits-of-detection comparable to those obtained through traditional laboratory techniques. Interfacing microfluidic devices with the external world can be difficult especially in aspects involving fluid handling and the need for simple sample insertion that avoids special equipment or trained personnel. In this work we present a point-of-care prototype system by integrating capillary microfluidics with a microfabricated photodiode array and electronic instrumentation into a hand-held unit. The capillary microfluidic device is capable of autonomous and sequential fluid flow, including control of the average fluid velocity at any given point of the analysis. To demonstrate the functionality of the prototype, a model chemiluminescence ELISA was performed. The performance of the integrated optical detection in the point-of-care prototype is equal to that obtained with traditional bench-top instrumentation. The photodiode signals were acquired, displayed and processed by a simple graphical user interface using a computer connected to the microcontroller through USB. The prototype performed integrated chemiluminescence ELISA detection in about 15 min with a limit-of-detection of ≈2 nM with an antibody-antigen affinity constant of ≈2×10(7) M(-1). Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Thermally Stable Heterocyclic Imines as New Potential Nonlinear Optical Materials

    Science.gov (United States)

    Nesterov, Volodymyr V.; Antipin, Mikhail Y.; Nesterov, Vladimir N.; Moore, Craig E.; Cardelino, Beatriz H.; Timofeeva, Tatiana V.

    2004-01-01

    In the course of a search for new thermostable acentric nonlinear optical crystalline materials, several heterocyclic imine derivatives were designed, with the general structure D-pi-A(D'). Introduction of a donor amino group (D') into the acceptor moiety was expected to bring H-bonds into their crystal structures, and so to elevate their melting points and assist in an acentric molecular packing. Six heterocycle-containing compounds of this type were prepared, single crystals were grown for five of them, and these crystals were characterized by X-ray analysis. A significant melting temperature elevation was found for all of the synthesized compounds. Three of the compounds were also found to crystallize in acentric space groups. One of the acentric compounds is built as a three-dimensional H-bonded molecular network. In the other two compounds, with very similar molecular structure, the molecules form one-dimensional H-bonded head-to-head associates (chains). These chains are parallel in two different crystallographic directions and form very unusual interpenetrating chain patterns in an acentric crystal. Two of the compounds crystallized with centrosymmetric molecular packing.

  14. Analysis of nonlinear optical properties in donor–acceptor materials

    Energy Technology Data Exchange (ETDEWEB)

    Day, Paul N. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); General Dynamics Information Technology, Inc., Dayton, Ohio 45431 (United States); Pachter, Ruth [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); Nguyen, Kiet A. [Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio 45433 (United States); UES, Inc., Dayton, Ohio 45432 (United States)

    2014-05-14

    Time-dependent density functional theory has been used to calculate nonlinear optical (NLO) properties, including the first and second hyperpolarizabilities as well as the two-photon absorption cross-section, for the donor-acceptor molecules p-nitroaniline and dimethylamino nitrostilbene, and for respective materials attached to a gold dimer. The CAMB3LYP, B3LYP, PBE0, and PBE exchange-correlation functionals all had fair but variable performance when compared to higher-level theory and to experiment. The CAMB3LYP functional had the best performance on these compounds of the functionals tested. However, our comprehensive analysis has shown that quantitative prediction of hyperpolarizabilities is still a challenge, hampered by inadequate functionals, basis sets, and solvation models, requiring further experimental characterization. Attachment of the Au{sub 2}S group to molecules already known for their relatively large NLO properties was found to further enhance the response. While our calculations show a modest enhancement for the first hyperpolarizability, the enhancement of the second hyperpolarizability is predicted to be more than an order of magnitude.

  15. Study of the physical mechanisms involved in the femtosecond laser optical breakdown of dielectric materials

    International Nuclear Information System (INIS)

    Mouskeftaras, Alexandros

    2013-01-01

    We have carried out detailed time resolved experimental studies of the mechanism of electron excitation-relaxation, when an ultrashort (60 fs -1 ps) laser (UV and IR) pulse interacts with a wide band gap dielectric material. The studies cover a range of different dielectric materials and the investigated regimes span from nondestructive ionization of the material at the low power end (∼TW/cm 2 ) to ablative domain at a higher laser power (∼10 TW/cm 2 ). This gives fundamental insight into the understanding of the laser damaging process taking place under our irradiation conditions. The usage of time-resolved spectral interferometry technique allows to directly measure the electron density of the irradiated material under different excitation conditions and hence leads to quantification of the process. The measurements, carried out at the optical breakdown threshold utilizing different pulse durations, raise questions regarding the usage of critical excitation density as a universal ablation criterion. A new criterion related to the exchanged energy is proposed. Additionally, the use of an experimental setup implementing a double pump pulse allows the identification of different excitation mechanisms taking place at time scales of the order of the pulse duration used. Electronic avalanche is observed in some materials (SiO 2 , NaCl) while this is not the case for others (Al 2 O 3 , MgO). These differences are discussed in detail. Next, we measure the energy spectrum of excited electrons with a complementary technique: the photoemission spectroscopy. These results allow us on one hand to show a crossed effect between the two 'pump' pulses and on the other hand to measure electron relaxation characteristic times, as a function of their kinetic energy. Finally, a morphological study of craters resulting from ablation in the case of a single pulse has been carried out for different irradiation parameters: number of shots, energy and pulse duration. This work has

  16. Process Optimization of Pontianak Aloe vera Powder (Aloe chinensis Beakker as Raw Material for Hand body lotion

    Directory of Open Access Journals (Sweden)

    Nana Supriyatna

    2010-12-01

    Full Text Available Process optimization of Pontianak aloe vera powder (Aloe chinensis Beaker  as raw material for hand body lotion have been conducted on laboratory scale with the aim of obtaining the optimum conditions of processing technologies through the addition of maltodextrin and Carboxy Methyl Cellulase. The optimum results achieved at the ratio of maltodextrin to the CMC by 90%: 10%. Characteristics of aloe vera powder produced showing yellowish white color, water content of 8:56%, 5:50 pH, total solid Aloe 25.5%, weight flour ratio and fresh aloe vera leaves 1.5: 100, aloin content of 164.40 ppm, 257.08 ppm malic acid content, 10.32 ppm vitamin E and 1.4 x 105 colonies/g total bacteria. Making hand body lotion of aloe vera powder optimization results show the characteristic white color with a fragrant aroma, acidity (pH 7:07, 10.34 ppm of malic acid, 1.1 x 104 colony/g total bacteria, and quite stable while storage.

  17. Optical limiting properties of fullerenes and related materials

    Science.gov (United States)

    Riggs, Jason Eric

    Optical limiting properties of fullerene C60 and different C60 derivatives (methano-, pyrrolidino-, and amino-) towards nanosecond laser pulses at 532 nm were studied. The results show that optical limiting responses of the C60 derivatives are similar to those of the parent C60 despite their different linear absorption and emission properties. For C60 and the derivatives in room-temperature solutions of varying concentrations and optical path length, the optical limiting responses are strongly concentration dependent. The concentration dependence is not due to any optical artifacts since the results obtained under the same experimental conditions for reference systems show no such dependence. Similarly, optical limiting results of fullerenes are strongly dependent on the medium viscosity, with responses in viscous media weaker than that in room-temperature solutions. The solution concentration and medium viscosity dependencies are not limited to fullerenes. In fact, the results from a systematic investigation of several classes of nonlinear absorptive organic dyes show that the optical limiting responses are also concentration and medium viscosity dependent. Interestingly, however, such dependencies are uniquely absent in the optical limiting responses of metallophthalocyanines. In classical photophysics, the strong solution concentration and medium viscosity dependencies are indicative of significant contributions from photoexcited-state bimolecular processes. Thus, the experimental results are discussed in terms of a significantly modified five-level reverse saturable absorption mechanism. Optical limiting properties of single-walled and multiple-walled carbon nanotubes toward nanosecond laser pulses at 532 nm were also investigated. When suspended in water, the single-walled and multiple-walled carbon nanotubes exhibit essentially the same optical limiting responses, and the results are also comparable with those of carbon black aqueous suspension. For

  18. Gold nanorods-silicone hybrid material films and their optical limiting property

    Science.gov (United States)

    Li, Chunfang; Qi, Yanhai; Hao, Xiongwen; Peng, Xue; Li, Dongxiang

    2015-10-01

    As a kind of new optical limiting materials, gold nanoparticles have optical limiting property owing to their optical nonlinearities induced by surface plasmon resonance (SPR). Gold nanorods (GNRs) possess transversal SPR absorption and tunable longitudinal SPR absorption in the visible and near-infrared region, so they can be used as potential optical limiting materials against tunable laser pulses. In this letter, GNRs were prepared using seed-mediated growth method and surface-modified by silica coating to obtain good dispersion in polydimethylsiloxane prepolymers. Then the silicone rubber films doped with GNRs were prepared after vulcanization, whose optical limiting property and optical nonlinearity were investigated. The silicone rubber samples doped with more GNRs were found to exhibit better optical limiting performance.

  19. Characterization of electrical and optical properties of silicon based materials

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Guobin

    2009-12-04

    characteristic DRL lines D1 to D4 has been detected, indicating the dislocations in the Alile sample are relatively clean. Test p-n junction diodes with dislocation networks (DNs) produced by silicon wafer direct bonding have been investigated by EBIC technique. Charge carriers collection and electrical conduction phenomena by the DNs were observed. Inhomogeneities in the charge collection were detected in n- and p-type samples under appropriate beam energy. The diffusion lengths in the thin top layer of silicon-on-insulator (SOI) have been measured by EBIC with full suppression of the surface recombination at the buried oxide (BOX) layer and at surface of the top layer by biasing method. The measured diffusion length is several times larger than the layer thickness. Silicon nanostructures are another important subject of this work. Electrical and optical properties of various silicon based materials like silicon nanowires, silicon nano rods, porous silicon, and Si/SiO{sub 2} multi quantum wells (MQWs) samples were investigated in this work. Silicon sub-bandgap infrared (IR) luminescence around 1570 nm was found in silicon nanowires, nano rods and porous silicon. PL measurements with samples immersed in different liquid media, for example, in aqueous HF (50%), concentrated H{sub 2}SO{sub 4} (98%) and H{sub 2}O{sub 2} established that the subbandgap IR luminescence originated from the Si/SiO{sub x} interface. EL in the sub-bandgap IR range has been observed in simple devices prepared on porous silicon and MQWs at room temperature. (orig.)

  20. Advanced materials and techniques for fibre-optic sensing

    International Nuclear Information System (INIS)

    Henderson, Philip J

    2014-01-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company – a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon

  1. OM85. Basic Properties of Optical Materials Summaries of Papers.

    Science.gov (United States)

    1985-05-01

    1984. [2] D. Marcuse : IEEE J. QE-14, 736 (1978). 163 ... . . . .. . . .. . . CALORIMETRIC MEASUREMENT OF OPTICAL ABSORPTION IN SAPPHIRE AT VISIBLE...ARSENIDE Herbert S. Bennett Semiconductor Devices and Circuits Division National Bureau of Standards Gaithersburg, MD 20899 Introduction Lasers, opto

  2. Advanced materials and techniques for fibre-optic sensing

    Science.gov (United States)

    Henderson, Philip J.

    2014-06-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. Keywords: Fibre-optic sensors, fibre Bragg gratings, MEMS, MOEMS, nanotechnology, plasmon.

  3. Characterization of temperature-dependent optical material properties of polymer powders

    Energy Technology Data Exchange (ETDEWEB)

    Laumer, Tobias [Bayerisches Laserzentrum GmbH, 91052 Erlangen (Germany); SAOT Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen (Germany); CRC Collaborative Research Center 814 - Additive Manufacturing, 91052 Erlangen (Germany); Stichel, Thomas; Bock, Thomas; Amend, Philipp [Bayerisches Laserzentrum GmbH, 91052 Erlangen (Germany); CRC Collaborative Research Center 814 - Additive Manufacturing, 91052 Erlangen (Germany); Schmidt, Michael [Bayerisches Laserzentrum GmbH, 91052 Erlangen (Germany); University of Erlangen-Nürnberg, Institute of Photonic Technologies, 91052 Erlangen (Germany); SAOT Erlangen Graduate School in Advanced Optical Technologies, 91052 Erlangen (Germany); CRC Collaborative Research Center 814 - Additive Manufacturing, 91052 Erlangen (Germany)

    2015-05-22

    In former works, the optical material properties of different polymer powders used for Laser Beam Melting (LBM) at room temperature have been analyzed. With a measurement setup using two integration spheres, it was shown that the optical material properties of polymer powders differ significantly due to multiple reflections within the powder compared to solid bodies of the same material. Additionally, the absorption behavior of the single particles shows an important influence on the overall optical material properties, especially the reflectance of the powder bed. Now the setup is modified to allow measurements at higher temperatures. Because crystalline areas of semi-crystalline thermoplastics are mainly responsible for the absorption of the laser radiation, the influence of the temperature increase on the overall optical material properties is analyzed. As material, conventional polyamide 12 and polypropylene as new polymer powder material, is used. By comparing results at room temperature and at higher temperatures towards the melting point, the temperature-dependent optical material properties and their influence on the beam-matter interaction during the process are discussed. It is shown that the phase transition during melting leads to significant changes of the optical material properties of the analyzed powders.

  4. Engineered Multifunctional Nanophotonic Materials for Ultrafast Optical Switching

    Science.gov (United States)

    2012-11-02

    and Co3 + placed at tetrahedral and octahedral sites, respectively. Single -layer thin films of Co3O4 nanoparticles have large optical nonlinearity and...the first two methodologies in systems having weakly resonant structures, including 3-D and/or 1-D photonic crystal structures (i.e. nonlinear Bragg...Nonlinear optical transmission of lead phthalocyanine-doped nematic liquid crystal composites for multiscale nonlinear switching from nanosecond to

  5. Optical and structural properties of Mo-doped NiTiO{sub 3} materials synthesized via modified Pechini methods

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Thanh-Truc; Kang, Sung Gu; Shin, Eun Woo, E-mail: ewshin@ulsan.ac.kr

    2017-07-31

    Highlights: • Mo-doped NiTiO{sub 3} materials were well prepared by a modified Pechini method. • Recombination rates of the materials were significantly inhibited by Mo doping. • Defect sites were generated by the substitution of Mo for Ni or Ti positions. • The generation of defect sites gradually decreased the grain sizes of the materials. • The surface areas of the materials were increased with decreasing the grain sizes. - Abstract: In this study, molybdenum (Mo)-doped nickel titanate (NiTiO{sub 3}) materials were successfully synthesized as a function of Mo content through a modified Pechini method followed by a solvothermal treatment process. Various characterization methods were employed to investigate the optical and structural properties of the materials. XRD patterns clearly showed that the NiTiO{sub 3} structure maintained a single phase with no observed crystalline structure transformations, even after the addition of 10 wt.% Mo. In the Raman spectra and XRD patterns, peak positions shifted with a change in Mo content, confirming that the NiTiO{sub 3} lattice was doped with Mo. On the other hand, Mo doping of NiTiO{sub 3} materials changed their optical properties. DRS-UV demonstrated that the addition of Mo increased photon absorption within the UV region. Relaxation processes were inhibited by Mo doping, which was evident in the PL spectra. Structural properties of the prepared materials were studied via FE-SEM and HR-TEM. The measured surface area increased proportionally with Mo content due to a reduction in grain size of the materials.

  6. Terahertz (THz) Optical Parameters of Three-Dimensional (3-D) Printing Materials

    Science.gov (United States)

    2017-03-01

    Terahertz (THz), Submillimeter Wave, Imaging 15. NUMBER OF PAGES 16 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT UNCLASSIFIED 18...and imaging has become a topic of research as an optical technique to study these materials because THz radiation can penetrate many visibly opaque...2) Three materials, each tinted with two different colors, were measured. The materials were High Impact polystyrene (HIPS

  7. Advanced materials and techniques for fiber-optic sensing

    International Nuclear Information System (INIS)

    Henderson, P. J.

    2013-01-01

    Fibre-optic monitoring systems came of age in about 1999 upon the emergence of the world's first significant commercialising company - a spin-out from the UK's collaborative MAST project. By using embedded fibre-optic technology, the MAST project successfully measured transient strain within high-performance composite yacht masts. Since then, applications have extended from smart composites into civil engineering, energy, military, aerospace, medicine and other sectors. Fibre-optic sensors come in various forms, and may be subject to embedment, retrofitting, and remote interrogation. The unique challenges presented by each implementation require careful scrutiny before widespread adoption can take place. Accordingly, various aspects of design and reliability are discussed spanning a range of representative technologies that include resonant microsilicon structures, MEMS, Bragg gratings, advanced forms of spectroscopy, and modern trends in nanotechnology. (author)

  8. Linac Coherent Light Source soft x-ray materials science instrument optical design and monochromator commissioning

    Czech Academy of Sciences Publication Activity Database

    Heimann, P.; Krupin, O.; Schlotter, W.F.; Turner, J.; Krzywinski, J.; Sorgenfrei, F.; Messerschmidt, M.; Bernstein, D.; Chalupský, Jaromír; Hájková, Věra; Hau-Riege, S.; Holmes, M.; Juha, Libor; Kelez, N.; Lüning, J.; Nordlund, D.; Perea, M.F.; Scherz, A.; Soufli, R.; Wurth, W.; Rowen, M.

    2011-01-01

    Roč. 82, č. 9 (2011), 093104/1-093104/8 ISSN 0034-6748 R&D Projects: GA MŠk(CZ) ME10046 Institutional research plan: CEZ:AV0Z10100523 Keywords : diffraction gratings * light sources * linear accelerators * optical materials * x-ray monochromators * x-ray optics Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.367, year: 2011

  9. Optical switching at 1.55um in silicon racetrack resonators using phase change materials

    NARCIS (Netherlands)

    Rudé, M.; Pello, J.; Simpson, R.E.; Osmond, J.; Roelkens, G.C.; Tol, van der J.J.G.M.; Pruneri, V.

    2013-01-01

    An optical switch operating at a wavelength of 1.55¿µm and showing a 12 dB modulation depth is introduced. The device is implemented in a silicon racetrack resonator using an overcladding layer of the phase change data storage material Ge2Sb2Te5, which exhibits high contrast in its optical

  10. Material Removal Rate for Magnetorheological Finishing (MRF) of Optical Glasses with Nanodiamond MR Fluid

    International Nuclear Information System (INIS)

    DeGroote, J.E.; Marino, A.E.; Wilson, J.P.; Bishop, A.L.; Jacobs, S.D.

    2007-01-01

    We present a material removal rate model for MRF of optical glasses using nanodiamond MR fluid. The new model incorporates terms for drag force, polishing particle properties, chemical durability and glass composition into an existing model that contains only terms for the glass mechanical properties. Experimental results for six optical glasses are given that support this model

  11. Ultraviolet and visible BRDF data on spacecraft thermal control and optical baffle materials

    Science.gov (United States)

    Viehmann, W.; Predmore, R. E.

    1987-01-01

    Bidirectional scattering functions of numerous optical baffle materials and of spacecraft thermal control coatings and surfaces are presented. Measurements were made at 254 nm and at 633 nm. The coatings and surfaces include high-reflectance white paints, low-reflectance optical blacks, thermal control blankets, and various conversion coatings on aluminum.

  12. Material Removal Rate for Magnetorheological Finishing (MRF) of Optical Glasses with Nanodiamond MR Fluid

    Energy Technology Data Exchange (ETDEWEB)

    DeGroote, J.E.; Marino, A.E.; Wilson, J.P.; Bishop, A.L.; Jacobs, S.D.

    2007-07-13

    We present a material removal rate model for MRF of optical glasses using nanodiamond MR fluid. The new model incorporates terms for drag force, polishing particle properties, chemical durability and glass composition into an existing model that contains only terms for the glass mechanical properties. Experimental results for six optical glasses are given that support this model.

  13. Optically stimulated luminescence dosimetry using natural and synthetic materials

    DEFF Research Database (Denmark)

    Bøtter-Jensen, L.; McKeever, S.W.S.

    1996-01-01

    The application of optically stimulated luminescence (OSL) for use in radiation dosimetry is reviewed. A broad description is given of OSL techniques developed at Riso National Laboratory and at Oklahoma State University, and recent collaborative investigations on the properties of a variety...

  14. Biopolymer-based material used in optical image correlation

    Czech Academy of Sciences Publication Activity Database

    Mysliwiec, J.; Kochalska, Anna; Miniewicz, A.

    2008-01-01

    Roč. 47, č. 11 (2008), s. 1902-1906 ISSN 0003-6935 Institutional research plan: CEZ:AV0Z40500505 Keywords : biopolymer * DNA * optical correlation Subject RIV: CD - Macromolecular Chemistry Impact factor: 1.763, year: 2008

  15. EPR and Optical Characterization of Photorefractive Materials Used in Agile Laser Protection

    National Research Council Canada - National Science Library

    Halliburton, Larry

    2003-01-01

    .... The specific materials investigated were LiNbO3 and LiTaO3. The experimental techniques used to characterize these crystals were optical absorption, thermoluminescence, and electron paramagnetic resonance (EPR...

  16. Mesomorphic glass nanocomposites made of metal alkanoates and nanoparticles as emerging nonlinear-optical materials

    Science.gov (United States)

    Garbovskiy, Y.; Klimusheva, G.; Mirnaya, T.

    2016-09-01

    Mesomorphic metal alkanoates is very promising yet overlooked class of nonlinear-optical materials. Metal alkanoates can exhibit a broad variety of condensed states of matter including solid crystals, plastic crystals, lyotropic and thermotropic ionic liquid crystals, liquids, mesomorphic glasses, and Langmuir-Blodgett films. Glass-forming properties of metal alkanoates combined with their use as nano-reactors and anisotropic host open up simple and efficient way to design various photonic nanomaterials. Despite very interesting physics, the experimental data on optical and nonlinearoptical properties of such materials are scarce. The goal of the present paper is to fill the gap by discussing recent advances in the field of photonic materials made of metal alkanoates, organic dyes, and nanoparticles. Optical and nonlinear-optical properties of the following materials are reviewed: (i) mesomorphic glass doped with organic dyes; (ii) smectic glass composed of cobalt alkanoates; (iii) semiconductor nanoparticles embedded in a glassy host; (iv) metal nanoparticles - glass (the cobalt octanoate) nanocomposites.

  17. Self-Assembly of Nanocomposite Nonlinear Optical Materials for Photonic Devices, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This program targets the development of new highly anisotropic nonlinear optical nanocomposite materials for NASA and non-NASA applications in advanced photonic and...

  18. Wash Your Hands

    Science.gov (United States)

    ... hand sanitizers might not remove harmful chemicals like pesticides and heavy metals from hands. Be cautious when ... Health Promotion Materials Fact Sheets Podcasts Posters Stickers Videos Web Features Training & Education Our Partners Publications, Data & ...

  19. Reflective and refractive optical materials for earth and space applications; Proceedings of the Meeting, Orlando, FL, Apr. 4, 5, 1991

    Science.gov (United States)

    Riedl, Max J.; Hale, Robert R.; Parsonage, Thomas B.

    The present conference discusses beryllium mirror design and fabrication, production of aspheric beryllium optical surfaces by HIP consolidation, the control of thermally induced porosity for the fabrication of beryllium optics, fine-grained beryllium optical coatings, light-absorbing beryllium baffle materials, and advanced broadband baffle materials. Also discussed are radiation-resistant optical glasses, a catalog of IR and cryooptical properties of selected materials, durable metal-dielectric mirror coatings, the optical stability of diffuse reflectance materials, and optical filters for space applications.

  20. Hand eczema

    DEFF Research Database (Denmark)

    Ibler, K.S.; Jemec, G.B.E.; Flyvholm, M.-A.

    2012-01-01

    Background. Healthcare workers are at increased risk of developing hand eczema. Objectives. To investigate the prevalence and severity of self-reported hand eczema, and to relate the findings to demographic data, occupation, medical speciality, wards, shifts, and working hours. Patients/materials......Background. Healthcare workers are at increased risk of developing hand eczema. Objectives. To investigate the prevalence and severity of self-reported hand eczema, and to relate the findings to demographic data, occupation, medical speciality, wards, shifts, and working hours. Patients...... dermatitis, younger age, male sex (male doctors), and working hours. Eighty nine per cent of subjects reported mild/moderate lesions. Atopic dermatitis was the only factor significantly related to severity. Sick leave was reported by 8% of subjects, and notification to the authorities by 12%. Conclusions...... or severity, but cultural differences between professions with respect to coping with the eczema were significant. Atopic dermatitis was related to increased prevalence and severity, and preventive efforts should be made for healthcare workers with atopic dermatitis....

  1. Hand Osteoblastoma

    Directory of Open Access Journals (Sweden)

    M. Farzan

    2006-06-01

    Full Text Available Background and Aim: Osteoblastoma is one of the rarest primary bone tumors. Although, small bones of the hands and feet are the third most common location for this tumor, the hand involvement is very rare and few case observations were published in the English-language literature. Materials and Methods: In this study, we report five cases of benign osteoblastoma of the hand, 3 in metacarpals and two in phalanxes. The clinical feature is not specific. The severe nocturnal, salicylate-responsive pain is not present in patients with osteoblastoma. The pain is dull, persistent and less localized. The clinical course is usually long and there is often symptoms for months before medical attention are sought. Swelling is a more persistent finding in osteoblastoma of the hand that we found in all of our patients. The radiologic findings are indistinctive, so preoperative diagnosis based on X-ray appearance is difficult. In all of our 5 cases, we fail to consider osteoblastoma as primary diagnosis. Pathologically, osteoblastoma consisting of a well-vascularized connective tissue stroma in which there is active production of osteoid and primitive woven bone. Treatment depends on the stage and localization of the tumor. Curettage and bone grafting is sufficient in stage 1 or stage 2, but in stage 3 wide resection is necessary for prevention of recurrence. Osteosarcoma is the most important differential diagnosis that may lead to inappropriate operation.

  2. Brillouin optical correlation domain analysis in composite material beams

    DEFF Research Database (Denmark)

    Stern, Yonatan; London, Yosef; Preter, Eyal

    2017-01-01

    Structural health monitoring is a critical requirement in many composites. Numerous monitoring strategies rely on measurements of temperature or strain (or both), however these are often restricted to point-sensing or to the coverage of small areas. Spatially-continuous data can be obtained...... with optical fiber sensors. In this work, we report high-resolution distributed Brillouin sensing over standard fibers that are embedded in composite structures. A phase-coded, Brillouin optical correlation domain analysis (B-OCDA) protocol was employed, with spatial resolution of 2 cm and sensitivity of 1 °K...... or 20 micro-strain. A portable measurement setup was designed and assembled on the premises of a composite structures manufacturer. The setup was successfully utilized in several structural health monitoring scenarios: (a) monitoring the production and curing of a composite beam over 60 h; (b...

  3. Design considerations for multi component molecular-polymeric nonlinear optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Singer, K.D. (Case Western Reserve Univ., Cleveland, OH (USA). Dept. of Physics); Kuzyk, M.G. (Washington State Univ., Pullman, WA (USA). Dept. of Physics); Fang, T.; Holland, W.R. (AT and T Bell Labs., Princeton, NJ (USA)); Cahill, P.A. (Sandia National Labs., Albuquerque, NM (USA))

    1990-01-01

    We review our work on multi component polymeric nonlinear optical materials. These materials consist of nonlinear optical molecules incorporated in a polymeric host. A cross-linked triazine polymer incorporating a dicyanovinyl terminated azo dye was found to be relatively stable at 85{degree} and posses an electro-optic coefficient of 11pm/V. We have also observed the zero dispersion condition in a new anomalous dispersion dye for phase matched second harmonic generation, and expect efficient conversion to the blue. A squarylium dye, ISQ, has been found to posses a large third order nonlinearity, and may display two-level behavior. 24 refs., 11 figs.

  4. Micro- and nanostructured sol-gel-based materials for optical chemical sensing (2005–2015)

    International Nuclear Information System (INIS)

    Barczak, Mariusz; McDonagh, Colette; Wencel, Dorota

    2016-01-01

    This review (with 172 references) highlights the progress made in the past 10 years in silica sol-gel-based materials for use in optical chemical sensing. Following an introduction, the processes leading to the sol-gel-based and ormosil materials, their printability and methods for characterisation are discussed. Then various classes of optical sensors, with a focus on sensors for pH values, oxygen, carbon dioxide, ammonia (also in dissolved form), and heavy metal ions are described. A further section covers nanoparticle-based optical sensors mainly for use in intracellular sensing of the above species. Recent developments in this area are also emphasised and future trends discussed. (author)

  5. Sol-Gel Material-Enabled Electro-Optic Polymer Modulators

    Science.gov (United States)

    Himmelhuber, Roland; Norwood, Robert A.; Enami, Yasufumi; Peyghambarian, Nasser

    2015-01-01

    Sol-gels are an important material class, as they provide easy modification of material properties, good processability and are easy to synthesize. In general, an electro-optic (EO) modulator transforms an electrical signal into an optical signal. The incoming electrical signal is most commonly information encoded in a voltage change. This voltage change is then transformed into either a phase change or an intensity change in the light signal. The less voltage needed to drive the modulator and the lower the optical loss, the higher the link gain and, therefore, the better the performance of the modulator. In this review, we will show how sol-gels can be used to enhance the performance of electro-optic modulators by allowing for designs with low optical loss, increased poling efficiency and manipulation of the electric field used for driving the modulator. The optical loss is influenced by the propagation loss in the device, as well as the losses occurring during fiber coupling in and out of the device. In both cases, the use of sol-gel materials can be beneficial due to the wide range of available refractive indices and low optical attenuation. The influence of material properties and synthesis conditions on the device performance will be discussed. PMID:26225971

  6. Materials for Concentrator Photovoltaic Systems: Optical Properties and Solar Radiation Durability

    Science.gov (United States)

    French, R. H.; Rodríguez-Parada, J. M.; Yang, M. K.; Lemon, M. F.; Romano, E. C.; Boydell, P.

    2010-10-01

    Concentrator photovoltaic (CPV) systems are designed to operate over a wide range of solar concentrations, from low concentrations of ˜1 to 12 Suns to medium concentrations in the range from 12 to 200 Suns, to high concentration CPV systems going up to 2000 Suns. Many transparent optical materials are used for a wide variety of functions ranging from refractive and reflective optics to homogenizers, encapsulants and even thermal management. The classes of materials used also span a wide spectrum from hydrocarbon polymers (HCP) and fluoropolymers (FP) to silicon containing polymers and polyimides (PI). The optical properties of these materials are essential to the optical behavior of the system. At the same time radiation durability of these materials under the extremely wide range of solar concentrations is a critical performance requirement for the required lifetime of a CPV system. As part of our research on materials for CPV we are evaluating the optical properties and solar radiation durability of various polymeric materials to define the optimum material combinations for various CPV systems.

  7. First principles study of the optical contrast in phase change materials

    Energy Technology Data Exchange (ETDEWEB)

    Caravati, S; Parrinello, M [Department of Chemistry and Applied Biosciences, ETH Zurich, USI Campus, Via Giuseppe Buffi 13, 6900 Lugano (Switzerland); Bernasconi, M, E-mail: marco.bernasconi@mater.unimib.i [Dipartimento di Scienza dei Materiali, Universita di Milano-Bicocca, Via R Cozzi 53, I-20125, Milano (Italy)

    2010-08-11

    We study from first principles the optical properties of the phase change materials Ge{sub 2}Sb{sub 2}Te{sub 5} (GST), GeTe and Sb{sub 2}Te{sub 3} in the crystalline phase and in realistic models of the amorphous phase generated by quenching from the melt in ab initio molecular dynamics simulations. The calculations reproduce the strong optical contrast between the crystalline and amorphous phases measured experimentally and exploited in optical data storage. It is demonstrated that the optical contrast is due to a change in the optical matrix elements across the phase change in all the compounds. It is concluded that the reduction of the optical matrix elements in the amorphous phases is due to angular disorder in p-bonding which dominates the amorphous network in agreement with previous proposals (Huang and Robertson 2010 Phys. Rev. B 81 081204) based on calculations on crystalline models.

  8. All-optical signal processing in quadratic nonlinear materials

    DEFF Research Database (Denmark)

    Johansen, Steffen Kjær

    2002-01-01

    of materials with a second order nonlinearity, the so-called X(2) materials, is faster and stronger than that of more conventional materials with a cubic nonlinearity. The X(2) materials support spatial solitons consisting of two coupled components, the fundamental wave (FW) and its second harmonic (SH......). During this project the interaction between such spatial solitons has been investigated theoretically through perturbation theory and experimentally via numerical simulations. The outcome of this research isnew theoretical tools for quantitatively predicting the escape angle, i.e. the angle of incidence...... are dedicated to this part of the research. In chapter 4 the generality of the theoretical approach is emphasised with the derivation and verification of equivalent tools for media with a saturable nonlinearity. The strength of the X(2) nonlinearity strongly depends on the phase mismatch between the FW...

  9. Biomimetic Polyaminoacids as Precursors for Optical-Active Intelligent Materials

    National Research Council Canada - National Science Library

    Popova, G

    2003-01-01

    ...; function on nanoscale; stimula-responsive study; intelligent materials formation. Modified polyglutamic acid with dyes regular set possesses specific ability to self-assembly with cooperative rearrangement under outer temperature...

  10. Optical investigations of various polymeric materials used in dental technology

    Science.gov (United States)

    Negrutiu, Meda Lavinia; Sinescu, Cosmin; Topala, Florin Ionel; Ionita, Ciprian; Goguta, Luciana; Marcauteanu, Corina; Rominu, Mihai; Podoleanu, Adrian Gh.

    2011-10-01

    Dental prosthetic restorations have to satisfy high stress as well as aesthetic requirements. In order to avoid deficiencies of dental prostheses, several alternative systems and procedures were imagined, directly related to the material used and also to the manufacturing technology. Increasing the biomechanical comportment of polymeric materials implies fiber reinforcing. The different fibers reinforcing products made very difficult the evaluation of their performances and biomechanical properties analysis. There are several known methods which are used to assess the quality of dental prostheses, but most are invasive. These lead to the destruction of the samples and often no conclusion could be drawn in the investigated areas of interest. Using a time domain en-face OCT system, we have recently demonstrated real time thorough evaluation of quality of various dental treatments. The aim of this study was to assess the quality of various polymeric materials used in dental technology and to validate the en face OCT imagistic evaluation of polymeric dental prostheses by using scanning electron microscopy (SEM) and microcomputer tomography (μCT). SEM investigations evidenced the nonlinear aspect of the interface between the polymeric material and the fiber reinforcement and materials defects in some samples. The results obtained by microCT revealed also some defects inside the polymeric materials and at the interfaces with the fiber reinforcement. The advantages of the OCT method consist in non-invasiveness and high resolution. In addition, en face OCT investigations permit visualization of the more complex stratified structure at the interface between the polymeric material and the fiber reinforcement.

  11. Brillouin Optical Correlation Domain Analysis in Composite Material Beams

    Directory of Open Access Journals (Sweden)

    Yonatan Stern

    2017-10-01

    Full Text Available Structural health monitoring is a critical requirement in many composites. Numerous monitoring strategies rely on measurements of temperature or strain (or both, however these are often restricted to point-sensing or to the coverage of small areas. Spatially-continuous data can be obtained with optical fiber sensors. In this work, we report high-resolution distributed Brillouin sensing over standard fibers that are embedded in composite structures. A phase-coded, Brillouin optical correlation domain analysis (B-OCDA protocol was employed, with spatial resolution of 2 cm and sensitivity of 1 °K or 20 micro-strain. A portable measurement setup was designed and assembled on the premises of a composite structures manufacturer. The setup was successfully utilized in several structural health monitoring scenarios: (a monitoring the production and curing of a composite beam over 60 h; (b estimating the stiffness and Young’s modulus of a composite beam; and (c distributed strain measurements across the surfaces of a model wing of an unmanned aerial vehicle. The measurements are supported by the predictions of structural analysis calculations. The results illustrate the potential added values of high-resolution, distributed Brillouin sensing in the structural health monitoring of composites.

  12. A Polymer Optical Fiber Temperature Sensor Based on Material Features.

    Science.gov (United States)

    Leal-Junior, Arnaldo; Frizera-Netoc, Anselmo; Marques, Carlos; Pontes, Maria José

    2018-01-19

    This paper presents a polymer optical fiber (POF)-based temperature sensor. The operation principle of the sensor is the variation in the POF mechanical properties with the temperature variation. Such mechanical property variation leads to a variation in the POF output power when a constant stress is applied to the fiber due to the stress-optical effect. The fiber mechanical properties are characterized through a dynamic mechanical analysis, and the output power variation with different temperatures is measured. The stress is applied to the fiber by means of a 180° curvature, and supports are positioned on the fiber to inhibit the variation in its curvature with the temperature variation. Results show that the sensor proposed has a sensitivity of 1.04 × 10 -3 °C -1 , a linearity of 0.994, and a root mean squared error of 1.48 °C, which indicates a relative error of below 2%, which is lower than the ones obtained for intensity-variation-based temperature sensors. Furthermore, the sensor is able to operate at temperatures up to 110 °C, which is higher than the ones obtained for similar POF sensors in the literature.

  13. Characterization of Materials for Use as Optical Phantoms

    International Nuclear Information System (INIS)

    Rascon, E. Ortiz; Bruce, N. C.; Flores Flores, J. O.; Berru, R. Sato

    2010-01-01

    We present the results of optical characterization of silicon dioxide nanoparticle solutions. These are spherical particles with a controlled diameter between 100 nm and 600 nm. The importance of this work lies in using these solutions to develop a phantom with optical properties that closely match those of human breast tissue at near-IR wavelengths. Characterization involves illuminating the solution with a laser beam transmitted through a recipient of known width containing the solution. Resulting intensity profiles from the light spot are measured as function of the detector position. The experiments were realized using light with wavelengths 633 nm and 820 nm. Measured intensity profiles were fitted to the calculated profiles obtained from diffusion theory, using the method of images. Fitting results give us the absorption and transport scatter coefficients. These coefficients can be modified by changing the particle concentration of the solution. We found that these coefficients are the same order of magnitude as those of human tissue reported in published studies.

  14. Brillouin Optical Correlation Domain Analysis in Composite Material Beams.

    Science.gov (United States)

    Stern, Yonatan; London, Yosef; Preter, Eyal; Antman, Yair; Diamandi, Hilel Hagai; Silbiger, Maayan; Adler, Gadi; Levenberg, Eyal; Shalev, Doron; Zadok, Avi

    2017-10-02

    Structural health monitoring is a critical requirement in many composites. Numerous monitoring strategies rely on measurements of temperature or strain (or both), however these are often restricted to point-sensing or to the coverage of small areas. Spatially-continuous data can be obtained with optical fiber sensors. In this work, we report high-resolution distributed Brillouin sensing over standard fibers that are embedded in composite structures. A phase-coded, Brillouin optical correlation domain analysis (B-OCDA) protocol was employed, with spatial resolution of 2 cm and sensitivity of 1 °K or 20 micro-strain. A portable measurement setup was designed and assembled on the premises of a composite structures manufacturer. The setup was successfully utilized in several structural health monitoring scenarios: (a) monitoring the production and curing of a composite beam over 60 h; (b) estimating the stiffness and Young's modulus of a composite beam; and (c) distributed strain measurements across the surfaces of a model wing of an unmanned aerial vehicle. The measurements are supported by the predictions of structural analysis calculations. The results illustrate the potential added values of high-resolution, distributed Brillouin sensing in the structural health monitoring of composites.

  15. Optical contrast for identifying the thickness of two-dimensional materials

    Science.gov (United States)

    Bing, Dan; Wang, Yingying; Bai, Jing; Du, Ruxia; Wu, Guoqing; Liu, Liyan

    2018-01-01

    One of the most intriguing properties of two-dimensional (2D) materials is their thickness dependent properties. A quick and precise technique to identify the layer number of 2D materials is therefore highly desirable. In this review, we will introduce the basic principle of using optical contrast to determine the thickness of 2D material and also its advantage as compared to other modern techniques. Different 2D materials, including graphene, graphene oxide, transitional metal dichalcogenides, black phosphorus, boron nitride, have been used as examples to demonstrate the capability of optical contrast methods. A simple and more efficient optical contrast image technique is also emphasized, which is suitable for quick and large-scale thickness identification. We have also discussed the factors that could affect the experimental results of optical contrast, including incident light angle, anisotropic nature of materials, and also the twisted angle between 2D layers. Finally, we give perspectives on future development of optical contrast methods for the study and application of 2D materials.

  16. 9th International Congress on Advanced Electromagnetic Materials in Microwaves and Optics

    CERN Document Server

    2015-01-01

    The Congress will provide a unique topical forum to share the latest results of the metamaterials research in Europe and worldwide and bring together the engineering, physics, and material science communities working on artificial materials and their applications from microwaves to optical frequencies, as well as in acoustics, mechanics, and thermodynamics.

  17. Theory-Guided Design of Organic Electro-Optic Materials and Devices

    Directory of Open Access Journals (Sweden)

    Stephanie Benight

    2011-08-01

    Full Text Available Integrated (multi-scale quantum and statistical mechanical theoretical methods have guided the nano-engineering of controlled intermolecular electrostatic interactions for the dramatic improvement of acentric order and thus electro-optic activity of melt-processable organic polymer and dendrimer electro-optic materials. New measurement techniques have permitted quantitative determination of the molecular order parameters, lattice dimensionality, and nanoscale viscoelasticity properties of these new soft matter materials and have facilitated comparison of theoretically-predicted structures and thermodynamic properties with experimentally-defined structures and properties. New processing protocols have permitted further enhancement of material properties and have facilitated the fabrication of complex device structures. The integration of organic electro-optic materials into silicon photonic, plasmonic, and metamaterial device architectures has led to impressive new performance metrics for a variety of technological applications.

  18. Stiff Hands

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Stiff Hands Email to a friend * required fields ...

  19. Hand Infections

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Hand Infections Email to a friend * required fields ...

  20. First International Conference on Organic Nonlinear Optics. Section B: Nonlinear Optics, Principles, Materials, Phenomena, and Devices.

    Science.gov (United States)

    1994-01-01

    HOSOTTE: Alignement and Orientation of Chromophores by Optical Pumping 327 CELINE FIORINI, FABRICE CHARRA, JEAN-MICHEL NUNZI and PAUL RAIMOND...Normandin, R. L. Williams and M. Dion , Electron. Lett., 28, 1540 (1992). 6. D. Vakhshoori and S. Wang, Appl. Phys. Lett., 53, 347 (1988). 7. D. Vakhshoori, J

  1. Sensitivity of corneal biomechanical and optical behavior to material parameters using design of experiments method.

    Science.gov (United States)

    Xu, Mengchen; Lerner, Amy L; Funkenbusch, Paul D; Richhariya, Ashutosh; Yoon, Geunyoung

    2018-02-01

    The optical performance of the human cornea under intraocular pressure (IOP) is the result of complex material properties and their interactions. The measurement of the numerous material parameters that define this material behavior may be key in the refinement of patient-specific models. The goal of this study was to investigate the relative contribution of these parameters to the biomechanical and optical responses of human cornea predicted by a widely accepted anisotropic hyperelastic finite element model, with regional variations in the alignment of fibers. Design of experiments methods were used to quantify the relative importance of material properties including matrix stiffness, fiber stiffness, fiber nonlinearity and fiber dispersion under physiological IOP. Our sensitivity results showed that corneal apical displacement was influenced nearly evenly by matrix stiffness, fiber stiffness and nonlinearity. However, the variations in corneal optical aberrations (refractive power and spherical aberration) were primarily dependent on the value of the matrix stiffness. The optical aberrations predicted by variations in this material parameter were sufficiently large to predict clinically important changes in retinal image quality. Therefore, well-characterized individual variations in matrix stiffness could be critical in cornea modeling in order to reliably predict optical behavior under different IOPs or after corneal surgery.

  2. Emerging Low-Dimensional Materials for Nonlinear Optics and Ultrafast Photonics.

    Science.gov (United States)

    Liu, Xiaofeng; Guo, Qiangbing; Qiu, Jianrong

    2017-04-01

    Low-dimensional (LD) materials demonstrate intriguing optical properties, which lead to applications in diverse fields, such as photonics, biomedicine and energy. Due to modulation of electronic structure by the reduced structural dimensionality, LD versions of metal, semiconductor and topological insulators (TIs) at the same time bear distinct nonlinear optical (NLO) properties as compared with their bulk counterparts. Their interaction with short pulse laser excitation exhibits a strong nonlinear character manifested by NLO absorption, giving rise to optical limiting or saturated absorption associated with excited state absorption and Pauli blocking in different materials. In particular, the saturable absorption of these emerging LD materials including two-dimensional semiconductors as well as colloidal TI nanoparticles has recently been utilized for Q-switching and mode-locking ultra-short pulse generation across the visible, near infrared and middle infrared wavelength regions. Beside the large operation bandwidth, these ultrafast photonics applications are especially benefit from the high recovery rate as well as the facile processibility of these LD materials. The prominent NLO response of these LD materials have also provided new avenues for the development of novel NLO and photonics devices for all-optical control as well as optical circuits beyond ultrafast lasers. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Unified treatment of coupled optical and acoustic phonons in piezoelectric cubic materials

    DEFF Research Database (Denmark)

    Willatzen, Morten; Wang, Zhong Lin

    2015-01-01

    A unified treatment of coupled optical and acoustic phonons in piezoelectric cubic materials is presented whereby the lattice displacement vector and the internal ionic displacement vector are found simultaneously. It is shown that phonon couplings exist in pairs only; either between the electric...... piezoelectricity in a cubic structured material slab. First, it is shown that isolated optical phonon modes generally cannot exist in piezoelectric cubic slabs. Second, we prove that confined acousto-optical phonon modes only exist for a discrete set of in-plane wave numbers in piezoelectric cubic slabs. Third...... potential and the lattice displacement coordinate perpendicular to the phonon wave vector or between the two other lattice displacement components. The former leads to coupled acousto-optical phonons by virtue of the piezoelectric effect. We then establish three new conjectures that entirely stem from...

  4. Application of nanostructural materials in electro optical measuring sets of big powers based on usage of optical effects

    Science.gov (United States)

    Salihov, Aidar I.; Tljavlin, Anfar Z.; Kusimov, Salavat M.

    2005-06-01

    Optically transparent nanostructural materials show to themselves a heightened interest owing to display in them the new physic mechanical properties. Variation of structure of the materials received by methods of intensive plastic deformation, results in variation of many fundamental parameters. Among them special interest was caused with variations of fundamental magnetic characteristics. One of them is the magnetization of saturation, which is usually structurally tolerant, but reflects changes in an atomic-crystal structure of solids. Even in the first probing of the transparent nanostructures, received by intensive deformation by torsion of samples, was found that the magnetization of saturation was revealed at room temperature in comparison with coarse-grained samples. High-power measuring devices are based on Faraday effect, representing itself rotation of a plane of polarization of linearly polarized light in optical active substances under action of a magnetic field. Application of nanostructural materials in the optical insulator, which is the main part of the measuring device, allows improving the measuring characteristics of instruments qualitatively. Brought losses in Faraday cell make 0,35 -0,89 dB instead of 0,7 - I,2 dB, and value of the backward losses makes not less than 62 dB instead of 55 dB. Undoubtedly, improvement of the given parameters allows making the measuring operations with the greater accuracy, reducing both absolute, and relative errors.

  5. Terahertz optical-Hall effect for multiple valley band materials: n-type silicon

    International Nuclear Information System (INIS)

    Kuehne, P.; Hofmann, T.; Herzinger, C.M.; Schubert, M.

    2011-01-01

    The optical-Hall effect comprises generalized ellipsometry at long wavelengths on samples with free-charge carriers placed within external magnetic fields. Measurement of the anisotropic magneto-optic response allows for the determination of the free-charge carrier properties including spatial anisotropy. In this work we employ the optical-Hall effect at terahertz frequencies for analysis of free-charge carrier properties in multiple valley band materials, for which the optical free-charge carrier contributions originate from multiple Brillouin-zone conduction or valence band minima or maxima, respectively. We investigate exemplarily the room temperature optical-Hall effect in low phosphorous-doped n-type silicon where free electrons are located in six equivalent conduction-band minima near the X-point. We simultaneously determine their free-charge carrier concentration, mobility, and longitudinal and transverse effective mass parameters.

  6. Overview of Fiber Optic Sensor Technologies for Strain/Temperature Sensing Applications in Composite Materials

    Science.gov (United States)

    Ramakrishnan, Manjusha; Rajan, Ginu; Semenova, Yuliya; Farrell, Gerald

    2016-01-01

    This paper provides an overview of the different types of fiber optic sensors (FOS) that can be used with composite materials and also their compatibility with and suitability for embedding inside a composite material. An overview of the different types of FOS used for strain/temperature sensing in composite materials is presented. Recent trends, and future challenges for FOS technology for condition monitoring in smart composite materials are also discussed. This comprehensive review provides essential information for the smart materials industry in selecting of appropriate types of FOS in accordance with end-user requirements. PMID:26784192

  7. Femtosecond laser excitation of dielectric materials: experiments and modeling of optical properties and ablation depths

    DEFF Research Database (Denmark)

    Wædegaard, Kristian Juncher; Frislev, Martin Thomas; Balling, Peter

    2013-01-01

    Modeling of the interaction between a dielec- tric material and ultrashort laser pulses provides the tem- poral evolution of the electronic excitation and the optical properties of the dielectric. Experimentally determined re- flectances and ablation depths for sapphire are compared...... to the calculations. A decrease in reflectance at high fluences is observed experimentally, which demonstrates the neces- sity of a temperature-dependent electron scattering rate in the model. The comparison thus provides new constraints on the optical parameters of the model....

  8. Active 2D materials for on-chip nanophotonics and quantum optics

    Directory of Open Access Journals (Sweden)

    Shiue Ren-Jye

    2017-03-01

    Full Text Available Two-dimensional materials have emerged as promising candidates to augment existing optical networks for metrology, sensing, and telecommunication, both in the classical and quantum mechanical regimes. Here, we review the development of several on-chip photonic components ranging from electro-optic modulators, photodetectors, bolometers, and light sources that are essential building blocks for a fully integrated nanophotonic and quantum photonic circuit.

  9. 2D materials in electro-optic modulation: energy efficiency, electrostatics, mode overlap, material transfer and integration

    Science.gov (United States)

    Ma, Zhizhen; Hemnani, Rohit; Bartels, Ludwig; Agarwal, Ritesh; Sorger, Volker J.

    2018-02-01

    Here we discuss the physics of electro-optic modulators deploying 2D materials. We include a scaling laws analysis and show how energy-efficiency and speed change for three underlying cavity systems as a function of critical device length scaling. A key result is that the energy-per-bit of the modulator is proportional to the volume of the device, thus making the case for submicron-scale modulators possible deploying a plasmonic optical mode. We then show how Graphene's Pauli-blocking modulation mechanism is sensitive to the device operation temperature, whereby a reduction of the temperature enables a 10× reduction in modulator energy efficiency. Furthermore, we show how the high-index tunability of graphene is able to compensate for the small optical overlap factor of 2D-based material modulators, which is unlike classical silicon-based dispersion devices. Lastly, we demonstrate a novel method towards a 2D material printer suitable for cross-contamination free and on-demand printing. The latter paves the way to integrate 2D materials seamlessly into taped-out photonic chips.

  10. Molecular Architectural Approach to Novel Electro-Optical Materials

    Energy Technology Data Exchange (ETDEWEB)

    Li, D.; Johal, M.S.; Smilowitz, L.B.; Robinson, J.M.

    1999-06-29

    This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal is to construct polar multilayers with nonlinear optical coefficients larger than classical inorganic crystals such as KDP or quartz. The strategy is to use various chemical interactions such as covalent bonds or hydrogen bonding to build polar structures. We have synthesized novel barbituric acid and melamine derivatives that will spontaneously self-assemble into a supramolecular ribbon according to their complementary H-bond motif. This supramolecular ribbon can then stack into a polar multilayer structure as verified by sum frequency generation (w{sub 1}+w{sub 2}) or second harmonic generation (when w{sub 1}=w{sub 2}). Second harmonic generation yields a value of d{sub 33}=3.2 pm/V for the self-assembled films and sum frequency generation shows a net polar orientation of the methyl groups in the multilayer along the surface normal. X-ray diffraction confirms the layered structure and produces the periodicity of {approximately}41 A, which corresponds well to the width of the supramolecular ribbons ({approximately}40 A).

  11. Large-area parallel near-field optical nanopatterning of functional materials using microsphere mask

    Energy Technology Data Exchange (ETDEWEB)

    Chen, G.X. [NUS Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Hong, M.H. [NUS Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Data Storage Institute, ASTAR, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore)], E-mail: Hong_Minghui@dsi.a-star.edu.sg; Lin, Y. [NUS Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Wang, Z.B. [Data Storage Institute, ASTAR, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore); Ng, D.K.T. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Data Storage Institute, ASTAR, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore); Xie, Q. [Data Storage Institute, ASTAR, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore); Tan, L.S. [NUS Nanoscience and Nanotechnology Initiative, National University of Singapore, 2 Engineering Drive 3, Singapore 117576 (Singapore); Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Chong, T.C. [Department of Electrical and Computer Engineering, National University of Singapore, 4 Engineering Drive 3, Singapore 117576 (Singapore); Data Storage Institute, ASTAR, DSI Building, 5 Engineering Drive 1, Singapore 117608 (Singapore)

    2008-01-31

    Large-area parallel near-field optical nanopatterning on functional material surfaces was investigated with KrF excimer laser irradiation. A monolayer of silicon dioxide microspheres was self-assembled on the sample surfaces as the processing mask. Nanoholes and nanospots were obtained on silicon surfaces and thin silver films, respectively. The nanopatterning results were affected by the refractive indices of the surrounding media. Near-field optical enhancement beneath the microspheres is the physical origin of nanostructure formation. Theoretical calculation was performed to study the intensity of optical field distributions under the microspheres according to the light scattering model of a sphere on the substrate.

  12. Numerical analysis of ALADIN optics contamination due to outgassing of solar array materials

    International Nuclear Information System (INIS)

    Markelov, G; Endemann, M; Wernham, D

    2008-01-01

    ALADIN is the very first space-based lidar that will provide global wind profile and a special attention has been paid to contamination of ALADIN optics. The paper presents a numerical approach, which is based on the direct simulation Monte Carlo method. The method allows one to accurately compute collisions between various species, in the case under consideration, free-stream flow and outgassing from solar array materials. The collisions create a contamination flux onto the optics despite there is no line-of-sight from the solar arrays to the optics. Comparison of obtained results with a simple analytical model prediction shows that the analytical model underpredicts mass fluxes

  13. Photo-induced optical activity in phase-change memory materials.

    Science.gov (United States)

    Borisenko, Konstantin B; Shanmugam, Janaki; Williams, Benjamin A O; Ewart, Paul; Gholipour, Behrad; Hewak, Daniel W; Hussain, Rohanah; Jávorfi, Tamás; Siligardi, Giuliano; Kirkland, Angus I

    2015-03-05

    We demonstrate that optical activity in amorphous isotropic thin films of pure Ge2Sb2Te5 and N-doped Ge2Sb2Te5N phase-change memory materials can be induced using rapid photo crystallisation with circularly polarised laser light. The new anisotropic phase transition has been confirmed by circular dichroism measurements. This opens up the possibility of controlled induction of optical activity at the nanosecond time scale for exploitation in a new generation of high-density optical memory, fast chiroptical switches and chiral metamaterials.

  14. Numerical analysis of ALADIN optics contamination due to outgassing of solar array materials

    Energy Technology Data Exchange (ETDEWEB)

    Markelov, G [Advanced Operations and Engineering Services (AOES) Group BV, Postbus 342, 2300 AH Leiden (Netherlands); Endemann, M [ESA-ESTEC/EOP-PAS, Postbus 299, 2200 AG Noordwijk (Netherlands); Wernham, D [ESA-ESTEC/EOP-PAQ, Postbus 299, 2200 AG Noordwijk (Netherlands)], E-mail: Gennady.Markelov@aoes.com

    2008-03-01

    ALADIN is the very first space-based lidar that will provide global wind profile and a special attention has been paid to contamination of ALADIN optics. The paper presents a numerical approach, which is based on the direct simulation Monte Carlo method. The method allows one to accurately compute collisions between various species, in the case under consideration, free-stream flow and outgassing from solar array materials. The collisions create a contamination flux onto the optics despite there is no line-of-sight from the solar arrays to the optics. Comparison of obtained results with a simple analytical model prediction shows that the analytical model underpredicts mass fluxes.

  15. Investigation of Optical Properties of Biomolecular Materials for Developing a Novel Fiber Optic Biosensor.

    Science.gov (United States)

    Gao, Harry Hong

    1995-01-01

    Recently considerable efforts have been devoted to the development of optical biosensors for applications such as environmental monitoring and biomedical technology. The research described in this thesis focuses on the development of a novel fiber optic biosensor system for pesticide detection based on enzyme catalyzed chemiluminescence. To optimize the collection efficiency, the tapering effect of a fiber tip has been studied in different cases of light source distribution utilizing fluorescence technique. Our results indicate that a continuously tapered tip with the largest tapering angle is the most efficient configuration when the light source is in a "thick" layer ({> }1 μm) while a combination tapered tip is the best configuration when the light source is either in a thin layer ({offers the flexibility of controlling the number of enzymes on a fiber surface. Multilayer of alkaline phosphatase have been characterized using various techniques including chemiluminescence, ellipsometry and surface plasma resonance. The results indicated that at least 3 layers of enzyme can be assembled on a fiber surface. With this approach, it is possible to immobilize different kinds of enzyme on a fiber surface for biosensors based on a multi-enzyme system. Based on the studies of tapered tip and immobilization schemes, a novel fiber optic biosensor system for the detection of organophosphorous-based pesticide has been developed. The detection mechanism is pesticide inhibition of alkaline phosphatase catalyzed chemiluminescence. Paraoxon with concentration as low as 167 ppb has been detected. This is the first fiber optic chemiluminescence-based biosensor utilizing tapered tips with enzyme immobilized on the fiber surface and a cooled CCD array detector.

  16. Mechanism for subgap optical conductivity in honeycomb Kitaev materials

    Science.gov (United States)

    Bolens, Adrien; Katsura, Hosho; Ogata, Masao; Miyashita, Seiji

    2018-04-01

    Motivated by recent terahertz absorption measurements in α -RuCl3 , we develop a theory for the electromagnetic absorption of materials described by the Kitaev model on the honeycomb lattice. We derive a mechanism for the polarization operator at second order in the nearest-neighbor hopping Hamiltonian. Using the exact results of the Kitaev honeycomb model, we then calculate the polarization dynamical correlation function corresponding to electric dipole transitions in addition to the spin dynamical correlation function corresponding to magnetic dipole transitions.

  17. Synthesis of polymeric micro- and nanostructural materials for application in non-linear optics

    International Nuclear Information System (INIS)

    Kravets, Lyubov; Palistrant, Natalia; Bivol, Valerii; Robu, Stepan; Barba, Nikolai; Orelovitch, Oleg

    2007-01-01

    The present paper describes a new approach developed for the preparation of micro- and nanostructural materials on the basis of polymeric compositions used as a matrix in non-linear optics. This approach consists in filling the pores of poly(ethylene terephthalate) track membranes (PET TM) from polymeric compositions using an impregnation method. It is shown that depending on the concentration of polymeric compositions in the solution it is possible to form a variety of micro- and nanostructural materials (tubules and wires as well as composite membranes) with a wide spectrum of characteristics. The developed method of producing micro- and nanostructural materials provides a possible way for creating polymeric objects with non-linear optic properties which can be used to design electronic micro- and nanodevices and to obtain chemical and optical sensors

  18. Determination of multielement in optical waveguide and standard reference materials by instrumental neutron activation analysis

    International Nuclear Information System (INIS)

    Kobayashi, K.; Kudo, K.

    1979-01-01

    Trace amounts of transition elements (Co, Cr, Cu, Fe, Mn and V) and other seven elements in optical waveguide samples were determined by INAA. The contents of impurities in ultre-pure materials are less than those of high-purity materials and of G.R. grade. The increase of contamination of trace transition elements and iridium from furnace or crucible are observed in the production of optical glass fibers. Up to seventeen elements were determined in five NBS biological standard reference materials: Oyster Tissue: SRM-1566, Brewers Yeast: SRM-1569, Spinach: SRM-1570, Orchard Leaves: SRM-1571 and Tuna Fish, and in four Japanese biological standard reference materials: Tea Leaves B and C, Pepperbush and Shark Meat. The analytical results in NBS and Japanese standard reference materials are in good agreement with published values and certified values by NBS. (author)

  19. Mechanical properties and production quality of hand-layup and vacuum infusion processed hybrid composite materials for GFRP marine structures

    Science.gov (United States)

    Kim, Sang-Young; Shim, Chun Sik; Sturtevant, Caleb; Kim, Dave (Dae-Wook); Song, Ha Cheol

    2014-09-01

    Glass Fiber Reinforced Plastic (GFRP) structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties

  20. Mechanical properties and production quality of hand-layup and vacuum infusion processed hybrid composite materials for GFRP marine structures

    Directory of Open Access Journals (Sweden)

    Kim Sang-Young

    2014-09-01

    Full Text Available Glass Fiber Reinforced Plastic (GFRP structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties

  1. Mechanical properties and production quality of hand-layup and vacuum infusion processed hybrid composite materials for GFRP marine structures

    Directory of Open Access Journals (Sweden)

    Sang-Young Kim

    2014-09-01

    Full Text Available Glass Fiber Reinforced Plastic (GFRP structures are primarily manufactured using hand lay-up or vacuum infusion techniques, which are cost-effective for the construction of marine vessels. This paper aims to investigate the mechanical properties and failure mechanisms of the hybrid GFRP composites, formed by applying the hand lay-up processed exterior and the vacuum infusion processed interior layups, providing benefits for structural performance and ease of manufacturing. The hybrid GFRP composites contain one, two, and three vacuum infusion processed layer sets with consistent sets of hand lay-up processed layers. Mechanical properties assessed in this study include tensile, compressive and in-plane shear properties. Hybrid composites with three sets of vacuum infusion layers showed the highest tensile mechanical properties while those with two sets had the highest mechanical properties in compression. The batch homogeneity, for the GFRP fabrication processes, is evaluated using the experimentally obtained mechanical properties.

  2. Heteroepitaxy of orientation-patterned nonlinear optical materials

    Science.gov (United States)

    Tassev, Vladimir L.; Vangala, Shivashankar R.; Peterson, Rita D.; Snure, Michael

    2018-03-01

    We report some recent results on thick heteroepitaxial growth of GaP on GaAs substrates and on orientation-patterned (OP) GaAs templates conducted in a hot-wall horizontal quartz reactor for Hydride Vapor Phase Epitaxy. The growths on the plain substrates resulted in up to 500 μm thick GaP with smooth surface morphology (RMS following stages of growth, as well on the mechanisms of the strain relaxation from the lattice and thermal mismatch between layer and substrate. The efforts to accommodate the growing film to the foreign substrate by engineering an intermediate buffer layer were extended to thick growths of GaAsxP1-x ternary with the idea to combine in one material the best of the nonlinear properties of GaP and GaAs that are strictly relevant to the pursued applications.

  3. STRESS MODELING IN COMPOSITE PRODUCTS USING STANDARD OPTICALLY SENSITIVE MATERIAL

    Directory of Open Access Journals (Sweden)

    Elifkhan K. Agakhanov

    2017-01-01

    Full Text Available Abstract. Objectives The problem of physically modelling stresses in a compound solid body of revolution having a complex shape and with a complex load distribution is considered. According to the similarity criteria of stress, deformations and displacements from the volume forces decrease proportionally to the scale of similarity of geometric dimensions, which complicates their direct modelling by the photoelasticity method typically using models made from epoxy materials. Methods Based on the principle of the independent action of the forces, the initial problem is represented as the sum of two problems. In the first uniform problem, the stresses in the body of revolution from the centrifugal forces are simulated by the conventional “freezing” method. In order to solve the second nonuniform problem, the stresses in the region of the model, corresponding to the acting centrifugal forces, are “frozen”. The models are glued in a natural state at room temperature, and the compound model is annealed. Results The band patterns in sections as well as components of radial, tangential and axial stresses on contours and in sections of models are obtained by the methods of normal transmission and numerical integration of the equilibrium equation. According to the modelling criteria, the formula for the transition from stresses in models to stresses in the natural structure is established. The results of the analysis of the effect of a body's material density ratio on the stress state of the entire structure are obtained. Conclusion  Axial stresses have insignificant value as compared to radial and tangential stresses; in addition, the ratio of the densities of the compound body has both a quantitative and qualitative influence on the stress state of the structure.

  4. Optical Hole Burning of Materials for Frequency Domain Optical Storage and Processing

    National Research Council Canada - National Science Library

    Gorokhovsky, Anshel

    2002-01-01

    .... Hole burning parameters were determined for eight materials; in particular, the hole burning kinetics was analyzed and the quantum efficiencies were determined to be between 0.1% and 1%. Holograms (data pages...

  5. Optical filter based on Fabry-Perot structure using a suspension of goethite nanoparticles as electro-optic material

    Science.gov (United States)

    Abbas, Samir; Dupont, Laurent; Dozov, Ivan; Davidson, Patrick; Chanéac, Corinne

    2018-02-01

    We have investigated the feasibility of optical tunable filters based on a Fabry-Perot etalon that uses a suspension of goethite (α-FeOOH) nanorods as electro-optic material for application in optical telecommunications in the near IR range. These synthetic nanoparticles have a high optical anisotropy that give rise to a very strong Kerr effect in their colloidal suspensions. Currently, these particles are dispersed in aqueous solvent, with pH2 to ensure the colloidal electrostatic stability. However, the high conductivity of these suspensions requires using high-frequency electric fields (f > 1 MHz), which brings about a high power consumption of the driver. To decrease the field frequency, we have changed the solvent to ethylene glycol which has a lower electrical conductivity than the aqueous solvent. We have built a Fabry-Perot cell, filled with this colloidal suspension in the isotropic phase, and showed that a phase shift of 14 nm can be obtained in a field of 3V/μm. Therefore, the device can operate as a tunable filter. A key advantage of this filter is that it is, by principle, completely insensitive to the polarization of the input light. However, several technological issues still need to be solved, such as ionic contamination of the suspension from the blocking layers, and dielectrophoretic and thermal effects.

  6. Athermal silicon optical add-drop multiplexers based on thermo-optic coefficient tuning of sol-gel material.

    Science.gov (United States)

    Namnabat, Soha; Kim, Kyung-Jo; Jones, Adam; Himmelhuber, Roland; DeRose, Christopher T; Trotter, Douglas C; Starbuck, Andrew L; Pomerene, Andrew; Lentine, Anthony L; Norwood, Robert A

    2017-09-04

    Silicon photonics has gained interest for its potential to provide higher efficiency, bandwidth and reduced power consumption compared to electrical interconnects in datacenters and high performance computing environments. However, it is well known that silicon photonic devices suffer from temperature fluctuations due to silicon's high thermo-optic coefficient and therefore, temperature control in many applications is required. Here we present an athermal optical add-drop multiplexer fabricated from ring resonators. We used a sol-gel inorganic-organic hybrid material as an alternative to previously used materials such as polymers and titanium dioxide. In this work we studied the thermal curing parameters of the sol-gel and their effect on thermal wavelength shift of the rings. With this method, we were able to demonstrate a thermal shift down to -6.8 pm/°C for transverse electric (TE) polarization in ring resonators with waveguide widths of 325 nm when the sol-gel was cured at 130°C for 10.5 hours. We also achieved thermal shifts below 1 pm/°C for transverse magnetic (TM) polarization in the C band under different curing conditions. Curing time compared to curing temperature shows to be the most important factor to control sol-gel's thermo-optic value in order to obtain an athermal device in a wide temperature range.

  7. Growth, optical, thermal and dielectric studies of an amino acid organic nonlinear optical material: L-Alanine

    International Nuclear Information System (INIS)

    Caroline, M. Lydia; Sankar, R.; Indirani, R.M.; Vasudevan, S.

    2009-01-01

    Good transparent bulk single crystals of L-alanine (nonlinear optical material) have been grown successfully by slow cooling technique from aqueous solution at pH value of 2.0. Optically transparent crystals with dimensions 2.4 cm x 1.2 cm x 1.6 cm, were grown by optimizing the growth parameters within a growth period of 2 weeks. The crystallinity of L-alanine crystal was confirmed by the powder X-ray diffraction study and diffraction peaks are indexed. The vibrational structure of the molecule is elucidated from FTIR spectra. The thermal behaviour of the grown crystal was investigated by thermogravimetric (TG) and differential thermal analyses (DTA) techniques in a nitrogen atmosphere. The result showed that the material starts decomposing at 297 deg. C. Its optical behaviour has been examined by UV-vis spectral analysis, which shows the absence of absorbance between the wavelengths ranging from 200 to 1200 nm. The NLO property was confirmed by the powder technique of Kurtz and Perry. The dielectric behaviour of the sample was also studied for the first time

  8. Hand Fractures

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy ... DESCRIPTION The bones of the hand serve as a framework. This framework supports the muscles that make the wrist and fingers move. When ...

  9. Optical and magnetic properties of new luminescent inorganic materials

    International Nuclear Information System (INIS)

    Acevedo, R; Hurtado, O.F; Poblete, V; Navarro, G

    1999-01-01

    The theoretical and experimental study of radiative and non radiative processes in luminescent inorganic materials is a permanent topic of interest in lineal and non lineal physics. This article aims to present a review and update of the mechanistic aspects associated with spectral intensities in stoichiometric cubic crystals type elpasolite (Cs-2NaLnZ-6), where Ln 3+ is a positive trivalent lanthanide and Z represents a halogen, essentially fluorine, chlorine and bromine, which belong to the spatial Fm3m group. From a theoretical point of view we will be interested in focusing our attention on cutting edge topics such as: the preparation of new models and calculus formalisms for the case of electronic excitations prohibited by parity and electronic spin. We wish to show the set of different complementary and competitive processes that define the relative force values of the electric oscillator and the magnetic one for cubic crystals. We will illustrate our work with a novel system, Cs-2NaEuCI-6, which has theoretical and experimental complexities with unsuspected characteristics

  10. Optical properties of copper-oxygen planes in superconducting oxides and related materials

    International Nuclear Information System (INIS)

    Kelly, M.K.; Barboux, P.; Tarascon, J.; Aspnes, D.E.

    1989-01-01

    The optical spectra of YBa 2 Cu 3 O 7-x and other Cu-O-based superconductors have several common features in the visible and near uv. Chemical changes that affect the conductivity of these materials also have a strong effect on some of these features. By comparing the spectra of many materials containing similar Cu-O structures, we have determined that some of the optical features are associated with specific local structures within the unit cell. Of particular interest is a sharp feature at 1.7 eV that appears for nonmetallic compositions of many of the materials and is removed by the introduction of carriers. Similar features in materials not yet showing superconductivity encourage further investigation of them

  11. Design and optimization of carbon-nanotube-material/dielectric hybrid nonlinear optical waveguides

    International Nuclear Information System (INIS)

    Zhao, Xin; Zheng, Zheng; Lu, Zhiting; Zhu, Jinsong; Zhou, Tao

    2011-01-01

    The nonlinear optical characteristics of highly nonlinear waveguides utilizing carbon nanotube composite materials are investigated theoretically. The extremely high nonlinearity and relatively high loss of the carbon nanotube materials are shown to greatly affect the performance of such waveguides for nonlinear optical applications, in contrast to waveguides using conventional nonlinear materials. Different configurations based on applying the carbon nanotube materials to the popular ridge and buried waveguides are thoroughly studied, and the optimal geometries are derived through simulations. It is shown that, though the nonlinear coefficient is often huge for these waveguides, the loss characteristics can significantly limit the maximum achievable accumulated nonlinearity, e.g. the maximum nonlinear phase shift. Our results suggest that SOI-based high-index-contrast, carbon nanotube cladding waveguides, rather than the currently demonstrated low-contrast waveguides, could hold the promise of achieving significantly higher accumulated nonlinearity

  12. Optical properties of chalcopyrite-type intermediate transition metal band materials from first principles

    International Nuclear Information System (INIS)

    Aguilera, I.; Palacios, P.; Wahnon, P.

    2008-01-01

    The optical properties of a novel potential high-efficiency photovoltaic material have been studied. This material is based on a chalcopyrite-type semiconductor (CuGaS 2 ) with some Ga atom substituted by Ti and is characterized by the formation of an isolated transition-metal band between the valence band and the conduction band. We present a study in which ab-initio density functional theory calculations within the generalized gradient approximation are carried out to determine the optical reflectivity and absorption coefficient of the materials of interest. Calculations for the host semiconductor are in good agreement with experimental results within the limitations of the approach. We find, as desired, that because of the intermediate band, the new Ti-substituted material would be able to absorb photons of energy lower than the band-gap of the host chalcopyrite. We also analyze the partial contributions to the main peaks of its spectrum

  13. Damage detection in laminar thermoplastic composite materials by means of embedded optical fibers

    Directory of Open Access Journals (Sweden)

    Kojović Aleksandar M.

    2006-01-01

    Full Text Available This paper investigates the possibility of applying optical fibers as sensors for investigating low energy impact damage in laminar thermoplastic composite materials, in real time. Impact toughness testing by a Charpy impact pendulum with different loads was conducted in order to determine the method for comparative measurement of the resulting damage in the material. For that purpose intensity-based optical fibers were built in to specimens of composite materials with Kevlar 129 (the DuPont registered trade-mark for poly(p-phenylene terephthalamide woven fabric as reinforcement and thermoplastic PVB (poly(vinyl butyral as the matrix. In some specimens part of the layers of Kevlar was replaced with metal mesh (50% or 33% of the layers. Experimental testing was conducted in order to observe and analyze the response of the material under multiple low-energy impacts. Light from the light-emitting diode (LED was launched to the embedded optical fiber and was propagated to the phototransistor-based photo detector. During each impact, the signal level, which is proportional to the light intensity in the optical fiber, drops and then slowly recovers. The obtained signals were analyzed to determine the appropriate method for real time damage monitoring. The major part of the damage occurs during impact. The damage reflects as a local, temporary release of strain in the optical fiber and an increase of the signal level. The obtained results show that intensity-based optical fibers could be used for measuring the damage in laminar thermoplastic composite materials. The acquired optical fiber signals depend on the type of material, but the same set of rules (relatively different, depending on the type of material could be specified. Using real time measurement of the signal during impact and appropriate analysis enables quantitative evaluation of the impact damage in the material. Existing methods in most cases use just the intensity of the signal before

  14. Determination and interpretation of the optical constants for solar cell materials

    Science.gov (United States)

    Fujiwara, Hiroyuki; Fujimoto, Shohei; Tamakoshi, Masato; Kato, Masato; Kadowaki, Hideyuki; Miyadera, Tetsuhiko; Tampo, Hitoshi; Chikamatsu, Masayuki; Shibata, Hajime

    2017-11-01

    Solar cell materials in thin film form often exhibit quite rough surface, which makes the accurate determination of the optical constants using spectroscopic ellipsometry (SE) quite difficult. In this study, we investigate the effect of the rough surface on the SE analysis and establish an analysis procedure, which is quite helpful for the correction of the underestimated roughness contribution. As examples, the roughness analyses for CuInSe2 and CH3NH3PbI3 hybrid-perovskite thin films are presented. Moreover, to interpret the dielectric functions of emerging solar cell materials, such as CH3NH3PbI3 and Cu2ZnSnSe4, the optical transition analyses are performed based on density functional theory (DFT). The excellent agreement observed between the experimental and DFT results allows the detailed assignment of the transition peaks, confirming the importance of DFT for revealing fundamental optical characteristics.

  15. A new method of surgical navigation for orthognathic surgery: optical tracking guided free-hand repositioning of the maxillomandibular complex.

    Science.gov (United States)

    Li, Biao; Zhang, Lei; Sun, Hao; Shen, Steve G F; Wang, Xudong

    2014-03-01

    In bimaxillary orthognathic surgery, the positioning of the maxilla and the mandible is typically accomplished via 2-splint technique, which may be the sources of several types of inaccuracy. To overcome the limitations of the 2-splint technique, we developed a new navigation method, which guided the surgeon to free-hand reposition the maxillomandibular complex as a whole intraoperatively, without the intermediate splint. In this preliminary study, the feasibility was demonstrated. Five patients with dental maxillofacial deformities were enrolled. Before the surgery, 3-dimensional planning was conducted and imported into a navigation system. During the operation, a tracker was connected to the osteotomized maxillomandibular complex via a splint. The navigation system tracked the movement of the complex and displayed it on the screen in real time to guide the surgeon to reposition the complex. The postoperative result was compared with the plan by analyzing the measured distances between the maxillary landmarks and reference planes, as determined from computed tomography data. The mean absolute errors of the maxillary position were clinically acceptable (<1.0 mm). Preoperative preparation time was reduced to 100 minutes on average. All patients were satisfied with the aesthetic results. This navigation method without intraoperative image registration provided a feasible means of transferring virtual planning to the real orthognathic surgery. The real-time position of the maxillomandibular complex was displayed on a monitor to visually guide the surgeon to reposition the complex. In this method, the traditional model surgery and the intermediate splint were discarded, and the preoperative preparation was simplified.

  16. Materials and devices for all-optical helicity-dependent switching

    Science.gov (United States)

    Salah El Hadri, Mohammed; Hehn, Michel; Malinowski, Grégory; Mangin, Stéphane

    2017-04-01

    Since the first observation of ultrafast demagnetization in Ni thin films by Beaurepaire et al 20 years ago, understanding the interaction between ultrashort laser pulses and magnetization has become a topic of huge interest. In 2007, an intriguing discovery related to ultrafast demagnetization was the observation of all-optical switching (AOS) of magnetization in ferrimagnetic GdFeCo alloy films using only femtosecond laser pulses. This review discusses the recent studies elucidating several key issues regarding the all-optical switching phenomenon. Although AOS had long been restricted to GdFeCo alloys, it turned out to be a more general phenomenon for a variety of ferrimagnetic as well as ferromagnetic materials. This discovery helped pave the way for the integration of all-optical writing in data storage industries. Nevertheless, theoretical models explaining the switching in GdFeCo alloy films do not appear to apply in the other materials, thus questioning the uniqueness of the microscopic origin of all-optical switching. By investigating the integration of all-optical switching in spintronic devices, two types of all-optical switching mechanism have been distinguished: a single-pulse heat-only switching in ferrimagnetic GdFeCo alloys, and a two regime helicity-dependent switching in both ferrimagnetic TbCo alloys and ferromagnetic Co/Pt multilayers. Another key issue discussed in this review is the necessary condition for the observation of all-optical switching. Many models have been proposed but are strongly challenged by the discovery of such switching in ferromagnets. A comprehensive investigation of the magnetic parameters governing all-optical switching demonstrate that its observation requires magnetic domains larger than the laser spot size during the cooling process; such a criterion is common for both ferri- and ferro-magnets. These investigations strongly improve our understanding and give intriguing insights into the rich physics of the ultrafast

  17. Rare earth doped nanoparticles in organic and inorganic host materials for application in integrated optics

    NARCIS (Netherlands)

    Dekker, R.; Hilderink, L.T.H.; Diemeer, Mart; Stouwdam, J.W.; Sudarsan, V; van Veggel, F.C.J.M.; Driessen, A.; Worhoff, Kerstin; Misra, D; Masscher, P.; Sundaram, K.; Yen, W.M.; Capobianco, J.

    2006-01-01

    The preparation and the optical properties of lanthanum fluoride (LaF3) nanoparticles doped with erbium and neodymium will be discussed. Organic and inorganic materials in the form of polymers and sol-gels were used to serve as the hosts for the inorganic nanoparticles, respectively. The organic

  18. TRUE COLORS: LEDS AND THE RELATIONSHIP BETWEEN CCT, CRI, OPTICAL SAFETY, MATERIAL DEGRADATION, AND PHOTOBIOLOGICAL STIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Royer, Michael P.

    2014-08-30

    This document analyzes the optical, material, and photobiological hazards of LED light sources compared to conventional light sources. It documents that LEDs generally produce the same amount of blue light, which is the primary contributor to the risks, as other sources at the same CCT. Duv may have some effect on the amount of blue light, but CRI does not.

  19. Optical properties of ion beam modified waveguide materials doped with erbium and silver

    NARCIS (Netherlands)

    Strohhöfer, C. (Christof)

    2001-01-01

    In the first part of this thesis we investigate codoping of erbium-doped waveguide materials with different ions in order to increase the efficiency of erbium-doped optical amplifiers. Codoping with ytterbium can overcome the limitations due to the small absorption cross section of Er3+ in Al2O3 at

  20. Determination of optical properties of tissue and other bio-materials

    CSIR Research Space (South Africa)

    Singh, A

    2008-11-01

    Full Text Available appears less diffusively scattered. Determination of optical properties of tissue and other bio-materials A SINGH, AE KARSTEN, JS DAM CSIR National Laser Centre, Biophotonics Group PO Box 395, Pretoria, 0001, South Africa Email: ASingh1@csir.co.za K...

  1. Computerized versus hand-scored health literacy tools: a comparison of Simple Measure of Gobbledygook (SMOG) and Flesch-Kincaid in printed patient education materials.

    Science.gov (United States)

    Grabeel, Kelsey Leonard; Russomanno, Jennifer; Oelschlegel, Sandy; Tester, Emily; Heidel, Robert Eric

    2018-01-01

    The research compared and contrasted hand-scoring and computerized methods of evaluating the grade level of patient education materials that are distributed at an academic medical center in east Tennessee and sought to determine if these materials adhered to the American Medical Association's (AMA's) recommended reading level of sixth grade. Librarians at an academic medical center located in the heart of Appalachian Tennessee initiated the assessment of 150 of the most used printed patient education materials. Based on the Flesch-Kincaid (F-K) scoring rubric, 2 of the 150 documents were excluded from statistical comparisons due to the absence of text (images only). Researchers assessed the remaining 148 documents using the hand-scored Simple Measure of Gobbledygook (SMOG) method and the computerized F-K grade level method. For SMOG, 3 independent reviewers hand-scored each of the 150 documents. For F-K, documents were analyzed using Microsoft Word. Reading grade levels scores were entered into a database for statistical analysis. Inter-rater reliability was calculated using intra-class correlation coefficients (ICC). Paired t -tests were used to compare readability means. Acceptable inter-rater reliability was found for SMOG (ICC=0.95). For the 148 documents assessed, SMOG produced a significantly higher mean reading grade level (M=9.6, SD=1.3) than F-K (M=6.5, SD=1.3; p SMOG method of assessment, 147 of the 148 documents (99.3%) scored above the AMA's recommended reading level of sixth grade. Computerized health literacy assessment tools, used by many national patient education material providers, might not be representative of the actual reading grade levels of patient education materials. This is problematic in regions like Appalachia because materials may not be comprehensible to the area's low-literacy patients. Medical librarians have the potential to advance their role in patient education to better serve their patient populations.

  2. Porous Materials with Ultralow Optical Constants for Integrated Optical Device Applications

    Science.gov (United States)

    Chen, Hsuen-Li; Hsieh, Chung-I; Cheng, Chao-Chia; Chang, Chia-Pin; Hsu, Wen-Hau; Wang, Way-Seen; Liu, Po-Tsun

    2005-07-01

    Ultralow dielectric constant (polymers. We demonstrate two structures, ridge waveguides and large-angle Y-branch power splitters, composed of PPSZ and SU8 films to illustrate the use of low dielectric constant (K) cladding materials. The simulation results indicate that the PPSZ films provide better confinement of light. Experimentally, a large-angle Y-branch power splitter with PPSZ cladding can be used to guide waves with the large branching angle of 33.58°.

  3. Optics and children

    International Nuclear Information System (INIS)

    Costa, Manuel F M; De Campos, J Ayres; Lira, Madalena; Franco, Sandra; Vazquez-Dorrio, Jose B

    2011-01-01

    Light and Optics are subjects that 'naturally' attracts the interest and sympathy of children even from very early ages. In this communication, we present a series of experiments and support material designed in this hands-on perspective, to be used to introduce the study of light and optics to kindergarten and early basic school students. Our hands-on investigative approach leads the students, aged 4 to 10 years, to observe the experiment and discover themselves, in a critical and active way, different aspects of light and optics. Preparing funny eye catching situations and experiments predispose the children to work, effectively, enjoying themselves while building up their self-confidence.

  4. A deterministic guide for material and mode dependence of on-chip electro-optic modulator performance

    Science.gov (United States)

    Amin, Rubab; Suer, Can; Ma, Zhizhen; Sarpkaya, Ibrahim; Khurgin, Jacob B.; Agarwal, Ritesh; Sorger, Volker J.

    2017-10-01

    Electro-optic modulation is a key function in optical data communication and possible future optical computing engines. The performance of modulators intricately depends on the interaction between the actively modulated material and the propagating waveguide mode. While high-performing modulators were demonstrated before, the approaches were taken as ad-hoc. Here we show the first systematic investigation to incorporate a holistic analysis for high-performance and ultra-compact electro-optic modulators on-chip. We show that intricate interplay between active modulation material and optical mode plays a key role in the device operation. Based on physical tradeoffs such as index modulation, loss, optical confinement factors and slow-light effects, we find that bias-material-mode regions exist where high phase modulation and high loss (absorption) modulation is found. This work paves the way for a holistic design rule of electro-optic modulators for on-chip integration.

  5. Hand-held optical sensor using denatured antibody coated electro-active polymer for ultra-trace detection of copper in blood serum and environmental samples.

    Science.gov (United States)

    Chandra, Sutapa; Dhawangale, Arvind; Mukherji, Soumyo

    2018-07-01

    An optimum copper concentration in environment is highly desired for all forms of life. We have developed an ultrasensitive copper sensor which functions from femto to micro molar concentration accurately (R 2 = 0.98). The sensor is based on denatured antibody immunoglobulin G (IgG), immobilized on polyaniline (PAni) which in turn is the coating on the core of an optical fiber. The sensing relies on changes in evanescent wave absorbance in the presence of the analyte. The sensor showed excellent selectivity towards Cu (II) ions over all other metal ions. The sensor was tested with lake and marine water samples to determine unknown concentrations of copper ions and the recovery results were within 90-115%, indicating reasonable accuracy. We further integrated the fiber-optic sensor with a miniaturized hand-held instrumentation platform to develop an accurate and field deployable device which can broadly be applicable to determine Cu (II) concentration in a wide range of systems - natural water bodies, soil as well as blood serum. Copyright © 2018 Elsevier B.V. All rights reserved.

  6. Hand Therapy

    Science.gov (United States)

    ... from conditions such as carpal tunnel syndrome and tennis elbow , as well as from chronic problems such as ... Tools Advice from a Certified Hand Therapist on Tennis Elbow Advice from a Certified Hand Therapist: Living with( ...

  7. The usefulness of contrast material injection at the dorsal vein of the hand in 64-detecter row helical CT coronary angiography

    International Nuclear Information System (INIS)

    Kawano, Youji; Yakabe, Kazuaki; Urata, Jungo; Eto, Miyuki; Yamaguchi, Hiroichiro

    2011-01-01

    In 315 cases of multi detector row CT (MDCT) coronary angiography contrast material were injected at the dorsal vein of the hand. Early 168 cases were used 80 ml of 370 mgI/ml contrast material and later 147 cases were used 350-480 mgI/kg contrast material. In all cases contrast material was injected by 4 ml/sec with post injection of 30-40 ml physiologic saline. The attenuation of RCA No.3 and other coronary arteries or coronary artery bypass graft (CABG) graft was measured. In later cases the usefulness of above 300 HU was 95.2%. In all cases the usefulness was 92.6%. (author)

  8. Measuring and analyzing excitation-induced decoherence in rare-earth-doped optical materials

    International Nuclear Information System (INIS)

    Thiel, C W; Macfarlane, R M; Cone, R L; Sun, Y; Böttger, T; Sinclair, N; Tittel, W

    2014-01-01

    A method is introduced for quantitatively analyzing photon echo decay measurements to characterize excitation-induced decoherence resulting from the phenomenon of instantaneous spectral diffusion. Detailed analysis is presented that allows fundamental material properties to be extracted that predict and describe excitation-induced decoherence for a broad range of measurements, applications and experimental conditions. Motivated by the need for a method that enables systematic studies of ultra-low decoherence systems and direct comparison of properties between optical materials, this approach employs simple techniques and analytical expressions that avoid the need for difficult to measure and often unknown material parameters or numerical simulations. This measurement and analysis approach is demonstrated for the 3 H 6 to 3 H 4 optical transition of three thulium-doped crystals, Tm 3+ :YAG, Tm 3+ :LiNbO 3 and Tm 3+ :YGG, that are currently employed in quantum information and classical signal processing demonstrations where minimizing decoherence is essential to achieve high efficiencies and large signal bandwidths. These new results reveal more than two orders of magnitude variation in sensitivity to excitation-induced decoherence among the materials studied and establish that the Tm 3+ :YGG system offers the longest optical coherence lifetimes and the lowest levels of excitation-induced decoherence yet observed for any known thulium-doped material. (paper)

  9. Strongly nonlinear optical glass fibers from noncentrosymmetric phase-change chalcogenide materials.

    Science.gov (United States)

    Chung, In; Jang, Joon I; Malliakas, Christos D; Ketterson, John B; Kanatzidis, Mercouri G

    2010-01-13

    We report that the one-dimensional polar selenophosphate compounds APSe(6) (A = K, Rb), which show crystal-glass phase-change behavior, exhibit strong second harmonic generation (SHG) response in both crystal and glassy forms. The crystalline materials are type-I phase-matchable with SHG coefficients chi((2)) of 151.3 and 149.4 pm V(-1) for K(+) and Rb(+) salts, respectively, which is the highest among phase-matchable nonlinear optical (NLO) materials with band gaps over 1.0 eV. The glass of APSe(6) exhibits comparable SHG intensities to the top infrared NLO material AgGaSe(2) without any poling treatments. APSe(6) exhibit excellent mid-IR transparency. We demonstrate that starting from noncentrosymmetric phase-change materials such as APSe(6) (A = K, Rb), we can obtain optical glass fibers with strong, intrinsic, and temporally stable second-order nonlinear optical (NLO) response. The as-prepared glass fibers exhibit SHG and difference frequency generation (DFG) responses over a wide range of wavelengths. Raman spectroscopy and pair distribution function (PDF) analyses provide further understanding of the local structure in amorphous state of KPSe(6) bulk glass and glass fiber. We propose that this approach can be widely applied to prepare permanent NLO glass from materials that undergo a phase-change process.

  10. Thermophysical and Optical Properties of Materials Considered for Use on the LDSD Test Vehicle

    Science.gov (United States)

    Redmond, Matthew; Mastropietro, A.J.

    2015-01-01

    In June 2014, the first of multiple flights in the Low Density Supersonic Decelerator (LDSD) technology development program took place and successfully demonstrated a Supersonic Inflatable Aerodynamic Decelerator (SIAD) in Mars-like conditions. Although the primary goal of the technology program was the development of new decelerators for landing heavier payloads on Mars, the low-cost thermal design of the test vehicle was only possible through the innovative use of a combination of both commercial off the shelf (COTS) and aerospace grade materials. As a result, numerous thermophysical and optical property measurements were undertaken to characterize material candidates before the final material selection was made. This paper presents thermophysical and optical property measurements performed over the course of the LDSD test vehicle development, including those not ultimately selected for use on the vehicle. These properties are compared and contrasted with the existing measurements available in previous literature.

  11. Hand Anatomy

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy Bones Joints Muscles Nerves Vessels Tendons Anatomy The upper extremity is ...

  12. Synthesis, crystal structure, growth, optical and third order nonlinear optical studies of 8HQ2C5N single crystal - An efficient third-order nonlinear optical material

    Energy Technology Data Exchange (ETDEWEB)

    Divya Bharathi, M.; Ahila, G.; Mohana, J. [Department of Physics, Presidency College, Chennai 600005 (India); Chakkaravarthi, G. [Department of Physics, CPCL Polytechnic College, Chennai 600068 (India); Anbalagan, G., E-mail: anbu24663@yahoo.co.in [Department of Nuclear Physics, University of Madras, Chennai 600025 (India)

    2017-05-01

    A neoteric organic third order nonlinear optical material 8-hydroxyquinolinium 2-chloro-5-nitrobenzoate dihydrate (8HQ2C5N) was grown by slow cooling technique using ethanol: water (1:1) mixed solvent. The calculated low value of average etch pit solidity (4.12 × 10{sup 3} cm{sup −2}) indicated that the title crystal contain less defects. From the single crystal X-ray diffraction data, it was endowed that 8HQ2C5N crystal belongs to the monoclinic system with centrosymmetric space group P2{sub 1}/c and the cell parameters values, a = 9.6546 (4) Ǻ, b = 7.1637(3) Ǻ, c = 24.3606 (12) Ǻ, α = γ = 90°, β = 92.458(2)° and volume = 1683.29(13) Ǻ{sup 3}. The FT-IR and FT-Raman spectrum were used to affirm the functional group of the title compound. The chemical structure of 8HQ2C5N was scrutinized by {sup 13}C and {sup 1}H NMR spectral analysis and thermal stability through the differential scanning calorimetry study. Using optical studies the lower cut-off wavelength and optical band gap of 8HQ2C5N were found to be 364 nm and 3.17 eV respectively. Using the single oscillator model suggested by Wemple – Didomenico, the oscillator energy (E{sub o}), the dispersion energy (E{sub d}) and static dielectric constant (ε{sub o}) were estimated. The third-order susceptibility were determined as Im χ{sup (3)} = 2.51 × 10{sup −5} esu and Re χ{sup (3)} = 4.46 × 10{sup −7} esu. The theoretical third-order nonlinear optical susceptibility χ{sup (3)} was calculated and the results were compared with experimental value. Photoluminescence spectrum of 8HQ2C5N crystal showed the yellow emission. The crystal had the single shot laser damage threshold of 5.562 GW/cm{sup 2}. Microhardness measurement showed that 8HQ2C5N belongs to a soft material category. - Highlights: • A new organic single crystals were grown and the crystal structure was reported. • Crystal possess, good transmittance, thermal and mechanical stability. • Single shot LDT value is found to be

  13. Optical waveguides with memory effect using photochromic material for neural network

    Science.gov (United States)

    Tanimoto, Keisuke; Amemiya, Yoshiteru; Yokoyama, Shin

    2018-04-01

    An optical neural network using a waveguide with a memory effect, a photodiode, CMOS circuits and LEDs was proposed. To realize the neural network, optical waveguides with a memory effect were fabricated using a cladding layer containing the photochromic material “diarylethene”. The transmittance of green light was decreased by UV light irradiation and recovered by the passage of green light through the waveguide. It was confirmed that the transmittance versus total energy of the green light that passed through the waveguide well fit the universal exponential curve.

  14. PC-Based systems for experiments in optical characterization of materials

    International Nuclear Information System (INIS)

    Lopez-Mora, C C; Trejo-Duran, M; Alvarado-Mendez, E; Rojas-Laguna, R; Vargas-Rodriguez, E; Estudillo-Ayala, J M; Mata-Chavez, R; Sukhoivanov, I; Garcia-Perez, A; Ibarra-Manzano, O G; Andrade-Lucio, J A

    2011-01-01

    An automatic control for applications of optical characterization of materials using the optical Z-Scan technique is presented in this work. The emphasis is placed in the design of the graphical user interface (GUI) and the automation process. For this purpose, we use a USB data acquisition module with programmable I/O ports for control and signals acquisition for the complete system. The control software was developed using the graphical programming language LabVIEW (registered) and compiled in order to obtain a portable system with the hardware used in this work.

  15. [Hand osteoarthritis].

    Science.gov (United States)

    Šenolt, Ladislav

    Hand osteoarthritis (OA) is a common chronic disorder causing pain and limitation of mobility of affected joints. The prevalence of hand OA increases with age and more often affects females. Clinical signs obviously do not correlate with radiographic findings - symptomatic hand OA affects approximately 26 % of adult subjects, but radiographic changes can be found in up to two thirds of females and half of males older than 55 years.Disease course differ among individual patients. Hand OA is a heterogeneous disease. Nodal hand OA is the most common subtype affecting interphalangeal joints, thumb base OA affects first carpometacarpal joint. Erosive OA represents a specific subtype of hand OA, which is associated with joint inflammation, more pain, functional limitation and erosive findings on radiographs.Treatment of OA is limited. Analgesics and nonsteroidal anti-inflammatory drugs are the only agents reducing symptoms. New insights into the pathogenesis of disease should contribute to the development of novel effective treatment of hand OA.

  16. Utilizing strongly absorbing materials for low-loss surface-wave nonlinear optics

    Science.gov (United States)

    Grosse, Nicolai B.; Franz, Philipp; Heckmann, Jan; Pufahl, Karsten; Woggon, Ulrike

    2018-04-01

    Optical media endowed with large nonlinear susceptibilities are highly prized for their employment in frequency conversion and the generation of nonclassical states of light. Although the presence of an optical resonance can greatly increase the nonlinear response (e.g., in epsilon-near-zero materials), the non-negligible increase in linear absorption often precludes the application of such materials in nonlinear optics. Absorbing materials prepared as thin films, however, can support a low-loss surface wave: the long-range surface exciton polariton (LRSEP). Its propagation lifetime increases with greater intrinsic absorption and reduced film thickness, provided that the film is embedded in a transparent medium (symmetric cladding). We explore LRSEP propagation in a molybdenum film by way of a prism-coupling configuration. Our observations show that excitation of the LRSEP mode leads to a dramatic increase in the yield of second-harmonic generation. This implies that the LRSEP mode is an effective vehicle for utilizing the nonlinear response of absorbing materials.

  17. Dielectric strength behaviour and mechanical properties of transparent insulation materials suitable to optical monitoring of partial discharges

    International Nuclear Information System (INIS)

    Lothongkam, Chaiyaporn

    2014-01-01

    statistical analysis based on the 2-parameter Weibull distribution function. The investigations revealed that the virgin translucent silicone rubber has a large elastic region with an acceptable plastic deformation and also provides an AC 50 Hz dielectric strength of approximately 24 kV/mm for 0.5 mm thickness. These values enable considering the tested translucent silicone as replacement material for an opaque elastomer that is currently used for a rubber stress cone of HV cable accessories.. Unfortunately, its optical transmittance is poor compared to optically clear transparent silicone rubbers. On the other hand, the mechanical properties of virgin transparent silicone rubbers do not comply with those demanded from push-on stress cones. In particular, their elongation at break is considered too low for that application. However they provide the AC dielectric strength values in either 28 kV/mm or 29 kV/mm for 0.5 mm thickness, which are higher than those of the translucent type. Moreover, it was found that the post-curing process does not provide a positive impact on the ultimate elongation of silicone rubbers. Hence, the elongation at break of virgin transparent silicone rubbers must be improved before they can be used as insulating material for a rubber stress cone. In addition, the influence of mechanical tensile stress on the dielectric strength of the virgin translucent silicone rubber was investigated. The results show that mechanical tensile stress does not negatively influence on dielectric strength of such silicone rubber, so it can be well-operated under combined electrical and mechanical stresses. Beside the improvement of optical PD detection performance in the translucent silicone insulation materials, the influence of fluorescent dye's modification was investigated. The results indicate that the commercially available fluorescent dyes of 0.02 wt. % mixed into the translucent silicone polymer do not negatively influence on the E b value of such silicone

  18. National Ignition Facility quality assurance plan for laser materials and optical technology

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, C.R.

    1996-05-01

    Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This subtier Quality Assurance Plan (QAP) applies to activities of the Laser Materials & Optical Technology (LM&OT) organization and its subcontractors. It responds to the NIF Quality Assurance Program Plan (QAPP, L-15958-2, NIF-95-499) and Department of Energy (DOE) Order 5700.6C. This Plan is organized according to 10 Quality Assurance (QA) criteria and subelements of a management system as outlined in the NIF QAPP. This Plan describes how those QA requirements are met. This Plan is authorized by the Associate Project Leader for the LM&OT organization, who has assigned responsibility to the Optics QA engineer to maintain this plan, with the assistance of the NIF QA organization. This Plan governs quality-affecting activities associated with: design; procurement; fabrication; testing and acceptance; handling and storage; and installation of NIF Project optical components into mounts and subassemblies.

  19. Femtosecond laser ablation of dielectric materials in the optical breakdown regime: Expansion of a transparent shell

    International Nuclear Information System (INIS)

    Garcia-Lechuga, M.; Siegel, J.; Hernandez-Rueda, J.; Solis, J.

    2014-01-01

    Phase transition pathways of matter upon ablation with ultrashort laser pulses have been considered to be understood long-since for metals and semiconductors. We provide evidence that also certain dielectrics follow the same pathway, even at high pulse energies triggering optical breakdown. Employing femtosecond microscopy, we observe a characteristic ring pattern within the ablating region that dynamically changes for increasing time delays between pump and probe pulse. These transient Newton rings are related to optical interference of the probe beam reflected at the front surface of the ablating layer with the reflection at the interface of the non-ablating substrate. Analysis of the ring structure shows that the ablation mechanism is initiated by a rarefaction wave leading within a few tens of picoseconds to the formation of a transparent thin shell of reduced density and refractive index, featuring optically sharp interfaces. The shell expands and eventually detaches from the solid material at delays of the order of 100 ps.

  20. Femtosecond laser ablation of dielectric materials in the optical breakdown regime: Expansion of a transparent shell

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Lechuga, M.; Siegel, J., E-mail: j.siegel@io.cfmac.csic.es; Hernandez-Rueda, J.; Solis, J. [Laser Processing Group, Instituto de Optica, Serrano 121, 28006 Madrid (Spain)

    2014-09-15

    Phase transition pathways of matter upon ablation with ultrashort laser pulses have been considered to be understood long-since for metals and semiconductors. We provide evidence that also certain dielectrics follow the same pathway, even at high pulse energies triggering optical breakdown. Employing femtosecond microscopy, we observe a characteristic ring pattern within the ablating region that dynamically changes for increasing time delays between pump and probe pulse. These transient Newton rings are related to optical interference of the probe beam reflected at the front surface of the ablating layer with the reflection at the interface of the non-ablating substrate. Analysis of the ring structure shows that the ablation mechanism is initiated by a rarefaction wave leading within a few tens of picoseconds to the formation of a transparent thin shell of reduced density and refractive index, featuring optically sharp interfaces. The shell expands and eventually detaches from the solid material at delays of the order of 100 ps.

  1. Modern reflective optics for material processing with high power CO/sub 2/-laser beams

    International Nuclear Information System (INIS)

    Juptner, W.P.O.; Sepold, G.; Rothe, R.R.

    1986-01-01

    The state of the art in diamond turning of parabolic mirrors allows to manufacture high quality surfaces at a reasonable low price. In this paper a report is given on mirror optics and systems which were developed with the following aims: Small losses of laser power in the system with a high efficiency of the laser beam processing system; Long lifetime of the mirrors under material processing conditions; High Standard of the optical quality; Flexibility for different applications. The requested qualities are guaranteed by the whole construction of the optics and the system. The theoretical works, the state of the art of the development and the future aspects of these laser working head systems are reported

  2. New radiological material detection technologies for nuclear forensics: Remote optical imaging and graphene-based sensors.

    Energy Technology Data Exchange (ETDEWEB)

    Harrison, Richard Karl [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Martin, Jeffrey B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wiemann, Dora K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Choi, Junoh [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Howell, Stephen W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-09-01

    We developed new detector technologies to identify the presence of radioactive materials for nuclear forensics applications. First, we investigated an optical radiation detection technique based on imaging nitrogen fluorescence excited by ionizing radiation. We demonstrated optical detection in air under indoor and outdoor conditions for alpha particles and gamma radiation at distances up to 75 meters. We also contributed to the development of next generation systems and concepts that could enable remote detection at distances greater than 1 km, and originated a concept that could enable daytime operation of the technique. A second area of research was the development of room-temperature graphene-based sensors for radiation detection and measurement. In this project, we observed tunable optical and charged particle detection, and developed improved devices. With further development, the advancements described in this report could enable new capabilities for nuclear forensics applications.

  3. Influence of material removal programming on ion beam figuring of high-precision optical surfaces

    Science.gov (United States)

    Liao, Wenlin; Dai, Yifan; Xie, Xuhui

    2014-09-01

    Ion beam figuring (IBF) provides a nanometer/subnanometer precision fabrication technology for optical components, where the surface materials on highlands are gradually removed by the physical sputtering effect. In this deterministic method, the figuring process is usually divided into several iterations and the sum of the removed material in each iteration is expected to approach the ideally removed material as nearly as possible. However, we find that the material removal programming in each iteration would influence the surface error convergence of the figuring process. The influence of material removal programming on the surface error evolution is investigated through the comparative study of the contour removal method (CRM) and the geometric proportion removal method (PRM). The research results indicate that the PRM can maintenance the smoothness of the surface topography during the whole figuring process, which would benefit the stable operation of the machine tool and avoid the production of mid-to-high spatial frequency surface errors. Additionally, the CRM only has the corrective effect on the area above the contour line in each iteration, which would result in the nonuniform convergence of the surface errors in various areas. All these advantages distinguish PRM as an appropriate material removal method for ultraprecision optical surfaces.

  4. 3D printing of optical materials: an investigation of the microscopic properties

    Science.gov (United States)

    Persano, Luana; Cardarelli, Francesco; Arinstein, Arkadii; Uttiya, Sureeporn; Zussman, Eyal; Pisignano, Dario; Camposeo, Andrea

    2018-02-01

    3D printing technologies are currently enabling the fabrication of objects with complex architectures and tailored properties. In such framework, the production of 3D optical structures, which are typically based on optical transparent matrices, optionally doped with active molecular compounds and nanoparticles, is still limited by the poor uniformity of the printed structures. Both bulk inhomogeneities and surface roughness of the printed structures can negatively affect the propagation of light in 3D printed optical components. Here we investigate photopolymerization-based printing processes by laser confocal microscopy. The experimental method we developed allows the printing process to be investigated in-situ, with microscale spatial resolution, and in real-time. The modelling of the photo-polymerization kinetics allows the different polymerization regimes to be investigated and the influence of process variables to be rationalized. In addition, the origin of the factors limiting light propagation in printed materials are rationalized, with the aim of envisaging effective experimental strategies to improve optical properties of printed materials.

  5. Vibration measurement on composite material with embedded optical fiber based on phase-OTDR

    Science.gov (United States)

    Franciscangelis, C.; Margulis, W.; Floridia, C.; Rosolem, J. B.; Salgado, F. C.; Nyman, T.; Petersson, M.; Hallander, P.; Hällstrom, S.; Söderquist, I.; Fruett, F.

    2017-04-01

    Distributed sensors based on phase-optical time-domain reflectometry (phase-OTDR) are suitable for aircraft health monitoring due to electromagnetic interference immunity, small dimensions, low weight and flexibility. These features allow the fiber embedment into aircraft structures in a nearly non-intrusive way to measure vibrations along its length. The capability of measuring vibrations on avionics structures is of interest for what concerns the study of material fatigue or the occurrence of undesirable phenomena like flutter. In this work, we employed the phase-OTDR technique to measure vibrations ranging from some dozens of Hz to kHz in two layers of composite material board with embedded polyimide coating 0.24 numerical aperture single-mode optical fiber.

  6. Debonding Patch Detection in FRP-Strengthened Materials with Fiber-Optic Interferometer

    Institute of Scientific and Technical Information of China (English)

    Xu Ying; Wang Dexiang; Tang Tianyou; Lu Miaomiao

    2017-01-01

    The interfacial debonding in fiber-reinforced plastic(FRP) strengthened repair material will affect the bonding strength and lead to failure of the repair without warning.Unfortunately the interfacial damage is normally invisible and often in the form of a patch rather than a through-width crack.Therefore,a debonding patch detection technique based on fiber optic interferometry is proposed.A quasi impulse loading is applied with a rubberhead hammer and the total elongation of a surface mounted optical fiber along the length of the repair material is measured as a function of load position.When a debonding patch is present,the induced sudden slope or sign change on the plot of fiber integral strain v.s.load position will reveal the extent and the location of the debonded area.The results of the study indicate that the proposed technique is applicable for debonding patch detection in repaired members under various support conditions.

  7. Gamma-Ray Dosimetry System Using Radiation-Resistant Optical Fibers and a Luminescent Material

    International Nuclear Information System (INIS)

    Toh, K.; Nakamura, T.; Yamagishi, H.; Sakasai, K.; Soyama, K.; Shikama, T.; Nagata, S.

    2013-06-01

    Gamma-ray dosimetry system using radiation-resistant optical fibers and a luminescent material was developed for use in a damaged Fukushima Dai-ichi nuclear power plant. The system was designed to be compact and unnecessary of an external supply of electricity to a radiation sensor head with a contaminated working environment and restricted through-holes to a measurement point in the damaged reactor. The system can detect a gamma-ray dose rate at a measurement point using a couple of optical fibers and a luminescent material with a coincidence method. This system demonstrated a linear response with respect to the gamma-ray dose rate from 0.5 mGy/h to 0.1 Gy/h and the system had a capability to measure the dose rate of more than 10 2 Gy/h. (authors)

  8. All-optically tunable EIT-like dielectric metasurfaces hybridized with thin phase change material layers

    Science.gov (United States)

    Petronijevic, Emilija; Sibilia, Concita

    2017-05-01

    Electromagnetically induced transparency (EIT), a pump-induced narrow transparency window within the absorption region of a probe, had offered new perspectives in slow-light control in atomic physics. For applications in nanophotonics, the implementation on chip-scaled devices has later been obtained by mimicking this effect by metallic metamaterials. High losses in visible and near infrared range of metal-based metamaterialls have recently opened a new field of all-dielectric metamaterials; a proper configuration of high refractive index dielectric nanoresonators can mimick this effect without losses to get high Q, slow-light response. The next step would be the ability to tune their optical response, and in this work we investigate thin layers of phase change materials (PCM) for all-optical control of EIT-like all-dielectric metamaterials. PCM can be nonvolatively and reversibly switched between two stable phases that differ in optical properties by applying a visible laser pulse. The device is based on Si nanoresonators covered by a thin layer of PCM GeTe; optical and transient thermal simulations have been done to find and optimize the fabrication parameters and switching parameters such as the intensity and duration of the pulse. We have found that the EIT-like response can be switched on and off by applying the 532nm laser pulse to change the phase of the upper GeTe layer. We strongly believe that such approach could open new perspectives in all-optically controlled slow-light metamaterials.

  9. Laser Deposition of Polymer Nanocomposite Thin Films and Hard Materials and Their Optical Characterization

    Science.gov (United States)

    2013-12-05

    visible light on instruments such as microscope tips and micro- surgical tools. Hard carbon known as diamond-like carbon films produced by pulsed laser ...visible (610 nm) LED source and a supplemental infra-red 980-nm laser diode (for the studies of the upconversion fluorescence). The basic package...5/2013 Final Performance Report 15 Sep 2012- 14 Sep 2013 LASER DEPOSITION OF POLYMER NANOCOMPOSITE THIN FILMS AND HARD MATERIALS AND THEIR OPTICAL

  10. Optical Sensing Material for pH Detection based on the Use of Roselle Extract

    International Nuclear Information System (INIS)

    Nurul Huda Abd Karim; Musa Ahmad; Mohammad Osman Herman; Ahmad Mahir Mokhtar

    2008-01-01

    This research assessed the potential of natural colour extract of Hibiscus Sabdariffa L. (roselle) as sensing material.The pH sensor was developed based on the use of natural reddish colour in roselle calyx, delphinidin-3-sambubioside immobilised in a glass fibre filter paper. In free solution, roselle extract was characterised by using UV-visible spectrophotometer to study the effect of pH, extract concentration, response time, repeatability and photo stability. The study showed that natural colour extract can be used as sensing material for the development of an optical pH sensor. (author)

  11. Analysis of optical thickness determination of materials by THz-TDS

    International Nuclear Information System (INIS)

    Sushko, O; Dubrovka, R; Donnan, R S

    2013-01-01

    Terahertz time-domain spectrometry (THz TDS) is a sensitive probe of the complex dielectric response of materials. Methods vary for converting time-domain response into final material optical parameters together with estimation of associated uncertainties. Here we point out the importance of using an accurate extraction procedure with particular emphasis on the error introduced by associated inaccuracy in thickness determination of a sample. The Total Variation (TV) method is used to estimate sample thickness to sub-micron accuracy, by constructively using the phenomena of multiple internal reflections ('ringing') within a sample. The applicability and performance of the TV methodology is discussed

  12. Optical fiber magnetic field sensors with TbDyFe magnetostrictive thin films as sensing materials.

    Science.gov (United States)

    Yang, Minghong; Dai, Jixiang; Zhou, Ciming; Jiang, Desheng

    2009-11-09

    Different from usually-used bulk magnetostrictive materials, magnetostrictive TbDyFe thin films were firstly proposed as sensing materials for fiber-optic magnetic field sensing characterization. By magnetron sputtering process, TbDyFe thin films were deposited on etched side circle of a fiber Bragg Grating (FBG) as sensing element. There exists more than 45pm change of FBG wavelength when magnet field increase up to 50 mT. The response to magnetic field is reversible, and could be applicable for magnetic and current sensing.

  13. FOREX-A Fiber Optics Diagnostic System For Study Of Materials At High Temperatures And Pressures

    Science.gov (United States)

    Smith, D. E.; Roeske, F.

    1983-03-01

    We have successfully fielded a Fiber Optics Radiation EXperiment system (FOREX) designed for measuring material properties at high temperatures and pressures on an underground nuclear test. The system collects light from radiating materials and transmits it through several hundred meters of optical fibers to a recording station consisting of a streak camera with film readout. The use of fiber optics provides a faster time response than can presently be obtained with equalized coaxial cables over comparable distances. Fibers also have significant cost and physical size advantages over coax cables. The streak camera achieves a much higher information density than an equivalent oscilloscope system, and it also serves as the light detector. The result is a wide bandwidth high capacity system that can be fielded at a relatively low cost in manpower, space, and materials. For this experiment, the streak camera had a 120 ns time window with a 1.2 ns time resolution. Dynamic range for the system was about 1000. Beam current statistical limitations were approximately 8% for a 0.3 ns wide data point at one decade above the threshold recording intensity.

  14. [The affect of Erigeron Breviscapus (Vant.) Hand-Mazz on axoplasmic transport of optic nerve in rats with experimentally elevated intraocular pressure].

    Science.gov (United States)

    Zhu, Y; Jiang, Y; Liu, Z; Luo, X; Wu, Z

    2000-07-01

    To investigate whether Erigeron Breviscapus (Vant.) Hand-Mazz (EBHM) can improve the optic nerve axoplasmic transport in rats with experimentally elevated intraocular pressure (IOP). Thirty healthy SD rats were used for the study, acute elevated IOP model in the right eye was built, then they were divided into three groups randomly: Group A (0 day group) included six rats for retinal ganglion cell (RGC) counting via left superior colliculus retrograde horse radish perokidase labeling; Group B, twelve rats divided into EBHM treatment group and control group (6 rats in each subgroup) for RGC counting via left superior colliculus retrograde labeling after twenty days, and Group C included twelve rats submitted the same treatment and procedure as group B after 40 days. After 0 day of acute elevated IOP, no labeled RGCs were observed. After twenty days of acute elevated IOP, in the control and EBHM subgroups the density of labeled RGCs were (423 +/- 220)/mm(2) and (749 +/- 294)/mm(2) respectively, the difference between two subgroups showed statistical significance (P < 0.01). After 40 days of acute elevated IOP, the density of RGCs in the control and EBHM subgroups in group C were (610 +/- 315)/mm(2) and (1,048 +/- 393)/mm(2) respectively, the difference between the two subgroups being statistically significant (P < 0.01). After 20 days and 40 days of acute elevation of IOP, the density of RGCs is obviously higher in EBHM group than that in the control group. It is revealed that EBHM can improve the optic nerve axoplasmic transportation blocked by acute elevation of IOP in rats.

  15. Wavelength dependence of femtosecond laser-induced damage threshold of optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Gallais, L., E-mail: laurent.gallais@fresnel.fr; Douti, D.-B.; Commandré, M. [Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel UMR 7249, 13013 Marseille (France); Batavičiūtė, G.; Pupka, E.; Ščiuka, M.; Smalakys, L.; Sirutkaitis, V.; Melninkaitis, A. [Laser Research Center, Vilnius University, Saulétekio aléja 10, LT-10223 Vilnius (Lithuania)

    2015-06-14

    An experimental and numerical study of the laser-induced damage of the surface of optical material in the femtosecond regime is presented. The objective of this work is to investigate the different processes involved as a function of the ratio of photon to bandgap energies and compare the results to models based on nonlinear ionization processes. Experimentally, the laser-induced damage threshold of optical materials has been studied in a range of wavelengths from 1030 nm (1.2 eV) to 310 nm (4 eV) with pulse durations of 100 fs with the use of an optical parametric amplifier system. Semi-conductors and dielectrics materials, in bulk or thin film forms, in a range of bandgap from 1 to 10 eV have been tested in order to investigate the scaling of the femtosecond laser damage threshold with the bandgap and photon energy. A model based on the Keldysh photo-ionization theory and the description of impact ionization by a multiple-rate-equation system is used to explain the dependence of laser-breakdown with the photon energy. The calculated damage fluence threshold is found to be consistent with experimental results. From these results, the relative importance of the ionization processes can be derived depending on material properties and irradiation conditions. Moreover, the observed damage morphologies can be described within the framework of the model by taking into account the dynamics of energy deposition with one dimensional propagation simulations in the excited material and thermodynamical considerations.

  16. Novel silica surface charge density mediated control of the optical properties of embedded optically active materials and its application for fiber optic pH sensing at elevated temperatures.

    Science.gov (United States)

    Wang, Congjun; Ohodnicki, Paul R; Su, Xin; Keller, Murphy; Brown, Thomas D; Baltrus, John P

    2015-02-14

    Silica and silica incorporated nanocomposite materials have been extensively studied for a wide range of applications. Here we demonstrate an intriguing optical effect of silica that, depending on the solution pH, amplifies or attenuates the optical absorption of a variety of embedded optically active materials with very distinct properties, such as plasmonic Au nanoparticles, non-plasmonic Pt nanoparticles, and the organic dye rhodamine B (not a pH indicator), coated on an optical fiber. Interestingly, the observed optical response to varying pH appears to follow the surface charge density of the silica matrix for all the three different optically active materials. To the best of our knowledge, this optical effect has not been previously reported and it appears universal in that it is likely that any optically active material can be incorporated into the silica matrix to respond to solution pH or surface charge density variations. A direct application of this effect is for optical pH sensing which has very attractive features that can enable minimally invasive, remote, real time and continuous distributed pH monitoring. Particularly, as demonstrated here, using highly stable metal nanoparticles embedded in an inorganic silica matrix can significantly improve the capability of pH sensing in extremely harsh environments which is of increasing importance for applications in unconventional oil and gas resource recovery, carbon sequestration, water quality monitoring, etc. Our approach opens a pathway towards possible future development of robust optical pH sensors for the most demanding environmental conditions. The newly discovered optical effect of silica also offers the potential for control of the optical properties of optically active materials for a range of other potential applications such as electrochromic devices.

  17. Electronic, structural, and optical properties of host materials for inorganic phosphors

    International Nuclear Information System (INIS)

    Alemany, Pere; Moreira, Ibério de P.R.; Castillo, Rodrigo; Llanos, Jaime

    2012-01-01

    Highlights: ► We performed a first-principles DFT study of the electronic structures of several wide band gap insulators (La 2 O 3 , La 2 O 2 S, Y 2 O 3 Y 2 O 2 S, La 2 TeO 6 , and Y 2 TeO 6 ) used as host materials for inorganic phosphors. ► The electronic, structural, and optical properties calculated for these compounds are in good agreement with the available experimental data. ► The electronic structure of the M 2 TeO 6 phases exhibits distinct features that could allow a fine tuning of the optical properties of luminescent materials obtained by doping with rare earth metals. - Abstract: A family of large gap insulators used as host materials for inorganic phosphors (La 2 O 3 , La 2 O 2 S, Y 2 O 3 , Y 2 O 2 S, La 2 TeO 6 , and Y 2 TeO 6 ) have been studied by first-principles DFT based calculations. We have determined electronic, structural, and optical properties for all these compounds both at the LDA and GGA levels obtaining, in general, a good agreement with available experimental data and previous theoretical studies. The electronic structure for the M 2 TeO 6 phases, addressed in this work for the first time, reveals some significant differences with respect to the other compounds, especially in the region of the lower conduction band, where the appearance of a group of four isolated oxygen/tellurium based bands below the main part of the La (Y) centered conduction band is predicted to lead to significant changes in the optical properties of the two tellurium containing compounds with respect to the rest of compounds in the series.

  18. Amalgamation based optical and colorimetric sensing of mercury(II) ions with silver graphene oxide nanocomposite materials

    International Nuclear Information System (INIS)

    Kamali, Khosro Zangeneh; Pandikumar, Alagarsamy; Jayabal, Subramaniam; Huang, Nay Ming; Ramaraj, Ramasamy; Lim, Hong Ngee; Ong, Boon Hoong; Bien, Chia Sheng Daniel; Kee, Yeh Yee

    2016-01-01

    The article describes a facile method for the preparation of a conjugate composed of silver nanoparticles and graphene oxide (Ag GO) via chemical reduction of silver precursors in the presence of graphene oxide (GO) while sonicating the solution. The Ag GO was characterized by X-ray photoelectron spectroscopy, X-ray powder diffraction, and energy-dispersive X-ray spectroscopy. The nanocomposite undergoes a color change from yellow to colorless in presence of Hg(II), and this effect is based on the disappearance of the localized surface plasmon resonance absorption of the AgNPs due to the formation of silver-mercury amalgam. The presence of GO, on the other hand, prevents the agglomeration of the AgNPs and enhances the stability of the nanocomposite material in solution. Hence, the probe represents a viable optical probe for the determination of mercury(II) ions in that it can be used to visually detect Hg(II) concentrations as low as 100 μM. The instrumental LOD is 338 nM. (author)

  19. Surface hardening of optic materials by deposition of diamond like carbon coatings from separated plasma of arc discharge

    Science.gov (United States)

    Osipkov, A. S.; Bashkov, V. M.; Belyaeva, A. O.; Stepanov, R.; Mironov, Y. M.; Galinovsky, A. L.

    2015-02-01

    This article considers the issue of strengthening of optic materials used in the IR spectrum by deposition of diamond like carbon coatings from separated plasma arc discharge. The report shows results of tests of bare and strengthened optical materials such as BaF2, MgF2, Si, Ge, including the testing of their strength and spectral characteristics. Results for the determination of optical constants for the DLC coatings deposited on substrates of Ge and Si, by using separated plasma, are also presented. Investigations showed that surface hardening of optical materials operable in the IR range, by the deposition of diamond like carbon coating onto their surface, according to this technology, considerably improves operational properties and preserves or improves their optic properties.

  20. Investigation of nonlinear optical properties of various organic materials by the Z-scan method

    Science.gov (United States)

    Ganeev, R. A.; Boltaev, G. S.; Tugushev, R. I.; Usmanov, T.

    2012-06-01

    We have studied the nonlinear optical properties of various organic materials (vegetable oil, juice, wine, cognac, Coca-Cola and Fanta drinks, Nescafé coffee, tea, gasoline, clock oil, glycerol, and polyphenyl ether) that are used in everyday life. Their nonlinearities have been studied by the Z-scan method in the near-IR and visible spectral ranges. We have shown that the majority of samples possess a nonlinear absorption; however, some of the studied materials show a strong saturated absorption and nonlinear refraction. Red wine and glycerol proved to be the most interesting materials. For these samples, we have observed a change in the sign of the nonlinear absorption with increasing laser intensity, which was attributed to the competition between two-photon absorption and saturated absorption.

  1. Interactions between heavy metals and photosynthetic materials studied by optical techniques.

    Science.gov (United States)

    Ventrella, Andrea; Catucci, Lucia; Piletska, Elena; Piletsky, Sergey; Agostiano, Angela

    2009-11-01

    In this work studies on rapid inhibitory interactions between heavy metals and photosynthetic materials at different organization levels were carried out by optical assay techniques, investigating the possibility of applications in the heavy metal detection field. Spinach chloroplasts, thylakoids and Photosystem II proteins were employed as biotools in combination with colorimetric assays based on dichlorophenol indophenole (DCIP) photoreduction and on fluorescence emission techniques. It was found that copper and mercury demonstrated a strong and rapid photosynthetic activity inhibition, that varied from proteins to membranes, while other metals like nickel, cobalt and manganese produced only slight inhibition effects on all tested photosynthetic materials. By emission measurements, only copper was found to rapidly influence the photosynthetic material signals. These findings give interesting information about the rapid effects of heavy metals on isolated photosynthetic samples, and are in addition to the literature data concerning the effects of growth in heavy metal enriched media.

  2. Generating Bulk-Scale Ordered Optical Materials Using Shear-Assembly in Viscoelastic Media

    Directory of Open Access Journals (Sweden)

    Chris E. Finlayson

    2017-06-01

    Full Text Available We review recent advances in the generation of photonics materials over large areas and volumes, using the paradigm of shear-induced ordering of composite polymer nanoparticles. The hard-core/soft-shell design of these particles produces quasi-solid “gum-like” media, with a viscoelastic ensemble response to applied shear, in marked contrast to the behavior seen in colloidal and granular systems. Applying an oscillatory shearing method to sub-micron spherical nanoparticles gives elastomeric photonic crystals (or “polymer opals” with intense tunable structural color. The further engineering of this shear-ordering using a controllable “roll-to-roll” process known as Bending Induced Oscillatory Shear (BIOS, together with the interchangeable nature of the base composite particles, opens potentially transformative possibilities for mass manufacture of nano-ordered materials, including advances in optical materials, photonics, and metamaterials/plasmonics.

  3. Advanced materials for the optical delay line of frequency pulse modulator on the basis of semiconductor laser

    International Nuclear Information System (INIS)

    Abrarov, S.M.

    1999-01-01

    In the paper some materials which can be sued as an optical delay line of the pulse frequency modulator are considered. The structure and the principle are described as a modulator consisting of a laser diode with two Fabry Perot resonators and an optical wave guide providing a feedback loop. The optical wave guide fulfills the function of delay line and links the two resonators. The pulse sequence of the radiation of the semiconductor laser arises due to failure and recovery of optical generation. The pulse frequency modulation can be carried out by the action of electrical tension field on the electro optic martial of the wave guide. The selection of three electro-optic crystals for making of the optical wave guide of the considered modulator is justified. (author)

  4. Transient radiation effects in D.O.I. optical materials: Schott filter glass

    International Nuclear Information System (INIS)

    Simmons-Potter, K.

    1998-07-01

    Department of Energy and Defense Programs systems are becoming increasingly reliant on the use of optical technologies that must perform under a range of ionizing radiation environments. In particular, the radiation response of materials under consideration for applications in direct optical initiation (D.O.I.) schemes must be well characterized. In this report, transient radiation effects observed in Schott filter glass S-7010 are characterized. Under gamma exposure with 2 MeV photons in a 20--30 nsec pulse, the authors observe strong initial induced fluorescence in the red region of the spectrum followed by significant induced absorption over the same spectral region. Peak induced absorption coefficients of 0.113 cm -1 and 0.088 cm -1 were calculated at 800 nm and 660 nm respectively

  5. Transient radiation effects in D.O.I. optical materials: KD*P

    International Nuclear Information System (INIS)

    Simmons-Potter, K.

    1998-07-01

    Department of Energy and Defense Programs systems are becoming increasingly reliant on the use of optical technologies that must perform under a range of ionizing radiation environments. In particular, the radiation response of materials under consideration for applications in direct optical initiation (D.O.I.) schemes must be well characterized. In this report, transient radiation effects observed in a KD*P crystal are characterized. Under gamma exposure with 2 MeV photons in a 20--30 nsec pulse, the authors observe induced absorption at 1.06 microm that causes a peak decrease in overall sample transmittance of only 10%. This induced loss is seen to recover fully within the first 30 microsec

  6. Optically stimulated luminescence of common plastic materials for accident dose reconstruction

    Energy Technology Data Exchange (ETDEWEB)

    Chang, I.; Lee, J. I.; Kim, J. L. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Chung, K. S. [Gyeongsang National Univ., Jinju (Korea, Republic of)

    2014-05-15

    Optically stimulate luminescence(OSL) has many applications in a variety of radiation dosimetry fields, including personal dosimetry, environmental radiation level monitor, retrospective dosimetry for dating, and reconstruction of radiation doses from radiation accident. In the reconstruction of radiation doses from radiation accident, OSL technique has been used to estimate the doses exposed to public area through analysis of housewares or house construing materials. Recently, many efforts have been carried out for dose reconstruction using personal electronic devices such as mobile phones and USB memory chips. Some of natural minerals such as quartz and feldspar have OSL properties. Quartz is the second most abundant mineral in continental crust of the Earth. In some of common plastics, inorganic fillers (quartz, alumina etc.) are added to make strengthen of their properties depends on applications areas. The aim of this research is to explore a possibility of use of the common plastic materials for dose reconstruction in radiation accident case. In this research the OSL dose response-curve and fading characteristics of the common plastics were tested and evaluated. Finally, we expect this work contribute to elevate the possibility of the dose reconstruction. The general conclusion of this work is that the possibility of dose reconstruction using common plastic materials is showed using the OSL characteristics of the materials. However, the tested common plastic materials have relatively low sensitivities. Further work is required to establish a database of OSL properties of common plastic materials for emergency dose reconstruction by using housewares.

  7. Systematic and material independent variation of electrical, optical, and chemical properties of Ln-materials over the Ln-series (Ln=La,Ce,Pr,..,Lu)

    NARCIS (Netherlands)

    Van der Kolk, E.; Dorenbos, P.

    2007-01-01

    A model is presented that successfully predicts electro-optical properties of Lanthanide materials, irrespective whether these materials are inorganic or organic, diluted or concentrated, metallic, semi-conducting or insulating. The model is firmly based on recent experimental data revealing that

  8. Temperature and strain registration by fibre-optic strain sensor in the polymer composite materials manufacturing

    Science.gov (United States)

    Matveenko; Kosheleva; Shardakov; Voronkov

    2018-04-01

    The presence of process-induced strains induced by various manufacturing and operational factors is one of the characteristics of polymer composite materials (PCM). Conventional methods of registration and evaluation of process-induced strains can be laborious, time-consuming and demanding in terms of technical applications. The employment of embedded fibre-optic strain sensors (FOSS) offers a real prospect of measuring residual strains. This paper demonstrates the potential for using embedded FOSS for recording technological strains in a PCM plate. The PCM plate is manufactured from prepreg, using the direct compression-moulding method. In this method, the prepared reinforcing package is placed inside a mould, heated, and then exposed to compaction pressure. The examined technology can be used for positioning FOSS between the layers of the composite material. Fibre-optic sensors, interacting with the material of the examined object, make it possible to register the evolution of the strain process during all stages of polymer-composite formation. FOSS data were recorded with interrogator ASTRO X 327. The obtained data were processed using specially developed algorithms.

  9. Fiber optic sensor for continuous health monitoring in CFRP composite materials

    Science.gov (United States)

    Rippert, Laurent; Papy, Jean-Michel; Wevers, Martine; Van Huffel, Sabine

    2002-07-01

    An intensity modulated sensor, based on the microbending concept, has been incorporated in laminates produced from a C/epoxy prepreg. Pencil lead break tests (Hsu-Neilsen sources) and tensile tests have been performed on this material. In this research study, fibre optic sensors will be proven to offer an alternative for the robust piezoelectric transducers used for Acoustic Emission (AE) monitoring. The main emphasis has been put on the use of advanced signal processing techniques based on time-frequency analysis. The signal Short Time Fourier Transform (STFT) has been computed and several robust noise reduction algorithms, such as Wiener adaptive filtering, improved spectral subtraction filtering, and Singular Value Decomposition (SVD) -based filtering, have been applied. An energy and frequency -based detection criterion is put forward to detect transient signals that can be correlated with Modal Acoustic Emission (MAE) results and thus damage in the composite material. There is a strong indication that time-frequency analysis and the Hankel Total Least Squares (HTLS) method can also be used for damage characterization. This study shows that the signal from a quite simple microbend optical sensor contains information on the elastic energy released whenever damage is being introduced in the host material by mechanical loading. Robust algorithms can be used to retrieve and analyze this information.

  10. Exotic Optical Fibers and Glasses: Innovative Material Processing Opportunities in Earth's Orbit.

    Science.gov (United States)

    Cozmuta, Ioana; Rasky, Daniel J

    2017-09-01

    Exotic optical fibers and glasses are the platform material for photonics applications, primarily due to their superior signal transmission (speed, low attenuation), with extending bandwidth deep into the infrared, exceeding that of silica fibers. Gravitational effects (convection sedimentation) have a direct impact on the phase diagram of these materials and influence melting properties, crystallization temperatures, and viscosity of the elemental mix during the manufacturing process. Such factors constitute limits to the yield, transmission quality, and strength and value of these fibers; they also constrain the range of applications. Manufacturing in a gravity-free environment such as the Earth's Orbit also helps with other aspects of the fabrication process (i.e., improved form factor of the manufacturing unit, sustainability). In this article, revolutionary developments in the field of photonics over the past decade merge with the paradigm shift in the privatization of government-owned capabilities supporting a more diverse infrastructure (parabolic, suborbital, orbital), reduced price, and increased frequency to access space and the microgravity environment. With the increased dependence on data (demand, bandwidth, efficiency), space and the microgravity environment provide opportunities for optimized performance of these exotic optical fibers and glasses underlying the development of enabling technologies to meet future data demand. Existing terrestrial markets (Internet, telecommunications, market transactions) and emerging space markets (on-orbit satellite servicing, space manufacturing, space resources, space communications, etc.) seem to converge, and this innovative material processing opportunity of exotic optical fibers and glasses might just be that "killer app": technologically competitive, economically viable, and with the ability to close the business case.

  11. Optical properties of graphene-based materials in transparent polymer matrices

    Energy Technology Data Exchange (ETDEWEB)

    Bayrak, Osman; Demirci, Emrah, E-mail: E.Demirci@lboro.ac.uk; Silberschmidt, Vadim V. [Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Loughborough, LE11 3TU (United Kingdom); Ionita, Mariana [Advanced Polymer Materials Group, University Politehnica of Bucharest, 132 Calea Grivitei, 010737 Bucharest (Romania)

    2016-08-22

    Different aspects of graphene-based materials (GBMs) and GBM-nanocomposites have been investigated due to their intriguing features; one of these features is their transparency. Transparency of GBMs has been of an interest to scientists and engineers mainly with regard to electronic devices. In this study, optical transmittance of structural, purpose-made nanocomposites reinforced with GBMs was analyzed to lay a foundation for optical microstructural characterization of nanocomposites in future studies. Two main types of GBM reinforcements were studied, graphene oxide (GO) and graphite nanoplates (GNPs). The nanocomposites investigated are GO/poly(vinyl alcohol), GO/sodium alginate, and GNP/epoxy with different volume fractions of GBMs. Together with UV-visible spectrophotometry, image-processing-assisted micro and macro photography were used to assess the transparency of GBMs embedded in the matrices. The micro and macro photography methods developed were proven to be an alternative way of measuring light transmittance of semi-transparent materials. It was found that there existed a linear relationship between light absorbance and a volume fraction of GBMs embedded in the same type of polymer matrices, provided that the nanocomposites of interest had the same thicknesses. This suggests that the GBM dispersion characteristics in the same type of polymer are similar and any possible change in crystal structure of polymer due to different volumetric contents of GBM does not have an effect on light transmittance of the matrices. The study also showed that the same types of GBMs could display different optical properties in different matrix materials. The results of this study will help to develop practical microstructural characterization techniques for GBM-based nanocomposites.

  12. Light-induced second-order nonlinear optical properties of molecular materials

    International Nuclear Information System (INIS)

    Fiorini, Celine

    1995-01-01

    We present a theoretical and experimental study of all-optical orientation. The work focusses more particularly on the realization of poled polymers for quadratic nonlinear optics. It is shown that the coherent superposition of two beams at fundamental and second harmonic frequencies results in the breaking of the former centro-symmetry of the material. The source is a Neodymium-YAG laser delivering 25 ps pulses at 1064 nm. The incident second-harmonic beam is obtained by frequency doubling in a KDP crystal. Using a phase conjugation configuration based on six-wave mixing interactions, we have Investigated in detail the mechanism of photo-induced second-harmonic generation in initially centrosymmetric materials. It is shown that the light-induced non-centro-symmetry is due to an orientational hole burning of the molecules. The process involves interference effects between one and two photon absorptions. Experiments are performed in various solutions of an azo-dye molecule (Disperse Red One). The possibility of inducing quasi-permanent second-order susceptibility in a PMMA polymer matrix doped with the azo-dye molecule of Disperse Red One is also demonstrated. The method of all-optical poling consists in a seeding type process with alternate writing and probing phases. Permanent orientation of the molecules can be described in terms of photo-isomerization processes. It leads to a poling of the molecules with a spatial modulation which is phase-matched for frequency doubling. Relevant parameters leading to an efficient polarisation of the sample are identified. A theoretical modelling of the different phenomena observed is proposed. Last part of the study is devoted to an enlarged study of the potentialities offered by this dual-frequency holography technique: orientation of octupolar molecules, polarisation of highly transparent materials. We also show that the new techniques developed during this work can also reveal to be complementary methods for nonlinear

  13. Soft X-ray excited optical luminescence from functional organic materials

    Energy Technology Data Exchange (ETDEWEB)

    Sham, T.K., E-mail: tsham@uwo.ca

    2015-10-01

    Highlights: • Many functional organic materials convert X-ray energy into visible light. • The X-ray induced luminescence (XEOL) across an absorption edge can be site and excitation channel specific. • XEOL is composition, morphology, size and crystallinity dependent. • XEOL using the time structure of a synchrotron can reveal the decay and energy transfer dynamics of the sample. • The combined use of XEOL and XAS in the analysis of functional organic materials is illustrated. - Abstract: This brief report reviews some of the recent findings in the study of synchrotron based X-ray excited optical luminescence (XEOL) from representative organic light emitting device (OLED) and related functional organic materials. The systems of interest include Alq{sub 3}, aluminium tris(8-hydroxylquinoline); Ru(bipy){sub 3}{sup 2+}, tris-(2,2-bipyridine) ruthenium(II); Ir(bpy){sub 3}, tris(2-phenyl-bipyridine)iridium; PVK (poly(N-vinylcarbazole)) and [Au{sub 2}(dppe)(bipy)]{sup 2+}, a Au(I) polymer containing 1,2-bis(diphenylphosphino)ethane and the 4,40-bipyridyl ligands, as well as TBPe (2,5,8,11-tetra-tert-butylperylene) polyhedral crystals and fluorescein isothiocyanate (FITC) and FITC-labelled proteins. It is shown that tunable and pulsed X-rays from synchrotron light sources enable the detailed tracking of the optical properties of organic functional materials by monitoring the luminescence in both the energy and time domain as the excitation energy is scanned across an element-specific absorption edge. The use of XEOL and X-ray absorption spectroscopy (XAS) in materials analysis is illustrated.

  14. Engineered materials for all-optical helicity-dependent magnetic switching

    Science.gov (United States)

    Fullerton, Eric

    2014-03-01

    The possibilities of manipulating magnetization without applied magnetic fields have attracted growing attention over the last fifteen years. The low-power manipulation of magnetization, preferably at ultra-short time scales, has become a fundamental challenge with implications for future magnetic information memory and storage technologies. Here we explore the optical manipulation of the magnetization of engineered materials and devices using 100 fs optical pulses. We demonstrate that all optical - helicity dependent switching (AO-HDS) can be observed not only in selected rare-earth transition-metal (RE-TM) alloy films but also in a much broader variety of materials, including alloys, multilayers, heterostructures and RE-free Co-Ir-based synthetic ferrimagnets. The discovery of AO-HDS in RE-free TM-based synthetic ferrimagnets can enable breakthroughs for numerous applications since it exploits materials that are currently used in magnetic data storage, memories and logic technologies. In addition, this materials study of AO-HDS offers valuable insight into the underlying mechanisms involved. Indeed the common denominator of the diverse structures showing AO-HDS in this study is that two ferromagnetic sub-lattices exhibit magnetization compensation (and therefore angular momentum compensation) at temperatures near or above room temperature. We are highlighting that compensation plays a major role and that this compensation can be established at the atomic level as in alloys but also over a larger nanometers scale as in the multilayers or in heterostructures. We will also discuss the potential to extend AO-HDS to new classes of magnetic materials. This work was done in collaboration with S. Mangin, M. Gottwald, C-H. Lambert, D. Steil, V. Uhlíř, L. Pang, M. Hehn, S. Alebrand, M. Cinchetti, G. Malinowski, Y. Fainman, and M. Aeschlimann. Supported by the ANR-10-BLANC-1005 ``Friends,'' a grant from the Advanced Storage Technology Consortium, Partner University Fund

  15. Dependences of optical properties of spherical two-layered nanoparticles on parameters of gold core and material shell

    International Nuclear Information System (INIS)

    Pustovalov, V.K.; Astafyeva, L.G.; Zharov, V.P.

    2013-01-01

    Modeling of nonlinear dependences of optical properties of spherical two-layered gold core and some material shell nanoparticles (NPs) placed in water on parameters of core and shell was carried out on the basis of the extended Mie theory. Efficiency cross-sections of absorption, scattering and extinction of radiation with wavelength 532 nm by core–shell NPs in the ranges of core radii r 00 =5–40 nm and of relative NP radii r 1 /r 00 =1–8 were calculated (r 1 —radius of two-layered nanoparticle). Shell materials were used with optical indexes in the ranges of refraction n 1 =0.2–1.5 and absorption k 1 =0–3.5 for the presentation of optical properties of wide classes of shell materials (including dielectrics, metals, polymers, vapor shell around gold core). Results show nonlinear dependences of optical properties of two-layered NPs on optical indexes of shell material, core r 00 and relative NP r 1 /r 00 radii. Regions with sharp decrease and increase of absorption, scattering and extinction efficiency cross-sections with changing of core and shell parameters were investigated. These dependences should be taken into account for applications of two-layered NPs in laser nanomedicine and optical diagnostics of tissues. The results can be used for experimental investigation of shell formation on NP core and optical determination of geometrical parameters of core and shell of two-layered NPs. -- Highlights: • Absorption, scattering and extinction of two-layered nanoparticles are studied. • Shell materials change in wide regions of materials (metals, dielectrics, vapor). • Effect of sharp decrease and increase of optical characteristics is established. • Explanation of sharp decreasing and increasing optical characteristics is presented

  16. 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

  17. Application of optical interferometric techniques for non-destructive evaluation of novel "green" composite materials

    Science.gov (United States)

    Pagliarulo, Vito; Russo, Pietro; Bianco, Vittorio; Ferraro, Pietro; Simeoli, Giorgio; Cimino, Francesca; Ruggiero, Berardo

    2018-04-01

    Nowadays the use of advanced composite materials in aeronautics, both civil and military, in automotive and in sport applications, citing some, is well established. The characteristics of composite materials in terms of weight, fatigue resistance and corrosion resistance make them competitive with respect to conventional ones. On the other side, the fabrication process of the most employed composites reinforced by carbon fibers or glass fibers, needs of complex steps that not always are environmental complaisant. Moreover, such fibers are not themselves "green". For these reasons, in the last decades, the use of natural reinforcing fibers has gained an increasing attention allowing the development of new materials with the same advantages of composite systems but respecting the environment. Furthermore, such materials for their structural complexity are not always compatible with the use of standard non-destructive evaluation as the ultrasounds methods. In this work the efficiency of the employment of optical interferometric techniques as nondestructive evaluation methods in full field modality is proved on novel "green" composite materials. In particular, Electronic Speckle Pattern Interferometry has been tested on different kinds of specimens after flexural tests.

  18. Constructive spin-orbital angular momentum coupling can twist materials to create spiral structures in optical vortex illumination

    Energy Technology Data Exchange (ETDEWEB)

    Barada, Daisuke [Graduate School of Engineering, Utsunomiya University, Utsunomiya 321-8585 (Japan); Center for Optical Research and Education (CORE), Utsunomiya University, Utsunomiya 321-8585 (Japan); Juman, Guzhaliayi; Yoshida, Itsuki [Graduate School of Advanced Integration Science, Chiba University, Chiba 263-8522 (Japan); Miyamoto, Katsuhiko; Omatsu, Takashige, E-mail: omatsu@faculty.chiba-u.jp [Graduate School of Advanced Integration Science, Chiba University, Chiba 263-8522 (Japan); Molecular Chirality Research Center, Chiba University, Chiba 263-8522 (Japan); Kawata, Shigeo [Graduate School of Engineering, Utsunomiya University, Utsunomiya 321-8585 (Japan); Ohno, Seigo [Graduate School of Science, Tohoku University, Sendai 980-8578 (Japan)

    2016-02-01

    It was discovered that optical vortices twist isotropic and homogenous materials, e.g., azo-polymer films to form spiral structures on a nano- or micro-scale. However, the formation mechanism has not yet been established theoretically. To understand the mechanism of the spiral surface relief formation in the azo-polymer film, we theoretically investigate the optical radiation force induced in an isotropic and homogeneous material under irradiation using a continuous-wave optical vortex with arbitrary topological charge and polarization. It is revealed that the spiral surface relief formation in azo-polymer films requires the irradiation of optical vortices with a positive (negative) spin angular momentum and a positive (negative) orbital angular momentum (constructive spin-orbital angular momentum coupling), i.e., the degeneracy among the optical vortices with the same total angular momentum is resolved.

  19. Fifty years old, and still going strong: Transmission electron optical studies of materials

    International Nuclear Information System (INIS)

    Brown, L.M.

    2008-01-01

    Highlights in the history of transmission electron microscopy and scanning transmission electron microscopy include the introduction of diffraction contrast, resolution of periodic lattices by phase contrast and incoherent imaging via the high-angle annular dark-field detector. Convergent-beam electron diffraction and analytical electron microscopy, especially the application of energy-dispersive X-ray and electron energy-loss spectrometry, have provided structural and chemical information in addition to strain contrast from lattice defects. From the outset, novel specimen stages and improvements to aid the operator enhanced the electron-optical engineering provided by the instrument makers. The spatial resolution achieved was mainly determined by the way the instrument was used, and not by the basic resolution limit set by the electron optics. However, the application of computer controlled correction of spherical (and higher order) aberration has resulted in a new generation of instruments capable of sub-Angstrom point-to-point resolution. This improved performance, combined with electron energy-loss spectrometry, promises genuine three-dimensional determination of atomic and electronic structure: an indispensable weapon in the battle to fabricate and control useful nanostructures. The uncertainty principle now fundamentally restricts some of the observations one can make, but much more technical development over the next decades must occur before one can say that the techniques of electron-optical imaging of material structure have reached their fundamental limitations. One can expect remarkable progress over the next few years

  20. National Ignition Facility quality assurance plan for laser materials and optical technology

    International Nuclear Information System (INIS)

    Wolfe, C.R.

    1996-05-01

    Quality achievement is the responsibility of the line organizations of the National Ignition Facility (NIF) Project. This subtier Quality Assurance Plan (QAP) applies to activities of the Laser Materials ampersand Optical Technology (LM ampersand OT) organization and its subcontractors. It responds to the NIF Quality Assurance Program Plan (QAPP, L-15958-2, NIF-95-499) and Department of Energy (DOE) Order 5700.6C. This Plan is organized according to 10 Quality Assurance (QA) criteria and subelements of a management system as outlined in the NIF QAPP. This Plan describes how those QA requirements are met. This Plan is authorized by the Associate Project Leader for the LM ampersand OT organization, who has assigned responsibility to the Optics QA engineer to maintain this plan, with the assistance of the NIF QA organization. This Plan governs quality-affecting activities associated with: design; procurement; fabrication; testing and acceptance; handling and storage; and installation of NIF Project optical components into mounts and subassemblies

  1. Optically reconfigurable metasurfaces and photonic devices based on phase change materials

    Science.gov (United States)

    Wang, Qian; Rogers, Edward T. F.; Gholipour, Behrad; Wang, Chih-Ming; Yuan, Guanghui; Teng, Jinghua; Zheludev, Nikolay I.

    2016-01-01

    Photonic components with adjustable parameters, such as variable-focal-length lenses or spectral filters, which can change functionality upon optical stimulation, could offer numerous useful applications. Tuning of such components is conventionally achieved by either micro- or nanomechanical actuation of their constituent parts, by stretching or by heating. Here, we report a novel approach for making reconfigurable optical components that are created with light in a non-volatile and reversible fashion. Such components are written, erased and rewritten as two-dimensional binary or greyscale patterns into a nanoscale film of phase-change material by inducing a refractive-index-changing phase transition with tailored trains of femtosecond pulses. We combine germanium-antimony-tellurium-based films with a diffraction-limited resolution optical writing process to demonstrate a variety of devices: visible-range reconfigurable bichromatic and multi-focus Fresnel zone plates, a super-oscillatory lens with subwavelength focus, a greyscale hologram, and a dielectric metamaterial with on-demand reflection and transmission resonances.

  2. High powered pulsed plasma enhanced deposition of thin film semiconductor and optical materials

    International Nuclear Information System (INIS)

    Llewellyn, I.P.; Sheach, K.J.A.; Heinecke, R.A.

    1993-01-01

    A glow discharge deposition technique is described which allows the deposition of a large range of high quality materials without the requirement for substrate heating. The method is differentiated from conventional plasma deposition techniques in that a much higher degree of dissociation is achieved in the gases prior to deposition, such that thermally activated surface reactions are no longer required in order to produce a dense film. The necessary discharge intensity (>300Wcm -3 ) is achieved using a high power radio frequency generator which is pulsed at a low duty cycle (1%) to keep the average energy of the discharge low (100W), in order to avoid the discharge heating the substrate. In addition, by varying the gas composition between discharge pulses, layered structures of materials can be produced, with a disordered interface about 8 A thick. Various uses of the technique in semiconductor and optical filter production are described, and the properties of films deposited using these technique are presented. (orig.)

  3. The effect of extended aging on the optical properties of different zirconia materials.

    Science.gov (United States)

    Alghazzawi, Tariq F

    2017-07-01

    The purpose of this study was to determine if the optical properties of zirconia and glass-ceramic (e.max) were affected by low-temperature degradation (aging). Experiment samples were fabricated with seven zirconia brands (n=10): Zenostar, Zirlux, Katana, Bruxzir, DD-BioZX 2 , DD-cubeX 2 , NexxZr; and e.max were used as a control. This resulted in a total of 80 samples in the experiment. The L*, a* and b* were measured for each sample, and then the optical properties including translucency parameter (TP), contrast ratio (CR), and opalescence parameter (OP) were calculated. The samples were aged (20, 40, 60, 80, 100h), and the optical properties were calculated after each interval. Most zirconia brands had lower L*, higher a*, higher b* with increased aging, which visually corresponds to darker, redder, and more yellow. Aging also increased CR, lowered TP, and lowered OP. e.max was also affected by aging but still had the highest TP (23.9±2.8), L* (81.7±3.4), and lowest CR (0.41±0.05) compared to any zirconia. The Zenostar had the closest TP (24.1±0.4), and L* (90.2±0.5) values to e.max before aging. However, after 100h of aging, the DD-cubeX 2 was least effected and had the highest TP (22.2±0.6) and lowest CR (0.43±0.01) compared with other zirconia samples and highest OP (11.3±0.2) of all ceramic samples. The optical properties of zirconia and e.max materials were affected by aging with the effects increasing with time. The magnitude of change was affected by seven brands of dental zirconia. Copyright © 2016 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  4. Temperature dependent optical characterization of Ni-TiO2 thin films as potential photocatalytic material

    Science.gov (United States)

    De, Rajnarayan; Haque, S. Maidul; Tripathi, S.; Rao, K. Divakar; Singh, Ranveer; Som, T.; Sahoo, N. K.

    2017-09-01

    Along with other transition metal doped titanium dioxide materials, Ni-TiO2 is considered to be one of the most efficient materials for catalytic applications due to its suitable energy band positions in the electronic structure. The present manuscript explores the possibility of improving the photocatalytic activity of RF magnetron sputtered Ni-TiO2 films upon heat treatment. Optical, structural and morphological and photocatalytic properties of the films have been investigated in detail for as deposited and heat treated samples. Evolution of refractive index (RI) and total film thickness as estimated from spectroscopic ellipsometry characterization are found to be in agreement with the trend in density and total film thickness estimated from grazing incidence X-ray reflectivity measurement. Interestingly, the evolution of these macroscopic properties were found to be correlated with the corresponding microstructural modifications realized in terms of anatase to rutile phase transformation and appearance of a secondary phase namely NiTiO3 at high temperature. Corresponding morphological properties of the films were also found to be temperature dependent which leads to modifications in the grain structure. An appreciable reduction of optical band gap from 2.9 to 2.5 eV of Ni-TiO2 thin films was also observed as a result of post deposition heat treatment. Testing of photocatalytic activity of the films performed under UV illumination demonstrates heat treatment under atmospheric ambience to be an effective means to enhance the photocatalytic efficiency of transition metal doped titania samples.

  5. Precise optical observation of 0.5-GPa shock waves in condensed materials

    Science.gov (United States)

    Nagayama, Kunihito; Mori, Yasuhito

    1999-06-01

    Precision optical observation method was developed to study impact-generated high-pressure shock waves in condensed materials. The present method makes it possible to sensitively detect the shock waves of the relatively low shock stress around 0.5 GPa. The principle of the present method is based on the use of total internal reflection by triangular prisms placed on the free surface of a target assembly. When a plane shock wave arrives at the free surface, the light reflected from the prisms extinguishes instantaneously. The reason is that the total internal reflection changes to the reflection depending on micron roughness of the free surface after the shock arrival. The shock arrival at the bottom face of the prisms can be detected here by two kinds of methods, i.e., a photographic method and a gauge method. The photographic method is an inclined prism method of using a high-speed streak camera. The shock velocity and the shock tilt angle can be estimated accurately from an obtained streak photograph. While in the gauge method, an in-material PVDF stress gauge is combined with an optical prism-pin. The PVDF gauge records electrically the stress profile behind the shockwave front, and the Hugoniot data can be precisely measured by combining the prism pin with the PVDF gauge.

  6. 3D optical printing of piezoelectric nanoparticle-polymer composite materials.

    Science.gov (United States)

    Kim, Kanguk; Zhu, Wei; Qu, Xin; Aaronson, Chase; McCall, William R; Chen, Shaochen; Sirbuly, Donald J

    2014-10-28

    Here we demonstrate that efficient piezoelectric nanoparticle-polymer composite materials can be optically printed into three-dimensional (3D) microstructures using digital projection printing. Piezoelectric polymers were fabricated by incorporating barium titanate (BaTiO3, BTO) nanoparticles into photoliable polymer solutions such as polyethylene glycol diacrylate and exposing to digital optical masks that could be dynamically altered to generate user-defined 3D microstructures. To enhance the mechanical-to-electrical conversion efficiency of the composites, the BTO nanoparticles were chemically modified with acrylate surface groups, which formed direct covalent linkages with the polymer matrix under light exposure. The composites with a 10% mass loading of the chemically modified BTO nanoparticles showed piezoelectric coefficients (d(33)) of ∼ 40 pC/N, which were over 10 times larger than composites synthesized with unmodified BTO nanoparticles and over 2 times larger than composites containing unmodified BTO nanoparticles and carbon nanotubes to boost mechanical stress transfer efficiencies. These results not only provide a tool for fabricating 3D piezoelectric polymers but lay the groundwork for creating highly efficient piezoelectric polymer materials via nanointerfacial tuning.

  7. Characterization of fatigue resistance in photochromic composite materials for 3D rewritable optical memory applications

    International Nuclear Information System (INIS)

    Samoylova, Elena; Dallari, William; Allione, Marco; Pignatelli, Francesca; Marini, Lara; Cingolani, Roberto; Diaspro, Alberto; Athanassiou, Athanassia

    2013-01-01

    Highlights: • Fatigue resistance of diarylethene–polymer composites was tested with optical absorption and fluorescence methods upon repetitive UV–VIS irradiation. • Significant differences in fatigue were found in different polymeric matrices and in one-photon and two-photon excitation experiments. • Several explanations for fatigue resistance of the composites are proposed based on the physico-chemical properties of the diarylethenes and polymeric matrices. -- Abstract: Fatigue resistance of the photochromic diarylethene molecules 1,2-bis[2-methylbenzo[b]thyophen-3-yl] -3,3,4,4,5,5-hexafluoro-1-cyclopentene embedded in three different acrylic polymers is studied upon multiple coloration–decoloration cycles. The resistance to photofatigue is found to be different in the three polymeric materials when one-photon excitation was used for the reversible photoconversion experiment. In particular, the photochromic molecules lose their photoisomerization ability faster if they are embedded in poly(methyl methacrylate) (PMMA) with respect to poly(ethyl methacrylate-co-methyl acrylate) (PEMMA) and poly(ethyl methacrylate) (PEMA). We propose several explanations based on the physico-chemical properties of the matrix and of the photochromic molecules. In the case of two-photon excitation, which is necessary for 3D optical writing, the fatigue resistance is found to be poorer than in the one-photon case. The accelerated photodegradation can be assigned to the non-linear nature of interaction between the polymeric composite material and light

  8. Characterization of fatigue resistance in photochromic composite materials for 3D rewritable optical memory applications

    Energy Technology Data Exchange (ETDEWEB)

    Samoylova, Elena, E-mail: Elena.Samoylova@physik.uni-muenchen.de [Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Dallari, William; Allione, Marco; Pignatelli, Francesca; Marini, Lara; Cingolani, Roberto; Diaspro, Alberto [Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Athanassiou, Athanassia, E-mail: athanassia.athanassiou@iit.it [Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Center for Biomolecular Nanotechnologies-Unile, Istituto Italiano di Tecnologia, via Barsanti, 73010 Arnesano, Lecce (Italy)

    2013-06-01

    Highlights: • Fatigue resistance of diarylethene–polymer composites was tested with optical absorption and fluorescence methods upon repetitive UV–VIS irradiation. • Significant differences in fatigue were found in different polymeric matrices and in one-photon and two-photon excitation experiments. • Several explanations for fatigue resistance of the composites are proposed based on the physico-chemical properties of the diarylethenes and polymeric matrices. -- Abstract: Fatigue resistance of the photochromic diarylethene molecules 1,2-bis[2-methylbenzo[b]thyophen-3-yl] -3,3,4,4,5,5-hexafluoro-1-cyclopentene embedded in three different acrylic polymers is studied upon multiple coloration–decoloration cycles. The resistance to photofatigue is found to be different in the three polymeric materials when one-photon excitation was used for the reversible photoconversion experiment. In particular, the photochromic molecules lose their photoisomerization ability faster if they are embedded in poly(methyl methacrylate) (PMMA) with respect to poly(ethyl methacrylate-co-methyl acrylate) (PEMMA) and poly(ethyl methacrylate) (PEMA). We propose several explanations based on the physico-chemical properties of the matrix and of the photochromic molecules. In the case of two-photon excitation, which is necessary for 3D optical writing, the fatigue resistance is found to be poorer than in the one-photon case. The accelerated photodegradation can be assigned to the non-linear nature of interaction between the polymeric composite material and light.

  9. Quantum formulation for nanoscale optical and material chirality: symmetry issues, space and time parity, and observables

    Science.gov (United States)

    Andrews, D. L.

    2018-03-01

    To properly represent the interplay and coupling of optical and material chirality at the photon-molecule or photon-nanoparticle level invites a recognition of quantum facets in the fundamental aspects and mechanisms of light-matter interaction. It is therefore appropriate to cast theory in a general quantum form, one that is applicable to both linear and nonlinear optics as well as various forms of chiroptical interaction including chiral optomechanics. Such a framework, fully accounting for both radiation and matter in quantum terms, facilitates the scrutiny and identification of key issues concerning spatial and temporal parity, scale, dissipation and measurement. Furthermore it fully provides for describing the interactions of structured or twisted light beams with a vortex character, and it leads to the complete identification of symmetry conditions for materials to provide for chiral discrimination. Quantum considerations also lend a distinctive perspective to the very different senses in which other aspects of chirality are recognized in metamaterials. Duly attending to the symmetry principles governing allowed or disallowed forms of chiral discrimination supports an objective appraisal of the experimental possibilities and developing applications.

  10. Factors influencing optical 3D scanning of vinyl polysiloxane impression materials.

    Science.gov (United States)

    DeLong, R; Pintado, M R; Ko, C C; Hodges, J S; Douglas, W H

    2001-06-01

    Future growth in dental practice lies in digital imaging enhancing many chairside procedures and functions. This revolution requires the fast, accurate, and 3D digitizing of clinical records. One such clinical record is the chairside impression. This study investigated how surface angle and surface roughness affect the digitizing of vinyl polysiloxane impression materials. Seventeen vinyl polysiloxane impression materials were digitized with a white light optical digitizing system. Each sample was digitized at 3 different angles: 0 degrees, 22.5 degrees, and 45 degrees, and 2 digitizer camera f-stops. The digitized images were rendered on a computer monitor using custom software developed under NIH/NIDCR grant DE12225. All the 3D images were rotated to the 0 degrees position, cropped using Corel Photo-Paint 8 (Corel Corp, Ottawa, Ontario, Canada), then saved in the TIFF file format. The impression material area that was successfully digitized was calculated as a percentage of the total sample area, using Optimas 5.22 image processing software (Media Cybernetics, LP, Silver Spring, MD). The dependent variable was a Performance Value calculated for each material by averaging the percentage of area that digitized over the 3 angles. New samples with smooth and rough surfaces were made using the 7 impression materials with the largest Performance Values. These samples were tested as before, but with the additional angle of 60 degrees. Silky-Rock die stone (Whip Mix Corp, Louisville, KY) was used as a control. The Performance Values for the 17 impression materials ranged from 0% to 100%. The Performance Values for the 7 best materials were equivalent to the control at f/11 out to a surface angle of 45 degrees; however, only Examix impression material (GC America Inc, Alsip, IL) was equivalent to the control at f/11/\\16. At the 60 degrees surface angle with f/11/\\16, the Performance Values were 0% for all the impression materials, whereas that for the control was 90

  11. Omnidirectional Photonic Band Gap Using Low Refractive Index Contrast Materials and its Application in Optical Waveguides

    KAUST Repository

    Vidal Faez, Angelo

    2012-07-01

    Researchers have argued for many years that one of the conditions for omnidirectional reflection in a one-dimensional photonic crystal is a strong refractive index contrast between the two constituent dielectric materials. Using numerical simulations and the theory of Anderson localization of light, in this work we demonstrate that an omnidirectional band gap can indeed be created utilizing low refractive index contrast materials when they are arranged in a disordered manner. Moreover, the size of the omnidirectional band gap becomes a controllable parameter, which now depends on the number of layers and not only on the refractive index contrast of the system, as it is widely accepted. This achievement constitutes a major breakthrough in the field since it allows for the development of cheaper and more efficient technologies. Of particular interest is the case of high index contrast one-dimensional photonic crystal fibers, where the propagation losses are mainly due to increased optical scattering from sidewall roughness at the interfaces of high index contrast materials. By using low index contrast materials these losses can be reduced dramatically, while maintaining the confinement capability of the waveguide. This is just one of many applications that could be proven useful for this discovery.

  12. Use of pre-pulse in laser spot welding of materials with high optical reflection

    Science.gov (United States)

    Mys, Ihor; Geiger, Manfred

    2003-11-01

    Laser micro welding has become a standard manufacturing technique, particularly in industry sectors, such as automotive and aerospace electronics or medical devices, where the requirements for strength, miniaturization and temperature resistance are constantly rising. So far the use of laser micro welding is limited due to the fluctuation of the quality of the welded joints, because the welding results for material with high optical reflection and thermal conductivity, such as copper and copper alloys, depend very strongly on the condition of the material surface. This paper presents investigations on the use of a laser pre-pulse in spot welding of electronic materials with Nd:YAG laser. In order to achieve reproducible joining results two strategies are followed-up. The first one utilizes a reflection-based process control for measuring the reflection during the short pre-pulse. The intensity of the reflected light is used to calculate an appropriated welding pulse power, which corresponds to the measured relative absorption. Adjustment of laser parameters according to the condition of the surface is done in real time before laser main pulse. A second possibility for the stabilization of copper welding is the employment of a short and powerful laser pre-pulse before laser main pulse. This pre-pulse affects the workpiece surface and creates more reproducible absorption conditions for the main pulse, independent from the initial situation on material surface.

  13. 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

  14. Combined effects of nonparaxiality, optical activity, and walk-off on rogue wave propagation in optical fibers filled with chiral materials

    Science.gov (United States)

    Temgoua, D. D. Estelle; Tchokonte, M. B. Tchoula; Kofane, T. C.

    2018-04-01

    The generalized nonparaxial nonlinear Schrödinger (NLS) equation in optical fibers filled with chiral materials is reduced to the higher-order integrable Hirota equation. Based on the modified Darboux transformation method, the nonparaxial chiral optical rogue waves are constructed from the scalar model with modulated coefficients. We show that the parameters of nonparaxiality, third-order dispersion, and differential gain or loss term are the main keys to control the amplitude, linear, and nonlinear effects in the model. Moreover, the influence of nonparaxiality, optical activity, and walk-off effect are also evidenced under the defocusing and focusing regimes of the vector nonparaxial NLS equations with constant and modulated coefficients. Through an algorithm scheme of wider applicability on nonparaxial beam propagation methods, the most influential effect and the simultaneous controllability of combined effects are underlined, showing their properties and their potential applications in optical fibers and in a variety of complex dynamical systems.

  15. Hand protection from ultraviolet exposure

    International Nuclear Information System (INIS)

    Khazova, M.; O'Hagan, J.B.

    2006-01-01

    Full text of publication follows: A number of industrial applications and public services involve exposure to ultraviolet radiation (U.V.R.) from a variety of lamps and lasers, for example, in forensic examination, biological trans-illuminators, dentistry, laser material processing, microelectronics, etc. The proposed European Union Directive on Optical Radiation would place specific requirements on employers to provide adequate safety measures to reduce exposure to U.V.R., including gloves for hand protection. The selection of gloves should be based on a risk assessment and on the performance characteristics of the gloves for the task. However, current International and national standards do not describe evaluation procedures of disposable gloves for hand protection against non-ionising radiation. A methodology for assessment of the UV protection level for disposable gloves and a simple measurement protocol are proposed, based on a common approach with UV protection by clothing and sunscreens. Glove Ultraviolet Protection Factor is defined as a time-scale increase in exposure permitted for the hand protected by a glove with respect to an unprotected hand. However, the wide variety of U.V.R. sources and the real-life conditions of glove use (stretching and wetting the surface by liquids) bring substantial challenges to the assessment method. Our study of ∼ 50 samples of widely used disposable gloves made of different materials (nitrile, vinyl, latex and chloroprene) showed that for all tested gloves a change in U.V.R. attenuation with stretching is characteristic for the type of glove material and can be included as a scaling factor in the definition of U.V.R. protection. Glove material has a bigger effect on U.V.R. protection level than variations in the glove thickness or its colour. The following approaches are suggested to overcome the problem of variable U.V.R. sources: - Worst case scenario minimal protection level, most restrictive case - Application

  16. Hand protection from ultraviolet exposure

    Energy Technology Data Exchange (ETDEWEB)

    Khazova, M.; O' Hagan, J.B. [Health Protection Agency, Radiation Protection Division, Chilton, Did cot (United Kingdom)

    2006-07-01

    Full text of publication follows: A number of industrial applications and public services involve exposure to ultraviolet radiation (U.V.R.) from a variety of lamps and lasers, for example, in forensic examination, biological trans-illuminators, dentistry, laser material processing, microelectronics, etc. The proposed European Union Directive on Optical Radiation would place specific requirements on employers to provide adequate safety measures to reduce exposure to U.V.R., including gloves for hand protection. The selection of gloves should be based on a risk assessment and on the performance characteristics of the gloves for the task. However, current International and national standards do not describe evaluation procedures of disposable gloves for hand protection against non-ionising radiation. A methodology for assessment of the UV protection level for disposable gloves and a simple measurement protocol are proposed, based on a common approach with UV protection by clothing and sunscreens. Glove Ultraviolet Protection Factor is defined as a time-scale increase in exposure permitted for the hand protected by a glove with respect to an unprotected hand. However, the wide variety of U.V.R. sources and the real-life conditions of glove use (stretching and wetting the surface by liquids) bring substantial challenges to the assessment method. Our study of {approx} 50 samples of widely used disposable gloves made of different materials (nitrile, vinyl, latex and chloroprene) showed that for all tested gloves a change in U.V.R. attenuation with stretching is characteristic for the type of glove material and can be included as a scaling factor in the definition of U.V.R. protection. Glove material has a bigger effect on U.V.R. protection level than variations in the glove thickness or its colour. The following approaches are suggested to overcome the problem of variable U.V.R. sources: - Worst case scenario minimal protection level, most restrictive case - Application

  17. Discussion on the interrelationship between structural, optical, electronic and elastic properties of materials

    International Nuclear Information System (INIS)

    Aly, Kamal A.

    2015-01-01

    Highlights: • The calculated values of bulk modulus in Reddy et al. [1] are now recalculated correctly. • Eq. (11) suggested by Reddy et al. [1] is not suitable to calculate the bulk modulus, B, for any element or material. • Eq. (12) in Ref. [1] is suitable to calculate, B, for all elements and materials except the underlined materials in Table 4. • All values of the electronic polarizability have been recalculated by different methods. • The bulk modulus, B, and microhardness parameter, H are different; Eq. (8) gives the relation between B and H. - Abstract: In reference Reddy et al. (2009) the correlations between energy gap, optical electronegativity and electronic polarizability for different materials have been studied. The authors of this paper (Reddy et al., 2009) aimed to make extinction or complete some previous works (Bahadur and Mishra, 2013; Reddy et al., 1999, 2000, 1998, 2005, 2008; Reddy and Nazeer Ahammed, 1996; Oshcherin, 1979; Neumann, 1983, 1987; Deus and Schneider; 1985; Deus et al., 1983; Kumar et al. 1992). However, this paper (Reddy et al., 2009) contains many fundamental errors in the calculation of bulk modulus, especially Tables 4–6. As a result, all the obtained values of the bulk modulus and consequently the electronic polarizability are incorrect. Moreover in Table 4 (Reddy et al., 2009), the bulk modulus of II−VI group semiconductors have been calculated by substituting the values of the band gap, E g , into Eq. (11) (B = 14.91 E g + 23.3). The obtained values of B using Eq. (11) are conflicted with that calculated values of B based on the electronegativity and the published previously data. Therefore Eq. (11) in reference Reddy et al. (2009) is not suitable for calculating the values of B for any element or materials. When I recalculated the values of B for all materials in Tables 1 and 4–6 in paper (Reddy et al., 2009) using Eq. (12), I found that, Eq. (12) gives acceptable values of B for all materials except the

  18. Optically stimulated luminescence techniques in retrospective dosimetry using single grains of quartz extracted from unheated materials

    Energy Technology Data Exchange (ETDEWEB)

    Joerkov Thomsen, Kristina

    2004-02-01

    This work investigates the possibility of applying optically stimulated luminescence (OSL) in retrospective dose determinations using unheated materials. It focuses on identifying materials suitable for use in assessment of doses absorbed as a consequence of radiation accidents (i.e. accident dosimetry). Special attention has been paid to quartz extracted from unheated building materials such as concrete and mortar. The single-aliquot regeneration-dose (SAR) protocol has been used to determine absorbed doses in small aliquots as well as single grains of quartz. It is shown that OSL measurements of single grains of quartz extracted from poorly-bleached building materials can provide useful information on radiation accident doses, even when the luminescence sensitivity is low. Sources of variance in well-bleached single grain dose distributions have been investigated in detail and it is concluded that the observed variability in the data is consistent with the sum (in quadrature) of a component, which depends on the number of photons detected from each grain, and a fixed component independent of light level. Dose depth profiles through laboratory irradiated concrete bricks have successfully been measured and minimum detection limits of less than 100 mGy are derived. Measurements of thermal transfer in single grains of poorly-bleached quartz show that thermal transfer is variable on a grain-to-grain basis and that it can be a source of variance in single-grain dose distributions. Furthermore, the potential of using common household and workplace chemicals, such as table salt, washing powder and water softener, in retrospective dosimetry has been investigated. It is concluded that such materials should be considered as retrospective dosimeters in the event of a radiation accident. (au)

  19. Calculating the optical properties of defects and surfaces in wide band gap materials

    Science.gov (United States)

    Deák, Peter

    2018-04-01

    The optical properties of a material critically depend on its defects, and understanding that requires substantial and accurate input from theory. This paper describes recent developments in the electronic structure theory of defects in wide band gap materials, where the standard local or semi-local approximations of density functional theory fail. The success of the HSE06 screened hybrid functional is analyzed in case of Group-IV semiconductors and TiO2, and shown that it is the consequence of error compensation between semi-local and non-local exchange, resulting in a proper derivative discontinuity (reproduction of the band gap) and a total energy which is a linear function of the fractional occupation numbers (removing most of the electron self-interaction). This allows the calculation of electronic transitions with accuracy unseen before, as demonstrated on the single-photon emitter NV(-) center in diamond and on polaronic states in TiO2. Having a reliable tool for electronic structure calculations, theory can contribute to the understanding of complicated cases of light-matter interaction. Two examples are considered here: surface termination effects on the blinking and bleaching of the light-emission of the NV(-) center in diamond, and on the efficiency of photocatalytic water-splitting by TiO2. Finally, an outlook is presented for the application of hybrid functionals in other materials, as, e.g., ZnO, Ga2O3 or CuGaS2.

  20. First principles crystal engineering of nonlinear optical materials. I. Prototypical case of urea

    Science.gov (United States)

    Masunov, Artëm E.; Tannu, Arman; Dyakov, Alexander A.; Matveeva, Anastasia D.; Freidzon, Alexandra Ya.; Odinokov, Alexey V.; Bagaturyants, Alexander A.

    2017-06-01

    The crystalline materials with nonlinear optical (NLO) properties are critically important for several technological applications, including nanophotonic and second harmonic generation devices. Urea is often considered to be a standard NLO material, due to the combination of non-centrosymmetric crystal packing and capacity for intramolecular charge transfer. Various approaches to crystal engineering of non-centrosymmetric molecular materials were reported in the literature. Here we propose using global lattice energy minimization to predict the crystal packing from the first principles. We developed a methodology that includes the following: (1) parameter derivation for polarizable force field AMOEBA; (2) local minimizations of crystal structures with these parameters, combined with the evolutionary algorithm for a global minimum search, implemented in program USPEX; (3) filtering out duplicate polymorphs produced; (4) reoptimization and final ranking based on density functional theory (DFT) with many-body dispersion (MBD) correction; and (5) prediction of the second-order susceptibility tensor by finite field approach. This methodology was applied to predict virtual urea polymorphs. After filtering based on packing similarity, only two distinct packing modes were predicted: one experimental and one hypothetical. DFT + MBD ranking established non-centrosymmetric crystal packing as the global minimum, in agreement with the experiment. Finite field approach was used to predict nonlinear susceptibility, and H-bonding was found to account for a 2.5-fold increase in molecular hyperpolarizability to the bulk value.

  1. Deterministic ion beam material adding technology for high-precision optical surfaces.

    Science.gov (United States)

    Liao, Wenlin; Dai, Yifan; Xie, Xuhui; Zhou, Lin

    2013-02-20

    Although ion beam figuring (IBF) provides a highly deterministic method for the precision figuring of optical components, several problems still need to be addressed, such as the limited correcting capability for mid-to-high spatial frequency surface errors and low machining efficiency for pit defects on surfaces. We propose a figuring method named deterministic ion beam material adding (IBA) technology to solve those problems in IBF. The current deterministic optical figuring mechanism, which is dedicated to removing local protuberances on optical surfaces, is enriched and developed by the IBA technology. Compared with IBF, this method can realize the uniform convergence of surface errors, where the particle transferring effect generated in the IBA process can effectively correct the mid-to-high spatial frequency errors. In addition, IBA can rapidly correct the pit defects on the surface and greatly improve the machining efficiency of the figuring process. The verification experiments are accomplished on our experimental installation to validate the feasibility of the IBA method. First, a fused silica sample with a rectangular pit defect is figured by using IBA. Through two iterations within only 47.5 min, this highly steep pit is effectively corrected, and the surface error is improved from the original 24.69 nm root mean square (RMS) to the final 3.68 nm RMS. Then another experiment is carried out to demonstrate the correcting capability of IBA for mid-to-high spatial frequency surface errors, and the final results indicate that the surface accuracy and surface quality can be simultaneously improved.

  2. 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

  3. Lambert-Beer law in ocean waters: optical properties of water and of dissolved/suspended material, optical energy budgets.

    Science.gov (United States)

    Stavn, R H

    1988-01-15

    The role of the Lambert-Beer law in ocean optics is critically examined. The Lambert-Beer law and the three-parameter model of the submarine light field are used to construct an optical energy budget for any hydrosol. It is further applied to the analytical exponential decay coefficient of the light field and used to estimate the optical properties and effects of the dissolved/suspended component in upper ocean layers. The concepts of the empirical exponential decay coefficient (diffuse attenuation coefficient) of the light field and a constant exponential decay coefficient for molecular water are analyzed quantitatively. A constant exponential decay coefficient for water is rejected. The analytical exponential decay coefficient is used to analyze optical gradients in ocean waters.

  4. Simultaneous interferometric measurement of linear coefficient of thermal expansion and temperature-dependent refractive index coefficient of optical materials.

    Science.gov (United States)

    Corsetti, James A; Green, William E; Ellis, Jonathan D; Schmidt, Greg R; Moore, Duncan T

    2016-10-10

    Characterizing the thermal properties of optical materials is necessary for understanding how to design an optical system for changing environmental conditions. A method is presented for simultaneously measuring both the linear coefficient of thermal expansion and the temperature-dependent refractive index coefficient of a sample interferometrically in air. Both the design and fabrication of the interferometer is presented as well as a discussion of the results of measuring both a steel and a CaF2 sample.

  5. Study of material properties important for an optical property modulation-based radiation detection method for positron emission tomography

    OpenAIRE

    Tao, Li; Daghighian, Henry M.; Levin, Craig S.

    2017-01-01

    We compare the performance of two detector materials, cadmium telluride (CdTe) and bismuth silicon oxide (BSO), for optical property modulation-based radiation detection method for positron emission tomography (PET), which is a potential new direction to dramatically improve the annihilation photon pair coincidence time resolution. We have shown that the induced current flow in the detector crystal resulting from ionizing radiation determines the strength of optical modulation signal. A large...

  6. X-ray topographic studies of organic and non-linear optical materials

    International Nuclear Information System (INIS)

    Halfpenny, P. J.; Sherwood, J. N.; Simpson, G. S.

    1997-01-01

    The flexible and non-destructive nature of X-ray topography is ideally suited to the study of large single crystals for both fundamental research and technological applications as well as the optimisation of crystal growth processes. Three examples are discussed, illustrating the application of X-ray topographic methods to non-linear optical (NLO) crystals. Synchrotron radiation section topography has been applied to the examination of large organic crystals. X-ray topography has been used to examine growth defects and the quality of crystals of m-nitroaniline (mNA) grown by the Bridgeman method. These studies allow evaluation of growth parameters together with their influence on defect density and show that in the case of mNA, remarkably low defect densities can be achieved under optimum growth conditions. Double-crystal reflection topography, with synchrotron radiation has been used to image defects intersecting the (011) faces of the inorganic NLO material potassium titanyl phosphate (KTP). X-ray images have been combined with optical microscopy and interferometry to provide valuable information on the crystal growth process

  7. Neutron optics concept for the materials engineering diffractometer at the ESS

    Science.gov (United States)

    Šaroun, J.; Fenske, J.; Rouijaa, M.; Beran, P.; Navrátil, J.; Lukáš, P.; Schreyer, A.; Strobl, M.

    2016-09-01

    The Beamline for European Materials Engineering Research (BEER) has been recently proposed to be built at the European Spallation Source (ESS). The presented concept of neutron delivery optics for this instrument addresses the problems of bi-spectral beam extraction from a small moderator, optimization of neutron guides profile for long-range neutron transport and focusing at the sample under various constraints. They include free space before and after the guides, a narrow guide section with gaps for choppers, closing of direct line of sight and cost reduction by optimization of the guides cross-section and coating. A system of slits and exchangeable focusing optics is proposed in order to match various wavelength resolution options provided by the pulse shaping and modulation choppers, which permits to efficiently trade resolution for intensity in a wide range. Simulated performance characteristics such as brilliance transfer ratio are complemented by the analysis of the histories of “useful” neutrons obtained by back tracing neutrons hitting the sample, which helps to optimize some of the neutron guide parameters such as supermirror coating.

  8. Neutron optics concept for the materials engineering diffractometer at the ESS

    International Nuclear Information System (INIS)

    Šaroun, J; Beran, P; Navrátil, J; Lukáš, P; Fenske, J; Rouijaa, M; Schreyer, A; Strobl, M

    2016-01-01

    The Beamline for European Materials Engineering Research (BEER) has been recently proposed to be built at the European Spallation Source (ESS). The presented concept of neutron delivery optics for this instrument addresses the problems of bi-spectral beam extraction from a small moderator, optimization of neutron guides profile for long-range neutron transport and focusing at the sample under various constraints. They include free space before and after the guides, a narrow guide section with gaps for choppers, closing of direct line of sight and cost reduction by optimization of the guides cross-section and coating. A system of slits and exchangeable focusing optics is proposed in order to match various wavelength resolution options provided by the pulse shaping and modulation choppers, which permits to efficiently trade resolution for intensity in a wide range. Simulated performance characteristics such as brilliance transfer ratio are complemented by the analysis of the histories of “useful” neutrons obtained by back tracing neutrons hitting the sample, which helps to optimize some of the neutron guide parameters such as supermirror coating. (paper)

  9. Effects of the LDEF orbital environment on the reflectance of optical mirror materials

    Science.gov (United States)

    Herzig, Howard; Fleetwood, Charles, Jr.

    1995-01-01

    Specimens of eight different optical mirror materials were flown in low earth orbit as part of the Long Duration Exposure Facility (LDEF) manifest to determine their ability to withstand exposure to the residual atomic oxygen and other environmental effects at those altitudes. Optical thin films of aluminum, gold, iridium, osmium, platinum, magnesium fluoride-overcoated aluminum and reactively deposited, silicon monoxide-protected aluminum, all of which were vacuum deposited on polished fused silica substrates, were included as part of Experiment S0010, Exposure of Spacecraft Coatings. Two specimens of polished, chemical vapor deposited (CVD) silicon carbide were installed in sites available in Experiment A0114, Interaction of Atomic Oxygen with Solid Surfaces at Orbital Altitudes, which included trays in two of the spacecraft bays, one on the leading edge and the other on the trailing edge. One of the silicon carbide samples was located in each of these trays. This paper will compare specular reflectance data from the preflight and postflight measurements made on each of these samples and attempt to explain the changes in light of the specific environments to which the experiments were exposed.

  10. Handbook of Coherent-Domain Optical Methods Biomedical Diagnostics, Environmental Monitoring, and Materials Science

    CERN Document Server

    2013-01-01

    This Handbook provides comprehensive coverage of laser and coherent-domain methods as applied to biomedicine, environmental monitoring, and materials science. Worldwide leaders in these fields describe the fundamentals of light interaction with random media and present an overview of basic research. The latest results on coherent and polarization properties of light scattered by random media, including tissues and blood, speckles formation in multiple scattering media, and other non-destructive interactions of coherent light with rough surfaces and tissues, allow the reader to understand the principles and applications of coherent diagnostic techniques. The expanded second edition has been thoroughly updated with particular emphasis on novel coherent-domain techniques and their applications in medicine and environmental science. Volume 1 describes state-of-the-art methods of coherent and polarization optical imaging, tomography and spectroscopy; diffusion wave spectroscopy; elastic, quasi-elastic and inelasti...

  11. Two-Photon Absorbing Molecules as Potential Materials for 3D Optical Memory

    Directory of Open Access Journals (Sweden)

    Kazuya Ogawa

    2014-01-01

    Full Text Available In this review, recent advances in two-photon absorbing photochromic molecules, as potential materials for 3D optical memory, are presented. The investigations introduced in this review indicate that 3D data storage processing at the molecular level is possible. As 3D memory using two-photon absorption allows advantages over existing systems, the use of two-photon absorbing photochromic molecules is preferable. Although there are some photochromic molecules with good properties for memory, in most cases, the two-photon absorption efficiency is not high. Photochromic molecules with high two-photon absorption efficiency are desired. Recently, molecules having much larger two-photon absorption cross sections over 10,000 GM (GM= 10−50 cm4 s molecule−1 photon−1 have been discovered and are expected to open the way to realize two-photon absorption 3D data storage.

  12. Ultrafast optical manipulation of atomic motion in multilayer Ge-Sb-Te phase change materials

    Directory of Open Access Journals (Sweden)

    Fons P.

    2013-03-01

    Full Text Available Phase change random access memory devices have evolved dramatically with the recent development of superlattice structure of Ge-Sb-Te material (GST-SL in terms of its low power consumption. The phase change in GST-SL is mainly characterized by the displacement of Ge atoms. Here we examine a new phase change method, that is the manipulation of Ge-Te bonds using linearly-polarized femtosecond near-infrared optical pulses. As a result, we found that the p-polarized pump pulse is more effective in inducing the reversible and irreversible displacement of Ge atoms along [111] direction in the local structure. This structural change would be induced by the anisotropic carrier-phonon interaction along the [111] direction created by the p-polarized pulse.

  13. Thermotropic resin systems. Relationships between formulation parameters, material structure and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Resch, Katharina [Polymer Competence Center Leoben GmbH, Leoben (Austria); Wallner, Gernot M. [Univ. of Leoben (Austria)

    2008-07-01

    This paper focuses on a comprehensive characterization of various thermotropic resins under polymer physical aspects. Numerous thermotropic layers were produced under systematic variation of resin base, thermotropic additives and additive concentration. A detailed investigation of optical properties, switching temperature, switching process and residual transmittance was performed with a UV/Vis/NIR spectrophotometer. Switching temperatures are compared with thermal transitions in the material determined by Differential Scanning Calorimetry (DSC). Whereas the different film types show a direct solar transparency between 64 and 83% in the clear state, the direct solar transmittance decreases to values of about 27% to 80% above the switching temperature. In general the thermotropic resins are characterized by a steep and rapid switching process. The switching temperature can be adapted by varying the additives. The comparison of films thermal transitions with the switching performance reveals a good correlation. (orig.)

  14. Nonlocality and particle-clustering effects on the optical response of composite materials with metallic nanoparticles

    Science.gov (United States)

    Chen, C. W.; Chung, H. Y.; Chiang, H.-P.; Lu, J. Y.; Chang, R.; Tsai, D. P.; Leung, P. T.

    2010-10-01

    The optical properties of composites with metallic nanoparticles are studied, taking into account the effects due to the nonlocal dielectric response of the metal and the coalescing of the particles to form clusters. An approach based on various effective medium theories is followed, and the modeling results are compared with those from the cases with local response and particles randomly distributed through the host medium. Possible observations of our modeling results are illustrated via a calculation of the transmission of light through a thin film made of these materials. It is found that the nonlocal effects are particularly significant when the particles coalesce, leading to blue-shifted resonances and slightly lower values in the dielectric functions. The dependence of these effects on the volume fraction and fractal dimension of the metal clusters is studied in detail.

  15. Photonic-resonant left-handed medium

    International Nuclear Information System (INIS)

    Shen Jianqi

    2006-01-01

    A new scheme to realize simultaneously negative permittivity and permeability in a coherent atomic vapor medium (photonic-resonant material) via a coherent driving mechanism is suggested. It is verified that the atomic system coherently driven by a strong optical field will give rise to a negative refractive index in certain probe frequency ranges. One of the most remarkable features of the present scheme is such that a slab fabricated by the left-handed vapor medium is an ideal candidate for designing perfect lenses since the photonic-resonant atomic vapor cannot only exhibit an isotropic negative refractive index, but also provide a good impedance match at the air-medium interfaces

  16. Using optical spectroscopy to characterize the material of a 16th c. stained glass window

    Science.gov (United States)

    Ceglia, A.; Meulebroeck, W.; Wouters, H.; Baert, K.; Nys, K.; Terryn, H.; Thienpont, H.

    In this paper we studied the transmittance spectra of a collection of several glass samples taken from a 16th century stained window of the Church of Our Lady in Bruges, Belgium. We recorded the optical spectra for all the samples in the region between 350 and 1600 nm. The goal of our research was to reveal information about the composition of the glass artifacts in a fast and non-destructive way. Analysis of the optical spectra allowed us in the first place to identify the type of colorants that were used. It was possible to recognize metal ions, such as Fe2+, Fe3+, Co2+, Mn3+, Cr3+ and Cu2+. Also colors made of metal nanoparticles, such as silver and copper colloids were successfully identified. The recognition of the coloring agents is of particular interest in dating the glass pieces. This is because some colorants were only used in certain periods. Green glass colored by chromium was produced only after the mid 19th century onwards. Our study showed that 3 of the 10 pieces were colored by this element and they originate as such from a later period. A second conclusion refers to the applied fluxing agent. By analyzing the spectral position of the first cobalt absorption band, we were able to classify the glass pieces as potash based (used in medieval times) or soda-based (used in modern times) and therefore to classify them as original or as restoration material. From the 10 blue colored samples, 7 of them were recognized as original material. Finally, for the naturally colored parts the analysis of the spectra allowed us to group them based on cobalt impurities.

  17. Analysis of the optical and thermal properties of transparent insulating materials containing gas bubbles

    International Nuclear Information System (INIS)

    Cai, Qilin; Ye, Hong; Lin, Qizhao

    2016-01-01

    Highlights: • Transparent insulating medium containing gas bubbles was proposed. • Radiative transfer and thermal conduction models were constructed. • Bulk transmittance increases first and then decreases with the bubble number. • Effective thermal conductivity decreases with increasing filling ratio. • High filling ratio with large bubbles is preferred for good performance. - Abstract: As a medium of low absorption and low thermal conduction, introducing gas bubbles into semitransparent mediums, such as glass and polycarbonate (PC), may simultaneously improve their light transmission and thermal insulation performances. However, gas bubbles can also enhance light scattering, which is in competition with the effect of the absorption decrease. Moreover, the balance between the visible light transmittance and the effective thermal conductivity should also be considered in the material design. Therefore, a radiative transfer model and the Maxwell–Eucken model for such material were employed to analyze the optical and thermal performances, respectively. The results demonstrate that the transmittance increases when the bubble radius (r) increases with a fixed volume fraction of the gas bubbles (f_v) due to the increased scattering intensity. In addition, the effective thermal conductivity always decreases with increasing f_v. Thus, to achieve both good optical and thermal performances, high f_v with large r is preferred. When f_v=0.5, the transmittance can be kept larger than 50% as long as r ≥ 0.7 mm. To elucidate the application performance, the heat transfer of a freezer adopting the glass or PC with gas bubbles as a cover was analyzed and the energy saving can be nearly 10%.

  18. Preparation, characterization and optical properties of Lanthanum-(nanometer MCM-41) composite materials

    International Nuclear Information System (INIS)

    Zhai, Q. Z.; Wang, P.

    2008-01-01

    Nanometer MCM-41 molecular sieve was prepared under a base condition by using cetyltrimethylammonium bromide as template and tetraethyl orthosilicate as silica source by means of hydrothermal method. Lanthanum(III) was incorporated into the nanometer MCM-41 by a liquid phase grafting method. The prepared nano composite materials were characterized by means of powder X-ray diffraction, spectrophotometric analysis, Fourier transform infrared spectroscopy, low temperature nitrogen adsorption-desorption technique, solid diffuse reflectance absorption spectra and luminescence. The powder X-ray diffraction studies show that the nanometer MCM-41 molecular sieve is successfully prepared. The highly ordered meso porous two-dimensional hexagonal channel structure and framework of the support MCM-41 is retained intact in the prepared composite material La-(nanometer MCM-41). The spectrophotometric analysis indicates that lanthanum exists in the prepared nano composite materials. The Fourier transform infrared spectra indicate that the framework of the MCM-41 molecular sieve still remains in the prepared nano composite materials and some framework vibration peaks show blue shifts relative to those of the MCM-41 molecular sieve. The low temperature nitrogen adsorption-desorption indicates that the guest locales in the channel of the molecular sieve. Compared with bulk lanthanum oxide, the guest in the channel of the molecular sieve has smaller particle size and shows a significant blue shift of optical absorption band in solid diffuse reflectance absorption spectra. The observed blue shift in the solid state diffuse reflectance absorption spectra of the lanthanum-(nanometer MCM-41) sample show the obvious stereoscopic confinement effect of the channel of the host on the guest, which further indicates the successful encapsulation of the guest in the host. The La-(nanometer MCM-41) sample shows luminescence

  19. Group IV all-semiconductor spintronics. Materials aspects and optical spin selection rules

    Energy Technology Data Exchange (ETDEWEB)

    Sircar, Narayan

    2012-04-03

    In the scope of the present thesis various aspects for the realization of spintronic applications based on group IV semiconductors are discussed. This work comprises a refined material characterization of the magnetic semiconductor GeMn. We furthermore present efforts to utilize this material as spin injector for a Si-based optical spintronic device. Applying transmission electron microscopy and atom probe tomography, we are able to resolve a vertical anisotropy in the self-assembly, leading to the stacking of well-defined clusters in the growth direction. Three-dimensional atom distribution maps confirm that clusters are built from a nonstoichiometric GeMn alloy and exhibit a high-Mn-concentration core with a decreasing Mn concentration toward a shell. An amorphous nature of the cluster cores as well as the crystallinity of the shells, coherent with the surrounding Ge lattice, are revealed in scanning transmission electron microscopy. We localize a strain field surrounding each GeMn cluster by scanning transmission electron microscopy. The importance of strain to the stacking phenomenon of the clusters becomes clear in studies of Ge/GeMn superlattice structures, where a vertical spatial correlation of clusters over 30 nm-thick Ge spacer layers is observed. We present evidence that electrical transport properties of the p-type GeMn thin films fabricated on high-resistivity Ge substrates are severely influenced by parallel conduction through the substrate. It is shown that substrate conduction persists also for wellconducting degenerate p-type reference thin films, giving rise to an effective two-layer conduction scheme. GeMn thin films fabricated on these substrates exhibit only a negligible magnetoresistance effect. Before integrating GeMn in an optical spintronic device, some key aspects important for an understanding of the optical injection and detection of carrier spins in Si and Si-based heterostructures are clarified in the second part of this thesis. In

  20. Optical oxygen sensing materials based on a novel dirhenium(I) complex assembled in mesoporous silica

    International Nuclear Information System (INIS)

    Liu Yanhong; Li Bin; Cong Yan; Zhang Liming; Fan Di; Shi Linfang

    2011-01-01

    A new dirhenium(I) complex fac-[{Re(CO) 3 (4,7-dinonadecyl-1,10-phenanthro -line)} 2 (4,4'-bipyridyl)] (trifluoromethanesulfonate) 2 (denoted as D-Re(I) ) is assembled in MCM-41 and SBA-15 type mesoporous silica support. The emission peaks of D-Re(I) in D-Re(I)/MCM-41 and D-Re(I)/SBA-15 are observed at 522 and 517 nm, respectively. Their long excited lifetimes, which are of the order of microseconds, indicate the presence of phosphorescence emission arising from the metal to ligand charge-transfer (MLCT) transition. The luminescence intensities of D-Re(I)/MCM-41 and D-Re(I)/SBA-15 decrease remarkably with increase in the oxygen concentration, meaning that they can be used as optical oxygen sensing materials based on luminescence quenching. The ratios I 0 /I 100 of D-Re(I)/MCM-41 and D-Re(I)/SBA-15 are estimated to be 5.6 and 20.1, respectively. The obtained Stern-Volmer oxygen quenching plots of the mesoporous sensing materials could be fitted well to the two-site Demas model and Lehrer model. - Research highlights: → Dirhenium(I) complex assembled in mesoporous molecular sieves for oxygen sensor design. → Large α-diimine ligand L used to improve oxygen sensing properties. → High sensitivity (I 0 /I 100 ) up to 20.1.

  1. Effect of birefringence of lens material on polarization status and optical imaging characteristics

    Science.gov (United States)

    Kim, Wan-Chin; Park, No-Cheol

    2018-04-01

    In most cases of molding with glass or optical polymers, it is expected that there will be birefringence caused by the internal mechanical stresses remaining in the molding material. The distribution of the residual stress can be annealed by slow cooling, but this approach is disadvantageous with respect to the shape accuracy and manufacturing time. In this study, we propose an analytical model to calculate the diffracted field near the focal plane by considering two primary parameters, the orientation angle of the fast axis and the path difference. In order to verify the reliability of the analytical model, we compared the measured beam spot of the F-theta lens of the laser scanning unit (LSU) with the analytical result. In addition, we analyzed the calculated result from the perspective of the polarization status in the exit pupil. The proposed analysis method can be applied to enhance the image quality for cases in which birefringence occurs in a lens material by suitably modeling the amplitude and phase of the incident light flux.

  2. Optical spectroscopic characterization of amorphous germanium carbide materials obtained by X-Ray Chemical Vapor Deposition

    Directory of Open Access Journals (Sweden)

    Paola Antoniotti

    2015-05-01

    Full Text Available Amorphous germanium carbides have been prepared by X-ray activated Chemical Vapor Deposition from germane/allene systems. The allene percentage and irradiation time (total dose were correlated to the composition, the structural features, and the optical coefficients of the films, as studied by IR and UV-VIS spectroscopic techniques. The materials composition is found to change depending on both the allene percentage in the mixture and the irradiation time. IR spectroscopy results indicate that the solids consist of randomly bound networks of carbon and germanium atoms with hydrogen atoms terminating all the dangling bonds. Moreover, the elemental analysis results, the absence of both unsaturated bonds and CH3 groups into the solids and the absence of allene autocondensation reactions products, indicate that polymerization reactions leading to mixed species, containing Ge-C bonds, are favored. Eopt values around 3.5 eV have been found in most of the cases, and are correlated with C sp3-bonding configuration. The B1/2 value, related to the order degree, has been found to be dependent on solid composition, atoms distribution in the material and hydrogenation degree of carbon atoms.

  3. Mechanical and optical characterization of bio-nanocomposite from pineapple leaf fiber material for food packaging

    Science.gov (United States)

    Nikmatin, Siti; Rudwiyanti, Jerry R.; Prasetyo, Kurnia W.; Yedi, Dwi A.

    2015-01-01

    The utilization of Bio-nanocomposite material that was derived from pineapple leaf fiber as filler and tapioca starch with plasticizer glycerol as a matrix for food packaging can reduce the use of plastic that usually was made from petroleum materials. It is important to develop and producethis environmental friendly plastic because of limited availability of petroleum nowadays. The process of synthesize and characterization tapioca starch with the plasticizer glycerol bionanocomposites using print method had been conducted. There were 3 samples with different filler concentration variation; 3%, 4% and 5%.The results of mechanical test from each sample showed that bio-nanocomposite with 5% filler concentration was the optimum sample with 4.6320 MPa for tensile strength test and 24.87% for the elongation test. Based on the result of optical test for each sample was gained that along with the increasing of concentration filler would make the absorbance value of the sample became decreased, bio-nanocomposite with 5% filler concentration had several peaks with low absorbance values. The first peak was in 253 nm of wavelength regionwith absorbance of 0.131%, and the second peak was in 343 nmwavelength region and absorbance was 0.087%.

  4. New Organic Semiconductor Materials Applied in Organic Photovoltaic and Optical Devices

    Directory of Open Access Journals (Sweden)

    Andre F. S. Guedes

    2015-04-01

    Full Text Available The development of flexible organic photovoltaic solar cells, using an optically transparent substrate material and organic semiconductor materials, has been widely utilized by the electronic industry when producing new technological products. The flexible organic photovoltaic solar cells are the base Poly (3,4-ethylenedioxythiophene, PEDOT, Poly(3-hexyl thiophene, P3HT, Phenyl-C61-butyric acid methyl ester, PCBM and Polyaniline, PANI, were deposited in Indium Tin Oxide, ITO, and characterized by Electrical Measurements and Scanning Electron Microscopy (SEM. In addition, the thin film obtained by the deposition of PANI, prepared in perchloric acid solution, was identified through PANI-X1. The result obtained by electrical Measurements has demonstrated that the PET/ITO/PEDOT/P3HT:PCBM Blend/PANI-X1 layer presents the characteristic curve of standard solar cell after spin-coating and electrodeposition. The Thin film obtained by electrodeposition of PANI-X1 on P3HT/PCBM Blend was prepared in perchloric acid solution. These flexible organic photovoltaic solar cells presented power conversion efficiency of 12%. The inclusion of the PANI-X1 layer reduced the effects of degradation these organic photovoltaic panels induced for solar irradiation. In Scanning Electron Microscopy (SEM these studies reveal that the surface of PANI-X1 layers is strongly conditioned by the surface morphology of the dielectric.

  5. 3D Printed Robotic Hand

    Science.gov (United States)

    Pizarro, Yaritzmar Rosario; Schuler, Jason M.; Lippitt, Thomas C.

    2013-01-01

    Dexterous robotic hands are changing the way robots and humans interact and use common tools. Unfortunately, the complexity of the joints and actuations drive up the manufacturing cost. Some cutting edge and commercially available rapid prototyping machines now have the ability to print multiple materials and even combine these materials in the same job. A 3D model of a robotic hand was designed using Creo Parametric 2.0. Combining "hard" and "soft" materials, the model was printed on the Object Connex350 3D printer with the purpose of resembling as much as possible the human appearance and mobility of a real hand while needing no assembly. After printing the prototype, strings where installed as actuators to test mobility. Based on printing materials, the manufacturing cost of the hand was $167, significantly lower than other robotic hands without the actuators since they have more complex assembly processes.

  6. Effect of substrate material selection on polychromatic integral diffraction efficiency for multilayer diffractive optics in oblique incident situation

    Science.gov (United States)

    Zhang, Bo; Cui, Qingfeng; Piao, Mingxu

    2018-05-01

    The effect of substrate material selection for multilayer diffractive optical elements (MLDOEs) on polychromatic integral diffraction efficiency (PIDE) is studied in the oblique incident situation. A mathematical model of substrate material selection is proposed to obtain the high PIDE with large incident angle. The extended expression of the microstructure heights with consideration of incident angle is deduced to calculate the PIDE difference Δ η bar(λ) for different substrate material combinations. The smaller value of Δ η bar(λ) indicates the more optimal substrate material combination in a wide incident angle range. Based on the deduced mathematical model, different MLDOEs are analyzed in visible and infrared wavebands. The results show that the three-layer DOEs can be applied in larger incident angle situation than the double-layer DOEs in visible waveband. When the two substrate materials are the same, polycarbonate (PC) is more reasonable than poly(methyl methacrylate) (PMMA) as the middle filling optical material for the three-layer DOEs. In the infrared waveband, the PIDE decreases in the LWIR are obviously smaller than that in the MWIR for the same substrate material combination, and the PIDE cannot be calculated when the incident angle larger than critical angle. The analysis results can be used to guide the hybrid optical system design with MLDOEs.

  7. Nano-particle doped hydroxyapatite material evaluation using spectroscopic polarization sensitive optical coherence tomography

    Science.gov (United States)

    Strąkowska, Paulina; Trojanowski, Michał; Gardas, Mateusz; Głowacki, Maciej J.; Kraszewski, Maciej; Strąkowski, Marcin R.

    2015-03-01

    Bio-ceramics such as hydroxyapatite (HAp) are widely used materials in medical applications, especially as an interface between implants and living tissues. There are many ways of creating structures from HAp like electrochemical assisted deposition, biomimetic, electrophoresis, pulsed laser deposition or sol-gel processing. Our research is based on analyzing the parameters of the sol-gel method for creating thin layers of HAp. In order to achieve this, we propose to use Optical Coherence Tomography (OCT) for non-destructive and non-invasive evaluation. Our system works in the IR spectrum range, which is helpful due to the wide range of nanocomposites being opaque in the VIS range. In order to use our method we need to measure two samples, one which is a reference HAp solution and second: a similar HAp solution with nanoparticles introduced inside. We use silver nanoparticles below 300 nm. The aim of this research is to analyze the concentration and dispersion of nanodopants in the bio-ceramic matrix. Furthermore, the quality of the HAp coating and deposition process repetition have been monitored. For this purpose the polarization sensitive OCT with additional spectroscopic analysis is being investigated. Despite the other methods, which are suitable for nanocomposite materials evaluation, the OCT with additional features seems to be one of the few which belong to the NDE/NDT group. Here we are presenting the OCT system for evaluation of the HAp with nano-particles, as well as HAp manufacturing process. A brief discussion on the usefulness of OCT for bio-ceramics materials examination is also being presented.

  8. Multi-Purpose Anthropomorphic Robotic Hand Design for Extra-Vehicular Activity Manipulation Tasks using Embedded Fiber Optic Sensors, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — IFOS proposes to design and build fiber-optically sensorized robotic fingers that can sense force and, objects using only tactile feedback, similar to the skin on a...

  9. Advanced processing methods to introduce and preserve dipole orientation in organic electro-optic materials for next generation photonic devices

    Science.gov (United States)

    Huang, Su

    Organic electro-optic (E-O) materials have attracted considerable research attention in the past 20 years due to their rising potentials in a lot of novel photonic applications, such as high-speed telecommunication, terahertz generation and ultra-fast optical interconnections. Chapter 2 of this dissertation focuses on a barrier layer approach to improve the poling efficiency of electro-optic polymers. First of all, high conduction current from excessive charge injection is identified as a fundamental challenge of effective poling. After analyzing the conduction mechanism, we introduce a sol-gel derived thin titanium dioxide (TiO2) layer that can significantly block excessive charge injection and reduce the leakage current during high field poling. Ultralarge E-O coefficients, up to 160-350 pm/V at 1310 nm have been achieved by poling with such a barrier, which are 26%-40% higher than the results poled without such a TiO2 layer. This enhancement is explained by the suppressed charge injection and space charge accumulation by the insertion of the high injection barrier from the TiO2 barrier layer. In Chapter 3, the impact of the inserted barrier layer on the temporal alignment stability of E-O polymers is discussed. Considerable stability enhancement is confirmed using both standard 500-hour temporal alignment stability test at 85 °C and thermally stimulated discharge method. We suggest that the enhancement comes from improved stability of the screening charge. During poling the additional barrier layer helps to lower the injection and thus the space charge accumulation. And this reduced space charge accumulation further helps to replace the space charge part in the total formulation of screening charge with more stable interface trapped charge. We thus expand this knowledge to a group of other materials that can also block excessive charge injection and suppressed space charge accumulation, including dielectric polymers polyvinyl alcohol (PVA), poly(4-vinylphenol

  10. Antifungal, optical, and mechanical properties of polymethylmethacrylate material incorporated with silanized zinc oxide nanoparticles

    Directory of Open Access Journals (Sweden)

    Kamonkhantikul K

    2017-03-01

    Full Text Available Krid Kamonkhantikul,1 Mansuang Arksornnukit,1 Hidekazu Takahashi2 1Department of Prosthodontics, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand; 2Oral Biomaterials Engineering, Graduate School of Medical and Dental Sciences, Tokyo Medical and Dental University, Tokyo, Japan Background: Fungal infected denture, which is typically composed of polymethylmethacrylate (PMMA, is a common problem for a denture wearer, especially an elderly patient with limited manual dexterity. Therefore, increasing the antifungal effect of denture by incorporating surface modification nanoparticles into the PMMA, while retaining its mechanical properties, is of interest. Aim of the study: This study aimed to evaluate antifungal, optical, and mechanical properties of heat-cured PMMA incorporated with different amounts of zinc oxide nanoparticles (ZnOnps with or without methacryloxypropyltrimethoxysilane modification. Materials and methods: Specimens made from heat-cured PMMA containing 1.25, 2.5, and 5% (w/w nonsilanized (Nosi or silanized (Si ZnOnps were evaluated. Specimens without filler served as control. The fungal assay was performed placing a Candida albicans suspension on the PMMA surface for 2 h, then Sabouraud Dextrose Broth was added, and growth after 24 h was determined by counting colony forming units on agar plates. A spectrophotometer was used to measure the color in L* (brightness, a* (red-green, b* (yellow-blue and opacity of the experimental groups. Flexural strength and flexural modulus were determined using a three-point bending test on universal testing machine after 37°C water storage for 48 h and 1 month. Results: The antifungal, optical, and mechanical properties of the PMMA incorporated with ZnOnps changed depending on the amount. With the same amount of ZnOnps, the silanized groups demonstrated a greater reduction in C. albicans compared with the Nosi groups. The color difference (ΔE and opacity of the Nosi groups were

  11. Robotically enhanced rubber hand illusion.

    Science.gov (United States)

    Arata, Jumpei; Hattori, Masashi; Ichikawa, Shohei; Sakaguchi, Masamichi

    2014-01-01

    The rubber hand illusion is a well-known multisensory illusion. In brief, watching a rubber hand being stroked by a paintbrush while one's own unseen hand is synchronously stroked causes the rubber hand to be attributed to one's own body and to "feel like it's my hand." The rubber hand illusion is thought to be triggered by the synchronized tactile stimulation of both the subject's hand and the fake hand. To extend the conventional rubber hand illusion, we introduce robotic technology in the form of a master-slave telemanipulator. The developed one degree-of-freedom master-slave system consists of an exoskeleton master equipped with an optical encoder that is worn on the subject's index finger and a motor-actuated index finger on the rubber hand, which allows the subject to perform unilateral telemanipulation. The moving rubber hand illusion has been studied by several researchers in the past with mechanically connected rigs between the subject's body and the fake limb. The robotic instruments let us investigate the moving rubber hand illusion with less constraints, thus behaving closer to the classic rubber hand illusion. In addition, the temporal delay between the body and the fake limb can be precisely manipulated. The experimental results revealed that the robotic instruments significantly enhance the rubber hand illusion. The time delay is significantly correlated with the effect of the multisensory illusion, and the effect significantly decreased at time delays over 100 ms. These findings can potentially contribute to the investigations of neural mechanisms in the field of neuroscience and of master-slave systems in the field of robotics.

  12. Improved algorithm for estimating optical properties of food and biological materials using spatially-resolved diffuse reflectance

    Science.gov (United States)

    In this research, the inverse algorithm for estimating optical properties of food and biological materials from spatially-resolved diffuse reflectance was optimized in terms of data smoothing, normalization and spatial region of reflectance profile for curve fitting. Monte Carlo simulation was used ...

  13. Optical, magnetic, and dielectric properties of opal matrices with intersphere nanocavities filled with crystalline multiferroic, piezoelectric, and segnetoelectric materials

    Czech Academy of Sciences Publication Activity Database

    Samoilovich, M.I.; Rinkevich, A.B.; Bovtun, Viktor; Belyanin, A.F.; Kempa, Martin; Nuzhnyy, Dmitry; Tsvetkov, M.Yu.; Klescheva, S.M.

    2013-01-01

    Roč. 83, č. 11 (2013), s. 2132-2147 ISSN 1070-3632 R&D Projects: GA ČR GAP204/12/0232 Institutional support: RVO:68378271 Keywords : composites * opal matrices * optical, magnetic, and dielectric properties Subject RIV: JI - Composite Materials Impact factor: 0.418, year: 2013

  14. Roles of epsilon-near-zero (ENZ) and mu-near-zero (MNZ) materials in optical metatronic circuit networks.

    Science.gov (United States)

    Abbasi, Fereshteh; Engheta, Nader

    2014-10-20

    The concept of metamaterial-inspired nanocircuits, dubbed metatronics, was introduced in [Science 317, 1698 (2007); Phys. Rev. Lett. 95, 095504 (2005)]. It was suggested how optical lumped elements (nanoelements) can be made using subwavelength plasmonic or non-plasmonic particles. As a result, the optical metatronic equivalents of a number of electronic circuits, such as frequency mixers and filters, were suggested. In this work we further expand the concept of electronic lumped element networks into optical metatronic circuits and suggest a conceptual model applicable to various metatronic passive networks. In particular, we differentiate between the series and parallel networks using epsilon-near-zero (ENZ) and mu-near-zero (MNZ) materials. We employ layered structures with subwavelength thicknesses for the nanoelements as the building blocks of collections of metatronic networks. Furthermore, we explore how by choosing the non-zero constitutive parameters of the materials with specific dispersions, either Drude or Lorentzian dispersion with suitable parameters, capacitive and inductive responses can be achieved in both series and parallel networks. Next, we proceed with the one-to-one analogy between electronic circuits and optical metatronic filter layered networks and justify our analogies by comparing the frequency response of the two paradigms. Finally, we examine the material dispersion of near-zero relative permittivity as well as other physically important material considerations such as losses.

  15. Proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices

    International Nuclear Information System (INIS)

    Singh, R.; Messick, L.J.

    1989-01-01

    This book contains the proceedings of the first international conference on indium phosphide and related materials for advanced electronic and optical devices. Topics covered include: Growth and characterization of bulk and epitaxial films, Passivation technology, Processing technology, High speed optoelectronic integrated circuits, and Solar cells

  16. UV-cured polymer optics

    Science.gov (United States)

    Piñón, Victor; Santiago, Freddie; Vogelsberg, Ashten; Davenport, Amelia; Cramer, Neil

    2017-10-01

    Although many optical-quality glass materials are available for use in optical systems, the range of polymeric materials is limited. Polymeric materials have some advantages over glass when it comes to large-scale manufacturing and production. In smaller scale systems, they offer a reduction in weight when compared to glass counterparts. This is especially important when designing optical systems meant to be carried by hand. We aimed to expand the availability of polymeric materials by exploring both crown-like and flint-like polymers. In addition, rapid and facile production was also a goal. By using UV-cured thiolene-based polymers, we were able to produce optical materials within seconds. This enabled the rapid screening of a variety of polymers from which we down-selected to produce optical flats and lenses. We will discuss problems with production and mitigation strategies in using UV-cured polymers for optical components. Using UV-cured polymers present a different set of problems than traditional injection-molded polymers, and these issues are discussed in detail. Using these produced optics, we integrated them into a modified direct view optical system, with the end goal being the development of drop-in replacements for glass components. This optical production strategy shows promise for use in lab-scale systems, where low-cost methods and flexibility are of paramount importance.

  17. Laser ablation inductively coupled plasma optical emission spectrometry for analysis of pellets of plant materials

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Marcos S. [Departamento de Química, Universidade Federal de São Carlos, Rod. Washington Luís, km 235, 13565-905 São Carlos, SP (Brazil); Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Schenk, Emily R. [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States); Santos, Dário [Departamento de Ciências Exatas e da Terra, Universidade Federal de São Paulo, Rua Professor Arthur Riedel 275, Diadema, SP (Brazil); Krug, Francisco José [Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Av. Centenário 303, 13416-000 Piracicaba, SP (Brazil); Almirall, José R., E-mail: almirall@fiu.edu [Department of Chemistry and Biochemistry, Florida International University, Miami, FL (United States); International Forensic Research Institute, Florida International University, Miami, FL (United States)

    2014-04-01

    An evaluation of laser ablation inductively coupled plasma optical emission spectroscopy (LAICP OES) for the direct analysis of pelleted plant material is reported. Ground leaves of orange citrus, soy and sugarcane were comminuted using a high-speed ball mill, pressed into pellets and sampled directly with laser ablation and analyzed by ICP OES. The limits of detection (LODs) for the method ranged from as low as 0.1 mg kg{sup −1} for Zn to as high as 94 mg kg{sup −1} for K but were generally below 6 mg kg{sup −1} for most of the elements of interest. A certified reference material consisting of a similar matrix (NIST SRM 1547 peach leaves) was used to check the accuracy of the calibration and the reported method resulted in an average bias of ∼ 5% for all the elements of interest. The precision for the reported method ranged from as low as 4% relative standard deviation (RSD) for Mn to as high as 17% RSD for Zn but averaged ∼ 6.5% RSD for all the elements (n = 10). The proposed method was tested for the determination of Ca, Mg, P, K, Fe, Mn, Zn and B, and the results were in good agreement with those obtained for the corresponding acid digests by ICP-OES, no differences being observed by applying a paired t-test at the 95% confidence level. The reported direct solid sampling method provides a fast alternative to acid digestion that results in similar and appropriate analytical figures of merit with regard to sensitivity, accuracy and precision for plant material analysis. - Highlights: • An evaluation of LA-ICP-OES for the direct analysis of pelleted plant material is reported. • Orange citrus, soy and sugarcane plants were pressed into pellets and sampled directly. • The element menu consisted of Ca, Mg, P, K, Fe, Mn, Zn and B. • LODs for the method ranged from 0.1 mg kg{sup −1} for Zn to 94 mg kg{sup −1} for K. • The precision ranged from 4% RSD for Mn to 17% RSD for Zn (∼ 6.5% RSD average)

  18. Analysis of the fractures of metallic materials using optical coherence tomography

    Science.gov (United States)

    Hutiu, Gh.; Duma, V.-F.; Demian, D.; Bradu, A.; Podoleanu, A. Gh.

    2017-06-01

    Forensic in situ investigations, for example for aviation, maritime, road, or rail accidents would benefit from a method that may allow to distinguish ductile from brittle fractures of metals - as material defects are one of the potential causes of such accidents. Currently, the gold standard in material studies is represented by scanning electron microscopy (SEM). However, SEM are large, lab-based systems, therefore in situ measurements are excluded. In addition, they are expensive and time-consuming. We have approached this problem and propose the use of Optical Coherence Tomography (OCT) in such investigations in order to overcome these disadvantages of SEM. In this respect, we demonstrate the capability to perform such fracture analysis by obtaining the topography of metallic surfaces using OCT. Different materials have been analyzed; in this presentation a sample of low soft carbon steel with the chemical composition of C 0.2%, Mn 1.15%, S 0.04%, P 0.05 % and Fe for the rest has been considered. An in-house developed Swept Source (SS) OCT system has been used, and height profiles have been generated for the sample surface. This profile allowed for concluding that the carbon steel sample was subjected to a ductile fracture. A validation of the OCT images obtained with a 10 microns resolution has been made with SEM images obtained with a 4 nm resolution. Although the OCT resolution is much lower than the one of SEM, we thus demonstrate that it is sufficient in order to obtain clear images of the grains of the metallic materials and thus to distinguish between ductile and brittle fractures. This study analysis opens avenues for a range of applications, including: (i) to determine the causes that have generated pipe ruptures, or structural failures of metallic bridges and buildings, as well as damages of machinery parts; (ii) to optimize the design of various machinery; (iii) to obtain data regarding the structure of metallic alloys); (iv) to improve the

  19. Optics and children

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Manuel F M; De Campos, J Ayres; Lira, Madalena; Franco, Sandra [Centro de Fisica da Universidade do Minho (Portugal); Vazquez-Dorrio, Jose B, E-mail: mfcosta@fisica.uminho.pt [Universidad de Vigo, EIM, Departamento de Fisica (Spain)

    2011-01-01

    Light and Optics are subjects that 'naturally' attracts the interest and sympathy of children even from very early ages. In this communication, we present a series of experiments and support material designed in this hands-on perspective, to be used to introduce the study of light and optics to kindergarten and early basic school students. Our hands-on investigative approach leads the students, aged 4 to 10 years, to observe the experiment and discover themselves, in a critical and active way, different aspects of light and optics. Preparing funny eye catching situations and experiments predispose the children to work, effectively, enjoying themselves while building up their self-confidence.

  20. Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

    Directory of Open Access Journals (Sweden)

    Andrea A Andrew

    2016-02-01

    Full Text Available Some properties of dissolved organic matter (DOM and chromophoric dissolved organic matter (CDOM can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB and the Equatorial Atlantic Ocean (EAO. Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4.C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  1. Are extracted materials truly representative of original samples? Impact of C18 extraction on CDOM optical and chemical properties

    Science.gov (United States)

    Andrew, Andrea; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil

    2016-02-01

    Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  2. Are Extracted Materials Truly Representative of Original Samples? Impact of C18 Extraction on CDOM Optical and Chemical Properties.

    Science.gov (United States)

    Andrew, Andrea A; Del Vecchio, Rossana; Zhang, Yi; Subramaniam, Ajit; Blough, Neil V

    2016-01-01

    Some properties of dissolved organic matter (DOM) and chromophoric dissolved organic matter (CDOM) can be easily measured directly on whole waters, while others require sample concentration and removal of natural salts. To increase CDOM content and eliminate salts, solid phase extraction (SPE) is often employed. Biases following extraction and elution are inevitable, thus raising the question of how truly representative the extracted material is of the original. In this context, we investigated the wavelength dependence of extraction efficiency for C18 cartridges with respect to CDOM optical properties using samples obtained from the Middle Atlantic Bight (MAB) and the Equatorial Atlantic Ocean (EAO). Further, we compared the optical changes of C18 extracts and the corresponding whole water following chemical reduction with sodium borohydride (NaBH4). C18 cartridges preferentially extracted long-wavelength absorbing/emitting material for samples impacted by riverine input. Extraction efficiency overall decreased with offshore distance away from riverine input. Spectral slopes of C18-OM samples were also almost always lower than those of their corresponding CDOM samples supporting the preferential extraction of higher molecular weight absorbing material. The wavelength dependence of the optical properties (absorption, fluorescence emission, and quantum yield) of the original water samples and their corresponding extracted material were very similar. C18 extracts and corresponding water samples further exhibited comparable optical changes following NaBH4 reduction, thus suggesting a similarity in nature (structure) of the optically active extracted material, independent of geographical locale. Altogether, these data suggested a strong similarity between C18 extracts and corresponding whole waters, thus indicating that extracts are representative of the CDOM content of original waters.

  3. Optical confinement and light guiding in high dielectric contrast materials systems

    Science.gov (United States)

    Foresi, James S.

    A study of silicon photonic devices, including waveguides and microcavities, is presented in this thesis. The high index difference of Silicon-On-Insulator materials is used to design submicron devices capable of light localization and routing. Losses due to interface roughness between the high and low index materials are measured to be 40dB/cm. An analysis of lithographically induced interface roughness is performed and a method for evaluating nanometer-scale roughness is presented. High index differences lead to compact bends and power splitters. Bends of 2.0μm radius are measured to have losses less than 0.5dB. Splitting angles of 5o with losses less than 1.5dB are demonstrated. The bends and splitters are the most compact devices of their kind. The design, fabrication and analysis of two light confining devices in the SOI system are presented: photonic band gap (PBG) and microdisk microcavities. A PBG waveguide microcavity with minimum dimensions of 0.10μm is fabricated and transmission measurements reveal cavity Q's of 265, a resonant wavelength of 1564nm, and a modal volume of 0.27/mu m3. This is the first demonstration of PBG resonance at optical frequencies. The PBG microcavity volume is two orders of magnitude smaller than has been achieved in other microcavity devices. Microdisk and microring resonators are demonstrated. A waveguide-coupled microring is shown to operate as a channel dropping filter with Q's of 250 and a free spectral range of 25nm. The application of the microcavity devices to spontaneous emission control of erbium-doped silicon is analyzed. (Copies available exclusively from MIT Libraries, Rm. 14-0551, Cambridge, MA 02139-4307. Ph. 617-253-5668; Fax 617-253-1690.)

  4. Novel nanostructured materials to develop oxygen-sensitive films for optical sensors

    International Nuclear Information System (INIS)

    Fernandez-Sanchez, Jorge F.; Cannas, Rita; Spichiger, Stefan; Steiger, Rolf; Spichiger-Keller, Ursula E.

    2006-01-01

    Novel nanostructured materials, such as aluminum oxide (AlOOH), silicon oxide (SiO 2 ) or zirconium oxide (ZrO 2 ) embedded into PVA, were investigated as potential matrices to incorporate organometallic compounds (OMCs) for the development of optical oxygen-sensitive sensors which make use of the principle of luminescence quenching. In order to assess the benefits and drawbacks of the nanoporous material, the luminescence quantum yield and the Stern-Volmer constants were investigated and compared with the values shown for the same OMCs solubilized in polymer films (polystyrene). Referred to polymer films, the incorporation of the dyes into nanoporous membranes increased the Stern-Volmer constant by more than a factor of 100. Their response time was less than 1 s and the optode membranes were stable at room temperature for at least 9 months. Sterilization by autoclavation and gamma irradiation resulted in a marginal loss in activity. The photostability and sterilizability of the oxygen-sensitive membranes and the performance of the optodes with respect to of different types of metal oxides are discussed in the paper, as well as the influence of the total pore volume (TPV), the pore diameter (PD), the transparency of the film and the geometry of the pores. The OMCs used in this work were: ETH T -3003 (tris(4,7-bis(4-octylphenyl)-1,10-phenanthroline) ruthenium(II)), N-926 (bis(2-phenylpyridinyl)-N 4 ,N 4 ,N 4 ',N 4 '-tetramethyl-(4,4'-diamine-2,2'-bipyridine) iridium(III) chlorate), N-833 (tetrabutylammonium bis(isothiocyanate) bis(2-phenylpyridinyl)-iridium(III)) and N-837 (tetrabutylammonium bis(cyanate) bis(2-phenylpyridinyl)-iridium(III))

  5. Analysis of secondary electron emission for conducting materials using 4-grid LEED/AES optics

    International Nuclear Information System (INIS)

    Patino, M I; Wirz, R E; Raitses, Y; Koel, B E

    2015-01-01

    A facility utilizing 4-grid optics for LEED/AES (low energy electron diffraction/Auger electron spectroscopy) was developed to measure the total secondary electron yield and secondary electron energy distribution function for conducting materials. The facility and experimental procedure were validated with measurements of 50–500 eV primary electrons impacting graphite. The total yield was calculated from measurements of the secondary electron current (i) from the sample and (ii) from the collection assembly, by biasing each surface. Secondary electron yield results from both methods agreed well with each other and were within the spread of previous results for the total yield from graphite. Additionally, measurements of the energy distribution function of secondary electrons from graphite are provided for a wider range of incident electron energies. These results can be used in modeling plasma-wall interactions in plasmas bounded by graphite walls, such as are found in plasma thrusters, and divertors and limiters of magnetic fusion devices. (paper)

  6. All-optical control and super-resolution imaging of quantum emitters in layered materials.

    Science.gov (United States)

    Kianinia, Mehran; Bradac, Carlo; Sontheimer, Bernd; Wang, Fan; Tran, Toan Trong; Nguyen, Minh; Kim, Sejeong; Xu, Zai-Quan; Jin, Dayong; Schell, Andreas W; Lobo, Charlene J; Aharonovich, Igor; Toth, Milos

    2018-02-28

    Layered van der Waals materials are emerging as compelling two-dimensional platforms for nanophotonics, polaritonics, valleytronics and spintronics, and have the potential to transform applications in sensing, imaging and quantum information processing. Among these, hexagonal boron nitride (hBN) is known to host ultra-bright, room-temperature quantum emitters, whose nature is yet to be fully understood. Here we present a set of measurements that give unique insight into the photophysical properties and level structure of hBN quantum emitters. Specifically, we report the existence of a class of hBN quantum emitters with a fast-decaying intermediate and a long-lived metastable state accessible from the first excited electronic state. Furthermore, by means of a two-laser repumping scheme, we show an enhanced photoluminescence and emission intensity, which can be utilized to realize a new modality of far-field super-resolution imaging. Our findings expand current understanding of quantum emitters in hBN and show new potential ways of harnessing their nonlinear optical properties in sub-diffraction nanoscopy.

  7. Electro-optic and magneto-dielectric properties of multifunctional nitride and oxide materials

    Science.gov (United States)

    Dixit, Ambesh

    Materials that simultaneously exhibit different physical properties provide a rich area of research leading to the development of new devices. For example, materials having a strong coupling between charge and spin degrees of freedom are essential to realizing a new class of devices referred to generally as spintronics. However, these multifunctional systems pose new scientific challenges in understanding the origin and mechanisms for cross-control of different functionalities. The core of this Ph.D. dissertation deals with multifunctional nitride and oxide compound semiconductors as well as multiferroic magnetic oxide systems by investigating structural, optical, electrical, magnetic, magnetodielectric and magnetoelectric properties. Thin films of InN nitride compound semiconductors and closely related alloys have been investigated to understand the effects of intrinsic defects on the materials properties while considering possible applications of highly degenerate InN thin films. As grown rf sputtered InN films on c-axis (0001) sapphire exhibit highly degenerate n-type behaviour due to oxygen defects introduced during growth. The effect of oxygen in InN matrix has been further investigated by intentionally adding oxygen into the films. These studies confirm that oxygen is one of the main sources of donor electrons in degenerate InN. Above some critical concentration of oxygen, secondary phases of In 2O3 and In-O-N complexes were formed. It was also possible to tune the carrier concentration to produce changes in the plasmon frequency, which varied from 0.45 eV to 0.8 eV. This characteristic energy scale suggests that these highly degenerate InN thin films could be used for thermophotovoltaic cells, optical filters, and other IR electro-optic applications. To probe the magnetism in transition metal doped InN system, In 0.98Cr0.02N and In0.95Cr0.05N thin films were fabricated. Our results suggest that these films develop ferromagnetic order above room temperature

  8. Mid-infrared materials and devices on a Si platform for optical sensing

    Science.gov (United States)

    Singh, Vivek; Lin, Pao Tai; Patel, Neil; Lin, Hongtao; Li, Lan; Zou, Yi; Deng, Fei; Ni, Chaoying; Hu, Juejun; Giammarco, James; Soliani, Anna Paola; Zdyrko, Bogdan; Luzinov, Igor; Novak, Spencer; Novak, Jackie; Wachtel, Peter; Danto, Sylvain; Musgraves, J David; Richardson, Kathleen; Kimerling, Lionel C; Agarwal, Anuradha M

    2014-01-01

    In this article, we review our recent work on mid-infrared (mid-IR) photonic materials and devices fabricated on silicon for on-chip sensing applications. Pedestal waveguides based on silicon are demonstrated as broadband mid-IR sensors. Our low-loss mid-IR directional couplers demonstrated in SiNx waveguides are useful in differential sensing applications. Photonic crystal cavities and microdisk resonators based on chalcogenide glasses for high sensitivity are also demonstrated as effective mid-IR sensors. Polymer-based functionalization layers, to enhance the sensitivity and selectivity of our sensor devices, are also presented. We discuss the design of mid-IR chalcogenide waveguides integrated with polycrystalline PbTe detectors on a monolithic silicon platform for optical sensing, wherein the use of a low-index spacer layer enables the evanescent coupling of mid-IR light from the waveguides to the detector. Finally, we show the successful fabrication processing of our first prototype mid-IR waveguide-integrated detectors. PMID:27877641

  9. Imaging of dental material by polarization-sensitive optical coherence tomography

    Science.gov (United States)

    Dichtl, Sabine; Baumgartner, Angela; Hitzenberger, Christoph K.; Moritz, Andreas; Wernisch, Johann; Robl, Barbara; Sattmann, Harald; Leitgeb, Rainer; Sperr, Wolfgang; Fercher, Adolf F.

    1999-05-01

    Partial coherence interferometry (PCI) and optical coherence tomography (OCT) are noninvasive and noncontact techniques for high precision biometry and for obtaining cross- sectional images of biologic structures. OCT was initially introduced to depict the transparent tissue of the eye. It is based on interferometry employing the partial coherence properties of a light source with high spatial coherence ut short coherence length to image structures with a resolution of the order of a few microns. Recently this technique has been modified for cross section al imaging of dental and periodontal tissues. In vitro and in vivo OCT images have been recorded, which distinguish enamel, cemento and dentin structures and provide detailed structural information on clinical abnormalities. In contrast to convention OCT, where the magnitude of backscattered light as a function of depth is imaged, polarization sensitive OCT uses backscattered light to image the magnitude of the birefringence in the sample as a function of depth. First polarization sensitive OCT recordings show, that changes in the mineralization status of enamel or dentin caused by caries or non-caries lesions can result in changes of the polarization state of the light backscattered by dental material. Therefore polarization sensitive OCT might provide a new diagnostic imaging modality in clinical and research dentistry.

  10. Growth and characterizaion of urea p-nitrophenol crystal: an organic nonlinear optical material for optoelectronic device application

    Science.gov (United States)

    Suresh, A.; Manikandan, N.; Jauhar, RO. MU.; Murugakoothan, P.; Vinitha, G.

    2018-06-01

    Urea p-nitrophenol, an organic nonlinear optical crystal was synthesized and grown adopting slow evaporation and seed rotation method. Single crystal X-ray diffraction study confirmed the formation of the desired crystal. High resolution X-ray diffraction study showed the defect nature of the crystal. The presence of functional groups in the material was confirmed by FTIR analysis. UV-Vis-NIR study indicates that the grown crystal has a wider transparency region with the lower cutoff wavelength at 423 nm. The grown crystal is thermally stable up to 120 °C as assessed by TG-DTA analysis. The optical homogeneity of the grown crystal was confirmed by birefringence study. The 1064 nm Nd-YAG laser was used to obtain laser induced surface damage threshold which was found to be 0.38, 0.25 and 0.33 GW/cm2 for (0 1 0), (1 1 - 1) and (0 1 1) planes, respectively. The dielectric study was performed to find the charge distribution inside the crystal. The hardness property of the titular material has been found using Vicker's microhardness study. The optical nonlinearity obtained from third order nonlinear optical measurements carried out using Z-scan technique showed that these samples could be exploited for optical limiting studies.

  11. Super-resolution nanofabrication with metal-ion doped hybrid material through an optical dual-beam approach

    International Nuclear Information System (INIS)

    Cao, Yaoyu; Li, Xiangping; Gu, Min

    2014-01-01

    We apply an optical dual-beam approach to a metal-ion doped hybrid material to achieve nanofeatures beyond the optical diffraction limit. By spatially inhibiting the photoreduction and the photopolymerization, we realize a nano-line, consisting of polymer matrix and in-situ generated gold nanoparticles, with a lateral size of sub 100 nm, corresponding to a factor of 7 improvement compared to the diffraction limit. With the existence of gold nanoparticles, a plasmon enhanced super-resolution fabrication mechanism in the hybrid material is observed, which benefits in a further reduction in size of the fabricated feature. The demonstrated nanofeature in hybrid materials paves the way for realizing functional nanostructures

  12. Rare-earth-doped materials with application to optical signal processing, quantum information science, and medical imaging technology

    Science.gov (United States)

    Cone, R. L.; Thiel, C. W.; Sun, Y.; Böttger, Thomas; Macfarlane, R. M.

    2012-02-01

    Unique spectroscopic properties of isolated rare earth ions in solids offer optical linewidths rivaling those of trapped single atoms and enable a variety of recent applications. We design rare-earth-doped crystals, ceramics, and fibers with persistent or transient "spectral hole" recording properties for applications including high-bandwidth optical signal processing where light and our solids replace the high-bandwidth portion of the electronics; quantum cryptography and information science including the goal of storage and recall of single photons; and medical imaging technology for the 700-900 nm therapeutic window. Ease of optically manipulating rare-earth ions in solids enables capturing complex spectral information in 105 to 108 frequency bins. Combining spatial holography and spectral hole burning provides a capability for processing high-bandwidth RF and optical signals with sub-MHz spectral resolution and bandwidths of tens to hundreds of GHz for applications including range-Doppler radar and high bandwidth RF spectral analysis. Simply stated, one can think of these crystals as holographic recording media capable of distinguishing up to 108 different colors. Ultra-narrow spectral holes also serve as a vibration-insensitive sub-kHz frequency reference for laser frequency stabilization to a part in 1013 over tens of milliseconds. The unusual properties and applications of spectral hole burning of rare earth ions in optical materials are reviewed. Experimental results on the promising Tm3+:LiNbO3 material system are presented and discussed for medical imaging applications. Finally, a new application of these materials as dynamic optical filters for laser noise suppression is discussed along with experimental demonstrations and theoretical modeling of the process.

  13. Recent developments of optically stimulated luminescence materials and techniques for radiation dosimetry and clinical applications

    Directory of Open Access Journals (Sweden)

    Pradhan A

    2008-01-01

    Full Text Available During the last 10 years, optically stimulated luminescence (OSL has emerged as a formidable competitor not only to thermoluminescence dosimetry (TLD but also to several other dosimetry systems. Though a large number of materials have been synthesized and studied for OSL, Al 2 O 3 :C continues to dominate the dosimetric applications. Re-investigations of OSL in BeOindicate that this material might provide an alternative to Al 2 O 3 :C. Study of OSL of electronic components of mobile phones and ID cards appears to have opened up a feasibility of dosimetry and dose reconstruction using the electronic components of gadgets of everyday use in the events of unforeseen situations of radiological accidents, including the event of a dirty bomb by terrorist groups. Among the newly reported materials, a very recent development of NaMgF 3 :Eu 2+ appears fascinating because of its high OSL sensitivity and tolerable tissue equivalence. In clinical dosimetry, an OSL as a passive dosimeter could do all that TLD can do, much faster with a better or at least the same efficiency; and in addition, it provides a possibility of repeated readout unlike TLD, in which all the dose information is lost in a single readout. Of late, OSL has also emerged as a practical real-time dosimeter for in vivo measurements in radiation therapy (for both external beams and brachytherapy and in various diagnostic radiological examinations including mammography and CT dosimetry. For in vivo measurements, a probe of Al 2 O 3 :C of size of a fraction of a millimeter provides the information on both the dose rate and the total dose from the readout of radioluminescence and OSL signals respectively, from the same probe. The availability of OSL dosimeters in various sizes and shapes and their performance characteristics as compared to established dosimeters such as plastic scintillation dosimeters, diode detectors, MOSFET detectors, radiochromic films, etc., shows that OSL may soon become

  14. The effect of carbon chain length of starting materials on the formation of carbon dots and their optical properties

    Science.gov (United States)

    Pan, Xiaohua; Zhang, Yan; Sun, Xiaobo; Pan, Wei; Yu, Guifeng; Si, Shuxin; Wang, Jinping

    2018-04-01

    Carbon dots (CDs) have attracted increasing attention due to their high performances and potential applications in wide range of areas. However, their emission mechanism is not clear so far. In order to reveal more factors contributing to the emission of CDs, the effect of carbon chain length of starting materials on the formation of CDs and their optical properties was experimentally investigated in this work. In order to focus on the effect of carbon chain length, the starting materials with C, O, N in fully identical forms and only carbon chain lengths being different were selected for synthesizing CDs, including citric acid (CA) and adipic acid (AA) as carbon sources, and diamines with different carbon chain lengths (H2N(CH2)nNH2, n = 2, 4, 6) as nitrogen sources, as well as ethylenediamine (EDA) as nitrogen source and diacids with different carbon chain lengths (HOOC(CH2)nCOOH, n = 0, 2, 4, 6) as carbon sources. Therefore, the effect of carbon chain length of starting materials on the formation and optical properties of CDs can be systematically investigated by characterizing and comparing the structures and optical properties of as-prepared nine types of CDs. Moreover, the density of –NH2 on the surface of the CDs was quantitatively detected by a spectrophotometry so as to elucidate the relationship between the –NH2 related surface state and the optical properties.

  15. Influence of substrate material on the microstructure and optical properties of hot wall deposited SnS thin films

    International Nuclear Information System (INIS)

    Bashkirov, S.A.; Gremenok, V.F.; Ivanov, V.A.; Shevtsova, V.V.; Gladyshev, P.P.

    2015-01-01

    Tin monosulfide SnS raises an interest as a promising material for photovoltaics. The influence of the substrate material on the microstructure and optical properties of SnS thin films with [111] texture obtained by hot wall vacuum deposition on glass, molybdenum and indium tin oxide substrates is reported. The lattice parameters for layers grown on different substrates were determined by X-ray diffraction and their deviations from the data reported in the literature for single α-SnS crystals were discussed. The change in the degree of preferred orientation of the films depending on the substrate material is observed. The direct nature of the optical transitions with the optical band gap of 1.15 ± 0.01 eV is reported. - Highlights: • SnS thin films were hot wall deposited on glass, molybdenum and indium tin oxide. • Physical properties of the films were studied with respect to the substrate type. • The SnS lattice parameter deviations were observed and the explanation was given. • The direct optical transitions with the band gap of 1.15 ± 0.01 eV were observed

  16. Research of developing and processing technology of new visual and optical materials

    International Nuclear Information System (INIS)

    Kim, Sun Jae; Kim, K. H.; Rhee, C. K.; Lee, H. G.; Kim, W. W.; Jeon, C. J.; Park, S.; Kim, H. S.

    2000-08-01

    Crystalline TiO 2 powder with rutile phase for the plastic lens material was prepared by the homogeneous precipitation process at ambient or low temperatures (HPPLT) using simply heating aqueous TiOCl 2 solution. The transparent TiO 2 thin films and CR39/TiO 2 composite lens were fabricated using dispersed TiO 2 particle in the aqueous or organic solution. The monodisperse TiO 2 ultrafine particles with the diameters of 40 ∼ 400 nm were obtained from aqueous TiOCl 2 solution with an appropriate Ti 4+ concentration by the HPPLT. The process was carried out under the conditions in the ranges of 17 ∼ 230 deg C to prevent H 2 O evaporation completely and to make it freely or to prevent it thoroughly. The existence of SO 4 2- ion in aqueous TiOCl 2 solution make the preferential growth of the acicular primary particles suppressed, resulting in the spherical or round primary particles with the anatase phase. The ultrafine TiO 2 powder by the HPPLT was well dispersed with sizes of 20 ∼ 50 nm in n-butyl alcohol solution. The mixture of TiO 2 particles with silica sol, corresponding to 1.0 wt.% SiO 2 in 99 wt.% (TiO 2 + H 2 O) aqueous solution was coated with 40 ∼ 50 nm thickness on the substrate. The optical transmittance of CR39/TiO 2 composite lens with increase in the addition of the ultrafine TiO 2 powder decreases gradually although TiO 2 particles were well dispersed in n-butyl alcohol solution. Thus, it can be thought that it is appropriate to add 0.3 mL of 1.0 g TiO 2 /1000 mL n-butyl alcohol solution to the CR39 solution for the CR39/TiO2 composite lens with optical transmittances more than 90 %. It was also confirmed that PMMA/TiO 2 composite thin films showed a similar transmittance like the CR39/TiO 2 composite lens

  17. Research of developing and processing technology of new visual and optical materials

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun Jae; Kim, K. H.; Rhee, C. K.; Lee, H. G.; Kim, W. W.; Jeon, C. J.; Park, S.; Kim, H. S

    2000-08-01

    Crystalline TiO{sub 2} powder with rutile phase for the plastic lens material was prepared by the homogeneous precipitation process at ambient or low temperatures (HPPLT) using simply heating aqueous TiOCl{sub 2} solution. The transparent TiO{sub 2} thin films and CR39/TiO{sub 2} composite lens were fabricated using dispersed TiO{sub 2} particle in the aqueous or organic solution. The monodisperse TiO{sub 2} ultrafine particles with the diameters of 40 {approx} 400 nm were obtained from aqueous TiOCl{sub 2} solution with an appropriate Ti{sup 4+} concentration by the HPPLT. The process was carried out under the conditions in the ranges of 17 {approx} 230 deg C to prevent H{sub 2}O evaporation completely and to make it freely or to prevent it thoroughly. The existence of SO{sub 4}{sup 2-} ion in aqueous TiOCl{sub 2} solution make the preferential growth of the acicular primary particles suppressed, resulting in the spherical or round primary particles with the anatase phase. The ultrafine TiO{sub 2} powder by the HPPLT was well dispersed with sizes of 20 {approx} 50 nm in n-butyl alcohol solution. The mixture of TiO{sub 2} particles with silica sol, corresponding to 1.0 wt.% SiO{sub 2} in 99 wt.% (TiO{sub 2} + H{sub 2}O) aqueous solution was coated with 40 {approx} 50 nm thickness on the substrate. The optical transmittance of CR39/TiO{sub 2} composite lens with increase in the addition of the ultrafine TiO{sub 2} powder decreases gradually although TiO{sub 2} particles were well dispersed in n-butyl alcohol solution. Thus, it can be thought that it is appropriate to add 0.3 mL of 1.0 g TiO{sub 2}/1000 mL n-butyl alcohol solution to the CR39 solution for the CR39/TiO2 composite lens with optical transmittances more than 90 %. It was also confirmed that PMMA/TiO{sub 2} composite thin films showed a similar transmittance like the CR39/TiO{sub 2} composite lens.

  18. [Optical characteristics of colored dissolved organic material (CDOM) in Yangtze Estuary].

    Science.gov (United States)

    Zhu, Wei-Jian; Shen, Fang; Hong, Guan-Lin

    2010-10-01

    Absorption property of colored dissolved organic material (CDOM) is one of the most important contents to remote sensing of ocean color in estuarine and coastal areas. In this study, the optical properties and mixing behavior of CDOM in surface water of Yangtze Estuary were discussed according to the two surveys in August of 2008 and May of 2009. Based on the research, the absorption coefficient and spectral slope were discussed. It was found that in summer of 2008 CDOM absorption coefficients at 440 nm [a(g) (440)], ranged from 0.20 m(-1) to 0.73 m(-1), while the coefficients in 2009 varied between 0.20 m(-1) and 0.77 m(-1). Statistics showed that the power function model fitted the best in the regression analysis of CDOM absorption spectral. The spectral slopes (S(g2)) of CDOM calculated by the power function model ranged from 5.10 to 7.90 in Summer of 2008 and from 2.95 to 6.11 in Spring of 2009. The highest absorption coefficients of two cruises appeared both in the south passage of the Yangtze Estuary. The absorption coefficient in surfer water was observed varied tremendously in the estuary and the offshore area. And the main reason is affected by the turbidity maximum zone. It is observed that the absorption coefficients of CDOM tended to a homogeneous distribution whilst the layers of water mixed tempestuously, but otherwise it always showed a conservative mixing behavior. Because of the frequent mixture, there is not assured correlativity between S(g2) and a(g) (440). In the offshore area of Yangtze Estuary, the effecting of local production cannot be negligent, which differed from the estuary area. Yet when the hydrological environment was relatively stable, the negative relationship between them was very clear. In conclusion, the optical properties and mixing behavior of CDOM had showed tremendous different characteristics from inside the estuary to outside the estuary because of the influence of complex physical, chemical and hydrology conditions.

  19. The Marble-Hand Illusion.

    Science.gov (United States)

    Senna, Irene; Maravita, Angelo; Bolognini, Nadia; Parise, Cesare V

    2014-01-01

    Our body is made of flesh and bones. We know it, and in our daily lives all the senses constantly provide converging information about this simple, factual truth. But is this always the case? Here we report a surprising bodily illusion demonstrating that humans rapidly update their assumptions about the material qualities of their body, based on their recent multisensory perceptual experience. To induce a misperception of the material properties of the hand, we repeatedly gently hit participants' hand with a small hammer, while progressively replacing the natural sound of the hammer against the skin with the sound of a hammer hitting a piece of marble. After five minutes, the hand started feeling stiffer, heavier, harder, less sensitive, unnatural, and showed enhanced Galvanic skin response (GSR) to threatening stimuli. Notably, such a change in skin conductivity positively correlated with changes in perceived hand stiffness. Conversely, when hammer hits and impact sounds were temporally uncorrelated, participants did not spontaneously report any changes in the perceived properties of the hand, nor did they show any modulation in GSR. In two further experiments, we ruled out that mere audio-tactile synchrony is the causal factor triggering the illusion, further demonstrating the key role of material information conveyed by impact sounds in modulating the perceived material properties of the hand. This novel bodily illusion, the 'Marble-Hand Illusion', demonstrates that the perceived material of our body, surely the most stable attribute of our bodily self, can be quickly updated through multisensory integration.

  20. Every photon counts: improving low, mid, and high-spatial frequency errors on astronomical optics and materials with MRF

    Science.gov (United States)

    Maloney, Chris; Lormeau, Jean Pierre; Dumas, Paul

    2016-07-01

    Many astronomical sensing applications operate in low-light conditions; for these applications every photon counts. Controlling mid-spatial frequencies and surface roughness on astronomical optics are critical for mitigating scattering effects such as flare and energy loss. By improving these two frequency regimes higher contrast images can be collected with improved efficiency. Classically, Magnetorheological Finishing (MRF) has offered an optical fabrication technique to correct low order errors as well has quilting/print-through errors left over in light-weighted optics from conventional polishing techniques. MRF is a deterministic, sub-aperture polishing process that has been used to improve figure on an ever expanding assortment of optical geometries, such as planos, spheres, on and off axis aspheres, primary mirrors and freeform optics. Precision optics are routinely manufactured by this technology with sizes ranging from 5-2,000mm in diameter. MRF can be used for form corrections; turning a sphere into an asphere or free form, but more commonly for figure corrections achieving figure errors as low as 1nm RMS while using careful metrology setups. Recent advancements in MRF technology have improved the polishing performance expected for astronomical optics in low, mid and high spatial frequency regimes. Deterministic figure correction with MRF is compatible with most materials, including some recent examples on Silicon Carbide and RSA905 Aluminum. MRF also has the ability to produce `perfectly-bad' compensating surfaces, which may be used to compensate for measured or modeled optical deformation from sources such as gravity or mounting. In addition, recent advances in MRF technology allow for corrections of mid-spatial wavelengths as small as 1mm simultaneously with form error correction. Efficient midspatial frequency corrections make use of optimized process conditions including raster polishing in combination with a small tool size. Furthermore, a novel MRF

  1. Optical materials technology for energy efficiency and solar energy conversion 7

    International Nuclear Information System (INIS)

    Granqvist, C.G.; Lampert, C.M.

    1989-01-01

    This book covers the following topics: smart window coatings; Transparent infrared reflectors; Holographic concentrators and reflectors; Solar collecting devices; Solar absorber coatings; Optical properties and durability

  2. Crystal growth, vibrational, optical, thermal and theoretical studies of a nonlinear optical material: 2-Methyl 3,5-dinitrobenzoic acid

    Energy Technology Data Exchange (ETDEWEB)

    Sangeetha, K. [Department of Physics, Sri Sarada College for Women, Salem-16 (India); Guru Prasad, L. [Department of Science & Humanities, M. Kumarasamy College of Engineering, Karur (India); Mathammal, R. [Department of Physics, Sri Sarada College for Women, Salem-16 (India)

    2016-11-15

    Single crystals of 2-methyl 3,5-dinitro benzoic acid with reasonable size have been grown by slow evaporation solution growth method using ethanol as solvent. Quantum chemical calculation of 2-methyl 3,5-Dinitro benzoic acid was carried out by using DFT/B3LYP/6-31+G(d,p) method. The powder X-ray diffraction pattern was recorded and indexed. Both the experimental and theoretical vibrational spectrum validates the presence of functional groups. Polarizability, first order hyperpolarizability and the electric dipole moment values have been computed theoretically. The {sup 1}H and {sup 13}C NMR chemical shift of the molecule was calculated and compared with experimental results. TG/DSC analysis has been employed to understand the thermal and physio-chemical stability of the title compound. Frequency conversion property of the crystal was tested by Kurtz and Perry method. Optical absorption behavior of the grown crystal was examined by recording the optical spectrum and band gap energy was also estimated. The calculated HOMO and LUMO energy shows the charge transfer nature of the molecule.

  3. Chalcogenide glasses as optical and ion-conducting materials. Kogaku oyobi ion dendo zairyo toshite no chalcogenide glass

    Energy Technology Data Exchange (ETDEWEB)

    Toge, N.; Minami, T. (Univ. of Osaka Prefecture, Osaka (Japan))

    1991-12-01

    Nonoxide glasses whose main constituent are chalcogen elements like S, Se, or Te etc. show a lot of various properties, for instance, high infrared transmittancy and semi-conductivity which are already well known. Additionally, the optical properties change a lot along with the phase transition's happening between crystal and noncrystal under comparative low temperature. Further, it is also observed that the glasses containing proper cation appear high ion-conductivity. This paper supplies a brief reviews of chalcogenide glasses used as materials for infrared fiber, phase transition optical memory and superionic conductor, wherein the former two have already on the stage of utilization, particularly the realization of a rewritable optical memory is possible by using chalcogenide glasses film, and ion-conductor is in the phase to have shown the possibility of high conductivity while the development thereof is being expected. 22 refs., 8 figs.

  4. Silicon as a virtual plasmonic material: Acquisition of its transient optical constants and the ultrafast surface plasmon-polariton excitation

    Energy Technology Data Exchange (ETDEWEB)

    Danilov, P. A.; Ionin, A. A.; Kudryashov, S. I., E-mail: sikudr@sci.lebedev.ru; Makarov, S. V.; Rudenko, A. A. [Lebedev Physical Institute (Russian Federation); Saltuganov, P. N. [Moscow Institute of Physics and Technology (State University) (Russian Federation); Seleznev, L. V.; Yurovskikh, V. I.; Zayarny, D. A. [Lebedev Physical Institute (Russian Federation); Apostolova, T. [Bulgarian Academy of Sciences, Institute for Nuclear Research and Nuclear Energetics (Bulgaria)

    2015-06-15

    Ultrafast intense photoexcitation of a silicon surface is complementarily studied experimentally and theoretically, with its prompt optical dielectric function obtained by means of time-resolved optical reflection microscopy and the underlying electron-hole plasma dynamics modeled numerically, using a quantum kinetic approach. The corresponding transient surface plasmon-polariton (SPP) dispersion curves of the photo-excited material were simulated as a function of the electron-hole plasma density, using the derived optical dielectric function model, and directly mapped at several laser photon energies, measuring spatial periods of the corresponding SPP-mediated surface relief nanogratings. The unusual spectral dynamics of the surface plasmon resonance, initially increasing with the increase in the electron-hole plasma density but damped at high interband absorption losses induced by the high-density electron-hole plasma through instantaneous bandgap renormalization, was envisioned through the multi-color mapping.

  5. Effects of antifreezes and bundled material on the stability and optical limiting in aqueous suspensions of carbon nanotubes

    Energy Technology Data Exchange (ETDEWEB)

    Vlasov, Andrey Yu.; Venediktova, Anastasia V.; Sokolova, Ekaterina P. [Department of Chemistry, St. Petersburg State University, Universitetsky Pr. 26, St. Petersburg 198504 (Russian Federation); Videnichev, Dmitry A. [S.I. Vavilov State Optical Institute, Birzhevaya line 12, St. Petersburg 199034 (Russian Federation); St. Petersburg National Research University ITMO, Kronverksky pr. 49, St. Petersburg 197101 (Russian Federation); Lasers and Optical Systems JSC, Birzhevaya line 12, St. Petersburg 199034 (Russian Federation); Kislyakov, Ivan M. [S.I. Vavilov State Optical Institute, Birzhevaya line 12, St. Petersburg 199034 (Russian Federation); St. Petersburg National Research University ITMO, Kronverksky pr. 49, St. Petersburg 197101 (Russian Federation); Obraztsova, Elena D. [A.M. Prokhorov Institute of General Physics, Russian Academy of Sciences, Vavilov Str. 38, Moscow 119991 (Russian Federation)

    2012-12-15

    This work gives data on the stability of dispersions of single wall carbon nanotubes stabilized by sodium dodecylbenzenesulfonate in binary polar solvents ''water + antifreeze'' (glycerol, polyethyleneglycole) with eutectic compositions. The absorption spectra of the suspensions demonstrate no changes during 1-year storage with temperature spanning from -40 to +40 C. The systems provide relevant optical power limiting properties, the one with glycerol showing good resistance to optical bleaching effects. We also demonstrate that aqueous dispersions of nanotubes exhibit considerable enhancement of optical limiting parameters alongside an increase of the bundled material populace. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  6. Structural, optical and electrical properties of europium picrate tetraethylene glycol complex as emissive material for OLED

    Energy Technology Data Exchange (ETDEWEB)

    Kusrini, Eny, E-mail: ekusrini@che.ui.ac.id [Department of Chemical Engineering, Faculty of Engineering, Universitas Indonesia, 16424 Depok (Indonesia); Saleh, Muhammad I.; Adnan, Rohana [School of Chemical Sciences, Universiti Sains Malaysia, 11800 Penang (Malaysia); Yulizar, Yoki [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Indonesia, 16424 Depok (Indonesia); Sha Shiong, Ng; Fun, H.K. [School of Physics, Universiti Sains Malaysia, 11800 Penang (Malaysia); Adhha Abdullah, M.A.; Mamat, Mazidah [Department of Chemical Sciences, Faculty of Science and Technology, Universiti Malaysia Terengganu, 21030 Kuala Terengganu, Terengganu Darul Iman (Malaysia); Za' aba, N.K.; Abd. Majid, W.H. [Solid State Research Laboratory, Department of Physics, Universiti Malaya, 50603 Kuala Lumpur (Malaysia)

    2012-01-15

    A new europium complex [Eu(Pic){sub 2}(H{sub 2}O)(EO4)](Pic).0.75H{sub 2}O was synthesized and used as the emission material for the single layer device structure of ITO/EO4-Eu-Pic/Al, using a spin-coating technique. Study on the optical properties of the [Eu(Pic){sub 2}(H{sub 2}O)(EO4)](Pic).0.75H{sub 2}O complex where EO4=tetraethylene glycol and Pic=picrate anion, had to be undertaken before being applicable to the study of an organic light emitting diode (OLED). The electrical property of an OLED using current-voltage (I-V) measurement was also studied. In complex, the Eu(III) ion was coordinated with the EO4 ligand as a pentadentate mode, one water molecule, and with two Pic anions as bidentate and monodentate modes, forming a nine-coordination number. The photoluminescence (PL) spectra of the crystalline complex in the solid state and its thin film showed a hypersensitive peak at 613.5-614.9 nm that assigned to the {sup 5}D{sub 0}{yields}{sup 7}F{sub 2} transition. A narrow band emission from the thin film EO4-Eu-Pic was obtained. The typical semiconductor I-V curve of device ITO/EO4-Eu-Pic/Al showed the threshold and turn on voltages at 1.08 and 4.6 V, respectively. The energy transfer process from the ligand to the Eu(III) ion was discussed by investigating the excitation and PL characteristics. Effect of the picrate anion on the device performance was also studied. - Highlights: > The [Eu(Pic){sub 2}(H{sub 2}O)(EO4)](Pic).0.75(H{sub 2}O) is crystallized in triclinic with space group P-1. > The complex is applied as a emissive center in single layer device structure of ITO/EO4-Eu-Pic/Al. > The complex displays a red luminescence in both the crystalline complex and its thin film state. > The low turn on voltage of the device (4.6 V), indicating that this material is suitable for OLED. > The roughness and morphology of the thin film affects luminance and electrical properties of OLED.

  7. Influence of implant abutment material and ceramic thickness on optical properties.

    Science.gov (United States)

    Jirajariyavej, Bundhit; Wanapirom, Peeraphorn; Anunmana, Chuchai

    2018-05-01

    Anterior shade matching is an essential factor influencing the esthetics of a ceramic restoration. Dentists face a challenge when the color of an implant abutment creates an unsatisfactory match with the ceramic restoration or neighboring teeth. The purpose of this in vitro study was to evaluate the influence of abutment material and ceramic thickness on the final color of different ceramic systems. Four experimental and control ceramic specimens in shade A3 were cut from IPS e.max CAD, IPS Empress CAD, and VITA Suprinity PC blocks. These specimens had thicknesses of 1.0 mm, 1.5 mm, 2.0 mm, and 2.5 mm, respectively, for the experimental groups, and 4 mm for the controls. Background abutment specimens were fabricated to yield 3 different shades: white zirconia, yellow zirconia, and titanium at a 3-mm thickness. All 3 ceramic specimens in each thickness were placed in succession on different abutment backgrounds with glycerin optical fluid in between, and the color was measured. A digital spectrophotometer was used to record the specimen color value in the Commission Internationale De L'éclairage (CIELab) color coordinates system and to calculate the color difference (ΔE) between the control and experimental groups. The Kruskal-Wallis test was used to analyze the effect of ceramic thickness on different abutments, and the pair-wise test was used to evaluate within the group (α=.05). The color differences between the test groups and the control decreased with increasing ceramic thickness for every background material. In every case, significant differences were found between 1.0- and 2.5-mm ceramic thicknesses. Only certain 2.5-mm e.max CAD, VITA Suprinity PC, and Empress CAD specimens on yellow-shade zirconia or VITA Suprinity PC on titanium were identified as clinically acceptable (ΔEabutment background decreased the color mismatch. Increasing the thickness of ceramic on a yellow-shaded zirconia abutment rather than on titanium or white zirconia yielded a more

  8. Self-Cleaning Coatings and Materials for Decontaminating Field-Deployable Land and Water-Based Optical Systems

    Science.gov (United States)

    Ryan, Robert; Underwood, Lauren; Holekamp, Kara; May, George; Spiering, Bruce; Davis, Bruce

    2011-01-01

    This technology exploits the organic decomposition capability and hydrophilic properties of the photocatalytic material titanium dioxide (TiO2), a nontoxic and non-hazardous substance, to address contamination and biofouling issues in field-deployed optical sensor systems. Specifically, this technology incorporates TiO2 coatings and materials applied to, or integrated as a part of, the optical surfaces of sensors and calibration sources, including lenses, windows, and mirrors that are used in remote, unattended, ground-based (land or maritime) optical sensor systems. Current methods used to address contamination or biofouling of these optical surfaces in deployed systems are costly, toxic, labor intensive, and non-preventative. By implementing this novel technology, many of these negative aspects can be reduced. The functionality of this innovative self-cleaning solution to address the problem of contamination or biofouling depends on the availability of a sufficient light source with the appropriate spectral properties, which can be attained naturally via sunlight or supplemented using artificial illumination such as UV LEDs (light emitting diodes). In land-based or above-water systems, the TiO2 optical surface is exposed to sunlight, which catalyzes the photocatalytic reaction, facilitating both the decomposition of inorganic and organic compounds, and the activation of superhydrophilic properties. Since underwater optical surfaces are submerged and have limited sunlight exposure, supplementary UV light sources would be required to activate the TiO2 on these optical surfaces. Nighttime operation of land-based or above-water systems would require this addition as well. For most superhydrophilic self-cleaning purposes, a rainwater wash will suffice; however, for some applications an attached rainwater collector/ dispenser or other fresh water dispensing system may be required to wash the optical surface and initiate the removal of contaminates. Deployment of this

  9. Energies of rare-earth ion states relative to host bands in optical materials from electron photoemission spectroscopy

    Science.gov (United States)

    Thiel, Charles Warren

    There are a vast number of applications for rare-earth-activated materials and much of today's cutting-edge optical technology and emerging innovations are enabled by their unique properties. In many of these applications, interactions between the rare-earth ion and the host material's electronic states can enhance or inhibit performance and provide mechanisms for manipulating the optical properties. Continued advances in these technologies require knowledge of the relative energies of rare-earth and crystal band states so that properties of available materials may be fully understood and new materials may be logically developed. Conventional and resonant electron photoemission techniques were used to measure 4f electron and valence band binding energies in important optical materials, including YAG, YAlO3, and LiYF4. The photoemission spectra were theoretically modeled and analyzed to accurately determine relative energies. By combining these energies with ultraviolet spectroscopy, binding energies of excited 4fN-15d and 4fN+1 states were determined. While the 4fN ground-state energies vary considerably between different trivalent ions and lie near or below the top of the valence band in optical materials, the lowest 4f N-15d states have similar energies and are near the bottom of the conduction band. As an example for YAG, the Tb3+ 4f N ground state is in the band gap at 0.7 eV above the valence band while the Lu3+ ground state is 4.7 eV below the valence band maximum; however, the lowest 4fN-15d states are 2.2 eV below the conduction band for both ions. We found that a simple model accurately describes the binding energies of the 4fN, 4fN-1 5d, and 4fN+1 states. The model's success across the entire rare-earth series indicates that measurements on two different ions in a host are sufficient to predict the energies of all rare-earth ions in that host. This information provides new insight into electron transfer transitions, luminescence quenching, and valence

  10. Analyses of significant features of L-Prolinium Picrate single crystal: An excellent material for non linear optical applications

    Energy Technology Data Exchange (ETDEWEB)

    Thukral, Kanika [Academy of Scientific and Innovative Research, CSIR- National Physical Laboratory, New Delhi, 110012 (India); CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Vijayan, N., E-mail: nvijayan@nplindia.org [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Vij, Mahak [CSIR-National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi, 110 012 (India); Nagaraja, C.M. [Department of Chemistry, Indian Institute of Technology Ropar, Rupnagar, 140001, Punjab (India); Jayaramakrishnan, V. [Centro De Investigations En Optica, Loma del Bosque 115, Colonia Lomas del Campestre, León, Guanajuato, Código Postal, 37150 (Mexico); Jayalakshmy, M.S. [International and Inter University Centre for Nanoscience and Nanotechnology, Mahatma Gandhi University, Kottayam, Kerala, 686560 (India); Kant, Rajni [Department of Physics and Electronics, University of Jammu, Jammu Tawi, 180006 (India)

    2017-06-15

    Today the fundamental aspect of the researchers is to explore maximum physical properties of the material for device fabrication. In the present article, single crystal X-ray diffraction has been carried out to verify the formation of the synthesized compound. In addition to that, powder X-ray diffraction has been performed to obtain diffraction pattern of L-Prolinium Picrate single crystal. The strain present inside the single crystal was measured using Hall-Williamson equation from PXRD measurements. The dark current and photon current was obtained from photoconductivity technique whose plot depicted that the sample was negative photoconducting material. Optical homogeneity of the single crystal was analyzed using birefringence technique. Its resistance towards Nd: YAG laser was scrutinized for L-Prolinium Picrate single crystal by applying 1 pulse per second. Different thermal parameters like thermal conductivity, thermal diffusivity, thermal effusivity and specific heat were computed using photo-pyroelectric technique. Solid state parameters were calculated from Clausius Mossotti relation by taking structural information of the title compound. Also, optical parameters like refractive index, reflectance etc were calculated through UV–Vis–NIR analysis. - Highlights: • An optically transparent L-Prolinium Picrate single crystal was harvested from slow evaporation solution growth technique. • The compound shows negative photoconducting nature. • Its optical homogeneity was analyzed using birefringence. • Single shot of laser was applied to sample to measure laser damage threshold value. • The thermal parameters were computed from Photopyroelectric technique.

  11. Non-Linear Optical Phenomena in Detecting Materials as a Possibility for Fast Timing in Detectors of Ionizing Radiation

    CERN Document Server

    Korjik, M. V.; Buganov, O.; Fedorov, A. A.; Emelianchik, I.; Griesmayer, E.; Mechinsky, V.; Nargelas, S.; Sidletskiy, O.; Tamulaitis, G.; Tikhomirov, S. N.; Vaitkevicius, A.

    2016-01-01

    The time resolution of the detectors currently in use is limited by 50-70 ps due to the spontaneous processes involved in the development of the response signal, which forms after the relaxation of carriers generated during the interaction. In this study, we investigate the feasibility of exploiting sub-picosecond phenomena occurring after the interaction of scintillator material with ionizing radiation by probing the material with ultra-short laser pulses. One of the phenomena is the elastic polarization due to the local lattice distortion caused by the displacement of electrons and holes generated by ionization. The key feature of the elastic polarization is its short response time, which makes it prospective for using as an optically detectable time mark. The nonlinear optical absorption of femtosecond light pulses of appropriate wavelength is demonstrated to be a prospective tool to form the mark. This study was aimed at searching for inorganic crystalline media combining scintillation properties and non-...

  12. Research progress of cholesteric liquid crystals with broadband reflection characteristics in application of intelligent optical modulation materials

    International Nuclear Information System (INIS)

    Zhang Lan-Ying; Gao Yan-Zi; Song Ping; Yuan Xiao; He Bao-Feng; Yang Huai; Wu Xiao-Juan; Chen Xing-Wu; Hu Wang; Guo Ren-Wei; Ding Hang-Jun; Xiao Jiu-Mei

    2016-01-01

    Cholesteric liquid crystals (CLCs) have recently sparked an enormous amount of interest in the development of soft matter materials due to their unique ability to self-organize into a helical supra-molecular architecture and their excellent selective reflection of light based on the Bragg relationship. Nowadays, by the virtue of building the self-organized nanostructures with pitch gradient or non-uniform pitch distribution, extensive work has already been performed to obtain CLC films with a broad reflection band. Based on authors’ many years’ research experience, this critical review systematically summarizes the physical and optical background of the CLCs with broadband reflection characteristics, methods to obtain broadband reflection of CLCs, as well as the application in the field of intelligent optical modulation materials. Combined with the research status and the advantages in the field, the important basic and applied scientific problems in the research direction are also introduced. (topical review)

  13. Quantum and Classical Optics of Plasmonic Systems: 3D/2D Materials and Photonic Topological Insulators

    Science.gov (United States)

    Hassani Gangaraj, Seyyed Ali

    waveguide edges can lead to a significant increase in entanglement compared to the case of the emitter coupled to an infinite plasmonic waveguide. Moreover, even for the infinite-length case, discontinuities in the waveguides do not always play a detrimental role, to be more specific, an increase in entanglement compared to the unperturbed waveguides can be achieved by introducing coupling slots (engineered perturbations) into the structure. In addition to 3D environments, two dimensional (2D) materials are of intense interest due to their extraordinary capabilities to manipulate reflection and transmission characteristics, and beam-forming. Some notable examples of 2D layered crystals include graphene, black phosphorus (BP) and boron nitride. Graphene in particular has received considerable attention as a promising 2D surface for many applications relating to its integrability and electronic tune-ability. Black phosphorus is also a layered material that has recently been exfoliated into its multilayers, showing good electrical transport properties and promising optical charactristics. Most of the previous studies of the electromagnetic response of 2D surfaces and metallic surface plasmons have considered isotropic structures with omnidirectional plasmonic surface wave propagation on the plane of these materials. Such an omnidirectional surface wave propagation does not allow for launching energy from electromagnetic source to a specific target on the surface, which is a desirable characteristic. However, an appropriate structured anisotropic surface can provide such a capability, such as an array of graphene strips. In addition, by tuning of the graphene doping it is possible to have a hyperbolic surface response. Working in this regime of surface conductivity, it is possible to launch SPPs along a specific direction, which is tunable via doping of the graphene. In this work, the electromagnetic response of anisotropic 2D surfaces has been investigated based on the

  14. Clean Hands Count

    Medline Plus

    Full Text Available ... has been rented. This feature is not available right now. Please try again later. Published on May ... 34 How The Clean Hands - Safe Hands System Works - Duration: 3:38. Clean Hands-Safe Hands 5, ...

  15. Optical-televiewer-based identification and characterization of material facies associated with an Antarctic ice-shelf rift

    OpenAIRE

    Hubbard, B.; Tison, J.-L.; Pattyn, F.; Dierckx, M.; Boereboom, T.; Samyn, D.

    2012-01-01

    We have drilled 13 boreholes within and around a through-cutting rift on the (unofficially named) Roi Baudouin Ice Shelf, East Antarctica. Logging by optical televiewer (OPTV) combined with core inspection has resulted in the identification and characterization of several material facies. Outside the rift, OPTV-imaged annual layering indicates ~150 years of accumulation over the 66m length of one of the boreholes. Luminosity analysis of this image also reveals the presence of numerous dark me...

  16. Optical roughness BRDF model for reverse Monte Carlo simulation of real material thermal radiation transfer.

    Science.gov (United States)

    Su, Peiran; Eri, Qitai; Wang, Qiang

    2014-04-10

    Optical roughness was introduced into the bidirectional reflectance distribution function (BRDF) model to simulate the reflectance characteristics of thermal radiation. The optical roughness BRDF model stemmed from the influence of surface roughness and wavelength on the ray reflectance calculation. This model was adopted to simulate real metal emissivity. The reverse Monte Carlo method was used to display the distribution of reflectance rays. The numerical simulations showed that the optical roughness BRDF model can calculate the wavelength effect on emissivity and simulate the real metal emissivity variance with incidence angles.

  17. Broader color gamut of color-modulating optical coating display based on indium tin oxide and phase change materials.

    Science.gov (United States)

    Ni, Zhigang; Mou, Shenghong; Zhou, Tong; Cheng, Zhiyuan

    2018-05-01

    A color-modulating optical coating display based on phase change materials (PCM) and indium tin oxide (ITO) is fabricated and analyzed. We demonstrate that altering the thickness of top-ITO in this PCM-based display device can effectively change color. The significant role of the top-ITO layer in the thin-film interference in this multilayer system is confirmed by experiment as well as simulation. The ternary-color modulation of devices with only 5 nano thin layer of phase change material is achieved. Furthermore, simulation work demonstrates that a stirringly broader color gamut can be obtained by introducing the control of the top-ITO thickness.

  18. Growth and characterization of benzaldehyde 4-nitro phenyl hydrazone (BPH) single crystal: A proficient second order nonlinear optical material

    Science.gov (United States)

    Saravanan, M.; Abraham Rajasekar, S.

    2016-04-01

    The crystals (benzaldehyde 4-nitro phenyl hydrazone (BPH)) appropriate for NLO appliance were grown by the slow cooling method. The solubility and metastable zone width measurement of BPH specimen was studied. The material crystallizes in the monoclinic crystal system with noncentrosymmetric space group of Cc. The optical precision in the whole visible region was found to be excellent for non-linear optical claim. Excellence of the grown crystal is ascertained by the HRXRD and etching studies. Laser Damage Threshold and Photoluminescence studies designate that the grown crystal contains less imperfection. The mechanical behaviour of BPH sample at different temperatures was investigated to determine the hardness stability of the grown specimen. The piezoelectric temperament and the relative Second Harmonic Generation (for diverse particle sizes) of the material were also studied. The dielectric studies were executed at varied temperatures and frequencies to investigate the electrical properties. Photoconductivity measurement enumerates consummate of inducing dipoles due to strong incident radiation and also divulge the nonlinear behaviour of the material. The third order nonlinear optical properties of BPH crystals were deliberate by Z-scan method.

  19. Characterization of an optically stimulated luminescence (OSL) material for thermal neutron detection: SrS:Ce,Sm,B

    International Nuclear Information System (INIS)

    Ravotti, Federico; Garcia, Pierre; Prevost, Hildegarde; Dusseau, Laurent; Lapraz, Dominique; Vaille, Jean-Roch; Benoit, David

    2008-01-01

    SrS:Ce,Sm exhibits some interesting phosphorescent and charge storage properties that are used in OSL (optically stimulated luminescence) radiation dosimetry. To enhance the thermal neutron sensitivity of this phosphor, a new material obtained by boron doping has been developed. This OSL, B material was analysed with respect to its optical and structural characteristics in order to study possible modifications induced by doping procedure. Optical study highlights a decrease in the material luminescence of about 40% with TL and OSL experiments. The emission spectrum remains the same after boron addition. This result is in agreement with the structural characterization analysis since the lattice parameters were not modified. 11B MAS NMR results indicate that boron atoms are present in the host lattice in form of BO4 groups. Consequences on dosimetry applications are discussed. The neutron response of the OSL, B irradiated in a nuclear reactor is linear up to a fluence of 5 x 1011 cm -2 and it is possible to separate the thermal neutron and gamma components. (copyright 2008 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  20. Handbook of coherent domain optical methods biomedical diagnostics, environmental and material science

    CERN Document Server

    2004-01-01

    For the first time in one set of books, coherent-domain optical methods are discussed in the framework of various applications, which are characterized by a strong light scattering. A few chapters describe basic research containing the updated results on coherent and polarized light non-destructive interactions with a scattering medium, in particular, diffraction, interference, and speckle formation at multiple scattering. These chapters allow for understanding coherent-domain diagnostic techniques presented in later chapters. A large portion of Volume I is dedicated to analysis of various aspects of optical coherence tomography (OCT) - a very new and growing field of coherent optics. Two chapters on laser scanning confocal microscopy give insight to recent extraordinary results on in vivo imaging and compare the possibilities and achievements of confocol, excitation multiphoton, and OCT microscopy. This two volume reference contains descriptions of holography, interferometry and optical heterodyning techniqu...

  1. Stechiometric neodymium compounds as new materials for light sources in integrated optics

    International Nuclear Information System (INIS)

    Malinowski, M.

    1981-01-01

    Short review of physico-chemical properties of stechiometric neodymium compounds has been presented. Several constructions of minilasers as promising light sources for integrated optics devices have been described. (author)

  2. Optical Trap Methods to Determine the Viscoelastic Properties of Biological Materials | NCI Technology Transfer Center | TTC

    Science.gov (United States)

    The National Cancer Institute seeks licensees and/or co-development partners for methods that provide significant improvements in examining clinically relevant tissue samples, by improving spatial resolution and tissue depth using optical trapping. 

  3. Improved Hand Hygiene Compliance is Associated with the Change of Perception toward Hand Hygiene among Medical Personnel

    OpenAIRE

    Lee, Seung Soon; Park, Se Jeong; Chung, Moon Joo; Lee, Ju Hee; Kang, Hyun Joo; Lee, Jeong-a; Kim, Yong Kyun

    2014-01-01

    Background Hand hygiene compliance has improved significantly through hand hygiene promotion programs that have included poster campaign, monitoring and performance feedback, and education with special attentions to perceived subjective norms. We investigated factors associated with improved hand hygiene compliance, focusing on whether the improvement of hand hygiene compliance is associated with changed perception toward hand hygiene among medical personnel. Materials and Methods Hand hygien...

  4. Quasi-optic millimeter-wave device application of liquid crystal material by using porous PMMA matrix

    Science.gov (United States)

    Nose, T.; Watanabe, Y.; Kon, A.; Ito, R.; Honma, M.

    2018-02-01

    Recently, millimeter-waves (MMWs) have become indispensable for application in next-generation high-speed wireless communication i.e., 5G, in addition to conventional applications such as in automobile collision avoidance radars and airport security inspection systems. Some manageable devices to control MMW propagation will be necessary with the development of this new technology field. We believe that liquid crystal (LC) devices are one of the major candidates for such applications because it is known that LC materials are excellent electro-optic materials. However, as the wavelength of MMWs is extremely longer than the optics region, extremely thick LC layers are necessary if we choose the quasioptic approach to attain LC MMW control devices. Therefore, we adopt a PDLC structure to attain the extremely thick LC layers by using porous (polymethyl methacrylate) PMMA materials, which can be easily obtained using a solvent consisting of a mixture of ethanol/water and a little heating. In this work, we focus on Fresnel lens, which is an important quasi-optic device for MMW application, to introduce a tunable property by using LC materials. Here, we adopt the thin film deposition method to obtain a porous PMMA matrix with the aim of obtaining final composite structure based on the Fresnel substrate. First, the fundamental material properties of porous PMMA are investigated to control the microscopic porous structure. Then, the LC-MMW Fresnel lens substrate is prepared using a 3D printer, and the fundamental MMW focusing properties of the prototype composite Fresnel structure are investigated.

  5. Evaluation of debris extruded apically during the removal of root canal filling material using ProTaper, D-RaCe, and R-Endo rotary nickel-titanium retreatment instruments and hand files.

    Science.gov (United States)

    Topçuoğlu, Hüseyin Sinan; Aktı, Ahmet; Tuncay, Öznur; Dinçer, Asiye Nur; Düzgün, Salih; Topçuoğlu, Gamze

    2014-12-01

    The aim of this study was to evaluate the amount of debris extruded apically during the removal of root canal filling material using ProTaper (Dentsply Maillefer, Ballaigues, Switzerland), D-RaCe (FKG Dentaire, La Chaux-de-Fonds, Switzerland), and R-Endo (Micro-Mega, Besançon, France) nickel-titanium (NiTi) rotary retreatment instruments and hand files. Sixty extracted single-rooted mandibular premolar teeth were prepared with K-files and filled with gutta-percha and AH Plus sealer (Dentsply DeTrey, Konstanz, Germany). The teeth were then randomly assigned to 4 groups (n = 15 for each group) for retreatment. The removal of canal filling material was performed as follows: hand files, ProTaper, D-RaCe, and R-Endo retreatment instruments. Debris extruded apically during the removal of canal filling material was collected into preweighed Eppendorf tubes. The tubes were then stored in an incubator at 70°C for 5 days. The weight of the dry extruded debris was established by subtracting the preretreatment and postretreatment weight of the Eppendorf tubes for each group. The data obtained were analyzed using 1-way analysis of variance and Tukey post hoc tests. All retreatment techniques caused the apical extrusion of debris. Hand files produced significantly more debris when compared with ProTaper, D-RaCe, and R-Endo rotary systems (P ProTaper, D-RaCe, and R-Endo retreatment systems (P > .05). The findings showed that during the removal of root canal filling material, rotary NiTi retreatment instruments used in this study caused less apical extrusion of debris compared with hand files. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  6. Technical Readiness and Gaps Analysis of Commercial Optical Materials and Measurement Systems for Advanced Small Modular Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Anheier, Norman C.; Suter, Jonathan D.; Qiao, Hong (Amy); Andersen, Eric S.; Berglin, Eric J.; Bliss, Mary; Cannon, Bret D.; Devanathan, Ramaswami; Mendoza, Albert; Sheen, David M.

    2013-08-06

    This report intends to support Department of Energy’s Office of Nuclear Energy (DOE-NE) Nuclear Energy Research and Development Roadmap and industry stakeholders by evaluating optical-based instrumentation and control (I&C) concepts for advanced small modular reactor (AdvSMR) applications. These advanced designs will require innovative thinking in terms of engineering approaches, materials integration, and I&C concepts to realize their eventual viability and deployability. The primary goals of this report include: 1. Establish preliminary I&C needs, performance requirements, and possible gaps for AdvSMR designs based on best available published design data. 2. Document commercial off-the-shelf (COTS) optical sensors, components, and materials in terms of their technical readiness to support essential AdvSMR in-vessel I&C systems. 3. Identify technology gaps by comparing the in-vessel monitoring requirements and environmental constraints to COTS optical sensor and materials performance specifications. 4. Outline a future research, development, and demonstration (RD&D) program plan that addresses these gaps and develops optical-based I&C systems that enhance the viability of future AdvSMR designs. The development of clean, affordable, safe, and proliferation-resistant nuclear power is a key goal that is documented in the Nuclear Energy Research and Development Roadmap. This roadmap outlines RD&D activities intended to overcome technical, economic, and other barriers, which currently limit advances in nuclear energy. These activities will ensure that nuclear energy remains a viable component to this nation’s energy security.

  7. Conformal Coating of a Phase Change Material on Ordered Plasmonic Nanorod Arrays for Broadband All-Optical Switching

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Peijun; Weimer, Matthew S. [Department; Emery, Jonathan D.; Diroll, Benjamin T.; Chen, Xinqi; Hock, Adam S. [Department; Chang, Robert P. H.; Martinson, Alex B. F.; Schaller, Richard D.

    2016-12-19

    Actively tunable optical transmission through artificial metamaterials holds great promise for next-generation nanophotonic devices and metasurfaces. Plasmonic nanostructures and phase change materials have been extensively studied to this end due to their respective strong interactions with light and tunable dielectric constants under external stimuli. Seamlessly integrating plasmonic components with phase change materials, as demonstrated in the present work, can facilitate phase change by plasmonically enabled light confinement and meanwhile make use of the high sensitivity of plasmon resonances to the variation of dielectric constant associated with the phase change. The hybrid platform here is composed of plasmonic indium tin-oxide nanorod arrays (ITO-NRAs) conformally coated with an ultrathin layer of a prototypical phase change material, vanadium dioxide (VO2), which enables all-optical modulation of the infrared as well as the visible spectral ranges. The interplay between the intrinsic plasmonic nonlinearity of ITO-NRAs and the phase transition induced permittivity change of VO2 gives rise to spectral and temporal responses that cannot be achieved with individual material components alone.

  8. Conformal Coating of a Phase Change Material on Ordered Plasmonic Nanorod Arrays for Broadband All-Optical Switching.

    Science.gov (United States)

    Guo, Peijun; Weimer, Matthew S; Emery, Jonathan D; Diroll, Benjamin T; Chen, Xinqi; Hock, Adam S; Chang, Robert P H; Martinson, Alex B F; Schaller, Richard D

    2017-01-24

    Actively tunable optical transmission through artificial metamaterials holds great promise for next-generation nanophotonic devices and metasurfaces. Plasmonic nanostructures and phase change materials have been extensively studied to this end due to their respective strong interactions with light and tunable dielectric constants under external stimuli. Seamlessly integrating plasmonic components with phase change materials, as demonstrated in the present work, can facilitate phase change by plasmonically enabled light confinement and meanwhile make use of the high sensitivity of plasmon resonances to the variation of dielectric constant associated with the phase change. The hybrid platform here is composed of plasmonic indium-tin-oxide nanorod arrays (ITO-NRAs) conformally coated with an ultrathin layer of a prototypical phase change material, vanadium dioxide (VO 2 ), which enables all-optical modulation of the infrared as well as the visible spectral ranges. The interplay between the intrinsic plasmonic nonlinearity of ITO-NRAs and the phase transition induced permittivity change of VO 2 gives rise to spectral and temporal responses that cannot be achieved with individual material components alone.

  9. Cell-to-module optical loss/gain analysis for various photovoltaic module materials through systematic characterization

    Science.gov (United States)

    Hsian Saw, Min; Khoo, Yong Sheng; Singh, Jai Prakash; Wang, Yan

    2017-08-01

    Reducing levelized cost of electricity (LCOE) is important for solar photovoltaics to compete against other energy sources. Thus, the focus should not only be on improving the solar cell efficiency, but also on continuously reducing the losses (or achieving gain) in the cell-to-module process. This can be achieved by choosing the appropriate module material and design. This paper presents a detailed and systematic characterization of various photovoltaic (PV) module materials (encapsulants, tabbing ribbons, and backsheets) and an evaluation of their impact on the output power of silicon wafer-based PV modules. Various characterization tools/techniques, such as UV-vis (reflectance) measurement, external quantum efficiency (EQE) measurement and EQE line-scan are used. Based on the characterization results, we use module materials with the best-evaluated optical performance to build “optimized modules”. Compared to the standard mini-module, an optical gain of more than 5% is achievable for the “optimized module” with selected module materials.

  10. Optical Fiber Chemical Sensor with Sol-Gel Derived Refractive Material as Transducer for High Temperature Gas Sensing in Clean Coal Technology

    Energy Technology Data Exchange (ETDEWEB)

    Shiquan Tao

    2006-12-31

    The chemistry of sol-gel derived silica and refractive metal oxide has been systematically studied. Sol-gel processes have been developed for preparing porous silica and semiconductor metal oxide materials. Micelle/reversed micelle techniques have been developed for preparing nanometer sized semiconductor metal oxides and noble metal particles. Techniques for doping metal ions, metal oxides and nanosized metal particles into porous sol-gel material have also been developed. Optical properties of sol-gel derived materials in ambient and high temperature gases have been studied by using fiber optic spectroscopic techniques, such as fiber optic ultraviolet/visible absorption spectrometry, fiber optic near infrared absorption spectrometry and fiber optic fluorescence spectrometry. Fiber optic spectrometric techniques have been developed for investigating the optical properties of these sol-gel derived materials prepared as porous optical fibers or as coatings on the surface of silica optical fibers. Optical and electron microscopic techniques have been used to observe the microstructure, such as pore size, pore shape, sensing agent distribution, of sol-gel derived material, as well as the size and morphology of nanometer metal particle doped in sol-gel derived porous silica, the nature of coating of sol-gel derived materials on silica optical fiber surface. In addition, the chemical reactions of metal ion, nanostructured semiconductor metal oxides and nanometer sized metal particles with gas components at room temperature and high temperatures have also been investigated with fiber optic spectrometric methods. Three classes of fiber optic sensors have been developed based on the thorough investigation of sol-gel chemistry and sol-gel derived materials. The first group of fiber optic sensors uses porous silica optical fibers doped with metal ions or metal oxide as transducers for sensing trace NH{sub 3} and H{sub 2}S in high temperature gas samples. The second group of

  11. Optical Properties Of Polymeric Films Of Bacteriorhodopsin And Its Functional Variants: New Materials For Optical Information Processing

    Science.gov (United States)

    Hampp, Norbert; Braeuchle, Christoph R.; Oesterhelt, Dieter

    1990-01-01

    Purple membrane (PM) from Halobacterium halobium consists of a two-dimensional crystal of the photochromic retinal protein bacteriorhodopsin (BR). Purple membrane embedded in inert polymer matrices can be used as reversible recording medium in holography. The thermal and photochemical stability (at least 100.000 recording cycles at room temperature), the high quantum yield (70%), the high resolution (~ 5000 lines/mm) and the wide spectral range (400-680 nm) of these films are promising features for any possible technical application. The variability of this material was restricted to chemical modifications of the chromophoric group for a long time. new class of BR based recording media is introduced by the availability of variants of BR with a modified amino acid sequence. After generation of a mutant strain PM variants can be easily produced by the same cultivation and purification procedures as the PM of the wildtype and therefore are available in virtually unlimited amounts, too. As an example the properties of PM-films containing the variant BR-326, which differs from the wildtype by a single amino acid, are reported here. The improved diffraction efficiency (~ 2-fold) and increased sensitivity (~ 50%) of films containing BR-326 give an impression of the new possibilities for optimizing reversible recording media by biochemical and gentechnological methods as an alternative or an addition to conventional chemical methods.

  12. The hand of Homo naledi

    Science.gov (United States)

    Kivell, Tracy L.; Deane, Andrew S.; Tocheri, Matthew W.; Orr, Caley M.; Schmid, Peter; Hawks, John; Berger, Lee R.; Churchill, Steven E.

    2015-01-01

    A nearly complete right hand of an adult hominin was recovered from the Rising Star cave system, South Africa. Based on associated hominin material, the bones of this hand are attributed to Homo naledi. This hand reveals a long, robust thumb and derived wrist morphology that is shared with Neandertals and modern humans, and considered adaptive for intensified manual manipulation. However, the finger bones are longer and more curved than in most australopiths, indicating frequent use of the hand during life for strong grasping during locomotor climbing and suspension. These markedly curved digits in combination with an otherwise human-like wrist and palm indicate a significant degree of climbing, despite the derived nature of many aspects of the hand and other regions of the postcranial skeleton in H. naledi. PMID:26441219

  13. Solitonic guide and multiphoton absorption processes in photopolymerizable materials for optical integrated circuits

    Science.gov (United States)

    Klein, Stephane; Barsella, Alberto; Acker, D.; Sutter, C.; Beyer, N.; Andraud, Chantal; Fort, Alain F.; Dorkenoo, Kokou D.

    2004-09-01

    Up to now, most of the optical integrated devices are realized on glass or III-V substrates and the waveguides are usually obtained by photolithography techniques. We present here a new approach based on the use of photopolymerizable compounds. The conditions of self-written channel creation by solitonic propagation inside the bulk of these photopolymerizable formulations are analyzed. Both experimental and theoretical results of the various stages of self-written guide propagation are presented. A further step has been achieved by using a two-photon absorption process for the polymerization via a confocal microscopy technique. Combined with the solitonic guide creation, this technique allows to draw 3D optical circuits. Finally, by doping the photopolymerizable mixtures with push-pull chromophores having a controlled orientation, it will be possible to create active optical integrated devices.

  14. Production and Characterization of Thin Film Materials for Indoor Optical Gas Sensing Applications

    International Nuclear Information System (INIS)

    Maggioni, Gianluigi; Carturan, Sara; Quaranta, Alberto; Vomiero, Alberto; Tonezzer, Michele; Mea, Gianantonio Della

    2006-01-01

    Pure and Nile-Red-doped polyimide and porphyrin films have been deposited and their optical response to different organic vapours has been tested. Polyimide films were obtained by spin coating a solution containing 4, 4'-4, 4'-(hexafluoroisopropylidene) diphthalic anhydride and 2, 3, 5, 6-tetramethyl-1, 4-phenylenediamine. Free, cobalt and iron chloride 5, 10, 15, 20 meso-tetraphenyl porphyrin films were deposited by spin coating and by high vacuum evaporation. Exposure to water, ethanol and isopropanol vapours produce reversible changes of the fluorescence features of both pure and doped polyimide films. Exposure to methanol, ethanol and isopropanol vapours gives rise to changes of the optical absorption of porphyrin films. The results of the optical measurements point out that the synthesized films can be used for the detection of volatile organic compounds

  15. Technical Progress Report for "Optical and Electrical Properties of III-Nitrides and Related Materials"

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Hongxing

    2008-10-31

    Investigations have been conducted focused on the fundamental material properties of AIN and high AI-content AIGaN alloys and further developed MOCVD growth technologies for obtaining these materials with improved crystalline quality and conductivities.

  16. Fabrication and Optical Measurements of Nanoscale Meta-Materials: Terahertz and Beyond

    OpenAIRE

    Martin, Michael C.; Hao, Zhao; Liddle, Alex; Anderson, Erik H.; Padilla, Willie J.; Schurig, David; Smith, David R.

    2005-01-01

    Recently, artificial meta-materials have been reported [1] that have a negative index of refraction, which allows a homogeneous flat slab of the material to behave as a perfect lens [2], possibly even creating sub-diffraction limited focusing. These novel artificial materials have numerous potential applications in science, technology, and medicine [3],especially if their novel behavior can be extended to the technologically critical near-infrared and visible region.The meta-materials co...

  17. Evaluation of the potential of optical switching materials for overheating protection of thermal solar collectors - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Huot, G.; Roecker, Ch.; Schueler, A.

    2008-01-15

    Providing renewable energy for domestic hot water production and space heating, thermal solar collectors are more and more widespread, and users' expectations with respect to performance and service lifetime are rising continuously. The durability of solar collector materials is a critical point as the collector lifetime should be at least 25 years. Overheating and the resulting stagnation of the collector is a common problem with solar thermal systems. During stagnation high temperatures lead to water evaporation, glycol degradation, and stresses in the collector with increasing pressure. Special precautions are necessary to release this pressure; only mechanical solutions exist nowadays. Additionally, the occurring elevated temperatures lead to degradation of the materials that compose collectors: seals, insulation materials, and also the selective coating which is the most important part of the collector. A promising way to achieve active cooling of collectors without any mechanical device for pressure release or collector emptying is to produce a selective coating which is able to switch its optical properties at a critical temperature Tc. An optical switch allows changing the selective coating efficiency; the goal is to obtain a coating with a poor selectivity above Tc (decreasing of absorptance, increasing of emittance). Obtaining self-cooling collectors will allow increasing collector surfaces on facades and roofs in order to get high efficiency and hot water production during winter without inconvenient overheating during summer. Optical switching of materials can be obtained by many ways. Inorganic and organic thermochromic compounds, and organic thermotropic coatings are the main types of switching coatings that have been studied at EPFL-LESO-PB. Aging studies of organic thermochromic paints fabricated at EPFL suggest that the durability of organic compounds might not be sufficient for glazed metallic collectors. First samples of inorganic coatings

  18. Interaction of InGa liquid alloy coolant with gold coated optical materials

    International Nuclear Information System (INIS)

    Hulbert, S.L.

    1991-01-01

    A significant reaction is reported between gold surfaces and an indium-gallium eutectic liquid alloy often used to transfer heat away from optical elements in high power synchrotron radiation beamlines. This reaction proceeds at the slightly elevated temperatures (70 degrees C) typical of conservative bakeouts used to achieve ultrahigh vacuum in the chambers which house these optical elements (mirrors, gratings, and crystals) without damaging their highly precise figure and finish. The nature and extent of this reaction is discussed, based mostly on the experience gained recently during the vacuum commissioning of two mirror chambers for a VUV wiggler-based synchrotron radiation beamline. 2 refs., 5 figs

  19. High sensitivity optical biosensor based on polymer materials and using the Vernier effect.

    Science.gov (United States)

    Azuelos, Paul; Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Guendouz, Mohammed; Thual, Monique; Lemaître, Jonathan; Pirasteh, Parastesh; Hardy, Isabelle; Charrier, Joël

    2017-11-27

    We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10 -6 RIU.

  20. 64Cu radiolabeled nano-materials as bimodal contrast agent for optical imaging and Positron Emission Tomography (PET)

    International Nuclear Information System (INIS)

    Nonat, A.M.; Roux, A.; Yahia-Ammar, A.; Charbonniere, L.J.; Platas-Iglesias, C.; Camerle, F.

    2015-01-01

    Fluorescent nano-crystals made of semiconductor material, also called Quantum Dots, are ideal agents for long-term or real-time optical imaging. They have been found to outperform traditional organic fluorescent dyes in many ways (size-tunable optical properties, high quantum yields, high extinction coefficients, resistance to photo bleaching). We have developed a microwave method for the synthesis of highly luminescent water soluble CdTe x S 1-x nano-crystals (Φ= 53% at 600 nm). Their surface functionalization has been developed and controlled using a Nile-Red derivative as a fluorescent marker. The same coupling strategy will be used to incorporate 64 Cu-radiotracers for PET imaging at the surface of the Quantum Dots. A large variety of poly-aza-macrocyclic ligands, have been studied in order to optimize the in vivo stability of the 64 Cu-radiolabeled complexes and their efficiency as radiopharmaceuticals

  1. Broadband nonvolatile photonic switching based on optical phase change materials: beyond the classical figure-of-merit.

    Science.gov (United States)

    Zhang, Qihang; Zhang, Yifei; Li, Junying; Soref, Richard; Gu, Tian; Hu, Juejun

    2018-01-01

    In this Letter, we propose a broadband, nonvolatile on-chip switch design in the telecommunication C-band with record low loss and crosstalk. The unprecedented device performance builds on: 1) a new optical phase change material (O-PCM) Ge 2 Sb 2 Se 4 Te 1 (GSST), which exhibits significantly reduced optical attenuation compared to traditional O-PCMs, and 2) a nonperturbative design that enables low-loss device operation beyond the classical figure-of-merit (FOM) limit. We further demonstrate that the 1-by-2 and 2-by-2 switches can serve as basic building blocks to construct nonblocking and nonvolatile on-chip switching fabric supporting arbitrary numbers of input and output ports.

  2. Nonlinear optics in germanium mid-infrared fiber material: Detuning oscillations in femtosecond mid-infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    M. Ordu

    2017-09-01

    Full Text Available Germanium optical fibers hold great promise in extending semiconductor photonics into the fundamentally important mid-infrared region of the electromagnetic spectrum. The demonstration of nonlinear response in fabricated Ge fiber samples is a key step in the development of mid-infrared fiber materials. Here we report the observation of detuning oscillations in a germanium fiber in the mid-infrared region using femtosecond dispersed pump-probe spectroscopy. Detuning oscillations are observed in the frequency-resolved response when mid-infrared pump and probe pulses are overlapped in a fiber segment. The oscillations arise from the nonlinear frequency resolved nonlinear (χ(3 response in the germanium semiconductor. Our work represents the first observation of coherent oscillations in the emerging field of germanium mid-infrared fiber optics.

  3. Hand-held spectrophotometer design for textile fabrics

    Science.gov (United States)

    Böcekçi, Veysel Gökhan; Yıldız, Kazım

    2017-09-01

    In this study, a hand-held spectrophotometer was designed by taking advantage of the developments in modern optoelectronic technology. Spectrophotometer devices are used to determine the color information from the optic properties of the materials. As an alternative to a desktop spectrophotometer device we have implemented, it is the first prototype, low cost and portable. The prototype model designed for the textile industry can detect the color tone of any fabric. The prototype model consists of optic sensor, processor, display floors. According to the color applied on the optic sensor, it produces special frequency information on its output at that color value. In Arduino type processor, the frequency information is evaluated by the program we have written and the color tone information between 0-255 ton is decided and displayed on the screen.

  4. Electronic and optical properties of new multifunctional materials via half-substituted hematite: First principles calculations

    KAUST Repository

    Yang, Hua; Mi, Wenbo; Bai, Haili; Cheng, Yingchun

    2012-01-01

    Electronic structure and optical properties of α-FeMO 3 systems (M = Sc, Ti, V, Cr, Cu, Cd or In) have been investigated using first principles calculations. All of the FeMO 3 systems have a large net magnetic moment. The ground state of pure α-Fe 2

  5. Measurement of optical properties of greenhouse cladding materials : harmonisation and standardisation

    NARCIS (Netherlands)

    Waaijenberg, D.; Gbiorczyk, K.; Feuillloley, P.; Verlodt, I.; Bonora, M.

    2003-01-01

    The aim of this European SMT (Standards, Measurements and Testing) project was the development of testing methods for measuring the ageing and the condensation behaviour of plastic films. For the ageing task, the degradation rates of the most important physical, optical and mechanical properties of

  6. Dispersion-modulation by high material loss in microstructured polymer optical fibers

    DEFF Research Database (Denmark)

    Frosz, Michael Henoch

    2009-01-01

    The influence of strong loss peaks on the dispersion (through the Kramers-Kronig relations) of a nonlinear waveguide is investigated theore­ti­cally. It is found specifically for degenerate four-wave mixing in a poly(methyl methacrylate) microstructured polymer optical fiber that the loss...

  7. Developments of a bonding technique for optical materials by a surface activation method

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Oda, Tomohiro; Abe, Tomoyuki; Kusunoki, Isao

    2005-01-01

    We started developing the laser crystal bounding by the surface activation method which can splice crystals together without using hydrogen bonding. For the surface activation, neutral argon beams were used for irradiation of specimens. In the bonding trials with sapphire crystals, we recognized possibility of the bonding method for optical elements. (author)

  8. Hand Surgery: Anesthesia

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Hand Surgery Anesthesia Email to a friend * required ...

  9. Development of a Database on the Changes in the Optical Properties of Materials used on the External Surfaces of Spacecraft Under the Action of the Space Environment Factors

    National Research Council Canada - National Science Library

    Khatipov, Sergey A

    2006-01-01

    .... The purpose of the project was a development of the Database (DB) in the electron format DBMS Access2000, including results of investigation of optical properties of external materials for space vehicles (SV...

  10. Correction: Conceptual design of tetraazaporphyrin- and subtetraazaporphyrin-based functional nanocarbon materials: electronic structures, topologies, optical properties, and methane storage capacities.

    Science.gov (United States)

    Belosludov, Rodion V; Rhoda, Hannah M; Zhdanov, Ravil K; Belosludov, Vladimir R; Kawazoe, Yoshiyuki; Nemykin, Victor N

    2017-08-02

    Correction for 'Conceptual design of tetraazaporphyrin- and subtetraazaporphyrin-based functional nanocarbon materials: electronic structures, topologies, optical properties, and methane storage capacities' by Rodion V. Belosludov et al., Phys. Chem. Chem. Phys., 2016, 18, 13503-13518.

  11. Applications of Ferromagnetic and Optical Materials, Storage and Magnetoelectronics: Symposia Held in San Francisco, California, U.S.A. on April 16-20, 2001

    National Research Council Canada - National Science Library

    Borg, Herman

    2001-01-01

    .... In the past decade there have been unprecedented developments; in ferromagnetic materials, resulting in much-improved magneto-optical, magneto-resistive, magnetostrictive, permanent and nanocrystalline soft magnetic...

  12. Optically-controlled long-term storage and release of thermal energy in phase-change materials.

    Science.gov (United States)

    Han, Grace G D; Li, Huashan; Grossman, Jeffrey C

    2017-11-13

    Thermal energy storage offers enormous potential for a wide range of energy technologies. Phase-change materials offer state-of-the-art thermal storage due to high latent heat. However, spontaneous heat loss from thermally charged phase-change materials to cooler surroundings occurs due to the absence of a significant energy barrier for the liquid-solid transition. This prevents control over the thermal storage, and developing effective methods to address this problem has remained an elusive goal. Herein, we report a combination of photo-switching dopants and organic phase-change materials as a way to introduce an activation energy barrier for phase-change materials solidification and to conserve thermal energy in the materials, allowing them to be triggered optically to release their stored latent heat. This approach enables the retention of thermal energy (about 200 J g -1 ) in the materials for at least 10 h at temperatures lower than the original crystallization point, unlocking opportunities for portable thermal energy storage systems.

  13. Color-Coded Batteries - Electro-Photonic Inverse Opal Materials for Enhanced Electrochemical Energy Storage and Optically Encoded Diagnostics.

    Science.gov (United States)

    O'Dwyer, Colm

    2016-07-01

    For consumer electronic devices, long-life, stable, and reasonably fast charging Li-ion batteries with good stable capacities are a necessity. For exciting and important advances in the materials that drive innovations in electrochemical energy storage (EES), modular thin-film solar cells, and wearable, flexible technology of the future, real-time analysis and indication of battery performance and health is crucial. Here, developments in color-coded assessment of battery material performance and diagnostics are described, and a vision for using electro-photonic inverse opal materials and all-optical probes to assess, characterize, and monitor the processes non-destructively in real time are outlined. By structuring any cathode or anode material in the form of a photonic crystal or as a 3D macroporous inverse opal, color-coded "chameleon" battery-strip electrodes may provide an amenable way to distinguish the type of process, the voltage, material and chemical phase changes, remaining capacity, cycle health, and state of charge or discharge of either existing or new materials in Li-ion or emerging alternative battery types, simply by monitoring its color change. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Spectroscopic investigations using density functional theory on 2-methoxy- 4(phenyliminomethyl)phenol: A non linear optical material

    Science.gov (United States)

    Hijas, K. M.; Madan Kumar, S.; Byrappa, K.; Geethakrishnan, T.; Jeyaram, S.; Nagalakshmi, R.

    2018-03-01

    Single crystals of 2-methoxy-4(phenyliminomethyl)phenol were grown from ethanol by slow evaporation solution growth technique. Single crystal X-ray diffraction experiment reveals the crystallization in orthorhombic system having non-centrosymmetric space group C2221. Geometrical optimization by density functional theory method was carried out using Gaussian program and compared with experimental results. Detailed experimental and theoretical vibrational analyses were carried out and the results were correlated to find close agreement. Thermal analyses show the material is thermally stable with a melting point of 159 °C. Natural bond orbital analysis was carried out to explain charge transfer interactions through hydrogen bonding. Relatively smaller HOMO-LUMO band gap favors the non linear optical activity of the molecule. Natural population analysis and molecular electrostatic potential calculations visualize the charge distribution in an isolated molecule. Calculated first-order molecular hyperpolarizability and preliminary second harmonic generation test carried out using Kurtz-Perry technique establish 2-methoxy-4(phenyliminomethyl)phenol crystal as a good non linear optical material. Z-scan proposes the material for reverse saturable absorption.

  15. SPONGE ROBOTIC HAND DESIGN FOR PROSTHESES

    OpenAIRE

    Mine Seçkin

    2016-01-01

    In this study robotic hands and fingers’ materials are investigated from past to present and a sponge robotic hand is designed for biomedical applications. Emergence and necessity of soft robotic technology are explained and description of soft robot is made. Because of the importance of hand in a person’s body, researchers have dealt with robotic hand prostheses for many centuries and developed many hand types. To mimic the best for the human limbs, softness of the hand is one of the importa...

  16. Mitigation of Critical Single Point Failure (SPF) Material - Laminac 4116 Binder Replacement Program for Parachute and Cluster Stars Illuminant Compositions for Hand Held Signals

    National Research Council Canada - National Science Library

    Lakshminarayanan, G. R; Chen, Gary; Ames, Richard; Lee, Wai T; Wejsa, James L

    2006-01-01

    Laminac 4116 binder has been identified as a single point failure (SPF) material since it is being produced by only one company and there is a possibility that the company may discontinue production due to low product demand...

  17. ICOM2012: 3rd International Conference on the Physics of Optical Materials and Devices (Belgrade, Serbia, 2-6 September 2012)

    Science.gov (United States)

    Dramićanin, Miroslav D.; Antić, Željka; Viana, Bruno

    2013-11-01

    The 3rd International Conference on the Physics of Optical Materials and Devices (ICOM2012) was held in Belgrade (Serbia) from 2 to 6 September 2012 (figure 1). The conference was organized by the Vinča Institute of Nuclear Sciences, University of Belgrade (Serbia) and the Laboratoire de Chimie de la Matière Condensée de Paris (France), and supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia and Optical Society of America. ICOM2012 was a follow-up to the two previous, successful ICOM conferences held in Herceg Novi in 2006 and 2009. The conference aimed at providing a forum for scientists in optical materials to debate on: • Luminescent materials and nanomaterials • Hybrid optical materials (organic/inorganic) • Characterization techniques of optical materials • Luminescence mechanisms and energy transfers • Theory and modeling of optical processes • Ultrafast-laser processing of materialsOptical sensors • Medical imaging • Advanced optical materials in photovoltaics and biophotonics • Photothermal and photoacoustic spectroscopy and phenomena The conference stressed the value of a fundamental scientific understanding of optical materials. A particular accent was put on wide band-gap materials in crystalline, glass and nanocrystalline forms. The applications mainly involved lasers, scintillators and phosphors. Rare earth and transition metal ions introduced as dopants in various hosts were considered, and their impact on the optical properties were detailed in several presentations. This volume contains selected contributions of speakers and participants of the ICOM2012 conference. The conference provided a unique opportunity for about 200 scientists from 32 countries to discuss recent progress in the field of optical materials. During the three and half days, 21 invited talks and 52 contributed lectures were given, with a special event in memory of our dear colleague Professor Dr Tsoltan

  18. Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

    Directory of Open Access Journals (Sweden)

    Musa Ahmad

    2017-11-01

    Full Text Available An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to any pH changes and could be used to determine the end-point of the acid-base titration.

  19. Optical ph sensing material prepared from doped sol-gel film for use in acid-base titration

    OpenAIRE

    Musa Ahmad; T.W. Tan

    2017-01-01

    An optical pH sensing material has been prepared in this study by using sol-gel technique. Bromothymol blue, bromophenol blue and thymol blue were chosen in this study as acidbase indicators for strong acid-strong base, strong acid-weak base and weak acid-strong base titration, respectively. The results show that these indicators could be successfully entrapped inside the sol-gel film and still maintain its chemical behaviour as in solution. The entrapped acid-base indicators respond well to ...

  20. Matching the optical properties of direct esthetic dental restorative materials to those of human enamel and dentin

    Science.gov (United States)

    Ragain, James Carlton, Jr.

    One of the goals of the restorative dentist is to restore the appearance of the natural dentition. Clinical matching of teeth and restorative materials are seldom accurate and shade selection techniques are subjective. The first specific aim of this research was to characterize the optical absorption and scattering that occurs within enamel, dentin, and composite resin and compomer restorative materials and to relate those phenomena to translucency and color. The second aim was to evaluate small color differences among composite restorative materials which would be detectable by humans. The last aim was to lay the foundation for developing an improved model of specifying layers of dental restorative materials in order to match the translucency and color to those of human enamel. The Kubelka-Munk theory was validated for enamel, dentin, and the restorative materials. These tissues and materials were then characterized in terms of their color parameters. Tooth cores were also characterized in terms of color space parameters. Human subjects were evaluated for their abilities to discriminate small color differences in the dental composite resin materials. The following conclusions were derived from this study: (1) Kubelka-Munk theory accurately predicts the diffuse reflectance spectra of enamel, dentin, and the direct esthetic dental restorative materials studied. (2) Scattering and absorption coefficients of the dental tissues and esthetic restorative materials can be directly calculated from diffuse reflectance measurements of a uniformly thick slab of tissue/material using black and white backings and the appropriate refractive index. (3) For tooth cores, there is a positive correlation between L* and b* and a negative correlation between L* and a*. (4) The range of translucency parameters for the restorative materials studied does not match those of enamel and dentin. (5) None of the shades of the dental composite resin restorative materials studied fit into the

  1. Electronic and optical properties of new multifunctional materials via half-substituted hematite: First principles calculations

    KAUST Repository

    Yang, Hua

    2012-01-01

    Electronic structure and optical properties of α-FeMO 3 systems (M = Sc, Ti, V, Cr, Cu, Cd or In) have been investigated using first principles calculations. All of the FeMO 3 systems have a large net magnetic moment. The ground state of pure α-Fe 2O 3 is an antiferromagnetic insulator. For M = Cu or Cd, the systems are half-metallic. Strong absorption in the visible region can be observed in the Cu and Cd-doped systems. Systems with M = Sc, Ti, V, Cr or In are not half-metallic and are insulators. The strongest peaks shift toward shorter wavelengths in the absorption spectra. It is concluded that transition metal doping can modify the electronic structure and optical properties of α-FeMO 3 systems. This journal is © 2012 The Royal Society of Chemistry.

  2. All-optical XOR logic gate using intersubband transition in III-V quantum well materials.

    Science.gov (United States)

    Feng, Jijun; Akimoto, Ryoichi; Gozu, Shin-ichiro; Mozume, Teruo

    2014-06-02

    A monolithically integrated all-optical exclusive-OR (XOR) logic gate is experimentally demonstrated based on a Michelson interferometer (MI) gating device in InGaAs/AlAsSb coupled double quantum wells (CDQWs). The MI arms can convert the pump data with return-to-zero ON-OFF keying (RZ OOK) to binary phase-shift keying (BPSK) format, then two BPSK signals can interfere with each other for realizing a desired logical operation. All-optical format conversion from the RZ OOK to BPSK is based on the cross-phase modulation to the transverse electric (TE) probe wave, which is caused by the intersubband transition excited by the transverse magnetic (TM) pump light. Bit error rate measurements show that error free operation for both BPSK format conversion and XOR logical operation can be achieved.

  3. Quantum Optics 6 - Quantum Engineering of Atoms and Photons - Conference Materials

    International Nuclear Information System (INIS)

    2005-01-01

    The conference organized by Center for Theoretical Physics, Institute of Physics and Warsaw University, sponsored by European Science Foundation, was held in Krynica (120 km south-east of Cracow), Poland, June 13-18 2005. This was the sixth conference of the cycle, the previous one was held in Koscielisko, Poland in 2001. This time the main subject of the conference was: Quantum Engineering of Atoms and Photons. The meeting was focused on the physics of ultracold quantum gases, which without doubts determines the frontiers of the modern atomic, molecular and optical physics. Special attention was also be given to quantum information processing, both from theoretical and experimental point of view, including possible realizations in ultracold quantum gases. The conference consisted of invited lectures and a poster session. Competition for the best poster was held, sponsored by Journal of Optics B and Journal of Physics B - for more on this, including the results of the competition visit. (author)

  4. Developments of a bonding technique for optical materials by a surface activation method

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Oda, Tomohiro; Abe, Tomoyuki; Kusunoki, Isao

    2007-01-01

    We have been developing a pair of sample holder used for optics in the surface activation bonding equipment. The holder can adjust the relative position of samples in the order of sub mm. To study the degree of dislocation appearing crystal surface activated by a fast atomic beam, irradiated sapphire crystals were examined by RBS, XPS, and AFM analysis. The heat treatment recovered the surface roughness of irradiated sapphire when the heating temperature reached at 1573 K. (author)

  5. Influence of the substituent on azobenzene side-chain polyester optical storage materials

    DEFF Research Database (Denmark)

    Pedersen, M; Hvilsted, Søren; Holme, NCR

    1999-01-01

    , chloro, and bromo. C-13 NMR spectroscopic and molecular mass investigations substantiate good film forming characteristics. The optical storage performance of thin polyester films are investigated through polarization holography. The resulting diffraction efficiency is mapped and discussed as a function...... of irradiation power and exposure time. Polytetradecanedioates with cyano-, nitro-, methyl-, fluoro-, or trinuoromethyl-azobenzene reach more than 50% diffraction efficiency. Investigations of anisotropy induced at different temperatures reveal that the polyesters are only photosensitive in a narrow temperature...

  6. 4TH Mediterranean Workshop and Tropical Meeting "Novel Optical Materials and Applications" NOMA 99.

    Science.gov (United States)

    1999-07-19

    Qu~mard", F. Smektalaa, V. Condereb, A. Barth616myb. aLaboratoire des Verres et Cramniques, Universit6 de Rennes 1, Avenue du G6n~raI Leclerc, 35042...and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE 3. REPORT TYPE AND DATES...insights toward a qualitative understanding of PDE’s. POLYMER CELL-WALL TYPE LIQUID CRYSTAL OPTICAL SHUTTERS AND THEIR APPLICATIONS TADAHIRO ASADA

  7. Structural and Optical Properties of Spray Coated Carbon Hybrid Materials Applied to Transparent and Flexible Electrodes

    Directory of Open Access Journals (Sweden)

    Grzegorz Wroblewski

    2017-01-01

    Full Text Available Transparent and flexible electrodes were fabricated with cost-effective spray coating technique on polyethylene terephthalate foil substrates. Particularly designed paint compositions contained mixtures of multiwalled carbon nanotubes and graphene platelets to achieve their desired rheology and electrooptical layers parameters. Electrodes were prepared in standard technological conditions without the need of clean rooms or high temperature processing. The sheet resistance and optical transmittance of fabricated layers were tuned with the number of coatings; then the most suitable relation of these parameters was designated through the figure of merit. Optical measurements were performed in the range of wavelengths from 250 to 2500 nm with a spectrophotometer with the integration sphere. Spectral dependence of total and diffusive optical transmission for thin films with graphene platelet covered by multiwalled carbon nanotubes was designated which allowed determining the relative absorbance. Layer parameters such as thickness, refractive index, energy gap, and effective reflectance coefficient show the correlation of electrooptical properties with the technological conditions. Moreover the structural properties of fabricated layers were examined by means of the X-ray diffraction.

  8. 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.

  9. Optical materials technology for energy efficiency and solar energy conversion III; Proceedings of the Meeting, San Diego, CA, August 21-23, 1984

    Science.gov (United States)

    Lampert, C. M.

    1984-01-01

    Transparent heat mirror films are discussed, taking into account bandgap widening in heavily doped oxide semiconductors used as transparent heat-reflectors, the characterization of a low emissivity coating in large scale production, an exact analysis of radiative and conductive heat transfer through radiative gray films, and process control for sputter deposition of low emissivity films in large scale production. Other topics explored are related to optical switching materials, selective absorber coatings, general solar optical materials and instrumentation, and technical needs of the energy related coatings industry and the building sciences. Attention is given to electrochromic coatings for 'smart windows', materials for electrochromic windows, optical frequencies free electron scattering studies on electrochromic materials for variable reflectivity windows, progress on solar absorber selective paint research, complex index interference films on metal substrates, luminescent solar concentrator daylighting, and research on passive solar materials in Canada.

  10. Tunable optical switching in the near-infrared spectral regime by employing plasmonic nanoantennas containing phase change materials.

    Science.gov (United States)

    Savaliya, Priten B; Thomas, Arun; Dua, Rishi; Dhawan, Anuj

    2017-10-02

    We propose the design of switchable plasmonic nanoantennas (SPNs) that can be employed for optical switching in the near-infrared regime. The proposed SPNs consist of nanoantenna structures made up of a plasmonic metal (gold) such that these nanoantennas are filled with a switchable material (vanadium dioxide). We compare the results of these SPNs with inverted SPN structures that consist of gold nanoantenna structures surrounded by a layer of vanadium dioxide (VO 2 ) on their outer surface. These nanoantennas demonstrate switching of electric-field intensity enhancement (EFIE) between two states (On and Off states), which can be induced thermally, optically or electrically. The On and Off states of the nanoantennas correspond to the metallic and semiconductor states, respectively of the VO 2 film inside or around the nanoantennas, as the VO 2 film exhibits phase transition from its semiconductor state to the metallic state upon application of thermal, optical, or electrical energy. We employ finite-difference time-domain (FDTD) simulations to demonstrate switching in the EFIE for four different SPN geometries - nanorod-dipole, bowtie, planar trapezoidal toothed log-periodic, and rod-disk - and compare their near-field distributions for the On and Off states of the SPNs. We also demonstrate that the resonance wavelength of the EFIE spectra gets substantially modified when these SPNs switch between the two states.

  11. Soft X-ray imaging of thick carbon-based materials using the normal incidence multilayer optics.

    Science.gov (United States)

    Artyukov, I A; Feschenko, R M; Vinogradov, A V; Bugayev, Ye A; Devizenko, O Y; Kondratenko, V V; Kasyanov, Yu S; Hatano, T; Yamamoto, M; Saveliev, S V

    2010-10-01

    The high transparency of carbon-containing materials in the spectral region of "carbon window" (lambda approximately 4.5-5nm) introduces new opportunities for various soft X-ray microscopy applications. The development of efficient multilayer coated X-ray optics operating at the wavelengths of about 4.5nm has stimulated a series of our imaging experiments to study thick biological and synthetic objects. Our experimental set-up consisted of a laser plasma X-ray source generated with the 2nd harmonics of Nd-glass laser, scandium-based thin-film filters, Co/C multilayer mirror and X-ray film UF-4. All soft X-ray images were produced with a single nanosecond exposure and demonstrated appropriate absorption contrast and detector-limited spatial resolution. A special attention was paid to the 3D imaging of thick low-density foam materials to be used in design of laser fusion targets.

  12. Production and characterization of nanostructured materials for optical aplications at Rovira i Virgili University

    OpenAIRE

    Carvajal, Joan J.; Aguiló, Magdalena; Díaz González, Francesc

    2008-01-01

    Quan la mida de materials òptics ben coneguts es redueix al rang dels nanómetres, apareixen noves propietats físiques. Això ha motivat l'aparició d'un gran interès per la síntesi i la caracterització d'aquests nanocristalls, cobrint tots els vessants, des dels materials amb aplicacions làser fins als materials per fenòmens de conversió de freqüència. En aquesta publicació, presentem tres noves estratègies en l'estudi d'aquests materials desenvolupades els últims anys als ...

  13. All-optical tuning of EIT-like dielectric metasurfaces by means of chalcogenide phase change materials.

    Science.gov (United States)

    Petronijevic, E; Sibilia, C

    2016-12-26

    Electromagnetically induced transparency (EIT) is a pump-induced narrowband transparency window within an absorption line of the probe beam spectrum in an atomic system. In this paper we propose a way to bring together the all-dielectric metamaterials to have EIT-like effects and to optically tune the response by hybridizing them with a layer of a phase change material. We propose a design of the metamaterial based on Si nanoresonators that can support an EIT-like resonant response. On the top of the resonators we consider a thin layer of a chalcogenide phase change material, which we will use to tune the optical response. Our choice is Ge2Sb2Te5 (GST), since it has two stable phases at room temperature, namely amorphous and crystalline, between which it can be switched quickly, nonvolatively and reversibly, sustaining a large number of switching cycles. They differ in optical properties, while still having moderately low losses in telecom range. Since such dielectric resonators do not have non-radiative losses of metals around 1550nm, they can lead to a high-Q factor of the EIT-like response in this range. Firstly, we optimize the starting structure so that it gives an EIT-like response at 1550 nm when the GST layer is in the amorphous state. Our starting design uses glass as a substrate, but we also consider implementation in SOI technology. If we then switch the thin layer of GST to its crystalline phase, which has higher losses, the EIT-like response is red shifted, providing around 10:1 contrast at 1550nm. This reversible tuning can be done with an ns visible pulsed laser. We discuss the results of the simulation of the dielectric metasurface for different configurations and the tuning possibility.

  14. A Research on Low Modulus Distributed Fiber Optical Sensor for Pavement Material Strain Monitoring.

    Science.gov (United States)

    Meng, Lingjian; Wang, Linbing; Hou, Yue; Yan, Guannan

    2017-10-19

    The accumulated irreversible deformation in pavement under repeated vehicle loadings will cause fatigue failure of asphalt concrete. It is necessary to monitor the mechanical response of pavement under load by using sensors. Previous studies have limitations in modulus accommodation between the sensor and asphalt pavement, and it is difficult to achieve the distributed monitoring goal. To solve these problems, a new type of low modulus distributed optical fiber sensor (DOFS) for asphalt pavement strain monitoring is fabricated. Laboratory experiments have proved the applicability and accuracy of the newly-designed sensor. This paper presents the results of the development.

  15. Electro-optical system for the nondestructive evaluation of bioengineering materials

    Science.gov (United States)

    Sciammarella, Cesar A.; Bhat, Gopalakrishna K.; Albertazzi, Armando, Jr.

    1991-08-01

    The paper presents a system that may be used in a wide range of biomedical fields. The system can be applied in conjunction with different optical techniques: (a) holography, (b) moire method, (c) speckle techniques, (d) photoelasticity. The system has been built in such a way that an operator with average skills will be able to use it; data acquisition and processing are fast and almost automatic. A brief description of the system, its main components and the basic theory behind it, are given. The use of the system is illustrated with examples in orthopedics and in the cardio-vascular area.

  16. Pure chiral optical fibres.

    Science.gov (United States)

    Poladian, L; Straton, M; Docherty, A; Argyros, A

    2011-01-17

    We investigate the properties of optical fibres made from chiral materials, in which a contrast in optical activity forms the waveguide, rather than a contrast in the refractive index; we refer to such structures as pure chiral fibres. We present a mathematical formulation for solving the modes of circularly symmetric examples of such fibres and examine the guidance and polarisation properties of pure chiral step-index, Bragg and photonic crystal fibre designs. Their behaviour is shown to differ for left- and right-hand circular polarisation, allowing circular polarisations to be isolated and/or guided by different mechanisms, as well as differing from equivalent non-chiral fibres. The strength of optical activity required in each case is quantified.

  17. Osteoarthritis of the Hand

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is a Hand Surgeon? What is a Hand Therapist? Media Find a Hand Surgeon Home Anatomy Osteoarthritis Email to a friend * required fields From * ...

  18. Hands in Systemic Disease

    Science.gov (United States)

    ... All Topics A-Z Videos Infographics Symptom Picker Anatomy Bones Joints Muscles Nerves Vessels Tendons About Hand Surgery What is ... Hand Therapist? Media Find a Hand Surgeon Home Anatomy ... hands, being composed of many types of tissue, including blood vessels, nerves, skin and skin-related tissues, bones, and muscles/tendons/ligaments, may show changes that reflect a ...

  19. Radiation impact on the characteristics of optical glasses test results on a selected set of materials

    Science.gov (United States)

    Fruit, Michel; Gussarov, Andrei; Berghmans, Francis; Doyle, Dominic; Ulbrich, Gerd

    2017-11-01

    It is well known within the Space optics community that radiation may significantly affect transmittance of glasses. To overcome this drawback, glass manufacturers have developed Cerium doped counterparts of classical glasses. This doped glasses display much less transmittance sensitivity to radiation. Still, the impact of radiation on refractive index is less known and may affect indifferently classical or Cerium doped glasses. ESTEC has initialised an R&D program with the aim of establishing a comprehensive data base gathering radiation sensitivity data, called Dose coefficients, for all the glass optical parameters (transmittance / refractive index / compaction……). The first part of this study, to define the methodology for such a data base, is run by ASTRIUM SAS in co-operation with SCK CEN. This covers theoretical studies associated to testing of a selected set of classical and "radiation hardened" glasses. It is proposed here to present first the theoretical backgrounds of this study and then to give results which have been obtained so far.

  20. The Impact of Ocular Pressures, Material Properties and Geometry on Optic Nerve Head Deformation

    Science.gov (United States)

    Feola, Andrew J.; Myers, Jerry G.; Raykin, Julia; Nelson, Emily S.; Samuels, Brian C.; Ethier C. Ross

    2017-01-01

    Alteration in intracranial pressure (ICP) has been associated with various diseases that cause visual impairment, including glaucoma, idiopathic intracranial hypertension and Visual Impairment and Intracranial Pressure (VIIP) syndrome. However, how changes in ICP lead to vision loss is unclear, although it is hypothesized to involve deformations of the tissues in the optic nerve head (ONH). Recently, understanding the effect of ICP alterations on ocular tissues has become a major concern for NASA, where 42 of astronauts that partake in long duration space missions suffer from VIIP syndrome. Astronauts with VIIP syndrome suffer from visual impairment and changes in ocular anatomy that persist after returning to earth (1). It is hypothesized that the cephalad fluid shift that occurs upon entering microgravity increases ICP, which leads to an altered biomechanical environment in the posterior globe and optic nerve sheath, and subsequently VIIP syndrome. Our goal was to develop a finite element (FE) model to simulate the acute effects of elevated ICP on the posterior eye. Here, we simulated how inter-individual differences affect the deformation of ONH tissues. Further, we examined how several different geometries influenced deformations when exposed to elevated ICP.

  1. Denmark: HAND in HAND Policy Questionnaire

    DEFF Research Database (Denmark)

    Laursen, Hilmar Dyrborg; Nielsen, Birgitte Lund

    2018-01-01

    Som del af det internationale EU finansierede projekt Hand in Hand, der fokuserer på de såkaldte SEI-kompetencer (Social, Emotional, Intercultural), er dansk policy i relation til elevernes sociale, emotionelle og interkulturelle læring kortlagt i denne rapport. Der refereres bl.a. til "elevernes...

  2. Optical amplifier operating at 1.3 microns useful for telecommunications and based on dysprosium-doped metal chloride host materials

    Energy Technology Data Exchange (ETDEWEB)

    Page, R.H.; Schaffers, K.I.; Payne, S.A.; Krupke, W.F.; Beach, R.J.

    1997-12-02

    Dysprosium-doped metal chloride materials offer laser properties advantageous for use as optical amplifiers in the 1.3 {micro}m telecommunications fiber optic network. The upper laser level is characterized by a millisecond lifetime, the host material possesses a moderately low refractive index, and the gain peak occurs near 1.31 {micro}m. Related halide materials, including bromides and iodides, are also useful. The Dy{sup 3+}-doped metal chlorides can be pumped with laser diodes and yield 1.3 {micro}m signal gain levels significantly beyond those currently available. 9 figs.

  3. Optical amplifier operating at 1.3 microns useful for telecommunications and based on dysprosium-doped metal chloride host materials

    Energy Technology Data Exchange (ETDEWEB)

    Page, Ralph H. (San Ramon, CA); Schaffers, Kathleen I. (Pleasanton, CA); Payne, Stephen A. (Castro Valley, CA); Krupke, William F. (Pleasanton, CA); Beach, Raymond J. (Livermore, CA)

    1997-01-01

    Dysprosium-doped metal chloride materials offer laser properties advantageous for use as optical amplifiers in the 1.3 .mu.m telecommunications fiber optic network. The upper laser level is characterized by a millisecond lifetime, the host material possesses a moderately low refractive index, and the gain peak occurs near 1.31 .mu.m. Related halide materials, including bromides and iodides, are also useful. The Dy.sup.3+ -doped metal chlorides can be pumped with laser diodes and yield 1.3 .mu.m signal gain levels significantly beyond those currently available.

  4. Potential for efficient frequency conversion at high average power using solid state nonlinear optical materials

    International Nuclear Information System (INIS)

    Eimerl, D.

    1985-01-01

    High-average-power frequency conversion using solid state nonlinear materials is discussed. Recent laboratory experience and new developments in design concepts show that current technology, a few tens of watts, may be extended by several orders of magnitude. For example, using KD*P, efficient doubling (>70%) of Nd:YAG at average powers approaching 100 KW is possible; and for doubling to the blue or ultraviolet regions, the average power may approach 1 MW. Configurations using segmented apertures permit essentially unlimited scaling of average power. High average power is achieved by configuring the nonlinear material as a set of thin plates with a large ratio of surface area to volume and by cooling the exposed surfaces with a flowing gas. The design and material fabrication of such a harmonic generator are well within current technology

  5. Experimental Determination of Damage Threshold Characteristics of IR Compatible Optical Materials

    International Nuclear Information System (INIS)

    Soong, Ken

    2011-01-01

    The accelerating gradient in a laser-driven dielectric accelerating structure is often limited by the laser damage threshold of the structure. For a given laser-driven dielectric accelerator design, we can maximize the accelerating gradient by choosing the best combination of the accelerator's constituent material and operating wavelength. We present here a model of the damage mechanism from ultrafast infrared pulses and compare that model with experimental measurements of the damage threshold of bulk silicon. Additionally, we present experimental measurements of a variety of candidate materials, thin films, and nanofabricated accelerating structures.

  6. First-Principles Calculations of Electronic, Optical, and Transport Properties of Materials for Energy Applications

    Science.gov (United States)

    Shi, Guangsha

    Solar electricity is a reliable and environmentally friendly method of sustainable energy production and a realistic alternative to conventional fossil fuels. Moreover, thermoelectric energy conversion is a promising technology for solid-state refrigeration and efficient waste-heat recovery. Predicting and optimizing new photovoltaic and thermoelectric materials composed of Earth-abundant elements that exceed the current state of the art, and understanding how nanoscale structuring and ordering improves their energy conversion efficiency pose a challenge for materials scientists. I approach this challenge by developing and applying predictive high-performance computing methods to guide research and development of new materials for energy-conversion applications. Advances in computer-simulation algorithms and high-performance computing resources promise to speed up the development of new compounds with desirable properties and significantly shorten the time delay between the discovery of new materials and their commercial deployment. I present my calculated results on the extraordinary properties of nanostructured semiconductor materials, including strong visible-light absorbance in nanoporous silicon and few-layer SnSe and GeSe. These findings highlight the capability of nanoscale structuring and ordering to improve the performance of Earth-abundant materials compared to their bulk counterparts for solar-cell applications. I also successfully identified the dominant mechanisms contributing to free-carrier absorption in n-type silicon. My findings help evaluate the impact of the energy loss from this absorption mechanism in doped silicon and are thus important for the design of silicon solar cells. In addition, I calculated the thermoelectric transport properties of p-type SnSe, a bulk material with a record thermoelectric figure of merit. I predicted the optimal temperatures and free-carrier concentrations for thermoelectric energy conversion, as well the

  7. Revisiting the Balazs thought experiment in the case of a left-handed material: electromagnetic-pulse-induced displacement of a dispersive, dissipative negative-index slab.

    Science.gov (United States)

    Chau, Kenneth J; Lezec, Henri J

    2012-04-23

    We propose a set of postulates to describe the mechanical interaction between a plane-wave electromagnetic pulse and a dispersive, dissipative slab having a refractive index of arbitrary sign. The postulates include the Abraham electromagnetic momentum density, a generalized Lorentz force law, and a model for absorption-driven mass transfer from the pulse to the medium. These opto-mechanical mechanisms are incorporated into a one-dimensional finite-difference time-domain algorithm that solves Maxwell's equations and calculates the instantaneous force densities exerted by the pulse onto the slab, the momentum-per-unit-area of the pulse and slab, and the trajectories of the slab and system center-of-mass. We show that the postulates are consistent with conservation of global energy, momentum, and center-of-mass velocity at all times, even for cases in which the refractive index of the slab is negative or zero. Consistency between the set of postulates and well-established conservation laws reinforces the Abraham momentum density as the one true electromagnetic momentum density and enables, for the first time, identification of the correct form of the electromagnetic mass density distribution and development of an explicit model for mass transfer due to absorption, for the most general case of a ponderable medium that is both dispersive and dissipative. © 2012 Optical Society of America

  8. Facile construction of dual bandgap optical encoding materials with PS@P(HEMA-co-AA)/SiO2-TMPTA colloidal photonic crystals

    Science.gov (United States)

    Tian, Yu; Zhang, Jing; Liu, Si-Si; Yang, Shengyang; Yin, Su-Na; Wang, Cai-Feng; Chen, Li; Chen, Su

    2016-07-01

    An operable strategy for the construction of dual-reflex optical code materials from bilayer or Janus-structure colloidal photonic crystals (CPCs) has been established in this work. In this process, monodispersed submicrometer polystryene@poly(2-hydroxyethyl methacrylate-co-acrylic acid) hydrogel microspheres with soft-shell/hard-core structure and monodispersed colloidal silica spheres were fabricated. These two kinds of colloidal units can be facilely integrated into a single material without optical signal interference because they are well isolated for the immiscibility between water and ethoxylated trimethylolpropane triacrylate (TMPTA) and the upper layer of SiO2-TMPTA is a kind of transparent. Moreover, diverse optical code series with different dual photonic bandgaps can be obtained via tuning the colloid sizes. Compared to the conventional single-reflex CPCs, the as-prepared dual-reflex optical code materials represented high information capacity in encoding process. More interesting, delicate code pattern has been also achieved on the optical film via the silk-screen printing technique, which will greatly extend the dual-reflex optical code materials to practical uses in areas containing bio-encoding, anti-counterfeiting, and flexible displays.

  9. Two-photon or higher-order absorbing optical materials and methods of use

    Science.gov (United States)

    Marder, Seth (Inventor); Perry, Joseph (Inventor)

    2012-01-01

    Compositions capable of simultaneous two-photon absorption and higher order absorptivities are provided. Compounds having a donor-pi-donor or acceptor-pi-acceptor structure are of particular interest, where the donor is an electron donating group, acceptor is an electron accepting group, and pi is a pi bridge linking the donor and/or acceptor groups. The pi bridge may additionally be substituted with electron donating or withdrawing groups to alter the absorptive wavelength of the structure. Also disclosed are methods of generating an excited state of such compounds through optical stimulation with light using simultaneous absorption of photons of energies individually insufficient to achieve an excited state of the compound, but capable of doing so upon simultaneous absorption of two or more such photons. Applications employing such methods are also provided, including controlled polymerization achieved through focusing of the light source(s) used.

  10. Polarization-dependent plasmonic splitter based on low-loss polymer optical materials

    Science.gov (United States)

    Qian, Guang; Fu, Xing-Chang; Zhang, Li-Jiang; Liu, Yi-Ran; Zhao, Ning; Zhang, Tong

    2018-01-01

    A polarization-dependent optical beam splitter consisting of a straight long-range surface plasmon polariton (LRSPP) waveguide and an S-bend polymer waveguide was designed, fabricated and measured in this paper. At the splitting section, the two different waveguides are vertically coupled. The measurenment results show that the splitter operated in dual-channel mode at TM polarization, and single-channel mode at TE polarization. In addition, the polymer waveguide and LRSPP waveguide in the splitter exhibit low propagation loss of 0.51 dB/cm and 1.7 dB/cm, respectively. The hybrid beam splitter has wide potential applications in three dimensional (3D) multilayer photonic integrated circuits (PICs).

  11. Crack growth monitoring in composite materials using embedded optical Fiber Bragg Grating sensor

    DEFF Research Database (Denmark)

    Pereira, Gilmar Ferreira; Mikkelsen, Lars Pilgaard; McGugan, Malcolm

    2015-01-01

    In this paper a novel method to assess a crack growing/damage event in fiber reinforced plastic, or adhesive using Fiber Bragg Grating (FBG) sensors embedded in a host material is shown. Different features of the crack mechanism that induce a change in the FBG response were identified. Double...

  12. Chiral-nematic liquid crystals as one dimensional photonic materials in optical sensors

    NARCIS (Netherlands)

    Mulder, D.J.; Schenning, A.P.H.J.; Bastiaansen, C.W.M.

    2014-01-01

    Current developments in the field of thermotropic chiral-nematic liquid crystals as sensors are discussed. These one dimensional photonic materials are based on low molecular weight liquid crystals and chiral-nematic polymeric networks. For both low molecular weight LCs and polymer networks,

  13. Behaviour of alkali halides as materials for optical components of high power lasers

    International Nuclear Information System (INIS)

    Apostol, D.I.; Mihailescu, N.I.; Ghiordanescu, V.; Nistor, C.L.; Nistor, V.S.; Teodorescu, V.; Voda, M.

    1978-01-01

    The physical phenomena taking place in alkali halides when a CO 2 laser radiation is passing through have been reviewed. A special emphasis has been put on the specific qualities which such materials should have for being used as components for high power lasers. (author)

  14. Computerized literature reference system: use of an optical scanner and optical character recognition software.

    Science.gov (United States)

    Lossef, S V; Schwartz, L H

    1990-09-01

    A computerized reference system for radiology journal articles was developed by using an IBM-compatible personal computer with a hand-held optical scanner and optical character recognition software. This allows direct entry of scanned text from printed material into word processing or data-base files. Additionally, line diagrams and photographs of radiographs can be incorporated into these files. A text search and retrieval software program enables rapid searching for keywords in scanned documents. The hand scanner and software programs are commercially available, relatively inexpensive, and easily used. This permits construction of a personalized radiology literature file of readily accessible text and images requiring minimal typing or keystroke entry.

  15. Large field of view quantitative phase imaging of induced pluripotent stem cells and optical pathlength reference materials

    Science.gov (United States)

    Kwee, Edward; Peterson, Alexander; Stinson, Jeffrey; Halter, Michael; Yu, Liya; Majurski, Michael; Chalfoun, Joe; Bajcsy, Peter; Elliott, John

    2018-02-01

    Induced pluripotent stem cells (iPSCs) are reprogrammed cells that can have heterogeneous biological potential. Quality assurance metrics of reprogrammed iPSCs will be critical to ensure reliable use in cell therapies and personalized diagnostic tests. We present a quantitative phase imaging (QPI) workflow which includes acquisition, processing, and stitching multiple adjacent image tiles across a large field of view (LFOV) of a culture vessel. Low magnification image tiles (10x) were acquired with a Phasics SID4BIO camera on a Zeiss microscope. iPSC cultures were maintained using a custom stage incubator on an automated stage. We implement an image acquisition strategy that compensates for non-flat illumination wavefronts to enable imaging of an entire well plate, including the meniscus region normally obscured in Zernike phase contrast imaging. Polynomial fitting and background mode correction was implemented to enable comparability and stitching between multiple tiles. LFOV imaging of reference materials indicated that image acquisition and processing strategies did not affect quantitative phase measurements across the LFOV. Analysis of iPSC colony images demonstrated mass doubling time was significantly different than area doubling time. These measurements were benchmarked with prototype microsphere beads and etched-glass gratings with specified spatial dimensions designed to be QPI reference materials with optical pathlength shifts suitable for cell microscopy. This QPI workflow and the use of reference materials can provide non-destructive traceable imaging method for novel iPSC heterogeneity characterization.

  16. Synthesis, growth, spectral, electrical, mechanical and thermal characterization of a potential optical material: γ-glycine single crystal

    Science.gov (United States)

    Sivakumar, N.; Jayavel, R.; Anbalagan, G.; Yadav, R. R.

    2018-06-01

    Gamma glycine, an organic material was grown by slow solvent evaporation method. Conventional polythermal method was employed in the temperature range, 30-50 °C to obtain the solubility and the metastable zonewidth. The crystal and molecular structures were analyzed by X-ray powder diffraction, FT-IR and FT-Raman spectral studies. Optical refractive index was determined by prism coupling technique and was found to be 1.4488. Electrical properties such as ac conductivity and activation energy were studied for different temperatures in the frequency range from 40 Hz to 6 MHz. The dc electrical conductivity was estimated from the Cole-Cole plot and the values were found to be 2.19 × 10-6 Sm-1 at 353K and 1.46 × 10-6 Sm-1 at 373K respectively. Mechanical studies on the grown crystal revealed that the material belongs to soft materials category. Thermal conductivity and specific heat capacities were estimated by Hot Disk Thermal Constants Analyzer.

  17. Robotic hand project

    OpenAIRE

    Karaçizmeli, Cengiz; Çakır, Gökçe; Tükel, Dilek

    2014-01-01

    In this work, the mechatronic based robotic hand is controlled by the position data taken from the glove which has flex sensors mounted to capture finger bending of the human hand. The angular movement of human hand’s fingers are perceived and processed by a microcontroller, and the robotic hand is controlled by actuating servo motors. It has seen that robotic hand can simulate the movement of the human hand that put on the glove, during tests have done. This robotic hand can be used not only...

  18. Surface Material Characterization from Non-resolved Multi-band Optical Observations

    Science.gov (United States)

    2012-09-01

    distribution estimation” ( RDE ), seeks to determine the bi-directional reflectance distribution functions (BRDFs) of the satellite’s components. Report...when applied to unknown or aging satellites. The second, RDE method was developed specifically to address these limitations. It does not require any...material BRDF information as input. Instead, the RDE method attempts to retrieve BRDF parameters for each satellite sub-component directly from the

  19. Development of Field-Controlled Smart Optic Materials (ScN, AlN) with Rare Earth Dopants

    Science.gov (United States)

    Kim, Hyun-Jung; Park, Yeonjoon; King, Glen C.; Choi, Sang H.

    2012-01-01

    The purpose of this investigation is to develop the fundamental materials and fabrication technology for field-controlled spectrally active optics that are essential for industry, NASA, and DOD applications such as: membrane optics, filters for LIDARs, windows for sensors, telescopes, spectroscopes, cameras, flat-panel displays, etc. ScN and AlN thin films were fabricated on c-axis Sapphire (0001) or quartz substrate with the RF and DC magnetron sputtering. The crystal structure of AlN in fcc (rocksalt) and hcp (wurtzite) were controlled. Advanced electrical characterizations were performed, including I-V and Hall Effect Measurement. ScN film has a free carrier density of 5.8 x 10(exp 20)/per cubic centimeter and a conductivity of 1.1 x 10(exp 3) per centimeter. The background ntype conductivity of as-grown ScN has enough free electrons that can readily interact with the photons. The high density of free electrons and relatively low mobility indicate that these films contain a high level of shallow donors as well as deep levels. Also, the UV-Vis spectrum of ScN and AlN thin films with rare earth elements (Er or Ho) were measured at room temperature. Their optical band gaps were estimated to be about 2.33eV and 2.24eV, respectively, which are obviously smaller than that of undoped thin film ScN (2.4eV). The red-shifted absorption onset gives direct evidence for the decrease of band gap (Eg) and the energy broadening of valence band states are attributable to the doping. As the doped elements enter the ScN crystal lattices, the localized band edge states form at the doped sites with a reduction of Eg. Using a variable angle spectroscopic ellipsometer, the decrease in refractive index with applied field is observed with a smaller shift in absorption coefficient.

  20. Study of material properties important for an optical property modulation-based radiation detection method for positron emission tomography.

    Science.gov (United States)

    Tao, Li; Daghighian, Henry M; Levin, Craig S

    2017-01-01

    We compare the performance of two detector materials, cadmium telluride (CdTe) and bismuth silicon oxide (BSO), for optical property modulation-based radiation detection method for positron emission tomography (PET), which is a potential new direction to dramatically improve the annihilation photon pair coincidence time resolution. We have shown that the induced current flow in the detector crystal resulting from ionizing radiation determines the strength of optical modulation signal. A larger resistivity is favorable for reducing the dark current (noise) in the detector crystal, and thus the higher resistivity BSO crystal has a lower (50% lower on average) noise level than CdTe. The CdTe and BSO crystals can achieve the same sensitivity under laser diode illumination at the same crystal bias voltage condition while the BSO crystal is not as sensitive to 511-keV photons as the CdTe crystal under the same crystal bias voltage. The amplitude of the modulation signal induced by 511-keV photons in BSO crystal is around 30% of that induced in CdTe crystal under the same bias condition. In addition, we have found that the optical modulation strength increases linearly with crystal bias voltage before saturation. The modulation signal with CdTe tends to saturate at bias voltages higher than 1500 V due to its lower resistivity (thus larger dark current) while the modulation signal strength with BSO still increases after 3500 V. Further increasing the bias voltage for BSO could potentially further enhance the modulation strength and thus, the sensitivity.