WorldWideScience

Sample records for optical interferometric read-out

  1. Description of an Advantageous Optical Label-Free Biosensing Interferometric Read-Out Method to Measure Biological Species

    Directory of Open Access Journals (Sweden)

    Miguel Holgado

    2014-02-01

    Full Text Available In this article we report a new, simple, and reliable optical read-out detection method able to assess Rotavirus present in human sera as well as in the viral pollution sources. It is based on the interference of two interferometers used as biophotonic transducers. The method significantly improves the optical label-free biosensing response measuring both, the concentration of the AgR and its corresponding size. Two different immunoassays were carried out: Bovine Serum Albumin (BSA, and the recognition by its antibody (anti-BSA; and Rotavirus (AgR and the recognition by its antibody (anti-AgR. In the cases studied, and using as model interferometer a simple Fabry-Perot transducer, we demonstrate a biosensing enhancement of two orders of magnitude in the Limit of Detection (LoD. In fact, this read-out optical method may have significant implications to enhance other optical label-free photonic transducers reported in the scientific literature.

  2. Cantilever-based sensor with integrated optical read-out using single mode waveguides

    DEFF Research Database (Denmark)

    Nordström, Maria; Zauner, Dan; Calleja, Montserrat;

    2007-01-01

    This work presents the design, fabrication and mechanical characterisation of an integrated optical read-out scheme for cantilever-based biosensors. A cantilever can be used as a biosensor by monitoring its bending caused by the surface stress generated due to chemical reactions occurring on its ...

  3. Optically read out GEM-based TPC operation and preliminary scintillation studies

    CERN Document Server

    Galgoczi, Gabor

    2016-01-01

    The main goal of this project was to realise the reconstruction of tracks in an optically read out GEM (Gas Electron Multiplier) based Time Projection Chamber (TPC). Secondary goal was to initialise a series of systematic studies on the scintillation of particles in Ar/CF4 (80-20%) mixture. Track reconstruction is needed for primary scintillation studies as only tracks fully contained can be considered. A vetoing and trigerring logic was built for the TPC from NIM modules.

  4. Integrated optical read-out for polymeric cantilever-based sensors

    DEFF Research Database (Denmark)

    Tenje, Maria

    2007-01-01

    This thesis presents a novel read-out method developed for cantilever-based sensors. Cantilevers are thin beams clamped at one end and during the last 10 years they have emerged as an interesting new type of bio/chemical sensor. The specific recognition of a chemical manifests itself as a bending...... Young’s modulus instead of the conventional materials Si and Si3N4. Here, a novel read-out method is presented where optical waveguides are used to integrate the light into the cantilever. It is an all-polymer device where both the cantilever and the waveguides are fabricated in the negative resist SU-8....... Waveguides are structured on either side of the cantilever that is free-hanging in a microfluidic channel. Light is guided into the system and is either transmitted through the cantilever or reflected off the cantilever front-end, depending on the mode of operation. This work shows that waveguides, only...

  5. Interferometric Fiber Optic Sensors

    Directory of Open Access Journals (Sweden)

    Hae Young Choi

    2012-02-01

    Full Text Available Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  6. Interferometric fiber optic sensors.

    Science.gov (United States)

    Lee, Byeong Ha; Kim, Young Ho; Park, Kwan Seob; Eom, Joo Beom; Kim, Myoung Jin; Rho, Byung Sup; Choi, Hae Young

    2012-01-01

    Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.

  7. ORANGE: A high sensitivity particle tracker based on optically read out GEM

    Science.gov (United States)

    Marafini, M.; Patera, V.; Pinci, D.; Sarti, A.; Sciubba, A.; Spiriti, E.

    2017-02-01

    GEM-based detectors had a noticeable development in last years and have successfully been employed in different fields from High Energy Physics to imaging applications. Light production associated to the electron multiplication allows to perform an optical readout of these devices. The big progress achieved in CMOS-based photosensors makes possible to develop a high sensitivity, high granularity and low noise readout. In this paper we present the results obtained by reading out the light produced by a triple-GEM structure by means of a 4 mega-pixel CMOS sensor having a noise level less than two photons per pixel. The choice of a CF4 rich gas mixture (He/CF4 60/40) and a detailed optimisation of the electric fields allowed to reach a light-yield high enough to obtain very visible signals from minimum ionizing particles. In a test performed with 450 MeV electron beam, 800 photons per millimeter were collected and a space resolution of about 75 μ m was obtained.

  8. The use and calibration of read-out streaks to increase the dynamic range of the Swift Ultraviolet/Optical Telescope

    CERN Document Server

    Page, M J; Breeveld, A A; Hancock, B; Holland, S T; Marshall, F E; Oates, S; Roming, P W A; Siegel, M H; Smith, P J; Carter, M; De Pasquale, M; Symeonidis, M; Yershov, V; Beardmore, A P

    2013-01-01

    The dynamic range of photon counting micro-channel-plate (MCP) intensified charged-coupled device (CCD) instruments such as the Swift Ultraviolet/Optical Telescope (UVOT) and the XMM-Newton Optical Monitor (XMM-OM) is limited at the bright end by coincidence loss, the superposition of multiple photons in the individual frames recorded by the CCD. Photons which arrive during the brief period in which the image frame is transferred for read out of the CCD are displaced in the transfer direction in the recorded images. For sufficiently bright sources, these displaced counts form read-out streaks. Using UVOT observations of Tycho-2 stars, we investigate the use of these read-out streaks to obtain photometry for sources which are too bright (and hence have too much coincidence loss) for normal aperture photometry to be reliable. For read-out-streak photometry, the bright-source limiting factor is coincidence loss within the MCPs rather than the CCD. We find that photometric measurements can be obtained for stars u...

  9. Interferometric Fiber-Optic Gyroscope

    Science.gov (United States)

    Depaula, Ramon P.; Bogert, Gail A.; Minford, William J.

    1990-01-01

    Integrated three-waveguide directional coupler functions as polarizer and splitter. Designed with transverse electric (TE) polarization in bar state (two coupling lengths) and transverse magnetic (TM) polarization in cross state (one coupling length). Intended for eventual fabrication as in mass-producible integrated optical circuit that provides advantages including low drive voltage, large-bandwidth phase modulation, preservation of polarization in transmission between devices on same substrate, and low cost.

  10. Photostimulated near-infrared persistent luminescence as a new optical read-out from Cr3+-doped LiGa5O8

    Science.gov (United States)

    Liu, Feng; Yan, Wuzhao; Chuang, Yen-Jun; Zhen, Zipeng; Xie, Jin; Pan, Zhengwei

    2013-01-01

    In conventional photostimulable storage phosphors, the optical information written by x-ray or ultraviolet irradiation is usually read out as a visible photostimulated luminescence (PSL) signal under the stimulation of a low-energy light with appropriate wavelength. Unlike the transient PSL, here we report a new optical read-out form, photostimulated persistent luminescence (PSPL) in the near-infrared (NIR), from a Cr3+-doped LiGa5O8 NIR persistent phosphor exhibiting a super-long NIR persistent luminescence of more than 1,000 h. An intense PSPL signal peaking at 716 nm can be repeatedly obtained in a period of more than 1,000 h when an ultraviolet-light (250–360 nm) pre-irradiated LiGa5O8:Cr3+ phosphor is repeatedly stimulated with a visible light or a NIR light. The LiGa5O8:Cr3+ phosphor has promising applications in optical information storage, night-vision surveillance, and in vivo bio-imaging. PMID:23532003

  11. The case for optical interferometric polarimetry

    CERN Document Server

    Elias, Nicholas M; Schmitt, Henrique R; Jorgensen, Anders M; Ireland, Michael J; Perraut, Karine

    2008-01-01

    Within the last 10 years, long-baseline optical interferometry (LBOI) has benefited significantly from increased sensitivity, spatial resolution, and spectral resolution, e.g., measuring the diameters and asymmetries of single stars, imaging/fitting the orbits of multiple stars, modeling Be star disks, and modeling AGN nuclei. Similarly, polarimetry has also yielded excellent astrophysical results, e.g., characterizing the atmospheres and shells of red giants/supergiants, modeling the envelopes of AGB stars, studying the morphology of Be stars, and monitoring the short- and long- term behavior of AGNs. The next logical evolutionary step in instrumentation is to combine LBOI with polarimetry, which is called optical interferometric polarimetry (OIP). In other words, measurements of spatial coherence are performed simultaneously with measurements of coherence between orthogonal polarization states.

  12. Optical read-out of the quantum motion of an array of atoms-based mechanical oscillators

    CERN Document Server

    Botter, Thierry; Schreppler, Sydney; Brahms, Nathan; Stamper-Kurn, Dan M

    2012-01-01

    We create an ultracold-atoms-based cavity optomechanical system in which as many as six distinguishable mechanical oscillators are prepared, and optically detected, near their ground states of motion. We demonstrate that the motional state of one oscillator can be selectively addressed while preserving neighboring oscillators near their ground states to better than 95% per excitation quantum. We also show that our system offers nanometer-scale spatial resolution of each mechanical element via optomechanical imaging. This technique enables in-situ, parallel sensing of potential landscapes, a capability relevant to active research areas of atomic physics and force-field detection in optomechanics.

  13. Fiber-optic interferometric acoustic sensors for wind tunnel applications

    Science.gov (United States)

    Cho, Y. C.

    1993-01-01

    Progress in developing fiber-optic interferometric sensors for aeroacoustic measurements in wind tunnels, performed under the NASA program, is reported. Preliminary results show that the fiber-optic interferometer sensor array is a powerful instrument for solving complex acoustic measurement problems in wind tunnels, which cannot be resolved with the conventional transducer technique.

  14. Fiber-optic interferometric acoustic sensors for wind tunnel applications

    Science.gov (United States)

    Cho, Y. C.

    1993-01-01

    Progress in developing fiber-optic interferometric sensors for aeroacoustic measurements in wind tunnels, performed under the NASA program, is reported. Preliminary results show that the fiber-optic interferometer sensor array is a powerful instrument for solving complex acoustic measurement problems in wind tunnels, which cannot be resolved with the conventional transducer technique.

  15. Synchronous phase detection for optical fiber interferometric sensors.

    Science.gov (United States)

    Bush, I J; Phillips, R L

    1983-08-01

    A system has been developed to accurately detect phase signals produced in optical interferometric sensors. The system employs optical heterodyning and synchronously detects optical phase by feeding back an error signal to a phase modulator in the reference leg of the interferometer. This system is seen to have properties similar to a phase-locked loop. The system is mathematically analyzed and a simple second-order model developed which accurately predicts the system response.

  16. Computed Optical Interferometric Imaging: Methods, Achievements, and Challenges.

    Science.gov (United States)

    South, Fredrick A; Liu, Yuan-Zhi; Carney, P Scott; Boppart, Stephen A

    2016-01-01

    Three-dimensional high-resolution optical imaging systems are generally restricted by the trade-off between resolution and depth-of-field as well as imperfections in the imaging system or sample. Computed optical interferometric imaging is able to overcome these longstanding limitations using methods such as interferometric synthetic aperture microscopy (ISAM) and computational adaptive optics (CAO) which manipulate the complex interferometric data. These techniques correct for limited depth-of-field and optical aberrations without the need for additional hardware. This paper aims to outline these computational methods, making them readily available to the research community. Achievements of the techniques will be highlighted, along with past and present challenges in implementing the techniques. Challenges such as phase instability and determination of the appropriate aberration correction have been largely overcome so that imaging of living tissues using ISAM and CAO is now possible. Computed imaging in optics is becoming a mature technology poised to make a significant impact in medicine and biology.

  17. Recovering Signals from Optical Fiber Interferometric Sensors

    Science.gov (United States)

    1991-06-01

    explained in numerous books on operational amplifiers (for example, see Sedra and Smith [Ref. 171) and so will not be further discussed here, except to say...618. 1 October 1982. 17. Sedra , A. S.. and Smith .- K. C.. Microelectronic CrciimHolt. Rinehart and Winston, 1982. 18. Abramowitz, M. and- Stegun. I.A...Interfcromctcrse, Applied Optics. Volume 21. Number 4. 689-693. 1982. 46. Smith , L. and Sheingold, D.H.. "Noise and Operational Amplifier Circuits’, Analog

  18. Quantitative interferometric microscopy cytometer based on regularized optical flow algorithm

    Science.gov (United States)

    Xue, Liang; Vargas, Javier; Wang, Shouyu; Li, Zhenhua; Liu, Fei

    2015-09-01

    Cell detections and analysis are important in various fields, such as medical observations and disease diagnoses. In order to analyze the cell parameters as well as observe the samples directly, in this paper, we present an improved quantitative interferometric microscopy cytometer, which can monitor the quantitative phase distributions of bio-samples and realize cellular parameter statistics. The proposed system is able to recover the phase imaging of biological samples in the expanded field of view via a regularized optical flow demodulation algorithm. This algorithm reconstructs the phase distribution with high accuracy with only two interferograms acquired at different time points simplifying the scanning system. Additionally, the method is totally automatic, and therefore it is convenient for establishing a quantitative phase cytometer. Moreover, the phase retrieval approach is robust against noise and background. Excitingly, red blood cells are readily investigated with the quantitative interferometric microscopy cytometer system.

  19. Asymmetric Fabry-Pérot interferometric cavity for fiber optical sensors

    Institute of Scientific and Technical Information of China (English)

    Shaoji Jiang; Youcheng Liang; Xi Zhu; Hezhou Wang

    2006-01-01

    Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot (F-P) interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an asymmetric F-P interferometric cavity with good linearity and wide dynamic range is designed. And by choosing the material of two different thin metallic layers, the asymmetric F-P interferometric cavity is successfully fabricated. The design theory and method of this asymmetric F-P interferometric cavity have been described in detailed. In this paper an asymmetric F-P interferometric cavity used in fiber optical sensor is reported.

  20. Nonlinear Interferometric Vibrational Imaging (NIVI) with Novel Optical Sources

    Science.gov (United States)

    Boppart, Stephen A.; King, Matthew D.; Liu, Yuan; Tu, Haohua; Gruebele, Martin

    Optical imaging is essential in medicine and in fundamental studies of biological systems. Although many existing imaging modalities can supply valuable information, not all are capable of label-free imaging with high-contrast and molecular specificity. The application of molecular or nanoparticle contrast agents may adversely influence the biological system under investigation. These substances also present ongoing concerns over toxicity or particle clearance, which must be properly addressed before their approval for in vivo human imaging. Hence there is an increasing appreciation for label-free imaging techniques. It is of primary importance to develop imaging techniques that can indiscriminately identify and quantify biochemical compositions to high degrees of sensitivity and specificity through only the intrinsic optical response of endogenous molecular species. The development and use of nonlinear interferometric vibrational imaging, which is based on the interferometric detection of optical signals from coherent anti-Stokes Raman scattering (CARS), along with novel optical sources, offers the potential for label-free molecular imaging.

  1. Interferometric and localized surface plasmon based fiber optic sensor

    Science.gov (United States)

    Muri, Harald Ian D. I.; Bano, Andon; Hjelme, Dag Roar

    2017-02-01

    We demonstrate a novel single point, multi-parameter, fiber optic sensor concept based on a combination of interferometric and plasmonic sensor modalities on an optical fiber end face. The sensor consists of a micro-Fabry-Perot interferometer in the form of a hemispherical stimuli-responsive hydrogel with immobilized gold nanoparticles. We present results of proof-of-concept experiments demonstrating local surface plasmon resonance (LSPR) sensing of refractive index (RI) in the visible range and interferometric measurements of volumetric changes of the pH stimuli-responsive hydrogel in near infrared range. The response of LSPR to RI (Δλr/ΔRI 877nm/RI) and the free spectral range (FSR) to pH (ΔpH/ΔFSR = 0.09624/nm) were measured with LSPR relatively constant for hydrogel swelling degree and FSR relatively constant for RI. We expect this novel sensor concept to be of great value for biosensors for medical applications.

  2. All-optical phase modulation for integrated interferometric biosensors.

    Science.gov (United States)

    Dante, Stefania; Duval, Daphné; Sepúlveda, Borja; González-Guerrero, Ana Belen; Sendra, José Ramón; Lechuga, Laura M

    2012-03-26

    We present the theoretical and the experimental implementation of an all-optical phase modulation system in integrated Mach-Zehnder Interferometers to solve the drawbacks related to the periodic nature of the interferometric signal. Sensor phase is tuned by modulating the emission wavelength of low-cost commercial laser diodes by changing their output power. FFT deconvolution of the signal allows for direct phase readout, immune to sensitivity variations and to light intensity fluctuations. This simple phase modulation scheme increases the signal-to-noise ratio of the measurements in one order of magnitude, rendering in a sensor with a detection limit of 1.9·10⁻⁷ RIU. The viability of the all-optical modulation approach is demonstrated with an immunoassay detection as a biosensing proof of concept.

  3. Parallel approach to MEMS and micro-optics interferometric testing

    Science.gov (United States)

    Kujawińska, M.; Beer, S.; Gastinger, K.; Gorecki, C.; Haugholt, K. H.; Józwik, M.; Lambelet, P.; Paris, R.; Styk, A.; Zeitner, U.

    2011-08-01

    The paper presents the novel approach to an interferometric, quantitative, massive parallel inspection of MicroElectroMechanicalSystems (MEMS), MicroOptoElectroMechanical Systems (MOEMS) and microoptics arrays. The basic idea is to adapt a micro-optical probing wafer to the M(O)EMS wafer under test. The probing wafer is exchangeable and contains one of the micro-optical interferometer arrays based on: (1) a low coherent interferometer array based on a Mirau configuration or (2) a laser interferometer array based on a Twyman-Green configuration. The optical, mechanical, and electro-optical design of the system and data analysis concept based on this approach is presented. The interferometer arrays are developed and integrated at a standard test station for micro-fabrication together with the illumination and imaging modules and special mechanics which includes scanning and electrostatic excitation systems. The smart-pixel approach is applied for massive parallel electro-optical detection and data reduction. The first results of functional tests of the system are presented. The concept is discussed in reference to the future M(O)EMS and microoptics manufacturers needs and requirements.

  4. Miniaturized fiber-optic Michelson-type interferometric sensors

    Science.gov (United States)

    Murphy, Kent A.; Miller, William V., III; Tran, Tuan A.; Vengsarkar, Ashish M.; Claus, Richard O.

    1991-01-01

    A novel, miniaturized Michelson-type fiber-optic interferometric sensor that is relatively insensitive to temperature drifts is presented. A fused-biconical tapered coupler is cleaved immediately after the coupled length and polished down to the region of the fused cladding, but short of the interaction region. The end of one core is selectively coated with a reflective surface and is used as the reference arm; the other core serves as the sensing arm. The detection of surface acoustic waves, microdisplacements, and magnetic fields is reported. The sensor is shown to be highly stable in comparison to a classic homodyne, uncompensated Michelson interferometer, and signal-to-noise ratios of 65 dB have been obtained.

  5. All-optical 40 Gbit/s compact integrated interferometric wavelength converter

    DEFF Research Database (Denmark)

    Jørgensen, Carsten; Danielsen, Søren Lykke; Hansen, Peter Bukhave;

    1997-01-01

    An interferometric Michelson wavelength converter is presented that combines a speed-optimized semiconductor optical amplifier technology with the benefits of the integrated interferometer showing 40-Gbit/s wavelength conversion. The optimized wavelength converter demonstrates noninverted converted...

  6. Interferometric microstructured polymer optical fiber ultrasound sensor for optoacoustic endoscopic imaging in biomedical applications

    DEFF Research Database (Denmark)

    Gallego, Daniel; Sáez-Rodríguez, David; Webb, David

    2014-01-01

    We report a characterization of the acoustic sensitivity of microstructured polymer optical fiber interferometric sensors at ultrasonic frequencies from 100kHz to 10MHz. The use of wide-band ultrasonic fiber optic sensors in biomedical ultrasonic and optoacoustic applications is an open alternative...... interferometric sensors depends strongly of the material which is composed of. In this work we compare experimentally the intrinsic ultrasonic sensitivities of a PMMA mPOF with other three optical fibers: a singlemode silica optical fiber, a single-mode polymer optical fiber and a multimode graded...

  7. An analog modulation and demodulation method employing LVDT signal conditioner for fiber-optic interferometric sensors

    Science.gov (United States)

    Zhou, Kejiang; Rao, Qi; Zhang, Minjie; Hu, Keke; Ruan, Yefeng

    2017-09-01

    An analog method to modulate and demodulate fiber-optic interferometric sensors employing a linear variable differential transformer signal conditioner to generate sine modulation wave and demodulate phase-modulated signal from the photodetector’s output is presented in this letter. No external lock-in amplifiers or digital components are used in this design. All the necessary components for signal processing are integrated in a single analog electronic microchip AD698, which reduces the system’s complexity significantly. After implementation on an interferometric fiber-optic gyroscope as an example, this method demonstrates a bias stability of 0.063 deg h-1 (i.e. 0.220 µrad).

  8. The TOTEM T1 read out card motherboard

    CERN Document Server

    Minutoli, S; Robutti, E

    2010-01-01

    This article describes the Read Out Card (ROC) motherboard, which is the main component of the T1 forward telescope front-end electronic system. The ROC main objectives are to acquire tracking data and trigger information from the detector. It performs data conversion from electrical to optical format and transfers the data streams to the next level of the system and it implements Slow Control modules which are able to receive, decode and distribute the LHC machine low jitter clock and fast command. The ROC also provides a spy mezzanine connection based on programmable FPGA and USB2.0 for laboratory and portable DAQ debugging system

  9. The TOTEM T1 read out card motherboard

    Science.gov (United States)

    Minutoli, S.; Lo Vetere, M.; Robutti, E.

    2010-12-01

    This article describes the Read Out Card (ROC) motherboard, which is the main component of the T1 forward telescope front-end electronic system. The ROC main objectives are to acquire tracking data and trigger information from the detector. It performs data conversion from electrical to optical format and transfers the data streams to the next level of the system and it implements Slow Control modules which are able to receive, decode and distribute the LHC machine low jitter clock and fast command. The ROC also provides a spy mezzanine connection based on programmable FPGA and USB2.0 for laboratory and portable DAQ debugging system.

  10. Pseudo working-point control measurement scheme for acoustic sensitivity of interferometric fiber-optic hydrophones

    Institute of Scientific and Technical Information of China (English)

    Zefeng Wang; Yongming Hu; Zhou Meng; Ming Ni

    2008-01-01

    A novel pseudo working-point control measurement scheme for the acoustic sensitivity of interferometric fiber-optic hydrophones is described and demonstrated.The measurement principle is introduced in detail.An experimental system,which interrogates an interferometric fiber-optic hydrophone with this method,is designed.The acoustic pressure phase sensitivity of the fiber-optic hydrophone is measured over the frequency range of 20-2500Hz.The measured acoustic sensitivity is about-156.5dB re 1rad/μPa with a fluctuation lower than ±1.2dB,which is in good agreement with the results obtained by the method of phase generated carrier.The experimental results testify the validity of this new method which has the advantages of no electric elements in the sensing head,the simplicity of signal processing,and wide working bandwidth.

  11. Interferometric pump-probe characterization of the nonlocal response of optically transparent ion implanted polymers

    Science.gov (United States)

    Stefanov, Ivan L.; Hadjichristov, Georgi B.

    2012-03-01

    Optical interferometric technique is applied to characterize the nonlocal response of optically transparent ion implanted polymers. The thermal nonlinearity of the ion-modified material in the near-surface region is induced by continuous wave (cw) laser irradiation at a relatively low intensity. The interferometry approach is demonstrated for a subsurface layer of a thickness of about 100 nm formed in bulk polymethylmethacrylate (PMMA) by implantation with silicon ions at an energy of 50 keV and fluence in the range 1014-1017 cm-2. The laser-induced thermooptic effect in this layer is finely probed by interferometric imaging. The interference phase distribution in the plane of the ion implanted layer is indicative for the thermal nonlinearity of the near-surface region of ion implanted optically transparent polymeric materials.

  12. Computational adaptive optics for broadband interferometric tomography of tissues and cells

    Science.gov (United States)

    Adie, Steven G.; Mulligan, Jeffrey A.

    2016-03-01

    Adaptive optics (AO) can shape aberrated optical wavefronts to physically restore the constructive interference needed for high-resolution imaging. With access to the complex optical field, however, many functions of optical hardware can be achieved computationally, including focusing and the compensation of optical aberrations to restore the constructive interference required for diffraction-limited imaging performance. Holography, which employs interferometric detection of the complex optical field, was developed based on this connection between hardware and computational image formation, although this link has only recently been exploited for 3D tomographic imaging in scattering biological tissues. This talk will present the underlying imaging science behind computational image formation with optical coherence tomography (OCT) -- a beam-scanned version of broadband digital holography. Analogous to hardware AO (HAO), we demonstrate computational adaptive optics (CAO) and optimization of the computed pupil correction in 'sensorless mode' (Zernike polynomial corrections with feedback from image metrics) or with the use of 'guide-stars' in the sample. We discuss the concept of an 'isotomic volume' as the volumetric extension of the 'isoplanatic patch' introduced in astronomical AO. Recent CAO results and ongoing work is highlighted to point to the potential biomedical impact of computed broadband interferometric tomography. We also discuss the advantages and disadvantages of HAO vs. CAO for the effective shaping of optical wavefronts, and highlight opportunities for hybrid approaches that synergistically combine the unique advantages of hardware and computational methods for rapid volumetric tomography with cellular resolution.

  13. JouFLU: upgrades to the fiber linked unit for optical recombination (FLUOR) interferometric beam combiner.

    Science.gov (United States)

    Scott, N. J.; Lhomé, E.; ten Brummelaar, T. A.; Coudé du Foresto, V.; Millan-Gabet, R.; Sturmann, J.; Sturmann, L.

    2014-07-01

    The Fiber Linked Unit for Optical Recombination (FLUOR) is a precision interferometric beam combiner operating at the CHARA Array on Mt. Wilson, CA. It has recently been upgraded as part of a mission known as "Jouvence of FLUOR" or JouFLU. As part of this program JouFLU has new mechanic stages and optical payloads, new alignment systems, and new command/control software. Furthermore, new capabilities have been implemented such as a Fourier Transform Spectrograph (FTS) mode and spectral dispersion mode. These upgrades provide new capabilities to JouFLU as well as improving statistical precision and increasing observing efficiency. With these new systems, measurements of interferometric visibility to the level of 0.1% precision are expected on targets as faint as 6th magnitude in the K band. Here we detail the upgrades of JouFLU and report on its current status.

  14. Dust Scattering in Miras R Car and RR Sco resolved by optical interferometric polarimetry

    CERN Document Server

    Ireland, M J; Davis, J; Tango, W

    2005-01-01

    We present optical interferometric polarimetry measurements of the Mira-like variables R Car and RR Sco, using the Sydney University Stellar Interferometer. By making visibility measurements in two perpendicular polarisations, the relatively low-surface brightness light scattered by atmospheric dust could be spatially separated from the bright Mira photospheric flux. This is the first reported successful use of long-baseline optical interferometric polarimetry. Observations were able to place constraints on the distribution of circumstellar material in R Car and RR Sco. The inner radius of dust formation for both stars was found to be less than 3 stellar radii: much closer than the expected innermost stable location for commonly-assumed astrophysical ``dirty silicate'' dust in these systems (silicate dust with a significant iron content). A model with the dust distributed over a shell which is geometrically thin compared to the stellar radius was preferred over an outflow. We propose dust components whose che...

  15. Visibility in magnetostrictive fiber-optic interferometric sensors and its dependence on the input SOP

    Institute of Scientific and Technical Information of China (English)

    Changhai Shi; Jianping Chen; Xinwan Li; Ailun Ye; Junhe Zhou; Yi Zhang; Qing Xue; Lin Hong

    2006-01-01

    The visibility in magnetostrictive fiber-optic interferometric sensors using a Gaussian laser beam is analyzed. It is shown that the conventional Gaussian laser beam has little influence on the visibility. The visibility depends strongly on the input state of polarization (SOP). We implement a cylindrical transducer and build a measurement setup with a polarization controller. The visibility dependent on the SOP of input light is measured. The estimated values are similar to the experiment results, which verifies the analysis.

  16. Stochastic Optics: A Scattering Mitigation Framework for Radio Interferometric Imaging

    CERN Document Server

    Johnson, Michael D

    2016-01-01

    Just as turbulence in the Earth's atmosphere can severely limit the angular resolution of optical telescopes, turbulence in the ionized interstellar medium fundamentally limits the resolution of radio telescopes. We present a scattering mitigation framework for radio imaging with very long baseline interferometry (VLBI) that partially overcomes this limitation. Our framework, "stochastic optics," derives from a simplification of strong interstellar scattering to separate small-scale ("diffractive") effects from large-scale ("refractive") effects, thereby separating deterministic and random contributions to the scattering. Stochastic optics extends traditional synthesis imaging by simultaneously reconstructing an unscattered image and its refractive perturbations. Its advantages over direct imaging come from utilizing the many deterministic properties of the scattering -- such as the time-averaged "blurring," polarization independence, and the deterministic evolution in frequency and time -- while still accoun...

  17. Reliable and redundant FPGA based read-out design in the ATLAS TileCal Demonstrator

    CERN Document Server

    Akerstedt, H; The ATLAS collaboration; Drake, Gary; Anderson, Kelby; Bohm, C; Oreglia, Mark; Tang, Fukun

    2015-01-01

    The Tile Calorimeter at ATLAS is a hadron calorimeter based on steel plates and scintillating tiles read out by PMTs. The current read-out system uses standard ADCs and custom ASICs to digitize and temporarily store the data on the detector. However, only a subset of the data is actually read out to the counting room. The on-detector electronics will be replaced around 2023. To achieve the required reliability the upgraded system will be highly redundant. Here the ASICs will be replaced with Kintex-7 FPGAs from Xilinx. This, in addition to the use of multiple 10 Gbps optical read-out links, will allow a full read-out of all detector data. Due to the higher radiation levels expected when the beam luminosity is increased, opportunities for repairs will be less frequent. The circuitry and firmware must therefore be designed for sufficiently high reliability using redundancy and radiation tolerant components. Within a year, a hybrid demonstrator including the new read-out system will be installed in one slice of ...

  18. Interferometric strain measurements with a fiber-optic probe

    Science.gov (United States)

    Burnham-Fay, E. D.; Jacobs-Perkins, D. W.; Ellis, J. D.

    2015-09-01

    Experience at the Laboratory for Laser Energetics has shown that broadband base vibrations make it difficult to position cryogenic inertial confinement fusion targets. These effects must be mitigated for National Ignition Facility-scale targets; to this end an active vibration stabilization system is proposed. A single-mode optical fiber strain probe and a novel fiber contained heterodyne interferometer have been developed as a position feedback sensor for the vibration control system. A resolution limit of 54.5 nƐ; is measured with the optical strain gauge, limited by the lock-in amplifier. Experimental measurements of the sensor that show good agreement with reference resistive strain gauge measurements are presented.

  19. Interferometric velocity measurements through a fluctuating gas-liquid interface employing adaptive optics.

    Science.gov (United States)

    Büttner, Lars; Leithold, Christoph; Czarske, Jürgen

    2013-12-16

    Optical transmission through fluctuating interfaces of mediums with different refractive indexes is limited by the occurring distortions. Temporal fluctuations of such distortions deteriorate optical measurements. In order to overcome this shortcoming we propose the use of adaptive optics. For the first time, an interferometric velocity measurement technique with embedded adaptive optics is presented for flow velocity measurements through a fluctuating air-water interface. A low order distortion correction technique using a fast deformable mirror and a Hartmann-Shack camera with high frame rate is employed. The obtained high control bandwidth enables precise measurements also at fast fluctuating media interfaces. This methodology paves the way for several kinds of optical flow measurements in various complex environments.

  20. Interferometric and nonlinear-optical spectral-imaging techniques for outer space and live cells

    Science.gov (United States)

    Itoh, Kazuyoshi

    2015-12-01

    Multidimensional signals such as the spectral images allow us to have deeper insights into the natures of objects. In this paper the spectral imaging techniques that are based on optical interferometry and nonlinear optics are presented. The interferometric imaging technique is based on the unified theory of Van Cittert-Zernike and Wiener-Khintchine theorems and allows us to retrieve a spectral image of an object in the far zone from the 3D spatial coherence function. The retrieval principle is explained using a very simple object. The promising applications to space interferometers for astronomy that are currently in progress will also be briefly touched on. An interesting extension of interferometric spectral imaging is a 3D and spectral imaging technique that records 4D information of objects where the 3D and spectral information is retrieved from the cross-spectral density function of optical field. The 3D imaging is realized via the numerical inverse propagation of the cross-spectral density. A few techniques suggested recently are introduced. The nonlinear optical technique that utilizes stimulated Raman scattering (SRS) for spectral imaging of biomedical targets is presented lastly. The strong signals of SRS permit us to get vibrational information of molecules in the live cell or tissue in real time. The vibrational information of unstained or unlabeled molecules is crucial especially for medical applications. The 3D information due to the optical nonlinearity is also the attractive feature of SRS spectral microscopy.

  1. Read-out electronics for DC squid magnetic measurements

    Science.gov (United States)

    Ganther, Jr., Kenneth R.; Snapp, Lowell D.

    2002-01-01

    Read-out electronics for DC SQUID sensor systems, the read-out electronics incorporating low Johnson noise radio-frequency flux-locked loop circuitry and digital signal processing algorithms in order to improve upon the prior art by a factor of at least ten, thereby alleviating problems caused by magnetic interference when operating DC SQUID sensor systems in magnetically unshielded environments.

  2. A regularized tri-linear approach for optical interferometric imaging

    Science.gov (United States)

    Birdi, Jasleen; Repetti, Audrey; Wiaux, Yves

    2017-06-01

    In the context of optical interferometry, only undersampled power spectrum and bispectrum data are accessible. It poses an ill-posed inverse problem for image recovery. Recently, a tri-linear model was proposed for monochromatic imaging, leading to an alternated minimization problem. In that work, only a positivity constraint was considered, and the problem was solved by an approximated Gauss-Seidel method. In this paper, we propose to improve the approach on three fundamental aspects. First, we define the estimated image as a solution of a regularized minimization problem, promoting sparsity in a fixed dictionary using either an ℓ1 or a (re)weighted-ℓ1 regularization term. Secondly, we solve the resultant non-convex minimization problem using a block-coordinate forward-backward algorithm. This algorithm is able to deal both with smooth and non-smooth functions, and benefits from convergence guarantees even in a non-convex context. Finally, we generalize our model and algorithm to the hyperspectral case, promoting a joint sparsity prior through an ℓ2,1 regularization term. We present simulation results, both for monochromatic and hyperspectral cases, to validate the proposed approach.

  3. A regularized tri-linear approach for optical interferometric imaging

    CERN Document Server

    Birdi, Jasleen; Wiaux, Yves

    2016-01-01

    In the context of optical interferometry, only under-sampled power spectrum and bispectrum data are accessible. It poses an ill-posed inverse problem for image recovery. Recently, a tri-linear model was proposed for monochromatic imaging, leading to an alternated minimization problem. In that work, only a positivity constraint was considered, and the problem was solved by an approximated Gauss-Seidel method. In this paper, we propose to improve the approach on three fundamental aspects. Firstly, we define the estimated image as a solution of a regularized minimization problem, promoting sparsity in a fixed dictionary using either an $\\ell_1$ or a weighted-$\\ell_1$ regularization term. Secondly, we solve the resultant non-convex minimization problem using a block-coordinate forward-backward algorithm. This algorithm is able to deal both with smooth and non-smooth functions, and benefits from convergence guarantees even in a non-convex context. Finally, we generalize our model and algorithm to the hyperspectral...

  4. Radiation-induced effects in polarization-maintaining optical fibers for interferometric gyroscope

    Institute of Scientific and Technical Information of China (English)

    Xueqin Wang; Chunxi Zhang; Jing Jin; Ningfang Song

    2011-01-01

    @@ Radiation-induced attenuation (RIA) in four types of polarization-maintaining optical fibers for interferometric fiberoptic gyroscope (IFOG) at 1310 nm is measured.The measurements are conducted during and after steady-state γ-ray irradiation using a 60Co source in order to observe significantly different RIA behavior and recovery kinetics.Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG.Medium-accuracy IFOG using Ge-F-codoped fiber and pure silica core fiber can survive in the space radiation environment.%Radiation-induced attenuation (RIA) in four types of polarization-maintaining optical fibers for interferometric fiberoptic gyroscope (IFOG) at 1310 nm is measured. The measurements are conducted during and after steady-state γ-ray irradiation using a 60Co source in order to observe significantly different RIA behavior and recovery kinetics. Mechanisms involving dopants and manufacturing process are introduced to analyze the RIA discrepancy as well as to guide the choice and hardening of optical fibers during the design of IFOG. Medium-accuracy IFOG using Ge-F-codoped fiber and pure silica core fiber can survive in the space radiation environment.

  5. Broadband polarization interferometric time-integrating acousto-optic correlator for random noise radar

    Science.gov (United States)

    Kim, Sangtaek; Wagner, Kelvin H.; Narayanan, Ram M.; Zhou, Wei

    2005-10-01

    We describe a time-integrating acousto-optic correlator (TIAOC) developed for imaging and target detection using a wideband random-noise radar system. This novel polarization interferometric in-line TIAOC uses an intensity-modulated laser diode for the random noise reference and a polarization-switching, self-collimating acoustic shear-mode gallium phosphide (GaP) acousto-optic device for traveling-wave modulation of the radar returns. The time-integrated correlation output is detected on a 1-D charge-coupled device (CCD) detector array and calibrated and demodulated in real time to produce the complex radar range profile. The complex radar reflectivity is measured in more than 150 radar range bins in parallel on the 3000 pixels of the CCD, improving target acquisition speeds and sensitivities by 150 over previous serial analog correlator approaches. The polarization interferometric detection of the correlation using the undiffracted light as the reference allows us to use the full acousto-optic device (AOD) bandwidth as the system bandwidth. Also, the experimental result shows the fully complex random-noise signal correlation and coherent demodulation without an explicit carrier, demonstrating that optically processed random-noise radars do not need a stable local oscillator.

  6. Non-scanning, non-interferometric, three-dimensional optical profilometer with nanometer resolution

    Institute of Scientific and Technical Information of China (English)

    Chen-Tai Tan; Yuan-Sheng Chan; Jhao-An Chen; Teh-Chao Liao; Ming-Hung Chiu

    2011-01-01

    A non-scanning, non-interferometric, three-dimensional (3D) optical profilometer based on geometric optics, critical angle principle, and the use of a charge-coupled device (CCD) camera is presented. The surface profile of the test specimen can be transferred into the reflectance profile. The reflectance profile, obtained from a CCD, is the ratio of the intensity at the critical angle to the intensity obtained at the total internal reflection angle. The optical profilometer provides a sub-micron measuring range with nanometer resolution and can be used to measure roughness or surface defects in real time.%A non-scanning,non-interferometric,three-dimensional (3D) optical profilometer based on geometric optics,critical angle principle,and the use of a charge-coupled device (CCD) camera is presented.The surface profile of the test specimen can be transferred into the reflectance profile.The reflectance profile,obtained from a CCD,is the ratio of the intensity at the critical angle to the intensity obtained at the total internal reflection angle.The optical profilometer provides a sub-micron measuring range with nanometer resolution and can be used to measure roughness or surface defects in real time.Optical profilometers may be distinguished into two types:scanning and non-scanning types.Scanning profilometers have better axial resolution but spend much time in measuring.For three-dimensional (3D) surface profile measurement,scanning approaches such as confocal microscopy[1- 3],or near-field microscopy[4],which have high axial and lateral resolutions for measuring a snall scanned area,arc usually not used to measure a large surface profile.Non-scanning approaches such as the noninterferometric method[5,6],interference microscopy[7-10],and second-harmonic generation[11],can measure a large surface field,but the surface height calculation based on the fringe analysis is more complex.

  7. High-temperature fiber-optic Fabry-Perot interferometric sensors

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Wenhui; Jiang, Yi; Gao, Ran, E-mail: bitjy@bit.edu.cn [School of Optoelectronics, Beijing Institute of Technology, Beijing 100081 (China); Liu, Yuewu [Key Laboratory for Mechanics in Fluid Solid Coupling Systems, Institute of Mechanics, Chinese Academy of Science, Beijing 100190 (China)

    2015-05-15

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved.

  8. High-temperature fiber-optic Fabry-Perot interferometric sensors.

    Science.gov (United States)

    Ding, Wenhui; Jiang, Yi; Gao, Ran; Liu, Yuewu

    2015-05-01

    A photonic crystal fiber (PCF) based high-temperature fiber-optic sensor is proposed and experimentally demonstrated. The sensor head is a Fabry-Perot cavity manufactured with a short section of endless single-mode photonic crystal fiber (ESM PCF). The interferometric spectrum of the Fabry-Perot interferometer is collected by a charge coupled device linear array based micro spectrometer. A high-resolution demodulation algorithm is used to interrogate the peak wavelengths. Experimental results show that the temperature range of 1200 °C and the temperature resolution of 1 °C are achieved.

  9. A new demodulation technique for optical fiber interferometric sensors with [3×3] directional couplers

    Institute of Scientific and Technical Information of China (English)

    Tingting Liu; Jie Cui; Desheng Chen; Ling Xiao; Dexing Sun

    2008-01-01

    2Optical fiber interferometric sensors based on [3 × 3] couplers have been used in many fields. A new technique is proposed to demodulate output signals of this kind of sensors. The technique recovers the signal of interest by fitting coefficients of elliptic (Lissajous) curves between each fiber pair. Different from other approaches, this technique eliminates the dependence on the idealization of [3 × 3] coupler, provides enhanced tolerance to the variance of photoelectric converters, and is anti-polarization in a certain extent. The main algorithm has been successfully demonstrated both by numerical simulation and experimental result.

  10. Dual-polarization interferometric fiber-optic gyroscope with an ultra-simple configuration.

    Science.gov (United States)

    Wang, Zinan; Yang, Yi; Lu, Ping; Luo, Rongya; Li, Yulin; Zhao, Dayu; Peng, Chao; Li, Zhengbin

    2014-04-15

    We demonstrate a novel dual-polarization interferometric fiber-optic gyroscope (IFOG), which needs only one coupler and no polarizer. Polarization nonreciprocity (PN) errors in common IFOGs will increase significantly if the polarizer is absent, or if only one coupler is used. In our setup, however, PN errors are effectively compensated by using two balanced polarizations. The 2 km coil, open-loop configuration obtains a bias instability of 0.02°/h in detecting the Earth's rotation rate. Its performance difference from the conventional two-coupler IFOG is only a stable bias, caused by coupler nonreciprocity.

  11. Reduction of the Shupe effect in interferometric fiber optic gyroscopes: The double cylinder-wound coil

    Science.gov (United States)

    Ling, Weiwei; Li, Xuyou; Yang, Hanrui; Liu, Pan; Xu, Zhenlong; Wei, Yanhui

    2016-07-01

    For the first time, we introduce a novel double-cylinder winding method for reducing the Shupe effect in interferometric fiber optic gyroscopes (IFOGs). Simulation by finite element method (FEM) is performed to calculate the dynamic temperature distribution of fiber coils, which can obtained thermal-induced rate errors in IFOGs with cross-wound coil and double cylinder-wound coil respectively. Simulation results reveal that thermal-induced rate errors in IFOGs by both winding methods can be substantially reduced under the same variable temperature conditions, but the latter has a simpler winding technology. This study is promising for reducing the temperature fragility of IFOGs.

  12. The COMPASS RICH-1 read-out system

    CERN Document Server

    Baum, G; Bradamante, Franco; Bressan, A; Chapiro, A; Cicuttin, A; Ciliberti, P; Colavita, A A; Costa, S; Crespo, M; Cristaudo, P; Dalla Torre, S; Díaz, V; Fauland, P; Fratnik, F

    2003-01-01

    This paper describes the reconfigurable read-out system for the 82944 RICH-1 channels of the COMPASS experiment (NA58) at CERN. The system is based on 192 identical large front-end boards (BORA board). BORA was designed for acquiring, digitizing, threshold subtracting and transmitting event data. The overall operation of the board is controlled and supervised by a DSP tightly interacting with an FPGA that acts as a parallel co-processor. The DSP allows characterizing each analog channel by locally calculating noise and pedestal. Each BORA communicates with the outside world through two optical fibers and through a dedicated DSP network. One optical fiber is used to receive event triggers, and the other one is used to transmit event data to subsequent processing stages of the acquisition system. The DSP network allows reconfiguring and reprogramming the DSPs and FPGAs as well as acquiring sample events to visualize the overall operation of the system. The whole RICH has eight DSP networks working in parallel. ...

  13. Optical birefringence and molecular orientation of crazed fibres utilizing the phase shifting interferometric technique

    Science.gov (United States)

    Sokkar, T. Z. N.; El-Farahaty, K. A.; El-Bakary, M. A.; Omar, E. Z.; Hamza, A. A.

    2017-09-01

    In this article, the features of the phase shifting interferometric technique were utilized to investigate the effect of the presence of crazes in both outer and inner layers on optical birefringence and molecular orientation of polypropylene fibres. The Pluta polarizing interference microscope was used as a phase shifting technique. This method includes adding a stepper motor with a control unit to the micrometer screw of the Pluta microscope. This optical system was calibrated to be used as a phase shifting interferometric technique. The advantage of this technique is that it can detect the crazes in both inner and outer layers of the sample under test. Via this method, the relation between the presence of the crazes (in both inner and outer layers) and the optical molecular orientation of polypropylene (PP) fibres was demonstrated. To clarify the role of this method, the spatial carrier frequency technique was used to show the effect of the presence of the crazes only in the outer layers on the phase distribution values and hence the structural properties of PP fibres.

  14. Quantum Interferometric Optical Lithography Exploiting Entanglement to Beat The Diffraction Limit

    CERN Document Server

    Boto, A N; Williams, C P; Dowling, J P; Boto, Agedi N.; Abrams, Daniel S; Williams, Colin P.; Dowling, Jonathan P.

    1999-01-01

    Classical, interferometric, optical lithography is diffraction limited to writing features of a size lambda/4 or greater, where lambda is the optical wavelength. Using nonclassical photon number states, entangled N at a time, we show that it is possible to write features of minimum size lambda/(4N) in an N-photon absorbing substrate. This result surpasses the usual classical diffraction limit by a factor of N. Since the number of features that can be etched on a two-dimensional surface scales inversely as the square of the feature size, this allows one to write a factor of N^2 more elements on a semiconductor chip. A factor of N = 2 can be achieved easily with entangled photon pairs generated from optical parametric downconversion.

  15. Reliable and redundant FPGA based read-out design in the ATLAS TileCal Demonstrator

    Energy Technology Data Exchange (ETDEWEB)

    Akerstedt, Henrik; Muschter, Steffen; Drake, Gary; Anderson, Kelby; Bohm, Christian; Oreglia, Mark; Tang, Fukun

    2015-10-01

    The Tile Calorimeter at ATLAS [1] is a hadron calorimeter based on steel plates and scintillating tiles read out by PMTs. The current read-out system uses standard ADCs and custom ASICs to digitize and temporarily store the data on the detector. However, only a subset of the data is actually read out to the counting room. The on-detector electronics will be replaced around 2023. To achieve the required reliability the upgraded system will be highly redundant. Here the ASICs will be replaced with Kintex-7 FPGAs from Xilinx. This, in addition to the use of multiple 10 Gbps optical read-out links, will allow a full read-out of all detector data. Due to the higher radiation levels expected when the beam luminosity is increased, opportunities for repairs will be less frequent. The circuitry and firmware must therefore be designed for sufficiently high reliability using redundancy and radiation tolerant components. Within a year, a hybrid demonstrator including the new readout system will be installed in one slice of the ATLAS Tile Calorimeter. This will allow the proposed upgrade to be thoroughly evaluated well before the planned 2023 deployment in all slices, especially with regard to long term reliability. Different firmware strategies alongside with their integration in the demonstrator are presented in the context of high reliability protection against hardware malfunction and radiation induced errors.

  16. Interferometric adaptive optics for high power laser pointing, wave-front control and phasing

    Energy Technology Data Exchange (ETDEWEB)

    Baker, K L; Stappaerts, E A; Homoelle, D C; Henesian, M A; Bliss, E S; Siders, C W; Barty, C J

    2009-01-21

    Implementing the capability to perform fast ignition experiments, as well as, radiography experiments on the National Ignition Facility (NIF) places stringent requirements on the control of each of the beam's pointing and overall wavefront quality. One quad of the NIF beams, 4 beam pairs, will be utilized for these experiments and hydrodynamic and particle-in-cell simulations indicate that for the fast ignition experiments, these beams will be required to deliver 50% (4.0 kJ) of their total energy (7.96 kJ) within a 40 {micro}m diameter spot at the end of a fast ignition cone target. This requirement implies a stringent pointing and overall phase conjugation error budget on the adaptive optics system used to correct these beam lines. The overall encircled energy requirement is more readily met by phasing of the beams in pairs but still requires high Strehl ratios, Sr, and rms tip/tilt errors of approximately one {micro}rad. To accomplish this task we have designed an interferometric adaptive optics system capable of beam pointing, high Strehl ratio and beam phasing with a single pixilated MEMS deformable mirror and interferometric wave-front sensor. We present the design of a testbed used to evaluate the performance of this wave-front sensor below along with simulations of its expected performance level.

  17. Upgrade of the ALICE-TPC read-out electronics

    Energy Technology Data Exchange (ETDEWEB)

    Junique, A; Mager, M; Musa, L; Rehman, A Ur, E-mail: Magnus.Mager@cern.ch [CERN, Geneva (Switzerland)

    2010-12-15

    The ALICE experiment at CERN LHC employs a large volume time projection chamber (TPC) as its main tracking device. Instigated by analyses indicating that the high level trigger is capable of sifting events with rare physics probes, it is endeavoured to read out the TPC an order of magnitude faster then was reckoned during the design of its read-out electronics. Based on an analysis of the read-out performance of the current system, an upgrade of the front-end read-out network is proposed. The performance of the foreseen architecture is simulated with raw data from real 7 TeV pp collisions. Events are superimposed in order to emulate the future ALICE running conditions: high multiplicity events generated either by PbPb collisions or by the superposition (pile-up) of a large number of pp collisions. The first prototype of the main building block has been produced and characterised, demonstrating the feasibility of the approach.

  18. Upgrade of the ALICE-TPC read-out electronics

    CERN Document Server

    Junique, A; Musa , L; Rehman , A U

    2010-01-01

    The ALICE experiment at CERN LHC employs a large volume time projection chamber (TPC) as its main tracking device. Instigated by analyses indicating that the high level trigger is capable of sifting events with rare physics probes, it is endeavoured to read out the TPC an order of magnitude faster then was reckoned during the design of its read-out electronics. Based on an analysis of the read-out performance of the current system, an upgrade of the front-end read-out network is proposed. The performance of the foreseen architecture is simulated with raw data from real 7 TeV pp collisions. Events are superimposed in order to emulate the future ALICE running conditions: high multiplicity events generated either by PbPb collisions or by the superposition (pile-up) of a large number of pp collisions. The first prototype of the main building block has been produced and characterised, demonstrating the feasibility of the approach

  19. Distributed fiber optic interferometric geophone system based on draw tower gratings

    Science.gov (United States)

    Xu, Ruquan; Guo, Huiyong; Liang, Lei

    2017-09-01

    A distributed fiber optic interferometric geophone array based on draw tower grating (DTG) array is proposed. The DTG geophone array is made by the DTG array fabricated based on a near-contact exposure through a phase mask during the fiber drawing process. A distributed sensing system with 96 identical DTGs in an equal separation of 20 m and an unbalanced Michelson interferometer for vibration measurement has been experimentally validated compared with a moving-coil geophone. The experimental results indicate that the sensing system can linearly demodulate the phase shift. Compared with the moving coil geophone, the fiber optic sensing system based on DTG has higher signal-to-noise ratio at low frequency.

  20. Fiber-optic interferometric two-dimensional scattering-measurement system.

    Science.gov (United States)

    Zhu, Yizheng; Giacomelli, Michael G; Wax, Adam

    2010-05-15

    We present a fiber-optic interferometric system for measuring depth-resolved scattering in two angular dimensions using Fourier-domain low-coherence interferometry. The system is a unique hybrid of the Michelson and Sagnac interferometer topologies. The collection arm of the interferometer is scanned in two dimensions to detect angular scattering from the sample, which can then be analyzed to determine the structure of the scatterers. A key feature of the system is the full control of polarization of both the illumination and the collection fields, allowing for polarization-sensitive detection, which is essential for two-dimensional angular measurements. System performance is demonstrated using a double-layer microsphere phantom. Experimental data from samples with different sizes and acquired with different polarizations show excellent agreement with Mie theory, producing structural measurements with subwavelength accuracy.

  1. Interferometric fiber-optic bending / nano-displacement sensor using plastic dual-core fiber

    CERN Document Server

    Qu, H; Skorobogatiy, M

    2014-01-01

    We demonstrate an interferometric fiber-optic bending/micro-displacement sensor based on a plastic dual-core fiber with one end coated with a silver mirror. The two fiber cores are first excited with the same laser beam, the light in each core is then back-reflected at the mirror-coated fiber-end, and, finally, the light from the two cores is made to interfere at the coupling end. Bending of the fiber leads to shifting interference fringes that can be interrogated with a slit and a single photodetector. We find experimentally that the resolution of our bending sensor is ~3x10-4 m-1 for sensing of bending curvature, as well as ~70 nm for sensing of displacement of the fiber tip. We demonstrate operation of our sensor using two examples. One is weighting of the individual micro-crystals of salt, while the other one is monitoring dynamics of isopropanol evaporation.

  2. Interferometric approach to measuring band topology in 2D optical lattices.

    Science.gov (United States)

    Abanin, Dmitry A; Kitagawa, Takuya; Bloch, Immanuel; Demler, Eugene

    2013-04-19

    Recently, optical lattices with nonzero Berry's phases of Bloch bands have been realized. New approaches for measuring Berry's phases and topological properties of bands with experimental tools appropriate for ultracold atoms need to be developed. In this Letter, we propose an interferometric method for measuring Berry's phases of two-dimensional Bloch bands. The key idea is to use a combination of Ramsey interference and Bloch oscillations to measure Zak phases, i.e., Berry's phases for closed trajectories corresponding to reciprocal lattice vectors. We demonstrate that this technique can be used to measure the Berry curvature of Bloch bands, the π Berry's phase of Dirac points, and the first Chern number of topological bands. We discuss several experimentally feasible realizations of this technique, which make it robust against low-frequency magnetic noise.

  3. Research on fiber-optic interferometric hydrophone array using frequency division multiplying technique

    Institute of Scientific and Technical Information of China (English)

    CAO Jianian; LI Xuyou; WANG Zhaoxia; LUO Jicheng; FU Lintai

    2001-01-01

    From the point of view of system design, a configuration of fiber-optic interferometric hydrophone array and its modulation and demodulation approach using frequency division multiplexing technique based on Phase Generated Carrier (PGC) is introduced. And the emphasis on demonstrating the relationship among the number of units N, the detectable signal amplitude D and the detectable frequency ωs through analyzing the frequency spectrum of the output signal of the J × K array and the key factor which restricts N, D, ωo for increasing are presented. The maximum phase shift and the law of its variation according to frequency are specially analyzed. The results induced from some relative theory were verified by experiments.

  4. Optical microscope using an interferometric source of two-color, two-beam entangled photons

    Science.gov (United States)

    Dress, William B.; Kisner, Roger A.; Richards, Roger K.

    2004-07-13

    Systems and methods are described for an optical microscope using an interferometric source of multi-color, multi-beam entangled photons. A method includes: downconverting a beam of coherent energy to provide a beam of multi-color entangled photons; converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; transforming at least a portion of the converged multi-color entangled photon beam by interaction with a sample to generate an entangled photon specimen beam; and combining the entangled photon specimen beam with an entangled photon reference beam within a single beamsplitter. An apparatus includes: a multi-refringent device providing a beam of multi-color entangled photons; a condenser device optically coupled to the multi-refringent device, the condenser device converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; a beam probe director and specimen assembly optically coupled to the condenser device; and a beam splitter optically coupled to the beam probe director and specimen assembly, the beam splitter combining an entangled photon specimen beam from the beam probe director and specimen assembly with an entangled photon reference beam.

  5. Spectral interferometric microscopy reveals absorption by individual optical nanoantennas from extinction phase.

    Science.gov (United States)

    Gennaro, Sylvain D; Sonnefraud, Yannick; Verellen, Niels; Van Dorpe, Pol; Moshchalkov, Victor V; Maier, Stefan A; Oulton, Rupert F

    2014-04-30

    Optical antennas transform light from freely propagating waves into highly localized excitations that interact strongly with matter. Unlike their radio frequency counterparts, optical antennas are nanoscopic and high frequency, making amplitude and phase measurements challenging and leaving some information hidden. Here we report a novel spectral interferometric microscopy technique to expose the amplitude and phase response of individual optical antennas across an octave of the visible to near-infrared spectrum. Although it is a far-field technique, we show that knowledge of the extinction phase allows quantitative estimation of nanoantenna absorption, which is a near-field quantity. To verify our method we characterize gold ring-disk dimers exhibiting Fano interference. Our results reveal that Fano interference only cancels a bright mode's scattering, leaving residual extinction dominated by absorption. Spectral interference microscopy has the potential for real-time and single-shot phase and amplitude investigations of isolated quantum and classical antennas with applications across the physical and life sciences.

  6. Optimised cantilever biosensor with piezoresistive read-out

    DEFF Research Database (Denmark)

    Rasmussen, Peter; Thaysen, J.; Hansen, Ole

    2003-01-01

    We present a cantilever-based biochemical sensor with piezoresistive read-out which has been optimised for measuring surface stress. The resistors and the electrical wiring on the chip are encapsulated in low-pressure chemical vapor deposition (LPCVD) silicon nitride, so that the chip is well sui...

  7. DS read-out transcription in transgenic tomato plants

    NARCIS (Netherlands)

    Rudenko, George N.; Nijkamp, H. John J.; Hille, Jacques

    1994-01-01

    To select for Ds transposition in transgenic tomato plants a phenotypic excision assay, based on restoration of hygromycin phosphotransferase (HPT II) gene expression, was employed. Some tomato plants, however, expressed the marker gene even though the Ds had not excised. Read-out transcriptional

  8. Optical fiber read-out for liquid argon scintillation light

    CERN Document Server

    Csáthy, J Janicskó; Kratz, J; Schönert, S; Wiesinger, Ch

    2016-01-01

    In this paper we describe the performance of a light detector for Ar scintillation light made of wavelength-shifting (WLS) fibers connected to Silicon-Photomultipliers (SiPM). The setup was conceived to be used as anti-Compton veto for high purity germanium (HPGe) detectors operated directly in liquid Argon (LAr). Background suppression efficiencies for different radioactive sources were measured in a test cryostat with about 800 kg LAr. This work was part of the R\\&D effort for the GERDA experiment.

  9. Combined optical fiber interferometric sensors for the detection of acoustic emission

    Institute of Scientific and Technical Information of China (English)

    LIANG Yi-jun; MU Lin-lin; LIU Jun-feng; YU Xiao-tao

    2008-01-01

    A type of combined optical fiber interferometric acoustic emission sensor is proposed.The sensor can be independent on the laser source and make light interference by matching the lengths of two arms,so it can be used to monitor the health of large structure.Theoretical analyses indicate that the system can be equivalent to the Michelson interferometer with two optical fiber loop reflectors,and its sensitivity has been remarkably increased because of the decrease of the losses of light energy.PZT is powered by DC regulator to control the operating point of the system,so the system can accurately detect feeble vibration which is generated by ultrasonic waves propagating on the surface of solid.The amplitude and the frequency of feeble vibration signal are obtained by detecting the output light intensity of intefferometer and using Fourier transform technique.The results indicate that the system can be used to detect the acoustic emission signals by the frequency characteristics.

  10. Simultaneous interferometric optical-figure characterizations for two optical elements in series: Proposition of an unconventional numerical integration scheme

    Energy Technology Data Exchange (ETDEWEB)

    Gwo, D

    2006-03-20

    The article proposes a scheme to break a catch-22 loop in an optical-figure/wavefont measurement. For instance, to measure the tilt-independent optical-figure of a nominal optical flat at cryogenic temperatures, it requires a cryogenic dewar-window system for a Fizeau interferometer outside the dewar to see through. The issue is: how to calibrate in situ the window system using the yet-to-be-calibrated nominal optical flat, and vice versa, in only one cryogenic cooldown? The proposition includes: (a) interferometric phase-map measurements with the test piece slightly offset in different transverse directions, and (b) for synthesizing the 2-dimensional WDF, an unconventional numerical scheme starting with 1-dimensional bi-direction integration. The numerical scheme helps minimize the non-uniformity in integrated noise-power distribution that results from integrating data, and thus the associated uncorrelated random noise, from raw phase-maps. The numerical scheme represents a new concept specifically for integrating noise-carrying experimental data.

  11. Remote and high precision step height measurement with an optical fiber multiplexing interferometric system

    Science.gov (United States)

    Wang, Yunzhi; Xie, Fang; Ma, Sen; Chen, Liang

    2015-03-01

    An optical fiber multiplexing low coherence and high coherence interferometric system, which includes a Fizeau interferometer as the sensing element and a Michelson interferometer as the demodulating element, is designed for remote and high precision step height measurement. The Fizeau interferometer is placed in the remote field for sensing the measurand, while the Michelson interferometer which works in both modes of low coherence interferometry and high coherence interferometry is employed for demodulating the measurand. The range of the step height is determined by the low coherence interferometry and the value of it is measured precisely by the high coherence interferometry. High precision has been obtained by searching precisely the peak of the low coherence interferogram symmetrically from two sides of the low coherence interferogram and stabilizing the Michelson interferometer with a feedback loop. The maximum step height that could be measured is 6 mm while the measurement resolution is less than 1 nm. The standard deviation of 10 times measurement results of a step height of 1 mm configurated with two gauge blocks is 0.5 nm.

  12. An optical fiber multiplexing interferometric system for measuring remote and high precision step height

    Science.gov (United States)

    Wang, Yunzhi; Xie, Fang; Ma, Sen; Chen, Liang

    2015-02-01

    In this paper, an optical fiber multiplexing interferometric system including a Fizeau interferometer and a Michelson interferometer is designed for remote and high precision step height measurement. The Fizeau interferometer which is inserted in the remote sensing field is used for sensing the measurand, while the Michelson interferometer which is stabilized by a feedback loop works in both modes of low coherence interferometry and high coherence interferometry to demodulate the measurand. The range of the step height is determined by the low coherence interferometry and the value of it is measured precisely by the high coherence interferometry. High precision has been obtained by using the symmetrical peak-searching method to address the peak of the low coherence interferogram precisely and stabilizing the Michelson interferometer with a feedback loop. The maximum step height that could be measured is 6 mm while the measurement resolution is less than 1 nm. The standard deviation of 10 times measurement results of a step height of 1 mm configurated with two gauge blocks is 0.5 nm.

  13. Optical fiber waist-enlarged bitaper-based Michelson interferometric humidity sensor

    Science.gov (United States)

    Hu, Pengbing; Chen, Zhemin; Pan, Sunqiang; Li, Guoshui; Zhang, Jianfeng; Cheng, Jia

    2015-02-01

    An optical fiber waist-enlarged bitaper-based Michelson interferometric sensor is proposed and experimentally demonstrated for humidity measurement. The waist enlarged bitaper is created for light coupling between core mode and cladding modes propagating in the fiber interferometer. A chitason layer is plated onto the surface of the interferometer to act as a humidity-to-refractive index (RI) transducer and thus humidity measurement can be realized by monitoring the wavelength shifts of its interferogram induced by RI variations. The influence of the coating thickness and concentration of chitason on relative humidity (RH) measurement is experimentally studied. The coating sensor demonstrates an optimal humidity-sensing ability, with a humidity sensitivity and fast time-response of ~26 pm/%RH and ~5 s respectively, when it is 3-dip coated in chitason solutions of the concentration of 1 wt.%. The proposed humidity sensor is compact, cost-effective and of easy-operation, therefore it has potentials in many practical applications.

  14. Spectral interferometric sensors for gases and liquids using integrated optical devices

    Science.gov (United States)

    Ingenhoff, Jan; Gauglitz, Guenter; Fabricius, Norbert

    1993-04-01

    Investigations for a sensor application with an integrated optical (IO) interferometric arrangement are presented. One of the two waveguide arms of an IO-Mach-Zehnder- interferometer is covered with a thin layer of polysiloxane (superstrate), which is sensitive to hydrocarbons. The dielectric IO-devices are fabricated by IOT. Gases of organic compounds including halogenated and non-halogenated hydrocarbons cause a change of the polysiloxan's refractive index followed by an increase or decrease of the effective refractive index of the covered waveguide arm. The resulting phase shift between the guided light in the measuring and the reference arm depends on the detection wavelength and the concentration of gas. Using an LED as the light source the spectral interferogram becomes observable and so order and phase of the signal can be determined. The aim of this work is the development of a reversibly working, miniaturized sensor with a short response time. The advantages of spectral observation of the interference are discussed. A comparison between measured and calculated spectral interference signals is given.

  15. Modeling and Validation of Performance Limitations for the Optimal Design of Interferometric and Intensity-Modulated Fiber Optic Displacement Sensors

    Energy Technology Data Exchange (ETDEWEB)

    Moro, Erik A. [Los Alamos National Laboratory

    2012-06-07

    Optical fiber sensors offer advantages over traditional electromechanical sensors, making them particularly well-suited for certain measurement applications. Generally speaking, optical fiber sensors respond to a desired measurand through modulation of an optical signal's intensity, phase, or wavelength. Practically, non-contacting fiber optic displacement sensors are limited to intensity-modulated and interferometric (or phase-modulated) methodologies. Intensity-modulated fiber optic displacement sensors relate target displacement to a power measurement. The simplest intensity-modulated sensor architectures are not robust to environmental and hardware fluctuations, since such variability may cause changes in the measured power level that falsely indicate target displacement. Differential intensity-modulated sensors have been implemented, offering robustness to such intensity fluctuations, and the speed of these sensors is limited only by the combined speed of the photodetection hardware and the data acquisition system (kHz-MHz). The primary disadvantages of intensity-modulated sensing are the relatively low accuracy (?m-mm for low-power sensors) and the lack of robustness, which consequently must be designed, often with great difficulty, into the sensor's architecture. White light interferometric displacement sensors, on the other hand, offer increased accuracy and robustness. Unlike their monochromatic-interferometer counterparts, white light interferometric sensors offer absolute, unambiguous displacement measurements over large displacement ranges (cm for low-power, 5 mW, sources), necessitating no initial calibration, and requiring no environmental or feedback control. The primary disadvantage of white light interferometric displacement sensors is that their utility in dynamic testing scenarios is limited, both by hardware bandwidth and by their inherent high-sensitivity to Doppler-effects. The decision of whether to use either an intensity

  16. Interferometric star tracker Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Optical Physics Company (OPC) proposes to develop a high accuracy version of its interferometric star tracker capable of meeting the milli-arcsecond-level pointing...

  17. Optical phase noise engineering via acousto-optic interaction and its interferometric applications

    CERN Document Server

    Satapathy, Nandan; Bannerjee, Sourish; Ramachandran, Hema

    2013-01-01

    We exercise rapid and fine control over the phase of light by transferring digitally gen- erated phase jumps from radio frequency (rf) electrical signals onto light by means of acousto-optic interaction. By tailoring the statistics of phase jumps in the electrical signal and thereby engineering the optical phase noise, we manipulate the visibil- ity of interference fringes in a Mach-Zehnder interferometer that incorporates two acousto-optic modulators. Such controlled dephasing finds applications in modern experiments involving the spread or diffusion of light in an optical network. Further, we analytically show how engineered partial phase noise can convert the dark port of a stabilised interferometer to a weak source of highly correlated photons.

  18. Design and Commissioning of the ATLAS Muon Spectrometer RPC Read Out Driver

    CERN Document Server

    Aloisio, A; Cevenini, F; Della Pietra; Della Volpe; Izzo, V

    2008-01-01

    The RPC subsystem of the ATLAS muon spectrometer provides the Level-1 trigger in the barrel and it is read out by a specific DAQ system. On-detector electronics pack the RPC data in frames, tagged with an event number assigned by the trigger logic, and transmit them to the counting room on optical fibre. Data from each sector are then routed together to a Read-Out Driver (ROD) board. This is a custom processor that parses the frames, checks their coherence and builds a data structure for all the RPCs of one of the 32 sectors of the spectrometer. Each ROD sends the event fragments to a Read-Out subsystem for further event building and analysis. The ROD is a VME64x board, designed around two Xilinx Virtex-II FPGAs and an ARM7 microcontroller. In this paper we describe the board architecture and the event binding algorithm. The boards have been installed in the ATLAS USA15 control room and have been successfully used in the ATLAS commissioning runs.

  19. A comparison measurement of nonlinear ultrasonic waves in tubes by a microphone and by an optical interferometric probe.

    Science.gov (United States)

    Slegrová, Zuzana; Bálek, Rudolf

    2005-03-01

    This paper deals with the analysis of ultrasonic fields inside waveguides generated by ultrasonic waves of high amplitude. These waves behave nonlinearly, so it is not possible to use standard linear equations to describe their behaviour. Therefore, we started with an experimental determination of the acoustic pressure of air in glass tubes. We chose two methods of measurement--by a microphone and by an optical interferometric probe. The conventional method by a microphone creates numerous problems, which can be avoided by using an optical method, a heterodyne laser interferometer.

  20. The Read Out Controller for the ATLAS New Small Wheel

    CERN Document Server

    Coliban, Radu Mihai; The ATLAS collaboration; Tulbure, Traian Tiberiu; Martoiu, Victor Sorin; Levinson, Lorne; Vermeulen, Jos

    2016-01-01

    In the context of the New Small Wheel data path, we designed the Read Out Controller (ROC) ASIC for handling, preprocessing and formatting the data generated by the NSW VMM upstream chips. The ROC will concentrate the data streams from 8VMMs, filter data based on the BCID and transmit the data to FELIX via the L1DDC. ROC is composed of 8 VMM Capture modules, a cross-bar and 4 SubROC modules. The output data is sent via 4 high-speed e-links.

  1. A new electronic read-out for the YAPPET scanner

    CERN Document Server

    Damiani, C; Malaguti, R; Guerra, A D; Domenico, G D; Zavattini, G

    2002-01-01

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper.

  2. Innovative multi-cantilever array sensor system with MOEMS read-out

    Science.gov (United States)

    Ivaldi, F.; Bieniek, T.; Janus, P.; Grabiec, P.; Majstrzyk, W.; Kopiec, D.; Gotszalk, T.

    2016-11-01

    Cantilever based sensor system are a well-established sensor family exploited in several every-day life applications as well as in high-end research areas. The very high sensitivity of such systems and the possibility to design and functionalize the cantilevers to create purpose built and highly selective sensors have increased the interest of the scientific community and the industry in further exploiting this promising sensors type. Optical deflection detection systems for cantilever sensors provide a reliable, flexible method for reading information from cantilevers with the highest sensitivity. However the need of using multi-cantilever arrays in several fields of application such as medicine, biology or safety related areas, make the optical method less suitable due to its structural complexity. Working in the frame of a the Joint Undertaking project Lab4MEMS II our group proposes a novel and innovative approach to solve this issue, by integrating a Micro-Opto-Electro-Mechanical-System (MOEMS) with dedicated optics, electronics and software with a MOEMS micro-mirror, ultimately developed in the frame of Lab4MEMSII. In this way we are able to present a closely packed, lightweight solution combining the advantages of standard optical read-out systems with the possibility of recording multiple read-outs from large cantilever arrays quasi simultaneously.

  3. A continuous read-out TPC for the ALICE upgrade

    Science.gov (United States)

    Lippmann, C.

    2016-07-01

    The largest gaseous Time Projection Chamber (TPC) in the world, the ALICE TPC, will be upgraded based on Micro Pattern Gas Detector technology during the second long shutdown of the CERN Large Hadron Collider in 2018/19. The upgraded detector will operate continuously without the use of a triggered gating grid. It will thus be able to read all minimum bias Pb-Pb events that the LHC will deliver at the anticipated peak interaction rate of 50 kHz for the high luminosity heavy-ion era. New read-out electronics will send the continuous data stream to a new online farm at rates up to 1 TByte/s. A fractional ion feedback of below 1% is required to keep distortions due to space charge in the TPC drift volume at a tolerable level. The new read-out chambers will consist of quadruple stacks of Gas Electron Multipliers (GEM), combining GEM foils with a different hole pitch. Other key requirements such as energy resolution and operational stability have to be met as well. A careful optimisation of the performance in terms of all these parameters was achieved during an extensive R&D program. A working point well within the design specifications was identified with an ion backflow of 0.63%, a local energy resolution of 11.3% (sigma) and a discharge probability comparable to that of standard triple GEM detectors.

  4. Dynamic full field optical coherence tomography: subcellular metabolic contrast revealed in tissues by temporal analysis of interferometric signals

    CERN Document Server

    Apelian, Clement; Thouvenin, Olivier; Boccara, A Claude

    2016-01-01

    We developed a new endogenous approach to reveal subcellular metabolic contrast in fresh ex vivo tissues taking advantage of the time dependence of the full field optical coherence tomography interferometric signals. This method reveals signals linked with local activity of the endogenous scattering elements which can reveal cells where other imaging techniques fail or need exogenous contrast agents. We benefit from the micrometric transverse resolution of full field OCT to image intracellular features. We used this time dependence to identify different dynamics at the millisecond scale on a wide range of organs in normal or pathological conditions.

  5. Precision Instrumentation Amplifiers and Read-Out Integrated Circuits

    CERN Document Server

    Wu, Rong; Makinwa, Kofi A A

    2013-01-01

    This book presents innovative solutions in the design of precision instrumentation amplifier and read-out ICs, which can be used to boost millivolt-level signals transmitted by modern sensors, to levels compatible with the input ranges of typical Analog-to-Digital Converters (ADCs).  The discussion includes the theory, design and realization of interface electronics for bridge transducers and thermocouples. It describes the use of power efficient techniques to mitigate low frequency errors, resulting in interface electronics with high accuracy, low noise and low drift. Since this book is mainly about techniques for eliminating low frequency errors, it describes the nature of these errors and the associated dynamic offset cancellation techniques used to mitigate them.  Surveys comprehensively offset cancellation and accuracy improvement techniques applied in precision amplifier designs; Presents techniques in precision circuit design to mitigate low frequency errors in millivolt-level signals transmitted by ...

  6. The ATLAS liquid Argon calorimeters read-out system

    CERN Document Server

    Blondel, A; Fayard, L; La Marra, D; Léger, A; Matricon, P; Perrot, G; Poggioli, L; Prast, J; Riu, I; Simion, S

    2004-01-01

    The calorimetry of the ATLAS experiment takes advantage of different detectors based on the liquid Argon (LAr) technology. Signals from the LAr calorimeters are processed by various stages before being delivered to the Data Acquisition system. The calorimeter cell signals are received by the front-end boards, which digitize a predetermined number of samples of the bipolar waveform and sends them to the Read-Out Driver (ROD) boards. The ROD board receives triggered data from 1028 calorimeter cells, and determines the precise energy and timing of the signals by processing the discrete samplings of the pulse. In addition, it formats the digital stream for the following elements of the DAQ chain, and performs monitoring. The architecture and functionality of the ATLAS LAr ROD board are discussed, along with the final design of the Processing Unit boards housing the Digital Signal Processors (DSP). (9 refs).

  7. The read-out ASIC for the Space NUCLEON project

    Science.gov (United States)

    Atkin, E.; Voronin, A.; Karmanov, D.; Kudryashov, I.; Podorozhniy, D.; Shumikhin, V.

    2015-04-01

    This paper summarizes the design results for the read-out ASIC for the space NUCLEON project of the Russian Federal Space Agency ROSCOSMOS. The ASIC with a unique high dynamic range (1-40 000 mip) at low power consumption ( 50, generated by silicon detectors, having capacitances up to 100 pF. The chip structure includes 32 analog channels, each consisting of a charge sensitive amplifier (CSA) with a p-MOS input transistor (W = 8 mm, L = 0.5 μ m), a shaper (peaking time of 2 us) and a T&H circuit. The ASIC showed a 120 pC dynamic range at a SNR of 2.5 for the particles with minimal ionization energy (1 mip). The chip was fabricated by the 0.35 um CMOS process via Europractice and tested both at lab conditions and in the SPS beam at CERN.

  8. Reduction of interferometric crosstalk induced penalty using a saturated semiconductor optical amplifier

    DEFF Research Database (Denmark)

    Liu, Fenghai; Zheng, Xueyan; Poulsen, Henrik Nørskov;

    2000-01-01

    We successfully demonstrated that a simple saturated SOA could be used to reduce the impact from the interferometric crosstalk at 2.5 and 10 Gb/s. It is shown that 4 dB more crosstalk power can be tolerated at 1 dB penalty by using the SOA. This will greatly reduce the crosstalk requirement on co...

  9. The Read Out Controller for the ATLAS New Small Wheel

    CERN Document Server

    AUTHOR|(SzGeCERN)781403; The ATLAS collaboration; Popa, Stefan; Tulbure, Traian Tiberiu; Ivanovici, Mihail; Martoiu, Victor Sorin; Levinson, Lorne; Vermeulen, Jos

    2016-01-01

    In the upgrade process of the ATLAS detector, the innermost stations of the endcaps (Small Wheels, SW) will be replaced. The New Small Wheel (NSW) will have two chamber technologies, one for the Level-1 trigger function (small-strip Thin Gap Chambers, sTGC) and one primarily dedicated to precision tracking (Micromegas detectors, MM). Custom front-end Application Specific Integrated Circuits (ASICs) will be used to read and filter information from both the sTGC and MM detectors. In the context of the New Small Wheel data path, we designed the Read Out Controller (ROC) ASIC for handling, preprocessing and formatting the data generated by the NSW VMM upstream chips. The ROC will concentrate the data streams from 8 VMMs, filter data based on the BCID and transmit the data to FELIX via the L1DDC. ROC is composed of 8 VMM Capture modules, a cross-bar and 4 SubROC modules. The output data is sent via 4 high-speed e-links.

  10. PARISROC, a Photomultiplier Array Integrated Read Out Chip

    CERN Document Server

    Di Lorenzo, S Conforti; Dulucq, F; De La Taille, C; Martin-Chassard, G; Berni, M El; Wei, W

    2010-01-01

    PARISROC is a complete read out chip, in AMS SiGe 0.35 !m technology, for photomultipliers array. It allows triggerless acquisition for next generation neutrino experiments and it belongs to an R&D program funded by the French national agency for research (ANR) called PMm2: ?Innovative electronics for photodetectors array used in High Energy Physics and Astroparticles? (ref.ANR-06-BLAN-0186). The ASIC (Application Specific Integrated Circuit) integrates 16 independent and auto triggered channels with variable gain and provides charge and time measurement by a Wilkinson ADC (Analog to Digital Converter) and a 24-bit Counter. The charge measurement should be performed from 1 up to 300 photo- electrons (p.e.) with a good linearity. The time measurement allowed to a coarse time with a 24-bit counter at 10 MHz and a fine time on a 100ns ramp to achieve a resolution of 1 ns. The ASIC sends out only the relevant data through network cables to the central data storage. This paper describes the front-end electroni...

  11. The selective read-out processor for the CMS electromagnetic calorimeter

    CERN Document Server

    Girão de Almeida, Nuño Miguel; Faure, Jean Louis; Gachelin, Olivier; Gras, Philippe; Mandjavidze, Irakli; Mur, Michel; Varela, João

    2005-01-01

    This paper describes the selective read-out processor (SRP) proposed for the electromagnetic calorimeter (ECAL) of the Compact Muon Solenoid (CMS) experiment at LHC (CERN). The aim is to reduce raw ECAL data to a level acceptable by the CMS data acquisition (DAQ) system. For each positive level 1 trigger, the SRP is guided by trigger primitive generation electronics to identify ECAL regions with energy deposition satisfying certain programmable criteria. It then directs the ECAL read-out electronics to apply predefined zero suppression levels to the crystal data, depending whether the crystals fall within these regions or not. The main challenges for the SRP are some 200 high speed (1.6 Gbit/s) I/O channels, asynchronous operation at up to 100 kHz level 1 trigger rate, a 5- mu s real-time latency requirement and a need to retain flexibility in choice of selection algorithms. The architecture adopted for the SRP is based on modern parallel optic pluggable modules and high density field programmable gate array ...

  12. Single-shot read-out of an individual electron spin in a quantum dot.

    Science.gov (United States)

    Elzerman, J M; Hanson, R; Willems Van Beveren, L H; Witkamp, B; Vandersypen, L M K; Kouwenhoven, L P

    2004-07-22

    Spin is a fundamental property of all elementary particles. Classically it can be viewed as a tiny magnetic moment, but a measurement of an electron spin along the direction of an external magnetic field can have only two outcomes: parallel or anti-parallel to the field. This discreteness reflects the quantum mechanical nature of spin. Ensembles of many spins have found diverse applications ranging from magnetic resonance imaging to magneto-electronic devices, while individual spins are considered as carriers for quantum information. Read-out of single spin states has been achieved using optical techniques, and is within reach of magnetic resonance force microscopy. However, electrical read-out of single spins has so far remained elusive. Here we demonstrate electrical single-shot measurement of the state of an individual electron spin in a semiconductor quantum dot. We use spin-to-charge conversion of a single electron confined in the dot, and detect the single-electron charge using a quantum point contact; the spin measurement visibility is approximately 65%. Furthermore, we observe very long single-spin energy relaxation times (up to approximately 0.85 ms at a magnetic field of 8 T), which are encouraging for the use of electron spins as carriers of quantum information.

  13. In situ non-destructive measurement of biofilm thickness and topology in an interferometric optical microscope

    Energy Technology Data Exchange (ETDEWEB)

    Larimer, Curtis [Pacific Northwest National Laboratory, Battelle for the USDOE, PO Box 999, MSIN P7-50 Richland WA 99354 USA; Suter, Jonathan D. [Pacific Northwest National Laboratory, Battelle for the USDOE, PO Box 999, MSIN P7-50 Richland WA 99354 USA; Bonheyo, George [Pacific Northwest National Laboratory, Battelle for the USDOE, PO Box 999, MSIN P7-50 Richland WA 99354 USA; Addleman, Raymond Shane [Pacific Northwest National Laboratory, Battelle for the USDOE, PO Box 999, MSIN P7-50 Richland WA 99354 USA

    2016-03-15

    Biofilms are ubiquitous and deleteriously impact a wide range of industrial processes, medical and dental health issues, and environmental problems such as transport of invasive species and the fuel efficiency of ocean going vessels. Biofilms are difficult to characterize when fully hydrated, especially in a non-destructive manner, because of their soft structure and water-like bulk properties. Herein we describe a non-destructive high resolution method of measuring and monitoring the thickness and topology of live biofilms of using white light interferometric optical microscopy. Using this technique, surface morphology, surface roughness, and biofilm thickness can be measured non-destructively and with high resolution as a function of time without disruption of the biofilm activity and processes. The thickness and surface topology of a P. putida biofilm were monitored growing from initial colonization to a mature biofilm. Typical bacterial growth curves were observed. Increase in surface roughness was a leading indicator of biofilm growth.

  14. Characterization of silica-based waveguides with an interferometric optical time-domain reflectometry system using a 1.3-microm-wavelength superluminescent diode.

    Science.gov (United States)

    Takada, K; Takato, N; Noda, J; Noguchi, Y

    1989-07-01

    Backscattering of silica-based glass waveguides is characterized for the first time to our knowledge by using an interferometric optical time-domain reflectometry system. High spatial resolution, as short as 15 microm, is obtained by using a newly developed 1.3-microm-wavelength superluminescent diode. Scattering centers produced by waveguide irregularities are clearly observed in glass optical waveguides. Waveguide loss and bend loss in the curved regions are estimated from the backscattered light intensity distribution.

  15. Evaluation of Fermi Read-out of the ATLAS Tilecal Prototype

    CERN Document Server

    Agnvall, S; Albiol, F; Alifanov, A; Amaral, P; Amelin, D V; Amorim, A; Anderson, K J; Angelini, C; Antola, A; Astesan, F; Astvatsaturov, A R; Autiero, D; Badaud, F; Barreira, G; Benetta, R; Berglund, S R; Blanchot, G; Blucher, E; Blaj, C; Bodö, P; Bogush, A A; Bohm, C; Boldea, V; Borisov, O N; Bosman, M; Bouhemaid, N; Brette, P; Breveglieri, L; Bromberg, C; Brossard, M; Budagov, Yu A; Calôba, L P; Carvalho, J; Casado, M P; Castera, A; Cattaneo, Paolo Walter; Cavalli-Sforza, M; Cavasinni, V; Chadelas, R; Chevaleyre, J C; Chirikov-Zorin, I E; Chlachidze, G; Cobal, M; Cogswell, F; Colaço, F; Constantinescu, S; Costanzo, D; Crouau, M; Dadda, L; Daudon, F; David, J; David, M; Davidek, T; Dawson, J; De, K; Del Prete, T; De Santo, A; Di Girolamo, B; Dita, S; Dolejsi, J; Dolezal, Z; Downing, R; Dugne, J J; Efthymiopoulos, I; Engström, M; Errede, D; Errede, S; Evans, H; Fenyuk, A; Ferrer, A; Flaminio, Vincenzo; Fristedt, A; Gallas, E J; Gaspar, M; Gildemeister, O; Givoletto, M; Glagolev, V V; Goggi, Giorgio V; Gómez, A; Gong, S; Guz, Yu; Grabskii, V; Grieco, M; Hakopian, H H; Haney, M W; Hansen, M; Hellman, S; Henriques, A; Hentzell, H; Holmberg, T; Holmgren, S O; Honoré, P F; Huston, J; Ivanyushenkov, Yu M; Jon-And, K; Juste, A; Kakurin, S; Karapetian, G V; Karyukhin, A N; Kérek, A; Khokhlov, Yu A; Kopikov, S V; Kostrikov, M E; Kostyukhin, V; Kukhtin, V V; Kulchitskii, Yu A; Kurzbauer, W; Lami, S; Landi, G; Lapin, V; Lazzeroni, C; Lebedev, A; Leitner, R; Li, J; Lippi, M; Le Dortz, O; Löfstedt, B; Lomakin, Yu F; Lomakina, O V; Lokajícek, M; Lund-Jensen, B; Maio, A; Malyukov, S N; Mariani, R; Marroquin, F; Martins, J P; Mazzoni, E; Merritt, F S; Michel, B; Miller, R; Minashvili, I A; Miralles, L; Mnatzakanian, E A; Montarou, G; Motto, S; Muanza, G S; Némécek, S; Nessi, Marzio; Ödmark, A; Onofre, A; Orteu, S; Padilla, C; Pallin, D; Pantea, D; Patriarca, J; Pereira, A; Perlas, J A; Persson, S T; Petit, P; Pilcher, J E; Pinhão, J; Poggioli, Luc; Poirot, S; Polesello, G; Price, L E; Proudfoot, J; Pukhov, O; Reinmuth, G; Renzoni, G; Richards, R; Riu, I; Romanov, V; Ronceux, B; Rumyantsev, V; Rusakovitch, N A; Sami, M; Sanders, H; Santos, J; Savoy-Navarro, Aurore; Sawyer, L; Says, L P; Schwemling, P; Seixas, J M; Selldén, B; Semenov, A A; Shchelchkov, A S; Shochet, M J; Simaitis, V J; Sissakian, A N; Solodkov, A A; Solovyanov, O; Sonderegger, P; Soustruznik, K; Stanek, R; Starchenko, E A; Stefanelli, R; Stephens, R; Suk, M; Sundblad, R; Svensson, C; Tang, F; Tardell, S; Tas, P; Teubert, F; Thaler, J J; Tokár, S; Topilin, N D; Trka, Z; Turcot, A S; Turcotte, M; Valkár, S; Varanda, M J; Vartapetian, A H; Vazeille, F; Vinogradov, V; Vivaldi, F; Vorozhtsov, S B; Wagner, D; White, A; Wolters, H; Yamdagni, N; Yarygin, G; Yosef, C; Yuan, J; Zaitsev, A; Zdrazil, M

    1998-01-01

    Prototypes of the \\fermi{} system have been used to read out a prototype of the \\atlas{} hadron calorimeter in a beam test at the CERN SPS. The \\fermi{} read-out system, using a compressor and a 40 MHz sampling ADC, is compared to a standard charge integrating read-out by measuring the energy resolution of the calorimeter separately with the two systems on the same events. Signal processing techniques have been designed to optimize the treatment of \\fermi{} data. The resulting energy resolution is better than the one obtained with the standard read-out.

  16. Effect of 60Co-gamma radiation on the random walk error of interferometric fiber optic gyroscopes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Two 60Co-gamma radiation experiments were launched to explore the radiation effect on optical components and interferometric fiber optic gyroscope (IFOG). In optical components radiation experiment, the result showed that polarization-maintaining (PM) fiber coil loss was the most affected parameter in all the RWC (random walk coefficient) related parameters, compared with the weak sensitivity of other components parameters. In the IFOG radiation experiment, the RWC performance degradation was found to be almost due to an increase of the PM fiber attenuation. Based on the experiment result, a RWC prediction model in radiation, which is obtained by embedding PM fiber loss expression into the RWC model, was built following a power law of dose and dose rate. An IFOG RWC in space radiation environment was predicted from radiation dose and dose rate by the RWC prediction model. This RWC value calculated from test data is fully accorded to the RWC value predicted from radiation dose.

  17. Feasibility of a Frequency-Multiplexed TES Read-Out Using Superconducting Tunnel Junctions

    NARCIS (Netherlands)

    de Lange, G.

    2014-01-01

    We describe a feasibility study of a frequency multiplexed read-out scheme for large number transition edge sensor arrays. The read-out makes use of frequency up- and down-conversion and RF-to-DC conversion with superconducting-isolator-superconducting tunnel junctions operating at GHz frequencies,

  18. Optical interferometric measurements of nighttime equatorial thermospheric winds at Arequipa, Peru

    Science.gov (United States)

    Meriwether, J. W., Jr.; Moody, J. W.; Biondi, M. A.; Roble, R. G.

    1986-01-01

    Nighttime measurements of equatorial thermospheric wind dynamics were obtained at Arequipa, Peru, with an automated field-widened Fabry-Perot interferometer between April 1983 and August 1983 and reduced data from 62 nights. Significant seasonal variations in both zonal and meridional components of the thermospheric neutral wind vector were observed. Near the equinox, between 2000 and 2300 LT, the zonal wind component is eastward with an amplitude between 100 and 150 m/s that gradually ebbs to zero by dawn. The meridional component is generally small throughout the night. In the winter months (May to August) and at the winter solstice, the zonal wind persists eastward throughout the night with speeds between 50 and 150 m/s. The meridional component is directed poleward (southward) toward the winter hemisphere with a speed of 50-75 m/s that decays to zero by midnight. Interferometric measurements of the 630.0-nm intensity at equinox showed a major reduction of the emission listing 1 or 2 hours in all directions but south shortly after evening twilight; this decrease was not observed during winter.

  19. Optical interferometric studies of the nighttime equatorial thermosphere: Enhanced temperatures and zonal wind gradients

    Science.gov (United States)

    Meriwether, J. W.; Biondi, M. A.; Herrero, F. A.; Fesen, C. G.; Hallenback, D. C.

    1997-09-01

    Fabry-Perot interferometric observations at 630 nm of equatorial thermospheric winds and temperatures in the four cardinal directions and zenith from Arequipa, Peru, during local winter for moderate and high solar fluxes showed elevated temperatures over the Andes Mountains that persisted through the night. The difference in temperature between east and west observations was typically ~100 to 200 K for moderate flux values and as high as 400 K at solar maximum. Correlated with these localized heating regions were differences in the zonal thermospheric wind of 50 to 70 m/s for observations to the west and to the east of the Arequipa observatory. Also noted in these periods for the region over the Andes was the increased variance of the temperature values above the measurement error. These effects of increased variability and localized heating were not observed at solar minimum. The lack of a significant local time dependence in the diurnal variation of the temperature enhancements suggests that the origin of the heating cannot be related to the coupling of the electrodynamics of the ionosphere to the thermosphere. Instead the hypothesis is advanced that gravity wave energy from the surface penetrates into the thermosphere, where viscous dissipation causes the heating. Such wave activity would also explain the increased variability of the temperatures for the thermosphere regions over mountainous terrain.

  20. In-Line Fiber Optic Interferometric Sensors in Single-Mode Fibers

    Directory of Open Access Journals (Sweden)

    De-Wen Duan

    2012-08-01

    Full Text Available In-line fiber optic interferometers have attracted intensive attention for their potential sensing applications in refractive index, temperature, pressure and strain measurement, etc. Typical in-line fiber-optic interferometers are of two types: Fabry-Perot interferometers and core-cladding-mode interferometers. It’s known that the in-line fiber optic interferometers based on single-mode fibers can exhibit compact structures, easy fabrication and low cost. In this paper, we review two kinds of typical in-line fiber optic interferometers formed in single-mode fibers fabricated with different post-processing techniques. Also, some recently reported specific technologies for fabricating such fiber optic interferometers are presented.

  1. Large-format distributed read-out imaging devices for X-ray imaging spectroscopy

    Science.gov (United States)

    den Hartog, Roland; Kozorezov, A.; Martin, D.; Brammertz, G.; Verhoeve, P.; Peacock, A.; Scholze, F.; Goldie, D. J.

    2002-02-01

    We present an experimental study of the performance of Distributed Read-Out Imaging Devices (DROIDs), based on two Ta/Al-based superconducting tunnel junctions (STJs) placed on either side of a Ta absorber strip. We focus our discussion on the prospects of building large-format photon-counting imaging spectrometers for applications at optical, UV and soft X-ray energies. Tunnel-limited spectroscopic resolutions have already been demonstrated for optical photons. With a 20×100 μm2 absorber we have measured an intrinsic energy resolution of 2 eV FWHM for 500 eV photons. This demonstrates that at soft X-ray energies resolutions close to the tunnel limit are also feasible for this type of detectors. A detailed analysis of pulse-shapes with numerical models allows us to assess the main parameters that determine the performance of these detectors. Extrapolation of these models indicates that it is possible to extend the length of the absorber to 1.5 mm, without a serious degradation of the detector's performance. .

  2. A new read-out architecture for the ATLAS Tile Calorimeter Phase-II Upgrade

    CERN Document Server

    Valero, Alberto; The ATLAS collaboration

    2015-01-01

    TileCal is the Tile hadronic calorimeter of the ATLAS experiment at the LHC. The LHC has planned a series of upgrades culminating in the High Luminosity LHC (HL-LHC) which will increase of order five to seven times the LHC nominal instantaneous luminosity. TileCal will undergo an upgrade to accommodate to the HL-LHC parameters. The TileCal read-out electronics will be redesigned introducing a new read-out strategy. The new TileCal read-out architecture is presented including a description of the main electronics modules and some preliminary results obtained with the first demonstrator system.

  3. Development of ATLAS Liquid Argon Calorimeter Read-out Electronics for the HL-LHC

    CERN Document Server

    Newcomer, Mitchel; The ATLAS collaboration

    2015-01-01

    The high-luminosity phase of the Large Hadron Collider will provide a 5-7 times greater instantaneous and total luminosities than assumed in the original design of the ATLAS Liquid Argon Calorimeters and their read-out system. An improved trigger system with higher acceptance rate and longer latency and a better radiation tolerance require an upgrade of the read-out electronics. Concepts for the future read-out of the 183.000 calorimeter channels at 40-80 MHz and 16 bit dynamic range, and the development of radiation tolerant, low noise, low power and high-bandwidth electronic components will be presented.

  4. Interferometric distributed sensing system with phase optical time-domain reflectometry

    Science.gov (United States)

    Wang, Chen; Shang, Ying; Liu, Xiaohui; Wang, Chang; Wang, Hongzhong; Peng, Gangding

    2016-11-01

    We demonstrate a distributed optical fiber sensing system based on the Michelson interferometer of the phase sensitive optical time domain reflectometer (φ-OTDR) for acoustic measurement. Phase, amplitude, frequency response, and location information can be directly obtained at the same time by using the passive 3×3 coupler demodulation. We also set an experiment and successfully restore the acoustic information. Meanwhile, our system has preliminary realized acoustic-phase sensitivity around -150 dB (re rad/μPa) in the experiment.

  5. An application of CCD read-out technique to neutron distribution measurement using the self-activation method with a CsI scintillator plate

    Science.gov (United States)

    Nohtomi, Akihiro; Kurihara, Ryosuke; Kinoshita, Hiroyuki; Honda, Soichiro; Tokunaga, Masaaki; Uno, Heita; Shinsho, Kiyomitsu; Wakabayashi, Genichiro; Koba, Yusuke; Fukunaga, Junichi; Umezu, Yoshiyuki; Nakamura, Yasuhiko; Ohga, Saiji

    2016-10-01

    In our previous paper, the self-activation of an NaI scintillator had been successfully utilized for detecting photo-neutrons around a high-energy X-ray radiotherapy machine; individual optical pulses from the self-activated scintillator are read-out by photo sensors such as a photomultiplier tube (PMT). In the present work, preliminary observations have been performed in order to apply a direct CCD read-out technique to the self-activation method with a CsI scintillator plate using a Pu-Be source and a 10-MV linac. In conclusion, it has been revealed that the CCD read-out technique is applicable to neutron measurement around a high-energy X-ray radiotherapy machine with the self-activation of a CsI plate. Such application may provide a possibility of novel method for simple neutron dose-distribution measurement.

  6. Distributed Read-out Imaging Device array for astronomical observations in UV/VIS

    Science.gov (United States)

    Hijmering, Richard A.

    2009-12-01

    STJ (Superconducting Tunneling Junctions) are being developed as spectro-photometers in wavelengths ranging from the NIR to X-rays. 10x12 arrays of STJs have already been successfully used as optical imaging spectrometers with the S-Cam 3, on the William Hershel Telescope on La Palma and on the Optical Ground Station on Tenerife. To overcome the limited field of view which can be achieved with single STJ arrays, DROIDS (Distributed Read Out Imaging Devices) are being developed which produce next to energy and timing also produce positional information with each detector element. These DROIDS consist of a superconducting absorber strip with proximized STJs on either end. The STJs are a Ta/Al/AlOx/Al/Ta 100/30/1/30/100nm sandwich of which the bottom electrode Ta layer is one with the 100nm thick absorber layer. The ratio of the two signals from the STJs provides information on the absorption position and the sum signal is a measure for the energy of the absorbed photon. In this thesis we present different important processes which are involved with the detection of optical photons using DROIDs. This includes the spatial and spectral resolution, confinement of the quasiparticles in the proximized STJs to enhance tunnelling and quasiparticle creation resulting from absorption of a photon in the proximized STJ. We have combined our findings in the development of a 2D theoretical model which describes the diffusion of quasiparticles and imperfect confinement via exchange of quasiparticles between the absorber and STJ. Finally we will present some of the first results obtained with an array of 60 360x33.5 μm2 DROIDs in 3x20 format.

  7. PCI Based Read-out Receiver Card in the ALICE DAQ System

    CERN Document Server

    Carena, W; Dénes, E; Divià, R; Schossmaier, K; Soós, C; Sulyán, J; Vascotto, Alessandro; Van de Vyvre, P

    2001-01-01

    The Detector Data Link (DDL) is the high-speed optical link for the ALICE experiment. This link shall transfer the data coming from the detectors at 100 MB/s rate. The main components of the link have been developed: the destination Interface Unit (DIU), the Source Interface Unit (SIU) and the Read-out Receiver Card (RORC). The first RORC version is based on the VME bus. The performance tests show that the maximum VME bandwidth could be reached. Meanwhile the PCI bus became very popular and is used in many platforms. The development of a PCI-based version has been started. The document describes the prototype version in three sections. An overview explains the main purpose of the card: to provide an interface between the DDL and the PCI bus. Acting as a 32bit/33MHz PCI master the card is able to write or read directly to or from the system memory from or to the DDL, respectively. Beside these functions the card can also be used as an autonomous data generator. The card has been designed to be well adapted to ...

  8. Evolution of the ReadOut System of the ATLAS experiment

    CERN Document Server

    Borga, A; The ATLAS collaboration; Joos, M; Schumacher, J; Tremblet, L; Vandelli, W; Vermeulen, J; Werner, P; Wickens, F

    2014-01-01

    The ReadOut System (ROS) is a central and essential part of the ATLAS data-acquisition system. It receives and buffers event data accepted from all sub-detectors and first-level trigger subsystems. Event data are subsequently forwarded to the High-Level Trigger system and Event Builder via a GbE-based network. The ATLAS ROS will be completely renewed in view of the demanding conditions expected during LHC Run 2 and Run 3. The new ROS will consist of roughly 100 Linux-based 2U-high rack-mounted server PCs, each equipped with 2 PCIe I/O cards and four 10GbE interfaces. The FPGA-based PCIe I/O cards, developed by the ALICE collaboration, will be configured with ATLAS-specific firmware, called RobinNP. They will provide connectivity to about 2000 point-to-point optical links conveying the ATLAS event data. This dense configuration provides an excellent test bench for studying I/O efficiency and challenges in current COTS PC architectures with non-uniform memory and I/O access paths. In this paper the requirements...

  9. Evolution of the ReadOut System of the ATLAS experiment

    CERN Document Server

    Borga, A; The ATLAS collaboration; Green, B; Kugel, A; Joos, M; Panduro Vazquez, W; Schumacher, J; Teixeira-Dias, P; Tremblet, L; Vandelli, W; Vermeulen, J; Werner, P; Wickens, F

    2014-01-01

    The ReadOut System (ROS) is a central and essential part of the ATLAS DAQ system. It receives and buffers data of events accepted by the first-level trigger from all subdetectors and first-level trigger subsystems. Event data are subsequently forwarded to the High-Level Trigger system and Event Builder via a 1 GbE-based network. The ATLAS ROS is completely renewed in view of the demanding conditions expected during LHC Run 2 and Run 3, to replace obsolete technologies and space constraints require it to be compact. The new ROS will consist of roughly 100 Linux-based 2U high rack mounted server PCs, each equipped with 2 PCIe I/O cards and two four 10 GbE interfaces. The FPGA-based PCIe I/O cards, developed by the ALICE collaboration, will be configured with ATLAS-specific firmware, the so-called RobinNP firmware. They will provide the connectivity to about 2000 optical point-to-point links conveying the ATLAS event data. This dense configuration provides an excellent test bench for studying I/O efficiency and ...

  10. The monitoring system of the ATLAS muon spectrometer read out driver

    CERN Document Server

    Capasso, Luciano

    My PhD work focuses upon the Read Out Driver (ROD) of the ATLAS Muon Spectrometer. The ROD is a VME64x board, designed around two Xilinx Virtex-II FPGAs and an ARM7 microcontroller and it is located off-detector, in a counting room of the ATLAS cavern at the CERN. The readout data of the ATLAS’ RPC Muon spectrometer are collected by the front-end electronics and transferred via optical fibres to the ROD boards in the counting room. The ROD arranges all the data fragments of a sector of the spectrometer in a unique event. This is made by the Event Builder Logic, a cluster of Finite State Machines that parses the fragments, checks their syntax and builds an event containing all the sector data. In the presentation I will describe the Builder Monitor, developed by me in order to analyze the Event Builder timing performance. It is designed around a 32-bit soft-core microprocessor, embedded in the same FPGA hosting the Builder logic. This approach makes it possible to track the algorithm execution in the field. ...

  11. Imaging interferometric microscopy-approaching the linear systems limits of optical resolution.

    Science.gov (United States)

    Kuznetsova, Yuliya; Neumann, Alexander; Brueck, S R

    2007-05-28

    The linear systems optical resolution limit is a dense grating pattern at a lambda/2 pitch or a critical dimension (resolution) of lambda/4. However, conventional microscopy provides a (Rayleigh) resolution of only ~ 0.6lambda/NA, approaching lambda/1.67 as NA ?lambda1. A synthetic aperture approach to reaching the lambda/4 linear-systems limit, extending previous developments in imaginginterferometric microscopy, is presented. Resolution of non-periodic 180-nm features using 633-nm illumination (lambda/3.52) and of a 170-nm grating (lambda/3.72) is demonstrated. These results are achieved with a 0.4-NA optical system and retain the working distance, field-of-view, and depth-of-field advantages of low-NA systems while approaching ultimate resolution limits.

  12. Studies of MaPMTs with beetle-chip read-out

    CERN Document Server

    Muheim, F

    2005-01-01

    We have evaluated the 64-channel Multianode Photo-Multiplier (MaPMT) with 8-stage dynodes for the LHCb RICH detectors. With a Beetle1.2 chip to read-out the MaPMT, we have demonstrated that the MaPMT performance is as expected using particle beams and LED light sources. We have also measured the pulse shape from 12-stage dynode MaPMTs, read out with the Beetle1.2-MA0 chip.

  13. Studies of MaPMTs with beetle-chip read-out

    CERN Document Server

    Muheim, F

    2005-01-01

    We have evaluated the 64-channel Multianode Photo-Multiplier (MaPMT) with 8-stage dynodes for the LHCb RICH detectors. With a Beetle 1.2 chip to read-out the MaPMT, we have demonstrated that the MaPMT performance is as expected using particle beams and LED light sources. We have also measured the pulse shape from 12-stage dynode MaPMTs, read out with the Beetle 1.2-MA0 chip.

  14. Low-coherence interferometric measurements of optical losses in autoclave cured composite samples with embedded optical fibers

    Science.gov (United States)

    Di Sante, Raffaella; Bastianini, Filippo; Donati, Lorenzo

    2013-05-01

    In this work a high-performance optical low-coherence reflectometer (OLCR) has been used to estimate the optical losses in optical fibers and fiber Bragg grating sensors embedded into CFRP material samples. An ASE tunable narrowband light source coupled to a Michelson interferometer allowed the high spatial resolution localization of both the concentrated and the distributed loss for different fiber coatings and type. In particular, acrylate- and polyimidecoated fibers and bend-insensitive fibers were tested. By using the OLCR it was possible to locate and identify the sources of optical loss introduced by the CFRP manufacturing process, therefore obtaining useful information on the efficiency of the embedding process.

  15. Interferometric measurement of injection nozzles using ultra-small fiber-optical probes

    Institute of Scientific and Technical Information of China (English)

    Tilo Pfeifer; Robert Schmitt; Niels K(o)nig; Guilherme Francisco Mallmann

    2011-01-01

    The measurement of boreholes with diameters smaller than 500 pm is a demanding task that cannot be performed using state-of-the-art production metrology.In this letter,a miniaturized fiber probe with a diameter of 80 pm is presented.A probe is used for low-coherence interferometry to conduct highly precise measurements of form deviations of small boreholes.Measurements conducted in nozzles are also presented.The results prove the potential of the fiber-optical sensor for quality inspection of high-precision parts,such as injection nozzles,for common-rail diesel engines.

  16. Characterization of miniature fiber-optic Fabry-Perot interferometric sensors based on hollow silica tube

    Science.gov (United States)

    Jia, Pinggang; Fang, Guocheng; Wang, Daihua

    2016-09-01

    A miniature fiber-optic Fabry-Perot interferometer (MOFPI) fabricated by splicing a hollow silica tube (HST) with inner diameter of 4 µm to the end of a single-mode fiber is investigated and experimentally demonstrated. The theoretical relationship between the free spectrum range and the length of HST is verified by fabricating several MOFPIs with different lengths. We characterize the MOFPIs for temperature, liquid refractive index, and strain. Experimental results show that the sensitivities of the temperature, liquid refractive index, and strain are 16.42 pm/°C,-118.56 dB/RIU, and 1.21 pm/µɛ, respectively.

  17. Quantitative measurements of electromechanical response with a combined optical beam and interferometric atomic force microscope

    Energy Technology Data Exchange (ETDEWEB)

    Labuda, Aleksander; Proksch, Roger [Asylum Research an Oxford Instruments Company, Santa Barbara, California 93117 (United States)

    2015-06-22

    An ongoing challenge in atomic force microscope (AFM) experiments is the quantitative measurement of cantilever motion. The vast majority of AFMs use the optical beam deflection (OBD) method to infer the deflection of the cantilever. The OBD method is easy to implement, has impressive noise performance, and tends to be mechanically robust. However, it represents an indirect measurement of the cantilever displacement, since it is fundamentally an angular rather than a displacement measurement. Here, we demonstrate a metrological AFM that combines an OBD sensor with a laser Doppler vibrometer (LDV) to enable accurate measurements of the cantilever velocity and displacement. The OBD/LDV AFM allows a host of quantitative measurements to be performed, including in-situ measurements of cantilever oscillation modes in piezoresponse force microscopy. As an example application, we demonstrate how this instrument can be used for accurate quantification of piezoelectric sensitivity—a longstanding goal in the electromechanical community.

  18. Optical interferometric observations of Theta 1 Orionis C from NPOI and implications for the system orbit

    CERN Document Server

    Patience, J; Prato, L; Franz, O; Wasserman, L; Tycner, C; Hutter, D J; Hummel, C A

    2008-01-01

    With the Navy Prototype Optical Interferometer (NPOI), the binary system Theta 1 Orionis C, the most massive member of the Trapezium, was spatially resolved over a time period extending from February 2006 to March 2007. The data show significant orbital motion over the 14 months, and, after combining the NPOI data with previous measurements of the system from the literature, the observations span 10 years of the orbit. Our results indicate that the secondary did not experience an unusually close periastron passage this year, in contradiction to the prediction of a recently published, highly eccentric ~11 year orbit. Future observations of this source will be required to improve the orbital solution. Possible implications of the results in terms of system distance are discussed, although a main conclusion of this work is that a definitive orbit solution will require more time to obtain sufficient phase coverage, and that the interaction effects expected at periastron did not occur in 2007.

  19. A noiseless kilohertz frame rate imaging detector based on microchannel plates read out with the Medipix2 CMOS pixel chip

    CERN Document Server

    Mikulec, Bettina; Ferrère, Didier; La Marra, Daniel; McPhate, J B; Tremsin, A S; Siegmund, O H W; Vallerga, J V; Clement, J; Ponchut, C; Rigal, J M; CERN. Geneva

    2006-01-01

    A new hybrid optical imaging detector is described that is being developed for the next generation adaptive optics (AO) wavefront sensors (WFS) for ground-based telescopes. The detector consists of a photocathode and proximity focused microchannel plates (MCPs) read out by the Medipix2 CMOS pixel ASIC. Each pixel of the Medipix2 device measures 55x55 um2 and comprises pre-amplifier, a window discriminator and a 14-bit counter. The 256x256 Medipix2 array can be read out noiselessly in 287 us. The readout can be electronically shuttered down to a temporal window of a few us. The Medipix2 is buttable on 3 sides to produce 512x(n*256) pixel devices. Measurements with ultraviolet light yield a spatial resolution of the detector at the Nyquist limit. Sub-pixel resolution can be achieved using centroiding algorithms. For the AO application, very high continuous frame rates of the order of 1 kHz are required for a matrix of 512x512 pixels. The design concepts of a parallel readout board are presented that will allow ...

  20. Thermal noise in interferometric gravitational wave detectors due to dielectric optical coatings

    CERN Document Server

    Harry, G M; Saulson, P R; Penn, S D; Startin, W J; Kittelberger, S E; Crooks, D R M; Hough, J; Cagnoli, G; Nakagawa, N; Rowan, S; Fejer, M M; Harry, Gregory M.; Gretarsson, Andri M.; Saulson, Peter R.; Penn, Steven D.; Startin, William J.; Kittelberger, Scott; Hough, Jim; Cagnoli, Gianpietro; Nakagawa, Norio; Rowan, Sheila; Fejer, Martin M.

    2002-01-01

    We report on thermal noise from the internal friction of dielectric coatings made from alternating layers of Ta2O5 and SiO2 deposited on fused silica substrates. We present calculations of the thermal noise in gravitational wave interferometers due to optical coatings, when the material properties of the coating are different from those of the substrate and the mechanical loss angle in the coating is anisotropic. The loss angle in the coatings for strains parallel to the substrate surface was determined from ringdown experiments. We measured the mechanical quality factor of three fused silica samples with coatings deposited on them. The loss angle of the coating material for strains parallel to the coated surface was found to be (4.2 +- 0.3)*10^(-4) for coatings deposited on commercially polished slides and (1.0 +- 0.3)*10^{-4} for a coating deposited on a superpolished disk. Using these numbers, we estimate the effect of coatings on thermal noise in the initial LIGO and advanced LIGO interferometers. We also...

  1. A read-out buffer prototype for ATLAS high level triggers

    CERN Document Server

    Calvet, D; Huet, M; Le Dû, P; Mandjavidze, I D; Mur, M

    2000-01-01

    Read-Out Buffers are critical components in the dataflow chain of the ATLAS Trigger/DAQ system. At up to 75 kHz, after each Level-1 trigger accept signal, these devices receive and store digitized data from groups of front-end electronic channels. Several Read-Out Buffers are grouped to form a Read-Out Buffer Complex that acts as a data server for the High Level Triggers selection algorithms and for the final data collection system. This paper describes a functional prototype of a Read-Out Buffer based on a custom made PCI mezzanine card that is designed to accept input data at up to 160 MB/s, to store up to 8 MB of data and to distribute data chunks at the desired request rate. We describe the hardware of the card that is based on an Intel I960 processor and CPLDs. We present the integration of several of these cards in a Read-Out Buffer Complex. We measure various performance figures and we discuss to which extent these can fulfill ATLAS needs. 5 Refs.

  2. Optimizing read-out of the NECTAr front-end electronics

    Energy Technology Data Exchange (ETDEWEB)

    Vorobiov, S., E-mail: vorobiov@lpta.in2p3.fr [LUPM, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); DESY-Zeuthen, Platanenallee 6, 15738 Zeuthen (Germany); Feinstein, F. [LUPM, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); Bolmont, J.; Corona, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France); Delagnes, E. [IRFU/DSM/CEA, Saclay, Gif-sur-Yvette (France); Falvard, A. [LUPM, Universite Montpellier II and IN2P3/CNRS, Montpellier (France); Gascon, D. [ICC-UB, Universitat Barcelona, Barcelona (Spain); Glicenstein, J.-F. [IRFU/DSM/CEA, Saclay, Gif-sur-Yvette (France); Naumann, C.L.; Nayman, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France); Ribo, M.; Sanuy, A. [ICC-UB, Universitat Barcelona, Barcelona (Spain); Tavernet, J.-P.; Toussenel, F.; Vincent, P. [LPNHE, Universite Paris VI and Universite Paris VII and IN2P3/CNRS, Paris (France)

    2012-12-11

    We describe the optimization of the read-out specifications of the NECTAr front-end electronics for the Cherenkov Telescope Array (CTA). The NECTAr project aims at building and testing a demonstrator module of a new front-end electronics design, which takes an advantage of the know-how acquired while building the cameras of the CAT, H.E.S.S.-I and H.E.S.S.-II experiments. The goal of the optimization work is to define the specifications of the digitizing electronics of a CTA camera, in particular integration time window, sampling rate, analog bandwidth using physics simulations. We employed for this work real photomultiplier pulses, sampled at 100 ps with a 600 MHz bandwidth oscilloscope. The individual pulses are drawn randomly at the times at which the photo-electrons, originating from atmospheric showers, arrive at the focal planes of imaging atmospheric Cherenkov telescopes. The timing information is extracted from the existing CTA simulations on the GRID and organized in a local database, together with all the relevant physical parameters (energy, primary particle type, zenith angle, distance from the shower axis, pixel offset from the optical axis, night-sky background level, etc.), and detector configurations (telescope types, camera/mirror configurations, etc.). While investigating the parameter space, an optimal pixel charge integration time window, which minimizes relative error in the measured charge, has been determined. This will allow to gain in sensitivity and to lower the energy threshold of CTA telescopes. We present results of our optimizations and first measurements obtained using the NECTAr demonstrator module.

  3. Distinguishing between ultrafast optical harmonic generation and multi-photon-induced luminescence from ZnO thin films by interferometric frequency-resolved autocorrelation microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Slawa; Mascheck, Manfred; Silies, Martin [Carl-von-Ossietzky-Universitaet, Oldenburg (Germany); Yatsui, Takashi; Kitamura, Kokoro; Ohtsu, Motoichi; Lienau, Christoph [University of Tokyo (Japan)

    2011-07-01

    The nonlinear optical properties of a thin ZnO film are studied using interferometric frequency-resolved autocorrelation (IFRAC) microscopy. By exciting the film with 6-fs, below-bandgap laser pulses at 800nm focused to a spot size of 1 {mu}m two emission bands in the blue and bluegreen spectral region with distinctly different coherence properties can be detected. We show that an analysis of the wavelength-dependence of the interference fringes in the IFRAC signal allows for an unambiguous assignment of these bands as coherent second harmonic emission and incoherent, multiphoton-induced photoluminescence, respectively. More generally our analysis shows that IFRAC allows for a complete characterization of the coherence properties of the nonlinear optical emission from nanostructures in a single-beam experiment. Since this technique combines a very high temporal and spatial resolution we anticipate broad applications in nonlinear nano-optics.

  4. Read-out calibration of a SOI capacitive transducer using the pull-in voltage

    Science.gov (United States)

    Mol, L.; Rocha, L. A.; Cretu, E.; Wolffenbuttel, R. F.

    2008-06-01

    The pull-in voltage of a parallel plate electrostatic transducer is used to determine the amount of over-etching in fabricated devices. A detailed analysis of the capacitor behaviour over the full displacement range yields a model, which is used to describe the relation between over-etching and measured pull-in voltage. SEM photos confirm the over-etching measurement based on pull-in voltage. This information is used to linearize a charge amplifying read-out circuit with an intrinsic nonlinear transfer function. The remaining nonlinearity error of the read-out is less than 1%.

  5. The Read-Out Shutter Unit of the Euclid VIS Instrument

    CERN Document Server

    Genolet, L; Paltani, S; Autissier, N; Larcheveque, C; Thomas, C

    2016-01-01

    Euclid is the second medium-size mission (M2) of the ESA Cosmic Vision Program, currently scheduled for a launch in 2020. The two instruments on-board Euclid, VIS and NISP, will provide key measurements to investigate the nature of dark energy, advancing our knowledge on cosmology. We present in this contribution the development and manufacturing status of the VIS Read-out Shutter Unit, whose main function is to prevent direct light from falling onto the VIS CCDs during the read-out of the scientific exposures and to allow the dark-current/bias calibrations of the instrument.

  6. An application of CCD read-out technique to neutron distribution measurement using the self-activation method with a CsI scintillator plate

    Energy Technology Data Exchange (ETDEWEB)

    Nohtomi, Akihiro, E-mail: nohtomi@hs.med.kyushu-u.ac.jp [Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Kurihara, Ryosuke; Kinoshita, Hiroyuki; Honda, Soichiro; Tokunaga, Masaaki; Uno, Heita [Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Shinsho, Kiyomitsu [Graduate School of Human Sciences, Tokyo Metropolitan University, 7-2-10 Higashi-oku, Arakawa-ku, Tokyo 116-8551 (Japan); Wakabayashi, Genichiro [Atomic Energy Research Institute, Kinki University, 3-4-1 Kowakae, Higashiosaka-shi, Osaka 577-8502 (Japan); Koba, Yusuke [National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba-shi, Chiba 263-8555 (Japan); Fukunaga, Junichi; Umezu, Yoshiyuki; Nakamura, Yasuhiko [Department of Radiology, Kyushu University Hospital, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan); Ohga, Saiji [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582 (Japan)

    2016-10-01

    In our previous paper, the self-activation of an NaI scintillator had been successfully utilized for detecting photo-neutrons around a high-energy X-ray radiotherapy machine; individual optical pulses from the self-activated scintillator are read-out by photo sensors such as a photomultiplier tube (PMT). In the present work, preliminary observations have been performed in order to apply a direct CCD read-out technique to the self-activation method with a CsI scintillator plate using a Pu-Be source and a 10-MV linac. In conclusion, it has been revealed that the CCD read-out technique is applicable to neutron measurement around a high-energy X-ray radiotherapy machine with the self-activation of a CsI plate. Such application may provide a possibility of novel method for simple neutron dose-distribution measurement. - Highlights: • Preliminary observations have been performed by a CCD for the CsI self-activation method. • It has been revealed that the CCD read-out technique is applicable to neutron measurement. • Such application may provide a novel method for simple neutron distribution measurement.

  7. Setup, tests and results for the ATLAS TileCal Read Out Driver production

    CERN Document Server

    Valero, Alberto; Castillo, V; Cuenca, C; Ferrer, A; Fullana, E; González, V; Higón, E; Munar, A; Poveda, J; Ruiz-Martínez, A; Salvachúa, B; Sanchís, E; Solans, C; Soret, J; Torres, J; Valls, J A

    2007-01-01

    In this paper we describe the performance and test results of the production of the 38 ATLAS TileCal Read Out Drivers (RODs). We first describe the basic hardware specifications and firmware functionality of the modules, the test-bench setup used for production and the test procedure to qualify the boards. We then finally show and discuss the performance results.

  8. Added value of IP-10 as a read-out of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Jenum, Synne; Dhanasekaran, Sivmakumaran; Ritz, Christian;

    2016-01-01

    We have explored the added value of IFNγ-inducible protein 10 as a read-out of Mycobacterium tuberculosis specific immunity in young Indian children where the sensitivity of the IGRA for tuberculosis (TB) is poor. Reduced frequency of indeterminate results and an increased sensitivity for TB...

  9. Controlling and Monitoring the Data Flow of the LHCb Read-out and DAQ Network

    CERN Document Server

    Schwemmer, Rainer; Neufeld, N; Svantesson, D

    2011-01-01

    The LHCb read-out uses a set of 320 FPGA based boards as interface between the on-detector hardware and the GBE DAQ network. The boards are the logical Level 1 (L1) read-out electronics and aggregate the experiment’s raw data into event fragments that are sent to the DAQ network. To control the many parameters of the read-out boards, an embedded PC is included on each board, connecting to the boards ICs and FPGAs. The data from the L1 boards is sent through an aggregation network into the High Level Trigger farm. The farm comprises approximately 1500 PCs which at first assemble the fragments from the L1 boards and then do a partial reconstruction and selection of the events. In total there are approximately 3500 network connections. Data is pushed through the network and there is no mechanism for resending packets. Loss of data on a small scale is acceptable but care has to be taken to avoid data loss if possible. To monitor and debug losses, different probes are inserted throughout the entire read-out cha...

  10. A new read-out architecture for the ATLAS Tile Calorimeter Phase-II Upgrade

    CERN Document Server

    Valero, Alberto; The ATLAS collaboration

    2015-01-01

    TileCal is the Tile hadronic calorimeter of the ATLAS experiment at the LHC. The LHC has planned a series of upgrades culminating in the High Luminosity LHC (HL-LHC) which will increase of order five times the LHC nominal instantaneous luminosity. TileCal will undergo an upgrade to accommodate to the HL-LHC parameters. The TileCal read-out electronics will be redesigned introducing a new read-out strategy. The data generated in the detector will be transferred to the new Read-Out Drivers (sRODs) located in off-detector for every bunch crossing before any event selection is applied. Furthermore, the sROD will be responsible of providing preprocessed trigger information to the ATLAS first level of trigger. It will implement pipeline memories to cope with the latencies and rates specified in the new trigger schema and in overall it will represent the interface between the data acquisition, trigger and control systems and the on-detector electronics. The new TileCal read-out architecture will be presented includi...

  11. A new pixel level digital read out integrated circuits for ultraviolet imaging sensors

    Science.gov (United States)

    Xu, Bin; Lan, Tian-yi; Yuan, Yong-gang; Li, Xiang-yang

    2014-11-01

    The ultraviolet imaging sensors consist of two important parts: the array of detectors and the read out integrated circuits. Along with the demand for the fine resolution, large input dynamic range and high integration degree of the imaging sensors, the functions of read out integrated circuits are becoming more and more important. The on chip analog to digital conversion is the main directions of research on this area. In this paper, we presented a new digital read out integrated circuits for ultraviolet imaging sensors. The proposed circuits have an analog to digital converter in each pixel, which enable the parallel analog to digital conversion of the whole pixel array. The developed circuits have a 50um×50um pixel area with a 128×128 size, and are designed in a 0.35um four metal double poly mixed signal CMOS process. The simulation results show that the designed analog to digital converter has an accuracy of 0.2mV and can achieve the dynamic range of 88dB. The proposed circuits realize the low noise and high speed digital output of read out integrated circuits for ultraviolet imaging sensors.

  12. Test beam results for silicon microstrip detectors with VLSI read-out

    Energy Technology Data Exchange (ETDEWEB)

    Adolphsen, C.; Litke, A.; Schwarz, A.; Turala, M.; Lueth, V.; Breakstone, A.; Parker, S.

    1986-04-01

    A telescope consisting of three silicon microstrip detectors has been tested in a high energy positron beam at SLAC. Each detector has trips with 25 micron pitch and is read out by two 128-channel NMOS integrated circuits (''Microplex''). Results on the signal-to-noise ratio, spatial resolution, and two-track separation are given.

  13. Self Calibrating Interferometric Sensor

    DEFF Research Database (Denmark)

    Sørensen, Henrik Schiøtt

    This thesis deals with the development of an optical sensor based on micro interferometric backscatter detection (MIBD). A price effective, highly sensitive and ready for mass production platform is the goal of this project. The thesis covers three areas. The first part of the thesis deals...... mask. The fabricated micro structures have been electroplated for later injection molding, showing the potential of the MIBD sensor to be mass produced with high reproducibility and sensitivity. In part three MIBD experiments on vital biological systems are described. Label–free binding studies of bio...

  14. N-slit Interferometer for Secure Free-Space Optical Communications: 527 m Intra Interferometric Path Length

    Science.gov (United States)

    2011-01-01

    7] Feynman R P, Leighton R B and Sands M 1965 The Feynman Lectures on Physics vol 3 (Reading, MA: Addison Wesley) [8] Dirac P A M 1978 The Principles...by Newton [5] and N-slit diffraction was discussed by Michelson [6]. In a more contemporaneous setting, Feynman [7] applied Dirac’s quantum notation [8...the integrity of the interferometric characters is protected by the fundamental physics of interference [2, 7], which Figure 8. Interferogram registered

  15. Characterization of the front-end EASIROC for read-out of SiPM in the ASTRI camera

    CERN Document Server

    Impiombato, D; Belluso, M; Bilotta, S; Bonanno, G; Catalano, O; Grillo, A; La Rosa, G; Marano, D; Mineo, T; Russo, F; Sottile, G

    2013-01-01

    The design and realization of a prototype for the Small-Size class Telescopes of the Cherenkov Telescope Array is one of the cornerstones of the ASTRI project. The prototype will adopt a focal plane camera based on Silicon Photo-Multiplier sensors that coupled with a dual mirror optics configuration represents an innovative solution for the detection of Atmospheric Cherenkov light. These detectors can be read by the Extended Analogue Silicon Photo-Multiplier Integrated Read Out Chip (EASIROC) equipped with 32-channels. In this paper, we report some preliminary results on measurements aimed to evaluate EASIROC capability of autotriggering and measurements of the trigger time walk, jitter, DAC linearity and trigger efficiency vs the injected charge. Moreover, the dynamic range of the ASIC is also reported.

  16. Two-Wavelength Interferometric Keratometer

    Science.gov (United States)

    Hochberg, Eric; Page, Norman

    1991-01-01

    Proposed interferometric keratometer measures shapes of corneas without touching them. Used to test strongly aspherical optics. Resembling present commercial lens-testing interferometers, generates interferograms representative of deviation of surfaces under test from sphericity. Such interferograms used to generate contour maps of surfaces. Measures corneal topography to diameters as large as 12 mm.

  17. Time and position sensitive single photon detector for scintillator read-out

    Science.gov (United States)

    Schössler, S.; Bromberger, B.; Brandis, M.; Schmidt, L. Ph H.; Tittelmeier, K.; Czasch, A.; Dangendorf, V.; Jagutzki, O.

    2012-02-01

    We have developed a photon counting detector system for combined neutron and γ radiography which can determine position, time and intensity of a secondary photon flash created by a high-energy particle or photon within a scintillator screen. The system is based on a micro-channel plate photomultiplier concept utilizing image charge coupling to a position- and time-sensitive read-out anode placed outside the vacuum tube in air, aided by a standard photomultiplier and very fast pulse-height analyzing electronics. Due to the low dead time of all system components it can cope with the high throughput demands of a proposed combined fast neutron and dual discrete energy γ radiography method (FNDDER). We show tests with different types of delay-line read-out anodes and present a novel pulse-height-to-time converter circuit with its potential to discriminate γ energies for the projected FNDDER devices for an automated cargo container inspection system (ACCIS).

  18. Read-out electronics for fast photon detection with COMPASS RICH-1

    CERN Document Server

    Abbon, P

    2008-01-01

    A new read-out electronics system has been developed for the fast photon detection of the central region of the COMPASS RICH-1. The project is based on multi-anode photomultipliers read out by the high-sensitivity MAD4 preamplifier-discriminator and the dead-time free F1 TDC chip characterised by high time resolution. The system has been designed taking into account the high photon flux in the central region of the detector and the high rate requirement of the COMPASS experiment. The system is described in detail together with the measured performances. The new electronics system has been installed and used for the 2006 data taking; it entirely fulfils the expected performances.

  19. Time and position sensitive single photon detector for scintillator read-out

    CERN Document Server

    Schössler, Sven; Brandis, Michal; Schmidt, Lothar Ph H; Tittelmeier, Kai; Czasch, Achim; Dangendorf, Volker; Jagutzki, Ottmar

    2012-01-01

    We have developed a photon counting detector system for combined neutron and gamma radiography which can determine position, time and intensity of a secondary photon flash created by a high-energy particle or photon within a scintillator screen. The system is based on a micro-channel plate photomultiplier concept utilizing image charge coupling to a position- and time-sensitive read-out anode placed outside the vacuum tube in air, aided by a standard photomultiplier and very fast pulse-height analyzing electronics. Due to the low dead time of all system components it can cope with the high throughput demands of a proposed combined fast neutron and dual discrete energy gamma radiography method (FNDDER). We show tests with different types of delay-line read-out anodes and present a novel pulse-height-to-time converter circuit with its potential to discriminate gamma energies for the projected FNDDER devices for an automated cargo container inspection system (ACCIS).

  20. Single-shot read-out of a superconducting qubit using a Josephson parametric oscillator

    Science.gov (United States)

    Krantz, Philip; Bengtsson, Andreas; Simoen, Michaël; Gustavsson, Simon; Shumeiko, Vitaly; Oliver, W. D.; Wilson, C. M.; Delsing, Per; Bylander, Jonas

    2016-05-01

    We propose and demonstrate a read-out technique for a superconducting qubit by dispersively coupling it with a Josephson parametric oscillator. We employ a tunable quarter wavelength superconducting resonator and modulate its resonant frequency at twice its value with an amplitude surpassing the threshold for parametric instability. We map the qubit states onto two distinct states of classical parametric oscillation: one oscillating state, with 185+/-15 photons in the resonator, and one with zero oscillation amplitude. This high contrast obviates a following quantum-limited amplifier. We demonstrate proof-of-principle, single-shot read-out performance, and present an error budget indicating that this method can surpass the fidelity threshold required for quantum computing.

  1. Single-shot read-out of a superconducting qubit using a Josephson parametric oscillator

    Science.gov (United States)

    Krantz, Philip; Bengtsson, Andreas; Simoen, Michaël; Gustavsson, Simon; Shumeiko, Vitaly; Oliver, W. D.; Wilson, C. M.; Delsing, Per; Bylander, Jonas

    2016-01-01

    We propose and demonstrate a read-out technique for a superconducting qubit by dispersively coupling it with a Josephson parametric oscillator. We employ a tunable quarter wavelength superconducting resonator and modulate its resonant frequency at twice its value with an amplitude surpassing the threshold for parametric instability. We map the qubit states onto two distinct states of classical parametric oscillation: one oscillating state, with 185±15 photons in the resonator, and one with zero oscillation amplitude. This high contrast obviates a following quantum-limited amplifier. We demonstrate proof-of-principle, single-shot read-out performance, and present an error budget indicating that this method can surpass the fidelity threshold required for quantum computing. PMID:27156732

  2. A Complete Set of Firmware for the TileCal Read-Out Driver

    CERN Document Server

    Valero, A; Cuenca, C; Ferrer, A; Fullana, E; González, V; Higón, E; Poveda, J; Ruiz-Martinez, A; Salvachúa, B; Sanchís, E; Solans, C; Torres, J; Valls, J A

    2007-01-01

    TileCal is the hadronic tile calorimeter of the ATLAS experiment at LHC/CERN. The Read-Out Driver (ROD) is the main component of the TileCal back-end electronics. The ROD is a VME 64x 9u board with multiple programmable devices which requires a complete set of firmware. This paper describes the firmware and functionalities of all these programmable devices, especially the DSP Processing Units daughterboards where the data processing takes place.

  3. Simulation of an efficiency measurement of the CMS pixel Read-Out Chip at high rates.

    CERN Document Server

    Delcourt, Martin

    2014-01-01

    My summer student project investigates the effects on the efficiency of out-of-sync events during a beam test at Fermilab on pixel detectors for the phase 1 upgrade of the CMS. While the best results of this project came from direct lab measurements, most of my work was focused on the development of a wider simulation to have a better understanding of the behaviour of the read-out chips during the beam test.

  4. High sensitivity phonon-mediated kinetic inductance detector with combined amplitude and phase read-out

    OpenAIRE

    Bellini, F.; Cardani, L; Casali, N.; Castellano, M. G.; Colantoni, I.; Cosmelli, C.; Cruciani, A.; D'Addabbo, A.; Di Domizio, S.; M. Martinez; Tomei, C.; Vignati, M.

    2016-01-01

    The development of wide-area cryogenic light detectors with good energy resolution is one of the priorities of next generation bolometric experiments searching for rare interactions, as the simultaneous read-out of the light and heat signals enables background suppression through particle identification. Among the proposed technological approaches for the phonon sensor, the naturally-multiplexed Kinetic Inductance Detectors (KIDs) stand out for their excellent intrinsic energy resolution and ...

  5. Characterisation and modelling of transition edge sensor distributed read-out imaging devices

    Science.gov (United States)

    Smith, Stephen J.; Whitford, Chris H.; Fraser, George W.; Goldie, David J.

    2006-04-01

    We report on the experimental characterisation and modelling of Transition Edge Sensor (TES)-based Distributed Read-Out Imaging Devices (DROIDs), for use as position-sensitive detectors in X-ray astronomy. Latest experimental results from prototype DROIDs using Ir TESs with Au absorbers are reported. Through modelling and the development of signal processing algorithms we are able to design the DROID for optimum spectral and spatial resolution depending upon application.

  6. Characterisation and modelling of transition edge sensor distributed read-out imaging devices

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Stephen J. [Department of Physics and Astronomy, Space Research Centre, Leicester University, Michael Atiyah Building, University Road, Leicester, LE1 7RH (United Kingdom)]. E-mail: sts@star.le.ac.uk; Whitford, Chris H. [Department of Physics and Astronomy, Space Research Centre, Leicester University, Michael Atiyah Building, University Road, Leicester, LE1 7RH (United Kingdom); Fraser, George W. [Department of Physics and Astronomy, Space Research Centre, Leicester University, Michael Atiyah Building, University Road, Leicester, LE1 7RH (United Kingdom); Goldie, David J. [Astrophysics Group, Cavendish Laboratory, Department of Physics, Cambridge University, Madingley Road Cambridge, CB3 OHE (United Kingdom)

    2006-04-15

    We report on the experimental characterisation and modelling of Transition Edge Sensor (TES)-based Distributed Read-Out Imaging Devices (DROIDs), for use as position-sensitive detectors in X-ray astronomy. Latest experimental results from prototype DROIDs using Ir TESs with Au absorbers are reported. Through modelling and the development of signal processing algorithms we are able to design the DROID for optimum spectral and spatial resolution depending upon application.

  7. The fresnel interferometric imager

    Science.gov (United States)

    Koechlin, Laurent; Serre, Denis; Deba, Paul; Pelló, Roser; Peillon, Christelle; Duchon, Paul; Gomez de Castro, Ana Ines; Karovska, Margarita; Désert, Jean-Michel; Ehrenreich, David; Hebrard, Guillaume; Lecavelier Des Etangs, Alain; Ferlet, Roger; Sing, David; Vidal-Madjar, Alfred

    2009-03-01

    The Fresnel Interferometric Imager has been proposed to the European Space Agency (ESA) Cosmic Vision plan as a class L mission. This mission addresses several themes of the CV Plan: Exoplanet study, Matter in extreme conditions, and The Universe taking shape. This paper is an abridged version of the original ESA proposal. We have removed most of the technical and financial issues, to concentrate on the instrumental design and astrophysical missions. The instrument proposed is an ultra-lightweight telescope, featuring a novel optical concept based on diffraction focussing. It yields high dynamic range images, while releasing constraints on positioning and manufacturing of the main optical elements. This concept should open the way to very large apertures in space. In this two spacecraft formation-flying instrument, one spacecraft holds the focussing element: the Fresnel interferometric array; the other spacecraft holds the field optics, focal instrumentation, and detectors. The Fresnel array proposed here is a 3.6 ×3.6 m square opaque foil punched with 105 to 106 void “subapertures”. Focusing is achieved with no other optical element: the shape and positioning of the subapertures (holes in the foil) is responsible for beam combining by diffraction, and 5% to 10% of the total incident light ends up into a sharp focus. The consequence of this high number of subapertures is high dynamic range images. In addition, as it uses only a combination of vacuum and opaque material, this focussing method is potentially efficient over a very broad wavelength domain. The focal length of such diffractive focussing devices is wavelength dependent. However, this can be corrected. We have tested optically the efficiency of the chromatism correction on artificial sources (500 < λ < 750 nm): the images are diffraction limited, and the dynamic range measured on an artificial double source reaches 6.2 10 - 6. We have also validated numerical simulation algorithms for larger Fresnel

  8. Controlling and Monitoring the Data Flow of the LHCb Read-out and DAQ Network

    CERN Multimedia

    Schwemmer, R; Neufeld, N; Svantesson, D

    2011-01-01

    The LHCb readout uses a set of 320 FPGA based boards as interface between the on-detector hardware and the GBE DAQ network. The boards are the logical Level 1 (L1) read-out electronics and aggregate the experiment's raw data into event fragments that are sent to the DAQ network. To control the many parameters of the read-out boards, an embedded PC is included on each board, connecting to the boards ICs and FPGAs. The data from the L1 boards is sent through an aggregation network into the High Level Trigger farm. The farm comprises approximately 1500 PCs which at first assemble the fragments from the L1 boards and then do a partial reconstruction and selection of the events. In total there are approximately 3500 network connections. Data is pushed through the network and there is no mechanism for resending packets. Loss of data on a small scale is acceptable but care has to be taken to avoid data loss if possible. To monitor and debug losses, different probes are inserted throughout the entire read-out chain t...

  9. AC Read-Out Circuits for Single Pixel Characterization of TES Microcalorimeters and Bolometers

    Science.gov (United States)

    Gottardi, L.; van de Kuur, J.; Bandler, S.; Bruijn, M.; de Korte, P.; Gao, J. R.; den Hartog, R.; Hijmering, R. A.; Hoevers, H.; Koshropanah, P.; Kilbourne, C.; Lindemann, M. A.; Parra Borderias, M.; Ridder, M.

    2011-01-01

    SRON is developing Frequency Domain Multiplexing (FDM) for the read-out of transition edge sensor (TES) soft x-ray microcalorimeters for the XMS instrument of the International X-ray Observatory and far-infrared bolometers for the SAFARI instrument on the Japanese mission SPICA. In FDM the TESs are AC voltage biased at frequencies from 0.5 to 6 MHz in a superconducting LC resonant circuit and the signal is read-out by low noise and high dynamic range SQUIDs amplifiers. The TES works as an amplitude modulator. We report on several AC bias experiments performed on different detectors. In particular, we discuss the results on the characterization of Goddard Space Flight Center x-ray pixels and SRON bolometers. The paper focuses on the analysis of different read-out configurations developed to optimize the noise and the impedance matching between the detectors and the SQUID amplifier. A novel feedback network electronics has been developed to keep the SQUID in flux locked loop, when coupled to superconducting high Q circuits, and to optimally tune the resonant bias circuit. The achieved detector performances are discussed in view of the instrument requirement for the two space missions.

  10. Quantum Interferometric Sensors

    CERN Document Server

    Kapale, K T; Lee, H; Kok, P; Dowling, J P; Kapale, Kishore T.; Didomenico, Leo D.; Lee, Hwang; Kok, Pieter; Dowling, Jonathan P.

    2005-01-01

    Quantum entanglement has the potential to revolutionize the entire field of interferometric sensing by providing many orders of magnitude improvement in interferometer sensitivity. The quantum-entangled particle interferometer approach is very general and applies to many types of interferometers. In particular, without nonlocal entanglement, a generic classical interferometer has a statistical-sampling shot-noise limited sensitivity that scales like $1/\\sqrt{N}$, where $N$ is the number of particles passing through the interferometer per unit time. However, if carefully prepared quantum correlations are engineered between the particles, then the interferometer sensitivity improves by a factor of $\\sqrt{N}$ to scale like 1/N, which is the limit imposed by the Heisenberg Uncertainty Principle. For optical interferometers operating at milliwatts of optical power, this quantum sensitivity boost corresponds to an eight-order-of-magnitude improvement of signal to noise. This effect can translate into a tremendous s...

  11. Atom-interferometric measurement of Stark level splittings

    CERN Document Server

    Wang, Limei; Zhang, Linjie; Raithel, Georg; Zhao, Jianming; Jia, Suotang

    2015-01-01

    Multiple adiabatic/diabatic passages through avoided crossings in the Stark map of cesium Rydberg atoms are employed as beam splitters and recombiners in an atom-interferometric measurement of energy-level splittings. We subject cold cesium atoms to laser-excitation, electric-field and detection sequences that constitute an (internal-state) atom interferometer. For the read-out of the interferometer we utilize state-dependent collisions, which selectively remove atoms of one kind from the detected signal. We investigate the dependence of the interferometric signal on timing and field parameters, and find good agreement with time-dependent quantum simulations of the interferometer. Fourier analysis of the interferometric signals yield coherence frequencies that agree with corresponding energy-level differences in calculated Stark maps. The method enables spectroscopy of states that are inaccessible to direct laser-spectroscopic observation, due to selection rules, and has applications in field metrology.

  12. 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.

  13. Construction and performance of large wire spark chambers with magnetostrictive read-out

    CERN Document Server

    Grayer, G; Dietl, H; Hyams, Bernard David; Jones, C; Koch, W; Lorenz, E; Lütjens, G; Männer, W; Meissburger, J; Stierlin, U; Weilhammer, P

    1972-01-01

    Describes the construction and performance of wire spark chambers having an active area of 3.60*0.90 m/sup 2/, a gap of 10 mm, and a wire spacing of 1 mm. Magnetostrictive read-out from both planes gives two coordinate values per chamber. Chambers of this type, together with smaller ones of similar construction, have been part of a magnet spectrometer which performed reliably between May 1970 and May 1971; during this time they were pulsed approximately 10/sup 7/ times. (9 refs).

  14. Design and performance testing of the read-out boards for the CMS-DT chambers

    CERN Document Server

    Fernández, C; Marin, J; Oller, J C; Willmott, C

    2002-01-01

    Read-out boards (ROB) are one of the key elements of readout system for CMS barrel muon drift chambers. To insure proper and reliable operation under all detector environmental conditions an exhaustive set of tests have been developed and performed on the 30 pre-series ROB's before production starts. These tests include operation under CMS radiation conditions to detect and estimate SEU rates, validation with real chamber signals and trigger rates, studies of time resolution and linearity, crosstalk analysis, track pattern generation for calibration and on-line tests, and temperature cycling to uncover marginal conditions. We present the status of the ROB and tests results. (5 refs).

  15. Photoelectron Yields of Scintillation Counters with Embedded Wavelength-Shifting Fibers Read Out With Silicon Photomultipliers

    Energy Technology Data Exchange (ETDEWEB)

    Artikov, Akram; et al.

    2017-09-19

    Photoelectron yields of extruded scintillation counters with titanium dioxide coating and embedded wavelength shifting fibers read out by silicon photomultipliers have been measured at the Fermilab Test Beam Facility using 120\\,GeV protons. The yields were measured as a function of transverse, longitudinal, and angular positions for a variety of scintillator compositions and reflective coating mixtures, fiber diameters, and photosensor sizes. Timing performance was also studied. These studies were carried out by the Cosmic Ray Veto Group of the Mu2e collaboration as part of their R\\&D program.

  16. Gafchromic EBT3 film dosimetry in electron beams - energy dependence and improved film read-out.

    Science.gov (United States)

    Sipilä, Petri; Ojala, Jarkko; Kaijaluoto, Sampsa; Jokelainen, Ilkka; Kosunen, Antti

    2016-01-01

    For megavoltage photon radiation, the fundamental dosimetry characteristics of Gafchromic EBT3 film were determined in 60Co gamma ray beam with addition of experimental and Monte Carlo (MC)-simulated energy dependence of the film for 6 MV photon beam and 6 MeV, 9 MeV, 12 MeV, and 16 MeV electron beams in water phantom. For the film read-out, two phase correction of scanner sensitivity was applied: a matrix correction for scanning area and dose-dependent correction by iterative procedure. With these corrections, the uniformity of response can be improved to be within ± 50 pixel values (PVs). To improve the read-out accuracy, a procedure with flipped film orientations was established. With the method, scanner uniformity can be improved further and dust particles, scratches and/or dirt on scan-ner glass can be detected and eliminated. Responses from red and green channels were averaged for read-out, which decreased the effect of noise present in values from separate channels. Since the signal level with the blue channel is considerably lower than with other channels, the signal variation due to different perturbation effects increases the noise level so that the blue channel is not recommended to be used for dose determination. However, the blue channel can be used for the detection of emulsion thickness variations for film quality evaluations with unexposed films. With electron beams ranging from 6 MeV to 16 MeV and at reference measurement conditions in water, the energy dependence of the EBT3 film is uniform within 0.5%, with uncertainties close to 1.6% (k = 2). Including 6 MV photon beam and the electron beams mentioned, the energy dependence is within 1.1%. No notable differences were found between the experimental and MC-simulated responses, indicating negligible change in intrinsic energy dependence of the EBT3 film for 6 MV photon beam and 6 MeV-16 MeV electron beams. Based on the dosimetric characteristics of the EBT3 film, the read-out procedure established

  17. Electronics for the CMS muon drift tube chambers the read-out minicrate

    CERN Document Server

    Fernandez Bedoya, Cristina; Oller, Juan Carlos; Willmott, Carlos

    2005-01-01

    On the Compact Muon Solenoid (CMS) experimentat the Large Hadron Collider (LHC) at the CERN laboratory, the drift tube chambers are responsible for muon detection and precise momentum measurement. In this paper the first level of the read out electronics for these drift tube chambers is described. These drift tube chambers will be located inside the muon barrel detector in the so-called minicrates (MCs), attached to the chambers. The read out boards (ROBs) are the main component of this first level data acquisition system, and they are responsible for the time digitalization related to Level 1 Accept (L1A) trigger of the incoming signals from the front-end electronics, followed by a consequent data merging to the next stages of the data acquisition system. ROBs' architecture and functionality have been exhaustively tested, as well as their capability of operation beyond the expected environmental conditions inside the CMS detector. Due to the satisfactory results obtained, final production of ROBs and their a...

  18. The NA62 Gigatracker: Detector properties and pixel read-out architectures

    Energy Technology Data Exchange (ETDEWEB)

    Fiorini, M., E-mail: Massimiliano.Fiorini@cern.c [CERN, CH-1211 Geneva 23 (Switzerland); Carassiti, V. [INFN Sezione di Ferrara, 44100 Ferrara (Italy); Ceccucci, A. [CERN, CH-1211 Geneva 23 (Switzerland); Cortina, E. [Universite Catholique de Louvain, 1348 Louvain-la-Neuve (Belgium); Cotta Ramusino, A. [INFN Sezione di Ferrara, 44100 Ferrara (Italy); Dellacasa, G. [INFN Sezione di Torino, 10125 Torino (Italy); Jarron, P.; Kaplon, J.; Kluge, A. [CERN, CH-1211 Geneva 23 (Switzerland); Marchetto, F. [INFN Sezione di Torino, 10125 Torino (Italy); Martin, E. [Universite Catholique de Louvain, 1348 Louvain-la-Neuve (Belgium); Martoiu, S.; Mazza, G. [INFN Sezione di Torino, 10125 Torino (Italy); Noy, M. [CERN, CH-1211 Geneva 23 (Switzerland); Petrucci, F. [INFN Sezione di Ferrara, 44100 Ferrara (Italy); Riedler, P. [CERN, CH-1211 Geneva 23 (Switzerland); Rivetti, A. [INFN Sezione di Torino, 10125 Torino (Italy); Tiuraniemi, S. [CERN, CH-1211 Geneva 23 (Switzerland)

    2010-12-11

    The beam spectrometer of the NA62 experiment, named Gigatracker, has to perform single track reconstruction with unprecedented time resolution (150 ps rms) in a harsh radiation environment. To meet these requirements, and in order to reduce material budget to a minimum, three hybrid silicon pixel detector stations will be installed in vacuum. An adequate strategy to compensate for the discriminator time-walk must be implemented and R and D investigating two different options is ongoing. Two read-out chip prototypes have been designed in order to compare their performance: one approach is based on the use of a constant-fraction discriminator followed by an on-pixel TDC, while the other one is based on the use of a time-over-threshold circuit followed by a TDC shared by a group of pixels. This paper describes the Gigatracker system, presents the global architectures of both read-out ASICs and reviews the current status of the R and D project.

  19. Radiation Tolerant Electronics and Digital Processing for the Phase-1 Read-out Upgrade of the ATLAS Liquid Argon Calorimeters

    Energy Technology Data Exchange (ETDEWEB)

    Milic, A. [Atlas Liquid Argon Calorimeter Group, CERN, Geneva (Switzerland)

    2015-07-01

    The ATLAS Liquid Argon calorimeters are designed and built to study proton-proton collisions produced at the LHC at centre-of-mass energies up to 14 TeV. Liquid argon (LAr) sampling calorimeters are employed for all electromagnetic calorimetry in the pseudorapidity region |η|<3.2, and for hadronic calorimetry in the region from |η|=1.5 to |η|=4.9. Although the nominal LHC experimental programme is still in progress, an upgrade of the read-out electronics is being launched to cope with luminosities of up to 3x10{sup 34} cm{sup -2}s{sup -1}, which are beyond the original design by a factor of 3. An improved spatial granularity of the trigger primitives is therefore proposed in order to improve the identification performance for trigger signatures, like electrons, photons, tau leptons, jets, total and missing energy, at high background rejection rates. For the upgrade Phase-1 in 2018, new LAr Trigger Digitizer Boards (LTDB) are being designed to receive higher granularity signals, digitize them on detector and send them via fast optical links to a new LAr digital processing system (LDPS). The LDPS applies a digital filtering and identifies significant energy depositions in each trigger channel. The refined trigger primitives are then transmitted to the first level trigger system to extract improved trigger signatures. The read-out of the trigger signals will process 34000 so-called Super Cells at every LHC bunch-crossing at a frequency of 40 MHz. The new LTDB on-detector electronics is designed to be radiation tolerant in order to be operated for the remaining live-time of the ATLAS detector up to a total luminosity of 3000 fb{sup -1}. For the analog-to-digital conversion (12-bit ADC at 40 MSPS), the data serialization and the fast optical link (5.44 Gb/s) custom components have been developed. They have been qualified for the expected radiation environment of a total ionization dose of 1.3 kGy and a hadron fluence of 6 x 10{sup 13} h/cm{sup 2} with energies above

  20. Interferometric detection of single gold nanoparticles calibrated against TEM size distributions

    DEFF Research Database (Denmark)

    Zhang, Lixue; Christensen, Sune; Bendix, Pól Martin

    2015-01-01

    Single nanoparticle analysis: An interferometric optical approach calibrates sizes of gold nanoparticles (AuNPs) from the interference intensities by calibrating their interferometric signals against the corresponding transmission electron microscopy measurements. This method is used to investigate...

  1. Analysis of read-out heating rate effects on the glow peaks of TLD-100 using WinGCF software

    Energy Technology Data Exchange (ETDEWEB)

    Bauk, Sabar, E-mail: sabar@usm.my [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Hussin, Siti Fatimah [School of Physics, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Alam, Md. Shah [Physics Section, School of Distance Education, Universiti Sains Malaysia, 11800 USM, Penang (Malaysia); Physics Department, Shahjalal University of Science and Technology, Sylhet (Bangladesh)

    2016-01-22

    This study was done to analyze the effects of the read-out heating rate on the LiF:Mg,Ti (TLD-100) thermoluminescent dosimeters (TLD) glow peaks using WinGCF computer software. The TLDs were exposed to X-ray photons with a potential difference of 72 kVp and 200 mAs in air and were read-out using a Harshaw 3500 TLD reader. The TLDs were read-out using four read-out heating rates at 10, 7, 4 and 1 °C s{sup −1}. It was observed that lowering the heating rate could separate more glow peaks. The activation energy for peak 5 was found to be lower than that for peak 4. The peak maximum temperature and the integral value of the main peak decreased as the heating rate decreases.

  2. CMOS Integrated Single Electron Transistor Electrometry (CMOS-SET) circuit design for nanosecond quantum-bit read-out.

    Energy Technology Data Exchange (ETDEWEB)

    Gurrieri, Thomas M.; Lilly, Michael Patrick; Carroll, Malcolm S.; Levy, James E.

    2008-08-01

    Novel single electron transistor (SET) read-out circuit designs are described. The circuits use a silicon SET interfaced to a CMOS voltage mode or current mode comparator to obtain a digital read-out of the state of the qubit. The design assumes standard submicron (0.35 um) CMOS SOI technology using room temperature SPICE models. Implications and uncertainties related to the temperature scaling of these models to 100mK operation are discussed. Using this technology, the simulations predict a read-out operation speed of approximately Ins and a power dissipation per cell as low as 2nW for single-shot read-out, which is a significant advantage over currently used radio frequency SET (RF-SET) approaches.

  3. A Prototype of the Read-out Subsystem of the BESⅢ DAQ Based on PowerPC

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    This article describes the prototype of the read-out subsystem which will be subject to the BESⅢ data acquisition system. According to the purpose of the BESⅢ, the event rate will be about 4000 Hz and the data rate up to 50 Mbytes/sec after Level 1 trigger. The read-out subsystem consists of some read-out crates and a read-out computer whose function is to initialize the hardware, to collect the event data from the front-end electronics after Level 1 trigger, to transfer data fragments to the computer in online form through two levels of computer pre-processing and high-speed network transmission. In this model, the crate level read-out implementation is based on the commercial single board computer MVME5100 running the VxWorks operating system.The article outlines the structure of the crate level testing platform of hardware and software. It puts emphasis on the framework of the read-out test model, data process flow and test method at crate level. Especially, it enumerates the key technologies in the process of design and analyses the test results. In addition, results which summarize the performance of the single board computer from the data transferring aspects will be presented.

  4. A Prototype of the Read-out Subsystem of the BESIII DAQ Based on PowerPC

    Science.gov (United States)

    Tao, Ning; Chu, Yuanping; Jin, Ge; Zhao, Jingwei

    2005-10-01

    This article describes the prototype of the read-out subsystem which will be subject to the BESIII data acquisition system. According to the purpose of the BESIII, the event rate will be about 4000 Hz and the data rate up to 50 Mbytes/sec after Level 1 trigger. The read-out subsystem consists of some read-out crates and a read-out computer whose function is to initialize the hardware, to collect the event data from the front-end electronics after Level 1 trigger, to transfer data fragments to the computer in online form through two levels of computer pre-processing and high-speed network transmission. In this model, the crate level read-out implementation is based on the commercial single board computer MVME5100 running the VxWorks operating system. The article outlines the structure of the crate level testing platform of hardware and software. It puts emphasis on the framework of the read-out test model, data process flow and test method at crate level. Especially, it enumerates the key technologies in the process of design and analyses the test results. In addition, results which summarize the performance of the single board computer from the data transferring aspects will be presented.

  5. A read-out system for the Medipix2 chip capable of 500 frames per second

    Energy Technology Data Exchange (ETDEWEB)

    Maiorino, M. [IFAE Institut de Fisica d' Altes Energies, UAB Campus, 08193 Barcelona (Spain)]. E-mail: maiorino@ifae.es; Martinez, R. [Centro Nacional de Microelectronica, IMB-CNM-CSIC, UAB Campus, 08193 Barcelona (Spain); Pellegrini, G. [Centro Nacional de Microelectronica, IMB-CNM-CSIC, UAB Campus, 08193 Barcelona (Spain); Blanchot, G. [IFAE Institut de Fisica d' Altes Energies, UAB Campus, 08193 Barcelona (Spain); Chmeissani, M. [IFAE Institut de Fisica d' Altes Energies, UAB Campus, 08193 Barcelona (Spain); Garcia, J. [IFAE Institut de Fisica d' Altes Energies, UAB Campus, 08193 Barcelona (Spain); Lozano, M. [Centro Nacional de Microelectronica, IMB-CNM-CSIC, UAB Campus, 08193 Barcelona (Spain); Puigdengoles, C. [IFAE Institut de Fisica d' Altes Energies, UAB Campus, 08193 Barcelona (Spain); Ullan, M. [Centro Nacional de Microelectronica, IMB-CNM-CSIC, UAB Campus, 08193 Barcelona (Spain)

    2006-07-01

    High-speed X-ray-imaging acquisition technique is a growing field that can be used to understand microscopic mechanism of different phenomena in biology and material science. IFAE and CNM developed a very high-speed readout system, named DEMAS, for the Medipix2. The system is able to read a single Medipix2 chip through the parallel bus at a rate of 1 kHz.With a duty cycle of 50%, the real sampling speed is 500 frames per second (fps). This implies that 1 ms is allocated to the exposure time and another millisecond is devoted to the read-out of the chip. In such configuration, the raw data throughput is about 500 Mbit/s. For the first time we present examples of acquisition at 500 fps of moving samples with X-rays working in direct capture and photon counting mode.

  6. Current feedback operational amplifiers as fast charge sensitive preamplifiers for photomultiplier read out

    Energy Technology Data Exchange (ETDEWEB)

    Giachero, A; Gotti, C; Maino, M; Pessina, G, E-mail: claudio.gotti@mib.infn.it [INFN - Sezione di Milano-Bicocca, I-20126, Milano (Italy)

    2011-05-01

    Fast charge sensitive preamplifiers were built using commercial current feedback operational amplifiers for fast read out of charge pulses from a photomultiplier tube. Current feedback opamps prove to be particularly well suited for this application where the charge from the detector is large, of the order of one million electrons, and high timing resolution is required. A proper circuit arrangement allows very fast signals, with rise times down to one nanosecond, while keeping the amplifier stable. After a review of current feedback circuit topology and stability constraints, we provide a 'recipe' to build stable and very fast charge sensitive preamplifiers from any current feedback opamp by adding just a few external components. The noise performance of the circuit topology has been evaluated and is reported in terms of equivalent noise charge.

  7. Current feedback operational amplifiers as fast charge sensitive preamplifiers for photomultiplier read out

    Science.gov (United States)

    Giachero, A.; Gotti, C.; Maino, M.; Pessina, G.

    2011-05-01

    Fast charge sensitive preamplifiers were built using commercial current feedback operational amplifiers for fast read out of charge pulses from a photomultiplier tube. Current feedback opamps prove to be particularly well suited for this application where the charge from the detector is large, of the order of one million electrons, and high timing resolution is required. A proper circuit arrangement allows very fast signals, with rise times down to one nanosecond, while keeping the amplifier stable. After a review of current feedback circuit topology and stability constraints, we provide a "recipe" to build stable and very fast charge sensitive preamplifiers from any current feedback opamp by adding just a few external components. The noise performance of the circuit topology has been evaluated and is reported in terms of equivalent noise charge.

  8. Distributed read-out imaging devices for x-ray imaging spectroscopy

    Science.gov (United States)

    den Hartog, Roland H.; Martin, Didier D.; Kozorezov, A. G.; Verhoeve, Peter; Rando, Nicola; Peacock, Anthony J.; Brammertz, G.; Krumrey, Michael K.; Goldie, D. J.; Venn, R.

    2000-07-01

    We present an experimental study of the performance of Distributed Read-Out Imaging Devices (DROIDs), 1- and 2-D photon-counting imaging spectrometers, based on Ta/Al-based STJs placed on a Ta absorber. Results obtained with highly collimated illumination with 10 keV X-ray photons clearly demonstrate the imaging capabilities of 2-D DROIDs. The derived spatial FWHM resolution is 7 micrometers for a 200 X 200 micrometers 2 absorber. With a 1-D DROID we have measured an intrinsic energy resolution of 15 eV FWHM for 6 keV photons. At high energies (E > 6 keV) the resolution is limited by spatial fluctuations in the qp recombination rate.

  9. High sensitivity phonon-mediated kinetic inductance detector with combined amplitude and phase read-out

    CERN Document Server

    Bellini, F; Casali, N; Castellano, M G; Colantoni, I; Cosmelli, C; Cruciani, A; D'Addabbo, A; Di Domizio, S; Martinez, M; Tomei, C; Vignati, M

    2016-01-01

    The development of wide-area cryogenic light detectors with good energy resolution is one of the priorities of next generation bolometric experiments searching for rare interactions, as the simultaneous read-out of the light and heat signals enables background suppression through particle identification. Among the proposed technological approaches for the phonon sensor, the naturally-multiplexed Kinetic Inductance Detectors (KIDs) stand out for their excellent intrinsic energy resolution and reproducibility. To satisfy the large surface requirement (several cm$^2$) KIDs are deposited on an insulating substrate that converts the impinging photons into phonons.A fraction of phonons is absorbed by the KID, producing a signal proportional to the energy of the original photons. The potential of this technique was proved by the CALDER project, that reached a baseline resolution of 154$\\pm$7 eV RMS by sampling a 2$\\times$2 cm$^2$ Silicon substrate with 4 Aluminum KIDs. In this paper we present a prototype of Aluminu...

  10. Study of the VMM1 read-out chip in a neutron irradiation environment

    Science.gov (United States)

    Alexopoulos, T.; Fanourakis, G.; Geralis, T.; Kokkoris, M.; Kourkoumeli-Charalampidi, A.; Papageorgiou, K.; Tsipolitis, G.

    2016-05-01

    Within 2015, the LHC operated close to the design energy of √s = 13-14 TeV delivering instantaneous luminosities up to Script L = 5 × 1033 cm-2s-1. The ATLAS Phase-I upgrade in 2018/19 will introduce the MicroMEGAS detectors in the area of the small wheel at the end caps. Accompanying new electronics are designed and built such as the VMM front end ASIC, which provides energy, timing and triggering information and allows fast data read-out. The first VMM version (VMM1) has been widely produced and tested in various test beams, whilst the second version (VMM2) is currently being tested. This paper focuses on the VMM1 single event upset studies and more specifically on the response of the configuration registers under harsh radiation environments. Similar conditions are expected at Run III with Script L = 2 × 1034 cm-2s-1 and a mean of 55 interactions per bunch crossing. Two VMM1s were exposed in a neutron irradiation environment using the TANDEM Van Der Graaff accelerator at NSCR Demokritos, Athens, Greece. The results showed a rate of SEU occurrences at a measured cross section of (4.1±0.8)×10-14 cm2/bit for each VMM. Consequently, when extrapolating this value to the luminosity expected in Run III, the occurrence is roughly 6 SEUs/min in all the read-out system comprising 40,000 VMMs installed during the Phase-I upgrade.

  11. Development of radiation tolerant monolithic active pixel sensors with fast column parallel read-out

    Science.gov (United States)

    Koziel, M.; Dorokhov, A.; Fontaine, J.-C.; De Masi, R.; Winter, M.

    2010-12-01

    Monolithic active pixel sensors (MAPS) [1] (Turchetta et al., 2001) are being developed at IPHC—Strasbourg to equip the EUDET telescope [2] (Haas, 2006) and vertex detectors for future high energy physics experiments, including the STAR upgrade at RHIC [3] (T.S. Collaboration, 2005) and the CBM experiment at FAIR/GSI [4] (Heuser, 2006). High granularity, low material budget and high read-out speed are systematically required for most applications, complemented, for some of them, with high radiation tolerance. A specific column-parallel architecture, implemented in the MIMOSA-22 sensor, was developed to achieve fast read-out MAPS. Previous studies of the front-end architecture integrated in this sensor, which includes in-pixel amplification, have shown that the fixed pattern noise increase consecutive to ionizing radiation can be controlled by means of a negative feedback [5] (Hu-Guo et al., 2008). However, an unexpected rise of the temporal noise was observed. A second version of this chip (MIMOSA-22bis) was produced in order to search for possible improvements of the radiation tolerance, regarding this type of noise. In this prototype, the feedback transistor was tuned in order to mitigate the sensitivity of the pixel to ionizing radiation. The performances of the pixels after irradiation were investigated for two types of feedback transistors: enclosed layout transistor (ELT) [6] (Snoeys et al., 2000) and "standard" transistor with either large or small transconductance. The noise performance of all test structures was studied in various conditions (expected in future experiments) regarding temperature, integration time and ionizing radiation dose. Test results are presented in this paper. Based on these observations, ideas for further improvement of the radiation tolerance of column parallel MAPS are derived.

  12. IRAN: interferometric remapped array nulling

    Science.gov (United States)

    Aristidi, Eric; Vakili, Farrokh; Abe, Lyu; Belu, Adrian; Lopez, Bruno; Lanteri, Henri; Schutz, A.; Menut, Jean-Luc

    2004-10-01

    This paper describes a method of beam-combination in the so-called hypertelescope imaging technique recently introduced by Labeyrie in optical interferometry. The method we propose is an alternative to the Michelson pupil reconfiguration that suffers from the loss of the classical object-image convolution relation. From elementary theory of Fourier optics we demonstrate that this problem can be solved by observing in a combined pupil plane instead of an image plane. The point-source intensity distribution (PSID) of this interferometric "image" tends towards a psuedo Airy disc (similar to that of a giant monolithic telescope) for a sufficiently large number of telescopes. Our method is applicable to snap-shot imaging of extended sources with a field comparable to the Airy pattern of single telescopes operated in a co-phased multi-aperture interferometric array. It thus allows to apply conveniently pupil plane coronagraphy. Our technique called Interferometric Remapped Array Nulling (IRAN) is particularly suitable for high dynamic imaging of extra-solar planetary companions, circumstellar nebulosities or extra-galactic objects where long baseline interferometry would closely probe the central regions of AGNs for instance.

  13. Compact all-optical interferometric logic gates based on one-dimensional metal-insulator-metal structures

    Science.gov (United States)

    Bian, Yusheng; Gong, Qihuang

    2014-02-01

    The whole set of fundamental all-optical logic gates is realized theoretically using a multi-channel configuration based on one-dimensional (1D) metal-insulator-metal (MIM) structures by leveraging the linear interference between surface plasmon polariton modes. The working principle and conditions for different logic functions are analyzed and demonstrated numerically by means of the finite element method. In contrast to most of the previous studies that require more than one type of configuration to achieve different logic functions, a single geometry with fixed physical dimensions can realize all fundamental functions in our case studies. It is shown that by switching the optical signals to different input channels, the presented device can realize simple logic functions such as OR, AND and XOR. By adding signal in the control channel, more functions including NOT, XNOR, NAND and NOR can be implemented. For these considered logic functions, high intensity contrast ratios between Boolean logic states "1" and "0" can be achieved at the telecom wavelength. The presented all-optical logic device is simple, compact and efficient. Moreover, the proposed scheme can be applied to many other nano-photonic logic devices as well, thereby potentially offering useful guidelines for their designs and further applications in on-chip optical computing and optical interconnection networks.

  14. Interferometric Motion Detection in Atomic Layer 2D Nanostructures: Visualizing Signal Transduction Efficiency and Optimization Pathways

    Science.gov (United States)

    Wang, Zenghui; Feng, Philip X.-L.

    2016-07-01

    Atomic layer crystals are emerging building blocks for enabling new two-dimensional (2D) nanomechanical systems, whose motions can be coupled to other attractive physical properties in such 2D systems. Optical interferometry has been very effective in reading out the infinitesimal motions of these 2D structures and spatially resolving different modes. To quantitatively understand the detection efficiency and its dependence on the device parameters and interferometric conditions, here we present a systematic study of the intrinsic motion responsivity in 2D nanomechanical systems using a Fresnel-law-based model. We find that in monolayer to 14-layer structures, MoS2 offers the highest responsivity among graphene, h-BN, and MoS2 devices and for the three commonly used visible laser wavelengths (633, 532, and 405 nm). We also find that the vacuum gap resulting from the widely used 300 nm-oxide substrate in making 2D devices, fortunately, leads to close-to-optimal responsivity for a wide range of 2D flakes. Our results elucidate and graphically visualize the dependence of motion transduction responsivity upon 2D material type and number of layers, vacuum gap, oxide thickness, and detecting wavelength, thus providing design guidelines for constructing 2D nanomechanical systems with optimal optical motion readout.

  15. Photodiode read-out of the ALICE photon spectrometer $PbWO_{4}$ crystals

    CERN Document Server

    Man'ko, V I; Sibiryak, Yu; Volkov, M; Klovning, A; Maeland, O A; Odland, O H; Rongved, R; Skaali, B

    1999-01-01

    Proposal of abstract for LEB99, Snowmass, Colorado, 20-24 September 1999The PHOton Spectrometer of the ALICE experiment is an electromagnetic calorimeter of high granularity consisting of 17280 lead-tungstate (PWO) crystals of dimensions 22x22x180 mm3, read out by large-area PIN-diodes with very low-noise front-end electronics. The crystal assembly is operated at -25C to increase the PWO light yield. A 16.1x17.1 mm2 photodiode, optimized for the PWO emissio spectrum at 400-500 nm, has been developed. The 20x20 mm2 preamplifier PCB is attached to the back side of the diode ceramic frame. The charge sensitive preamplifier is built in discrete logic with two input JFETs for optimum matching with the ~150pF PIN-diode. A prototype shaper has been designed and built in discrete logic. For a detector matrix of 64 units the measured ENCs are between 450-550e at -25C. Beam tests demonstrate that the required energy resolution is reached.Summary:The PHOton Spectrometer of the ALICE experiment is an electromagnetic calo...

  16. Systematic study of new types of Hamamatsu MPPCs read out with the NINO ASIC

    CERN Document Server

    Doroud, K; Williams, M C S; Yamamoto, K; Zichichi, A; Zuyeuski, R

    2014-01-01

    Over the last decade there have been commercial TOF-PET scanners constructed using Photo-Multiplier Tubes (PMT) that have achieved View the MathML source~500ps FWHM Coincidence Time Resolution (CTR). A new device known as the Silicon PhotoMultiplier (SiPM) has the potential to overcome some of the limitations of the PMT. Therefore implementing a SiPM based TOF-PET scanner is of high interest. Recently Philips has introduced a TOF-PET scanner that uses digital Silicon PhotoMultipliers (d-SiPMs) which has a CTR of 350 ps. Here we will report on the timing performance of two Hamamatsu 3×3 mm2 analogue-SiPMs read out with the NINO ASIC: this is an ultra-fast amplifier/discriminator with a differential architecture. The differential architecture is very important since the single-ended readout uses the ground as the signal return; as the ground is also the reference level for the discriminators, the result is high crosstalk and degraded time resolution. However differential readout allows the scaling up from a si...

  17. High sensitivity phonon-mediated kinetic inductance detector with combined amplitude and phase read-out

    Science.gov (United States)

    Cardani, L.; Casali, N.; Colantoni, I.; Cruciani, A.; Bellini, F.; Castellano, M. G.; Cosmelli, C.; D'Addabbo, A.; Di Domizio, S.; Martinez, M.; Tomei, C.; Vignati, M.

    2017-01-01

    Developing wide-area cryogenic light detectors with baseline resolution better than 20 eV is one of the priorities of next generation bolometric experiments searching for rare interactions, as the simultaneous read-out of the light and heat signals enables background suppression through particle identification. Among the proposed technological approaches for the phonon sensor, the naturally multiplexed Kinetic Inductance Detectors (KIDs) stand out for their excellent intrinsic energy resolution and reproducibility. The potential of this technique was proved by the CALDER project that reached a baseline resolution of 154 ± 7 eV RMS by sampling a 2 × 2 cm2 Silicon substrate with 4 Aluminum KIDs. In this paper, we present a prototype of Aluminum KID with improved geometry and quality factor. The design improvement, as well as the combined analysis of amplitude and phase signals, allowed to reach a baseline resolution of 82 ± 4 eV by sampling the same substrate with a single Aluminum KID.

  18. Prototyping the read-out chain of the CBM Microvertex Detector

    Science.gov (United States)

    Klaus, P.; Wiebusch, M.; Amar-Youcef, S.; Deveaux, M.; Koziel, M.; Michel, J.; Milanovic, B.; Müntz, C.; Tischler, T.; Stroth, J.

    2016-03-01

    The Compressed Baryonic Matter (CBM) Experiment at the future FAIR (Darmstadt/Germany) will study the phase diagram of hadronic matter in the regime of highest net-baryon densities. The fixed target experiment will explore the nuclear fireballs created in violent heavy ion reactions with a rich number of probes. To reconstruct the decay topologies of open-charm particles as well as to track low-momentum particles, an ultra-light and precise Microvertex Detector (MVD) is required. The necessary performance in terms of spatial resolution, material budget and rate capability will be reached by equipping the MVD with highly granular, radiation-hard CMOS Monolithic Active Pixel Sensors (CPS) developped at IPHC Strasbourg, which are operated in the target vacuum of the experiment. This contribution introduces the concept of the MVD and puts a focus on the latest results obtained from the R&D of the electronics and read-out chain of the device. Moreover, we briefly introduce the PRESTO project, which realises a prototype of a full size quadrant of an MVD detector station.

  19. Efficiency and timing resolution of scintillator tiles read out with silicon photomultipliers

    Science.gov (United States)

    Pooth, O.; Weingarten, S.; Weinstock, L.

    2016-01-01

    Silicon photomultipliers (SiPM) are semiconductor photo sensors that have the potential to replace photomultiplier tubes (PMT) in various fields of application. We present detectors consisting of 30 × 30 × 0.5 cm3 fast plastic scintillator tiles read out with SiPMs. The detectors offer great electronic and mechanical advantages over the classical PMT-scintillator combination. SiPMs are very compact devices that run independent of magnetic fields at low voltages and no light guides between the scintillator and the SiPM are necessary in the presented layouts. Three prototypes, two of which with integrated wavelength shifting fibres, have been tested in a proton beam at the COSY accelerator at Forschungszentrum Jülich. The different layouts are compared in terms of most probable pulse height, detection efficiency and noise behaviour as well as timing resolution. The spatial distributions of these properties across the scintillator surface are presented. The best layout can be operated at a mean efficiency of bar epsilon=99.9 % while sustaining low noise rates in the order of 10 Hz with a timing resolution of less than 3 ns. Both efficiency and timing resolution show good spatial homogeneity.

  20. Firmware development and testing of the ATLAS IBL Read-Out Driver card

    CERN Document Server

    Chen, S-P; The ATLAS collaboration; Falchieri, D; Gabrielli, A; Hauck, S; Hsu, S-C; Kretz, M; Kugel, A; Travaglini, R; Wensing, M

    2014-01-01

    The ATLAS Experiment is reworking and upgrading systems during the current LHC shutdown. In particular, the Pixel detector is inserting an additional inner layer called Insertable B-Layer (IBL). The Read-Out Driver card (ROD), the Back-of-Crate card (BOC), and the S-Link together form the essential frontend data path of the IBL’s off-detector DAQ system. The strategy for IBL ROD firmware development focused on migrating and tailoring HDL code blocks from Pixel ROD to ensure modular compatibility in future ROD upgrades, in which a unified code version will interface with IBL and Pixel layers. Essential features such as data formatting, frontend-specific error handling, and calibration are added to the ROD data path. An IBL DAQ testbench using a realistic frontend chip model was created to serve as an initial framework for full offline electronic system simulation. In this document, major firmware achievements concerning the IBL ROD data path implementation, tested in testbench and on ROD prototypes, will be ...

  1. Scintillating fiber detectors for precise time and position measurements read out with Si-PMs

    Science.gov (United States)

    Damyanova, A.; Bravar, A.

    2017-02-01

    We present the development and performance of compact scintillating fiber detectors read out with silicon photo-multipliers (Si-PMs). The compact size, fast response, and insensitivity to magnetic fields make these detectors suitable for a variety of applications where precise tracking and timing information is required. These detectors will be used with different particle beams (electrons, protons, heavy ions) at very high rates. In particular, we present the SciFi tracker/time of flight detector that is being developed for the Mu3e experiment at PSI (search for the lepton flavor violating decay μ → eee at very high rates). We also present the SciFi beam position detectors that will be employed in NA61 at CERN to track the incoming proton and heavy ion beam particles. We are considering different readout scenarios in which (a) each fiber is individually coupled to a single Si-PM photo-sensor and (b) fibers are arranged in columns and coupled to a Si-PM arrays.

  2. Studies of Read-Out Electronics and Trigger for Muon Drift Tube Detectors at High Luminosities

    CERN Document Server

    Nowak, Sebastian

    The Large Hadron Collider (LHC) at the European Centre for Particle Physics, CERN, collides protons with an unprecedentedly high centre-of-mass energy and luminosity. The collision products are recorded and analysed by four big experiments, one of which is the ATLAS detector. For precise measurements of the properties of the Higgs-Boson and searches for new phenomena beyond the Standard Model, the LHC luminosity of $L=10^{34}cm^{-2}s^{-1}$ is planned to be increased by a factor of ten leading to the High Luminosity LHC (HL-LHC). In order to cope with the higher background and data rates, the LHC experiments need to be upgraded. In this thesis, studies for the upgrade of the ATLAS Muon Spectrometer are presented with respect to the read-out electronics of the Monitored Drift Tube (MDT) and the small-diameter Muon Drift Tube (sMDT) chambers and the Level-1 muon trigger. Due to the reduced tube diameter of sMDT chambers, background occupancy and space charge effects are suppressed by an order of magnitude compar...

  3. Remembering words in context as predicted by an associative read-out model.

    Science.gov (United States)

    Hofmann, Markus J; Kuchinke, Lars; Biemann, Chris; Tamm, Sascha; Jacobs, Arthur M

    2011-01-01

    Interactive activation models (IAMs) simulate orthographic and phonological processes in implicit memory tasks, but they neither account for associative relations between words nor explicit memory performance. To overcome both limitations, we introduce the associative read-out model (AROM), an IAM extended by an associative layer implementing long-term associations between words. According to Hebbian learning, two words were defined as "associated" if they co-occurred significantly often in the sentences of a large corpus. In a study-test task, a greater amount of associated items in the stimulus set increased the "yes" response rates of non-learned and learned words. To model test-phase performance, the associative layer is initialized with greater activation for learned than for non-learned items. Because IAMs scale inhibitory activation changes by the initial activation, learned items gain a greater signal variability than non-learned items, irrespective of the choice of the free parameters. This explains why the slope of the z-transformed receiver-operating characteristics (z-ROCs) is lower one during recognition memory. When fitting the model to the empirical z-ROCs, it likewise predicted which word is recognized with which probability at the item-level. Since many of the strongest associates reflect semantic relations to the presented word (e.g., synonymy), the AROM merges form-based aspects of meaning representation with meaning relations between words.

  4. The ATLAS ReadOut System—Performance with first data and perspective for the future

    Science.gov (United States)

    Crone, G.; Della Volpe, D.; Gorini, B.; Green, B.; Joos, M.; Kieft, G.; Kordas, K.; Kugel, A.; Misiejuk, A.; Schroer, N.; Teixeira-Dias, P.; Tremblet, L.; Vermeulen, J.; Wickens, F.; Werner, P.

    2010-11-01

    The ATLAS ReadOut System (ROS) receives data fragments from ∼ 1600 detector readout links, buffers them and provides them on demand to the second-level trigger or to the event building system. The ROS is implemented with ∼ 150 PCs. Each PC houses a few, typically 4, custom-built PCI boards (ROBIN) and a 4-port PCIe Gigabit Ethernet NIC. The PCs run a multi-threaded object-oriented application managing the requests for data retrieval and for data deletion coming through the NIC, and the collection and output of data from the ROBINs. At a nominal event fragment arrival rate of 75 kHz the ROS has to concurrently service up to approximately 20 kHz of data requests from the second-level trigger and up to 3.5 kHz of requests from event building nodes. The full system has been commissioned in 2007. Performance of the system in terms of stability and reliability, results of laboratory rate capability measurements and upgrade scenarios are discussed in this paper.

  5. The ATLAS ReadOut System performance with first data and perspective for the future

    CERN Document Server

    Crone, G; Gorini, B; Green, B; Joos, M; Kieft, G; Kordas, K; Kugel, A; Misiejuk, A; Schroer, N; Teixeira-Dias, P; Tremblet, L; Vermeulen, J; Wickens, F; Werner, P

    2010-01-01

    The ATLAS ReadOut System (ROS) receives data fragments from ~1600 detector readout links, buffers them and provides them on demand to the second-level trigger or to the event building system. The ROS is implemented with ~150 PCs. Each PC houses a few, typically 4, custom-built PCI boards (ROBIN) and a 4-port PCIe Gigabit Ethernet NIC. The PCs run a multi-threaded object-oriented application managing the requests for data retrieval and for data deletion coming through the NIC, and the collection and output of data from the ROBINs. At a nominal event fragment arrival rate of 75 kHz the ROS has to concurrently service up to approximately 20 kHz of data requests from the second-level trigger and up to 3.5 kHz of requests from event building nodes. The full system has been commissioned in 2007. Performance of the system in terms of stability and reliability, results of laboratory rate capability measurements and upgrade scenarios are discussed in this paper.

  6. MCP detector read out with a bare quad Timepix at kilohertz frame rates

    Science.gov (United States)

    Vallerga, J.; Raffanti, R.; Tremsin, A.; McPhate, J.; Siegmund, O.

    2011-01-01

    The existing Berkeley neutron sensitive MCP/Timepix hybrid detector has been very successful at demonstrating energy resolved spatial imaging with a single Timepix ASIC read out at a ~ 30 Hz frame rate where each neutron's position and time (energy) is determined (X,Y,E). By increasing the detector format using a quad arrangement of Timepix readouts and increasing the frame rate to 1 kHz, we can increase our total event throughput by a factor of 120, thereby taking full advantage of the high fluxes of modern pulsed neutron sources (106 n cm-2 s-1). The key to this conversion is a new design for the ASIC readout, called the Berkeley Quad Timepix detector, consisting of 3 major subsystems. The first is a quad (2 × 2) bare Timepix ASIC board mounted directly behind the neutron sensitive MCPs in a hermetic vacuum enclosure with a sapphire window. The data from the Timepix ASICs flow to the second subsystem called the Interface board whose field programmable gate array (FPGA) rearranges and converts the digital bit stream to LVDS logic levels before sending downstream to the third subsystem, the Roach board. The Roach board is also FPGA based, and takes the data from all the ASICs and analyses the frames to extract information on the input events to pass on to the host PC. This paper describes in detail the hardware and firmware designs to accomplish this task.

  7. Systematic study of new types of Hamamatsu MPPCs read out with the NINO ASIC

    Energy Technology Data Exchange (ETDEWEB)

    Doroud, K. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); Rodriguez, A. [CERN, Geneva (Switzerland); ICSC World Laboratory, Geneva (Switzerland); Williams, M.C.S., E-mail: crispin.williams@cern.ch [CERN, Geneva (Switzerland); INFN and Dipartimento di Fisica e Astronomia, Università di Bologna (Italy); Yamamoto, K. [Solid State Division, Hamamatsu Photonics K.K., Hamamatsu (Japan); Zichichi, A. [Museo Storico della Fisica e Centro Studi e Ricerche E. Fermi, Roma (Italy); CERN, Geneva (Switzerland); INFN and Dipartimento di Fisica e Astronomia, Università di Bologna (Italy); Zuyeuski, R. [CERN, Geneva (Switzerland); ICSC World Laboratory, Geneva (Switzerland)

    2014-07-01

    Over the last decade there have been commercial TOF-PET scanners constructed using Photo-Multiplier Tubes (PMT) that have achieved ∼500ps FWHM Coincidence Time Resolution (CTR). A new device known as the Silicon PhotoMultiplier (SiPM) has the potential to overcome some of the limitations of the PMT. Therefore implementing a SiPM based TOF-PET scanner is of high interest. Recently Philips has introduced a TOF-PET scanner that uses digital Silicon PhotoMultipliers (d-SiPMs) which has a CTR of 350 ps. Here we will report on the timing performance of two Hamamatsu 3×3 mm{sup 2} analogue-SiPMs read out with the NINO ASIC: this is an ultra-fast amplifier/discriminator with a differential architecture. The differential architecture is very important since the single-ended readout uses the ground as the signal return; as the ground is also the reference level for the discriminators, the result is high crosstalk and degraded time resolution. However differential readout allows the scaling up from a single cell to a multi-cell device with no loss of time resolution; this becomes increasingly important for the highly segmented detectors that are being built today, both for particle and for medical instrumentation. We obtained excellent results for both the Single Photon Time Resolution (SPTR) and for the CTR using a LYSO crystal of 15 mm length. Such a crystal length has sufficient detection efficiency for 511 keV gammas to make an excellent PET device. The results presented here are proof that a TOF-PET detector with a CTR of 175 ps is indeed possible. This is the first step that defines the starting point of our SuperNINO project.

  8. A finite state machine read-out chip for integrated surface acoustic wave sensors

    Science.gov (United States)

    Rakshit, Sambarta; Iliadis, Agis A.

    2015-01-01

    A finite state machine based integrated sensor circuit suitable for the read-out module of a monolithically integrated SAW sensor on Si is reported. The primary sensor closed loop consists of a voltage controlled oscillator (VCO), a peak detecting comparator, a finite state machine (FSM), and a monolithically integrated SAW sensor device. The output of the system oscillates within a narrow voltage range that correlates with the SAW pass-band response. The period of oscillation is of the order of the SAW phase delay. We use timing information from the FSM to convert SAW phase delay to an on-chip 10 bit digital output operating on the principle of time to digital conversion (TDC). The control inputs of this digital conversion block are generated by a second finite state machine operating under a divided system clock. The average output varies with changes in SAW center frequency, thus tracking mass sensing events in real time. Based on measured VCO gain of 16 MHz/V our system will convert a 10 kHz SAW frequency shift to a corresponding mean voltage shift of 0.7 mV. A corresponding shift in phase delay is converted to a one or two bit shift in the TDC output code. The system can handle alternate SAW center frequencies and group delays simply by adjusting the VCO control and TDC delay control inputs. Because of frequency to voltage and phase to digital conversion, this topology does not require external frequency counter setups and is uniquely suitable for full monolithic integration of autonomous sensor systems and tags.

  9. High performance digital read out integrated circuit (DROIC) for infrared imaging

    Science.gov (United States)

    Mizuno, Genki; Olah, Robert; Oduor, Patrick; Dutta, Achyut K.; Dhar, Nibir K.

    2016-05-01

    Banpil Photonics has developed a high-performance Digital Read-Out Integrated Circuit (DROIC) for image sensors and camera systems targeting various military, industrial and commercial Infrared (IR) imaging applications. The on-chip digitization of the pixel output eliminates the necessity for an external analog-to-digital converter (ADC), which not only cuts costs, but also enables miniaturization of packaging to achieve SWaP-C camera systems. In addition, the DROIC offers new opportunities for greater on-chip processing intelligence that are not possible in conventional analog ROICs prevalent today. Conventional ROICs, which typically can enhance only one high performance attribute such as frame rate, power consumption or noise level, fail when simultaneously targeting the most aggressive performance requirements demanded in imaging applications today. Additionally, scaling analog readout circuits to meet such requirements leads to expensive, high-power consumption with large and complex systems that are untenable in the trend towards SWaP-C. We present the implementation of a VGA format (640x512 pixels 15μm pitch) capacitivetransimpedance amplifier (CTIA) DROIC architecture that incorporates a 12-bit ADC at the pixel level. The CTIA pixel input circuitry has two gain modes with programmable full-well capacity values of 100K e- and 500K e-. The DROIC has been developed with a system-on-chip architecture in mind, where all the timing and biasing are generated internally without requiring any critical external inputs. The chip is configurable with many parameters programmable through a serial programmable interface (SPI). It features a global shutter, low power, and high frame rates programmable from 30 up 500 frames per second in full VGA format supported through 24 LVDS outputs. This DROIC, suitable for hybridization with focal plane arrays (FPA) is ideal for high-performance uncooled camera applications ranging from near IR (NIR) and shortwave IR (SWIR) to mid

  10. Note: Near infrared interferometric silicon wafer metrology.

    Science.gov (United States)

    Choi, M S; Park, H M; Joo, K N

    2016-04-01

    In this investigation, two near infrared (NIR) interferometric techniques for silicon wafer metrology are described and verified with experimental results. Based on the transparent characteristic of NIR light to a silicon wafer, the fiber based spectrally resolved interferometry can measure the optical thickness of the wafer and stitching low coherence scanning interferometry can reconstruct entire surfaces of the wafer.

  11. An interferometric study of the post-AGB binary 89 Herculis I Spatially resolving the continuum circumstellar environment at optical and near-IR wavelengths with the VLTI, NPOI, IOTA, PTI, and the CHARA Array

    CERN Document Server

    Hillen, M; Van Winckel, H; Chesneau, O; Hummel, C A; Monnier, J D; Farrington, C; Tycner, C; Mourard, D; Brummelaar, T ten; Banerjee, D P K; Zavala, R T

    2013-01-01

    Binary post-AGB stars are interesting laboratories to study both the evolution of binaries as well as the structure of circumstellar disks. A multiwavelength high angular resolution study of the prototypical object 89 Herculis is performed with the aim of identifying and locating the different emission components seen in the SED. A large interferometric data set, collected over the past decade and covering optical and near-IR wavelengths, is analyzed with simple geometric models. Combining the interferometric constraints with the photometry and the optical spectra, we reassess the energy budget of the post-AGB star and its circumstellar environment. We report the first (direct) detection of a large (35-40%) optical circumstellar flux contribution and spatially resolve its emission region. Given this large amount of reprocessed and/or redistributed optical light, the fitted size of the emission region is rather compact and fits with(in) the inner rim of the circumbinary dust disk. This rim dominates our K band...

  12. Added value of IP-10 as a read-out of Mycobacterium tuberculosis

    DEFF Research Database (Denmark)

    Jenum, Synne; Dhanasekaran, Sivmakumaran; Ritz, Christian

    2016-01-01

    We have explored the added value of IFNγ-inducible protein 10 as a read-out of Mycobacterium tuberculosis specific immunity in young Indian children where the sensitivity of the IGRA for tuberculosis (TB) is poor. Reduced frequency of indeterminate results and an increased sensitivity for TB, sug...

  13. A flexible COME and KISS QDC and TDC read-out scheme for PMT, MAPD and diamond detector applications

    Energy Technology Data Exchange (ETDEWEB)

    Rost, Adrian [Technische Universitaet Darmstadt, Darmstadt (Germany); Collaboration: HADES-Collaboration

    2015-07-01

    A flexible COME and KISS Charge-to-Digital-Converter (QDC) and Time-to-Digital-Converter (TDC) read-out scheme will be presented which can be used in a wide range of read-out applications in high energy physics experiments. The focus is on a calorimeter detector read-out via photomultiplier tubes (PMTs) or via multi-pixel avalanche photo-diodes (MAPDs), as well as on diamond detectors for the HADES and CBM experiments at the future FAIR facility in Darmstadt. The detector input signals are integrated with the help of simple analogue electronics (KISS: Keep it Small and Simple). Afterwards the charge measurement is transformed into a Time-over-Threshold (ToT) measurement using an commercial (COME: Use Commercial Elements) FPGA as a discriminator. The well-established TRBv3 platform will provide a precise FPGA TDC for a ToT measurement of the discriminated signals. An 8-channel prototype board PaDiWa-AMPS was manufactured and successfully tested in the laboratory and under beam conditions. In this contribution the current status of the read-out concept is shown.

  14. Study and simulation of the read-out electronics design for a high-resolution plastic scintillating fiber based hodoscope

    Energy Technology Data Exchange (ETDEWEB)

    Blasco, José María, E-mail: jose.maria.blasco@uv.es [Universitat de València, Calle Gascó Oliag n" o5, 46010, Valencia (Spain); Sanchis, E. [Universitat de València, Calle Gascó Oliag n" o5, 46010, Valencia (Spain); Granero, D. [Eresa Grupo Médico (Spain); Martín, J.D.; González, V.; Sanchis-Sánchez, E. [Universitat de València, Calle Gascó Oliag n" o5, 46010, Valencia (Spain)

    2015-06-01

    Highlights: • Plastic Scintillating Fibers for high-resolution hodoscopy. • Silicon photodiode read-out electronics design. • Plastic scintillating fibers coupled to Silicon photodiodes read-out. • Charged particle detection with plastic scintillating fibers. - Abstract: This work presents the study and simulation of a high-resolution charged particle detection device for beam positioning, monitoring and calibration, together with its read-out proposal. To provide the precise positional information of the beam, the detection system has been based on Plastic Scintillating Fibers (PSF), while the read-out on a Silicon-PhotoDiode (Si-PD) array. To carry out the study, a PSF prototype with one detection plane has been experimentally tested with a β particle source. Besides, Monte Carlo simulations of the complete system have also been conducted. Both simulations and experimental tests give consistency to the results obtained. The work presented in this article show the usefulness of this proposal for high-precision charged particle positioning, achieving resolutions up to 100 µm.

  15. Measured Temperature Dependence of Scintillation Camera Signals Read Out by Geiger–Müller Mode Avalanche Photodiodes

    Science.gov (United States)

    Hunter, William C. J.; Miyaoka, Robert S.; MacDonald, L. R.; Lewellen, Thomas K.

    2010-01-01

    We are developing a prototype monolithic scintillation camera with optical sensors on the entrance surface (SES) for use with statistically-estimated depth-of-interaction in a continuous scintillator. We opt to use Geiger-Müller mode avalanche photodiodes (GM-APDs) for the SES camera since they possess many desirable properties; for the intended application (SES and PET/MR imaging), they offer a thin attenuation profile and an operational insensitivity to large magnetic fields. However, one issue that must be addressed in using GM-APDs in an RF environment (as in MR scanners) is the thermal dissipation that can occur in this semiconductor material. Signals of GM-APDs are strongly dependent on junction temperature. Consequently, we are developing a temperature-controlled GM-APD-based PET camera whose monitored temperature can be used to dynamically account for the temperature dependence of the output signals. Presently, we aim to characterize the output-signal dependence on temperature and bias for a GM-APD-based scintillation camera. We've examined two GM-APDs, a Zecotek prototype MAPD-3N, and a SensL commercial SPMArray2. The dominant effect of temperature on gain that we observe results from a linear dependence of breakdown voltage on temperature (0.071 V/°C and 0.024 V/°C, respectively); at 2.3 V excess bias (voltage above breakdown) the resulting change in gain with temperature (without adjusting bias voltage) is −8.5% per °C for the MAPD-3N and −1.5 % per °C for the SPMArray2. For fixed excess bias, change in dark current with temperature varied widely, decreasing by 25% to 40% as temperature was changed from 20 °C to 10 °C and again by 20% to 35% going from 10 °C to 0 °C. Finally, using two MAPD-3N to read out a pair of 3.5-by-3.5-by-20 mm3 Zecotek LFS-3 scintillators in coincidence, we observe a decrease from 1.7 nsec to 1.5 nsec in coincidence-time resolution as we lowered temperature from 23 °C to 10 °C. PMID:20625461

  16. Measured Temperature Dependence of Scintillation Camera Signals Read Out by Geiger-Müller Mode Avalanche Photodiodes.

    Science.gov (United States)

    Hunter, William C J; Miyaoka, Robert S; Macdonald, L R; Lewellen, Thomas K

    2009-10-24

    We are developing a prototype monolithic scintillation camera with optical sensors on the entrance surface (SES) for use with statistically-estimated depth-of-interaction in a continuous scintillator. We opt to use Geiger-Müller mode avalanche photodiodes (GM-APDs) for the SES camera since they possess many desirable properties; for the intended application (SES and PET/MR imaging), they offer a thin attenuation profile and an operational insensitivity to large magnetic fields. However, one issue that must be addressed in using GM-APDs in an RF environment (as in MR scanners) is the thermal dissipation that can occur in this semiconductor material.Signals of GM-APDs are strongly dependent on junction temperature. Consequently, we are developing a temperature-controlled GM-APD-based PET camera whose monitored temperature can be used to dynamically account for the temperature dependence of the output signals. Presently, we aim to characterize the output-signal dependence on temperature and bias for a GM-APD-based scintillation camera.We've examined two GM-APDs, a Zecotek prototype MAPD-3N, and a SensL commercial SPMArray2. The dominant effect of temperature on gain that we observe results from a linear dependence of breakdown voltage on temperature (0.071 V/°C and 0.024 V/°C, respectively); at 2.3 V excess bias (voltage above breakdown) the resulting change in gain with temperature (without adjusting bias voltage) is -8.5% per °C for the MAPD-3N and -1.5 % per °C for the SPMArray2. For fixed excess bias, change in dark current with temperature varied widely, decreasing by 25% to 40% as temperature was changed from 20 °C to 10 °C and again by 20% to 35% going from 10 °C to 0 °C. Finally, using two MAPD-3N to read out a pair of 3.5-by-3.5-by-20 mm(3) Zecotek LFS-3 scintillators in coincidence, we observe a decrease from 1.7 nsec to 1.5 nsec in coincidence-time resolution as we lowered temperature from 23 °C to 10 °C.

  17. Test of Ultra Fast Silicon Detectors for picosecond time measurements with a new multipurpose read-out board

    Science.gov (United States)

    Minafra, N.; Al Ghoul, H.; Arcidiacono, R.; Cartiglia, N.; Forthomme, L.; Mulargia, R.; Obertino, M.; Royon, C.

    2017-09-01

    Ultra Fast Silicon Detectors (UFSD) are sensors optimized for timing measurements employing a thin multiplication layer to increase the output signal. A multipurpose read-out board hosting a low-cost, low-power fast amplifier was designed at the University of Kansas and tested at the European Organization for Nuclear Research (CERN) using a 180 GeV pion beam. The amplifier has been designed to read out a wide range of detectors and it was optimized in this test for the UFSD output signal. In this paper we report the results of the experimental tests using 50 μm thick UFSD with a sensitive area of 1 . 4mm2. A timing precision below 30 ps was achieved.

  18. Study and simulation of the read-out electronics design for a high-resolution plastic scintillating fiber based hodoscope

    Science.gov (United States)

    Blasco, José María; Sanchis, E.; Granero, D.; Martín, J. D.; González, V.; Sanchis-Sánchez, E.

    2015-06-01

    This work presents the study and simulation of a high-resolution charged particle detection device for beam positioning, monitoring and calibration, together with its read-out proposal. To provide the precise positional information of the beam, the detection system has been based on Plastic Scintillating Fibers (PSF), while the read-out on a Silicon-PhotoDiode (Si-PD) array. To carry out the study, a PSF prototype with one detection plane has been experimentally tested with a β particle source. Besides, Monte Carlo simulations of the complete system have also been conducted. Both simulations and experimental tests give consistency to the results obtained. The work presented in this article show the usefulness of this proposal for high-precision charged particle positioning, achieving resolutions up to 100 μm.

  19. Validation of the Read Out Electronics for the CMS Muon Drift Chambers at Tests Beam in CERN/GIF

    CERN Document Server

    Fernández, C; Fouz-Iglesias, M C; Marin, J; Oller, J C; Willmott, C

    2002-01-01

    Part of the readout system for the CMS muon drift chambers has been tested in test beams at CERN/GIF. Read Out Board (ROB) and HPTD have been validated with signals from a real muon beam, with an structure and flux similar to LHC operating conditions and using one of the chambers produced in CIEMAT already located in the test beam area under normal gas and voltage conditions. (Author) 5 refs.

  20. A time resolution study with a plastic scintillator read out by a Geiger-mode Avalanche Photodiode

    Science.gov (United States)

    Stoykov, A.; Scheuermann, R.; Sedlak, K.

    2012-12-01

    In this work we attempt to establish the best time resolution attainable with a scintillation counter consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode. The measured time resolution is inversely proportional to the square root of the energy deposited in the scintillator, and scales to σ=18 ps at 1 MeV. This result competes with the best ones reported for photomultiplier tubes.

  1. A time resolution study with a plastic scintillator read out by a Geiger-mode Avalanche Photodiode

    Energy Technology Data Exchange (ETDEWEB)

    Stoykov, A., E-mail: alexey.stoykov@psi.ch [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Scheuermann, R.; Sedlak, K. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2012-12-11

    In this work we attempt to establish the best time resolution attainable with a scintillation counter consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode. The measured time resolution is inversely proportional to the square root of the energy deposited in the scintillator, and scales to {sigma}=18ps at 1 MeV. This result competes with the best ones reported for photomultiplier tubes.

  2. A time-resolution study with a plastic scintillator read out by a Geiger-mode Avalanche Photodiode

    CERN Document Server

    Stoykov, A; Sedlak, K

    2011-01-01

    In this work we attempt to establish the best time resolution attainable with a scintillation counter consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode. The measured time resolution is inversely proportional to the square root of the energy deposited in the scintillator, and scales to 18ps (sigma) at 1MeV. This result competes with the best ones reported for photomultiplier tubes.

  3. Charge collection and charge sharing in heavily irradiated n-side read-out silicon microstrip detectors

    Energy Technology Data Exchange (ETDEWEB)

    Casse, G. E-mail: gcasse@hep.ph.liv.ac.uk; Allport, P.P.; Biagi, S.F.; Bowcock, T.J.V.; Greenall, A.; Turner, P.R

    2003-09-21

    Hadron radiation damage of n-bulk silicon detectors leads to a change in the effective space charge from positive to negative. This effect is called type inversion. Type inversion occurs after exposure to a fluence of a few 10{sup 13} proton cm{sup -2} and is characterized by migration of the diode junction to the n{sup +} implanted side (n-side) of the detector. After inversion the charge collection efficiency (CCE) of segmented detectors at low voltage is higher when the n-side, rather than the p-side, is read out. A p-side read out (p-in-n) and an n-side read out (n-in-n) strip detector with identical strip geometry and a wafer thickness of 200 {mu}m were simultaneously and inhomogenously irradiated to a maximum fluence of 7x10{sup 14} proton cm{sup -2} with 24 GeV c{sup -1} protons. A comparison of the CCE at very high irradiation doses is shown with these two read out geometries. The inhomogeneous irradiation induces an inhomogenous distribution of the effective space charge with a transverse component of the electric field that could in principle affect the resolution properties of the microstrip detector. The inter-strip charge sharing properties, as a function of dose, for the n-in-n detector have been measured. No systematic distortion of the reconstructed cluster position was detected within the limits of the measurement accuracy. The detectors were manufactured using oxygen enriched silicon substrates to limit the degradation of the full depletion voltage under charged hadron irradiation. The measured CCE confirms that the use of oxygenated n-in-n detectors is viable up to fluences of 7x10{sup 14} proton cm{sup -2}.

  4. Read-out and coherent manipulation of an isolated nuclear spin using a single-molecule magnet spin-transistor

    OpenAIRE

    Thiele, Stefan

    2014-01-01

    The realization of a functional quantum computer is one of the most ambitious technologically goals of today's scientists. Its basic building block is composed of a two-level quantum system, namely a quantum bit (or qubit). Among the other existing concepts, spin based devices are very attractive since they benefit from the steady progress in nanofabrication and allow for the electrical read-out of the qubit state. In this context, nuclear spin based devices exhibit an additional gain of cohe...

  5. Resolution and Efficiency of Monitored Drift-Tube Chambers with Final Read-out Electronics at High Background Rates

    CERN Document Server

    Dubbert, J; Kortner, O; Kroha, H; Manz, A; Mohrdieck-Möck, S; Rauscher, F; Richter, R; Staude, A; Stiller, W

    2003-01-01

    The performance of a monitored drift-tube chamber for ATLAS with the final read-out electronics was tested at the Gamma Irradiation facility at CERN under varyin photon irradiation rates of up to 990~Hz\\,cm$^{-2}$ which corresponds to 10 times the highest background rate expected in ATLAS. The signal pulse-height measurement of the final read-out electronics was used to perform time-slewing corrections. The corrections improve the average single-tube resolution from 106~$\\mu$m to 89~$\\mu$m at the nominal discriminator threshold of 44~mV without irradiation, and from 114~$\\mu$m to 89~$\\mu$m at the maximum nominal irradiation rate in ATLAS of 100~Hz\\,cm$^{-2}$. The reduction of the threshold from 44~mV to 34~mV and the time-slewing corrections lead to an average single-tube resolution of 82~$\\mu$m without photon background and of 89~$\\mu$m at 100~Hz\\,cm$^{-2}$. The measured muon detection efficiency agrees with the expectation for the final read-out electronics.

  6. Design, construction, quality checks and test results of first resistive-Micromegas read-out boards for the ATLAS experiment

    CERN Document Server

    Iengo, Paolo; The ATLAS collaboration

    2015-01-01

    The development work carried out at CERN to push the Micromegas technology to a new frontier is now coming to an end. The construction of the first read-out boards for the upgrade of the ATLAS muon system will demonstrate in full-scale the feasibility of this ambitious project. The read-out boards, representing the heart of the detector, are manufactured in industries, making the Micromegas for ATLAS the first MPGD for a large experiment with a relevant part industrially produced. The boards are 50 cm wide and up to 220 cm long, carrying copper strips 315 μm wide with 415 μm pitch. Interconnected resistive strips, having the same pattern as the copper strips, provide spark protection. The boards are completed by the creation of cylindrical pillars 128 μm high, 280 μm in diameter and arranged in a triangular array 7 mm aside. The total number of boards to be produced for ATLAS is 2048 of 32 different types. We will review the main design parameters of the read-out boards for the ATLAS Micromegas, following...

  7. Distributed Read-out Imaging Device array for astronomical observations in UV/VIS

    NARCIS (Netherlands)

    Hijmering, R.A.

    2009-01-01

    STJ (Superconducting Tunneling Junctions) are being developed as spectro-photometers in wavelengths ranging from the NIR to X-rays. 10x12 arrays of STJs have already been successfully used as optical imaging spectrometers with the S-Cam 3, on the William Hershel Telescope on La Palma and on the Opti

  8. Nanoscale mechanical actuation and near-field read-out of photonic crystal molecules

    Science.gov (United States)

    Petruzzella, M.; La China, F.; Intonti, F.; Caselli, N.; De Pas, M.; van Otten, F. W. M.; Gurioli, M.; Fiore, A.

    2016-09-01

    We employed the contact forces induced by a near-field tip to tune and probe the optical resonances of a mechanically compliant photonic crystal molecule. Here, the pressure induced by the near-field tip is exploited to control the spectral proprieties of the coupled cavities in an ultrawide spectral range, demonstrating a reversible mode shift of 37.5 nm . Besides, by monitoring the coupling strength variation due to the vertical nanodeformation of the dielectric structure, distinct tip-sample interaction regimes have been unambiguously reconstructed with a nano-Newton sensitivity. These results demonstrate an optical method for mapping mechanical forces at the nanoscale with a lateral spatial resolution below 100 nm.

  9. Light-pulse atom interferometric device

    Science.gov (United States)

    Biedermann, Grant; McGuinness, Hayden James Evans; Rakholia, Akash; Jau, Yuan-Yu; Schwindt, Peter; Wheeler, David R.

    2016-03-22

    An atomic interferometric device useful, e.g., for measuring acceleration or rotation is provided. The device comprises at least one vapor cell containing a Raman-active chemical species, an optical system, and at least one detector. The optical system is conformed to implement a Raman pulse interferometer in which Raman transitions are stimulated in a warm vapor of the Raman-active chemical species. The detector is conformed to detect changes in the populations of different internal states of atoms that have been irradiated by the optical system.

  10. Phase 1 upgrade of the CMS Drift Tubes Read-Out system

    CERN Document Server

    Navarro Tobar, Alvaro

    2016-01-01

    In order to cope with up to a factor 2 nominal LHC luminosity, the second level of the readout system of the CMS Drift Tubes (DT) electronics needs to be redesigned to minimize event processing time and remove present bottlenecks. The uROS boards are uTCA modules, which include a Xilinx Virtex-7 FPGA and equip up to 6 12-channel optical receivers of the 240 Mbps input links. Each board collects the information from up to 72 input links (3 DT sectors), requiring a total of 25 boards. The design of the system and the first validation tests will be described.ation tests will be described.

  11. Electrical read out for coherent phenomena involving Rydberg atoms in thermal vapor cells

    CERN Document Server

    Barredo, D; Daschner, R; Löw, R; Pfau, T

    2012-01-01

    We present a very sensitive and scalable method to measure the population of highly excited Rydberg states in a thermal vapor cell of rubidium atoms. We detect the Rydberg ionization current in a 5 mm electrically contacted cell. The measured current is found to be in excellent agreement with a theory for the Rydberg population based on a master equation for the three level problem including an ionization channel and the full Doppler distributions at the corresponding temperatures. The signal-to-noise ratio of the current detection is substantially better than purely optical techniques.

  12. SU-8 cantilevers for bio/chemical sensing; Fabrication, characterisation and development of novel read-out methods

    DEFF Research Database (Denmark)

    Nordström, M.; Keller, Stephan Urs; Lillemose, Michael;

    2008-01-01

    Here, we present the activities within our research group over the last five years with cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interesting polymer for fabrication of cantilevers for bio/chemical sensing due to its simple processing and low Young's modulus. We show...... examples of different integrated read-out methods and their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity to changes in the environmental temperature and pH of the buffer solution. Moreover, we show that the SU-8 cantilever surface can be functionalised directly...

  13. Charge Identification of Highly Ionizing Particles in Desensitized Nuclear Emulsion Using High Speed Read-Out System

    Energy Technology Data Exchange (ETDEWEB)

    Toshito, T.; Kodama, K.; Yusa, K.; Ozaki, M.; Amako, K.; Kameoka, S.; Murakami, K.; Sasaki, T.; Aoki, S.; Ban, T.; Fukuda, T.; Naganawa, N.; Nakamura, T.; Natsume, M.; Niwa, K.; Takahashi, S.; Kanazawa, M.; Kanematsu, N.; Komori, M.; Sato, S.; Asai, M.; /Nagoya U. /Aichi U. of Education /Gunma U., Maebashi /JAXA, Sagamihara /KEK, Tsukuba /Kobe

    2006-05-10

    We performed an experimental study of charge identification of heavy ions from helium to carbon having energy of about 290 MeV/u using an emulsion chamber. Emulsion was desensitized by means of forced fading (refreshing) to expand a dynamic range of response to highly charged particles. For the track reconstruction and charge identification, the fully automated high speed emulsion read-out system, which was originally developed for identifying minimum ionizing particles, was used without any modification. Clear track by track charge identification up to Z=6 was demonstrated. The refreshing technique has proved to be a powerful technique to expand response of emulsion film to highly ionizing particles.

  14. M.i.p. detection performances of a 100 us read-out CMOS pixel sensor with digitised outputs

    CERN Document Server

    Winter, Marc; Besson, Auguste; Colledani, Claude; Degerli, Yavuz; De Masi, Rita; Dorokhov, Andrei; Doziere, Guy; Dulinski, Wojciech; Gelin, Marie; Guilloux, Fabrice; Himmi, Abdelkader; Hu-Guo, Christine; Morel, Frederic; Orsini, Fabienne; Valin, Isabelle; Voutsinas, Georgios

    2009-01-01

    Swift, high resolution CMOS pixel sensors are being developed for the ILC vertex detector, aiming to allow approaching the interaction point very closely. A major issue is the time resolution of the sensors needed to deal with the high occupancy generated by the beam related background. A 128x576 pixel sensor providing digitised outputs at a read-out time of 92.5 us, was fabricated in 2008 within the EU project EUDET, and tested with charged particles at the CERN-SPS. Its prominent performances in terms of noise, detection efficiency versus fake hit rate, spatial resolution and radiation tolerance are overviewed. They validate the sensor architecture.

  15. Estimation of the proton energy spectrum in knee region by analog read-out of ARGO-YBJ experiment

    Institute of Scientific and Technical Information of China (English)

    QU Xiao-Bo; CHEN Song-Zhan; ZHA Min; ZHANG Xue-Yao; FENG Cun-Feng

    2008-01-01

    Based on the six months data set of ARGO-YBJ experiment with analog read-out and its Monte Carlo simulation,we study the difference between different primaries induced showers by using the space-time information of the charged particles in Extensive Air Showers.With five parameters which can efficiently pick out primary proton induced showers as inputs of an artificial neural network,the proton spectrum from 100 TeV to 10 PeV can be obtained.

  16. Scintillation light read-out by thin photodiodes in silicon wells

    CERN Document Server

    Allier, C P; Sarro, P M; Eijk, C W E

    2000-01-01

    Several applications of X-ray and gamma ray imaging detectors, e.g. in medical diagnostics, require millimeter or sub-millimeter spatial resolution and good energy resolution. In order to achieve such features we have proposed a new type of camera, which takes advantage of micromachining technology. It consists of an array of scintillator crystals encapsulated in silicon wells with photodiodes at the bottom. Several parameters of the photodiode need to be optimised: uniformity and efficiency of the light detection, gain, electronic noise and breakdown voltage. In order to evaluate these parameters we have processed 3x3 arrays of 1.8 mm sup 2 , approx 10 mu m thick photodiodes using (1 0 0) wafers etched in a KOH solution. Their optical response at 675 nm wavelength is comparable to that of a 500 mu m thick silicon PIN diode. Their low light detection efficiency is compensated by internal amplification. Several scintillator materials have been positioned in the wells on top of the thin photodiodes, i.e. a 200 ...

  17. Skiroc A Front-end Chip to Read Out the Imaging Silicon-Tungsten Calorimeter for ILC

    CERN Document Server

    Bouchel, Michel; Fleury, Julien; de La Taille, Christophe; Martin-Chassard,Gisèle; Raux, Ludovic; Wicek, Francois; Bohner, Gérard; Gay, Pascal; Lecoq, Jacques; Manen, Samuel; Royer, Laurent

    2007-01-01

    Integration and low-power consumption of the read-out ASIC for the International Linear Collider (ILC) 82-millionchannel W-Si calorimeter must reach an unprecedented level as it will be embedded inside the detector. Uniformity and dynamic range performance has to reach the accuracy to achieve calorimetric measurement. A first step towards this goal has been a 10,000-channel physics prototype of 18*18 cm which is currently in test beam in CERN. A new version of a full integrated read out chip (SKIROC) has been designed to equip the technologic prototype to be built for 2009. Based on the running physics prototype ASIC (FLC_PHY3), it embeds most of the required features expected for the final detector. The dynamic range has been improved from 500 to 2000 MIP. An auto-trigger capability has been added allowing built-in zero suppress. The number of channel has been doubled reaching 36 to fit smaller silicon pads and the lownoise charge preamplifier now accepts both AC and DC coupled detectors. After an exhaustive...

  18. AIDA: A 16-channel amplifier ASIC to read out the advanced implantation detector array for experiments in nuclear decay spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Braga, D. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom); Coleman-Smith, P. J. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Davinson, T. [Dept. of Physics and Astronomy, Univ. of Edinburgh, Edinburgh EH9 3JZ (United Kingdom); Lazarus, I. H. [STFC Daresbury Laboratory, Warrington WA4 4AD (United Kingdom); Page, R. D. [Dept. of Physics, Univ. of Liverpool, Oliver Lodge Laboratory, Liverpool L69 7ZE (United Kingdom); Thomas, S. [STFC Rutherford Appleton Laboratory, Didcot, OX11 0QX (United Kingdom)

    2011-07-01

    We have designed a read-out ASIC for nuclear decay spectroscopy as part of the AIDA project - the Advanced Implantation Detector Array. AIDA will be installed in experiments at the Facility for Antiproton and Ion Research in GSI, Darmstadt. The AIDA ASIC will measure the signals when unstable nuclei are implanted into the detector, followed by the much smaller signals when the nuclei subsequently decay. Implant energies can be as high as 20 GeV; decay products need to be measured down to 25 keV within just a few microseconds of the initial implants. The ASIC uses two amplifiers per detector channel, one covering the 20 GeV dynamic range, the other selectable over a 20 MeV or 1 GeV range. The amplifiers are linked together by bypass transistors which are normally switched off. The arrival of a large signal causes saturation of the low-energy amplifier and a fluctuation of the input voltage, which activates the link to the high-energy amplifier. The bypass transistors switch on and the input charge is integrated by the high-energy amplifier. The signal is shaped and stored by a peak-hold, then read out on a multiplexed output. Control logic resets the amplifiers and bypass circuit, allowing the low-energy amplifier to measure the subsequent decay signal. We present simulations and test results, demonstrating the AIDA ASIC operation over a wide range of input signals. (authors)

  19. CMOS biosensor system for on-chip cell culture with read-out circuitry and microfluidic packaging.

    Science.gov (United States)

    Welch, David; Christen, Jennifer Blain

    2012-01-01

    A 1.5 mm × 3 mm CMOS chip with sensors for monitoring on-chip cell cultures has been designed. The chip is designed in a 0.5 µm CMOS process which has 3 metal layers and 2 poly layers and is a 5 volt process. The chip contains ion sensitive field effect transistors (ISFETs), as well as ISFETs with read-out circuitry, for monitoring the pH of solutions placed on top of the chip. Interdigitated electrode structures (IDESs) are made using the top metal of the process to be used for sensing cellular attachment and proliferation via impendence. IDES read-out circuits and IDES test structures are included. The chip also contains test amplifiers, bandgap reference test structures, and connections for post-processing. We designed the chip to accommodate packaging into an environment where it will be directly exposed to a cell culture environment. Specifically we designed the chip to have the incorporated sensors near the center of the chip allowing for connections made around the edge of the chip to be sealed off using an epoxy or similar material to prevent shorting. Preliminary electrical characterization results for our amplifier indicate a gain of 48 dB, a bandwidth of 1.65 kHz, and a common mode rejection ratio (CMRR) of 72 dB. We also present a packaging technique using a flexible pcb substrate.

  20. Particle Discrimination in TeO$_{2}$ Bolometers using Light Detectors read out by Transition Edge Sensors

    CERN Document Server

    Schäffner, K; Bellini, F; Casali, N; Ferroni, F; Hauff, D; Nagorny, N; Pattavina, L; Petricca, F; Pirro, S; Pröbst, F; Reindl, F; Seidel, W; Strauss, R

    2014-01-01

    An active discrimination of the dominant $\\alpha$-background is the prerequisite for future DBD experiments based on TeO$_{2}$ bolometers. We investigate such $\\alpha$-particle rejection in cryogenic TeO$_{2}$ bolometers by the detection of Cherenkov light. For a setup consisting of a large TeO$_{2}$ crystal 285 g and a separate cryogenic light detector, both read out by transition edge sensors at around 10 mK, we obtain an event-by-event identification of e/$\\gamma$- and $\\alpha$-events. In the energy interval ranging from 2400 keV to 2800 keV and covering the Q-value of $^{130}$Te a discrimination power of 3.7 could be demonstrated.

  1. SU-8 Cantilevers for Bio/chemical Sensing; Fabrication, Characterisation and Development of Novel Read-out Methods

    Directory of Open Access Journals (Sweden)

    Anja Boisen

    2008-03-01

    Full Text Available Here, we present the activities within our research group over the last five yearswith cantilevers fabricated in the polymer SU-8. We believe that SU-8 is an interestingpolymer for fabrication of cantilevers for bio/chemical sensing due to its simple processingand low Young’s modulus. We show examples of different integrated read-out methodsand their characterisation. We also show that SU-8 cantilevers have a reduced sensitivity tochanges in the environmental temperature and pH of the buffer solution. Moreover, weshow that the SU-8 cantilever surface can be functionalised directly with receptormolecules for analyte detection, thereby avoiding gold-thiol chemistry.

  2. High-speed single photon counting read out electronics for a digital detection system for clinical synchrotron radiation mammography

    Science.gov (United States)

    Bergamaschi, A.; Arfelli, F.; Dreossi, D.; Longo, R.; Olivo, A.; Pani, S.; Rigon, L.; Vallazza, E.; Venanzi, C.; Castelli, E.

    2004-02-01

    The SYRMEP beam line is currently in the upgrading phase for mammographic examinations on patients at Elettra in Trieste. At the same time, a digital detection system, suitable for in -vivo breast imaging, is under development; it consists of a silicon laminar detector array operating in single photon counting mode. The duration of a clinical examination should not exceed a few seconds. Fast read out electronics is therefore necessary with the aim of avoiding losses in image contrast in presence of high counting rates. A custom ASIC working with 100% efficiency for rates up to 100 kHz per pixel has been designed and tested, and other solutions based on commercially available ASICs are currently under test. Several detector prototypes have been assembled, and images of mammographic test objects have been acquired. Image quality, efficiency and contrast losses have been evaluated in all cases as a function of the counting rate.

  3. A GEANT4 study on the time resolution of a fast plastic scintillator read out by a G-APD

    Energy Technology Data Exchange (ETDEWEB)

    Sedlak, K., E-mail: kamil.sedlak@psi.ch [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland); Stoykov, A.; Scheuermann, R. [Paul Scherrer Institut, CH-5232 Villigen PSI (Switzerland)

    2012-12-22

    The time resolution of a fast scintillation counter, consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode, is studied over a wide range of the number of detected photons (primary photoelectrons) using the GEANT4 simulation toolkit. Different timing definitions such as first photon detection, leading edge and constant fraction discrimination are considered. In the latter case the predictions are compared with the existing experimental data. We also show that due to the finite scintillation rise time, finite scintillator dimensions and also due to the finite single photon time resolution in G-APD cells, the time resolution for the first detected photon in real detectors substantially deviates from the {sigma}{approx}1/N{sub phe} dependence, theoretically predicted for a scintillator with zero rise time.

  4. A GEANT4 study on the time resolution of a fast plastic scintillator read out by a G-APD

    Science.gov (United States)

    Sedlak, K.; Stoykov, A.; Scheuermann, R.

    2012-12-01

    The time resolution of a fast scintillation counter, consisting of a plastic scintillator read out by a Geiger-mode Avalanche Photodiode, is studied over a wide range of the number of detected photons (primary photoelectrons) using the GEANT4 simulation toolkit. Different timing definitions such as first photon detection, leading edge and constant fraction discrimination are considered. In the latter case the predictions are compared with the existing experimental data. We also show that due to the finite scintillation rise time, finite scintillator dimensions and also due to the finite single photon time resolution in G-APD cells, the time resolution for the first detected photon in real detectors substantially deviates from the σ˜1/Nphe dependence, theoretically predicted for a scintillator with zero rise time.

  5. A pixel read-out architecture implementing a two-stage token ring, zero suppression and compression

    Energy Technology Data Exchange (ETDEWEB)

    Heuvelmans, S; Boerrigter, M, E-mail: sander.heuvelmans@bruco.nl [Bruco integrated circuits BV, Oostermaat 2, 7623 CS (Netherlands)

    2011-01-15

    Increasing luminosity in high energy physics experiments leads to new challenges in the design of data acquisition systems for pixel detectors. With the upgrade of the LHCb experiment, the data processing will be changed; hit data from every collision will be transported off the pixel chip, without any trigger selection. A read-out architecture is proposed which is able to obtain low hit data loss on limited silicon area by using the logic beneath the pixels as a data buffer. Zero suppression and redundancy reduction ensure that the data rate off chip is minimized. A C++ model has been created for simulation of functionality and data loss, and for system development. A VHDL implementation has been derived from this model.

  6. Emulation and Calibration of the SALT Read-out Chip for the Upstream Tracker for Modernised LHCb Detector

    CERN Document Server

    Dendek, Adam

    2015-01-01

    The LHCb is one of the four major experiments currently operating at CERN. The main reason for constructing the LHCb forward spectrometer was a precise measurement of the CP violation in heavy quarks section as well as search for a New Physics. To obtain interesting results, the LHCb is mainly focused on study of B meson decays. Unfortunately, due to the present data acquisition architecture, the LHCb experiment is statistically limited for collecting such events. This fact led the LHCb Collaboration to decide to perform far-reaching upgrade. Key part of this upgrade will be replacement of the TT detector. To perform this action, it was requited to design new tracking detector with entirely new front-end electronics. This detector will be called the Upstream Tracker (UT) and the read-out chip — SALT. This note presents an overall discussion on SALT chip. In particular, the emulation process of the SALT data preformed via the software written by the author.

  7. Development and characterization of high-resolution neutron pixel detectors based on Timepix read-out chips

    Science.gov (United States)

    Krejci, F.; Zemlicka, J.; Jakubek, J.; Dudak, J.; Vavrik, D.; Köster, U.; Atkins, D.; Kaestner, A.; Soltes, J.; Viererbl, L.; Vacik, J.; Tomandl, I.

    2016-12-01

    Using a suitable isotope such as 6Li and 10B semiconductor hybrid pixel detectors can be successfully adapted for position sensitive detection of thermal and cold neutrons via conversion into energetic light ions. The adapted devices then typically provides spatial resolution at the level comparable to the pixel pitch (55 μm) and sensitive area of about few cm2. In this contribution, we describe further progress in neutron imaging performance based on the development of a large-area hybrid pixel detector providing practically continuous neutron sensitive area of 71 × 57 mm2. The measurements characterising the detector performance at the cold neutron imaging instrument ICON at PSI and high-flux imaging beam-line Neutrograph at ILL are presented. At both facilities, high-resolution high-contrast neutron radiography with the newly developed detector has been successfully applied for objects which imaging were previously difficult with hybrid pixel technology (such as various composite materials, objects of cultural heritage etc.). Further, a significant improvement in the spatial resolution of neutron radiography with hybrid semiconductor pixel detector based on the fast read-out Timepix-based detector is presented. The system is equipped with a thin planar 6LiF convertor operated effectively in the event-by-event mode enabling position sensitive detection with spatial resolution better than 10 μm.

  8. Functional Brachyury binding sites establish a temporal read-out of gene expression in the Ciona notochord.

    Directory of Open Access Journals (Sweden)

    Lavanya Katikala

    2013-10-01

    Full Text Available The appearance of the notochord represented a milestone in Deuterostome evolution. The notochord is necessary for the development of the chordate body plan and for the formation of the vertebral column and numerous organs. It is known that the transcription factor Brachyury is required for notochord formation in all chordates, and that it controls transcription of a large number of target genes. However, studies of the structure of the cis-regulatory modules (CRMs through which this control is exerted are complicated in vertebrates by the genomic complexity and the pan-mesodermal expression territory of Brachyury. We used the ascidian Ciona, in which the single-copy Brachyury is notochord-specific and CRMs are easily identifiable, to carry out a systematic characterization of Brachyury-downstream notochord CRMs. We found that Ciona Brachyury (Ci-Bra controls most of its targets directly, through non-palindromic binding sites that function either synergistically or individually to activate early- and middle-onset genes, respectively, while late-onset target CRMs are controlled indirectly, via transcriptional intermediaries. These results illustrate how a transcriptional regulator can efficiently shape a shallow gene regulatory network into a multi-tiered transcriptional output, and provide insights into the mechanisms that establish temporal read-outs of gene expression in a fast-developing chordate embryo.

  9. Terahertz interferometric imaging of RDX

    Science.gov (United States)

    Sinyukov, Alexander M.; Barat, Robert B.; Gary, Dale E.; Michalopoulou, Zoi-Heleni; Zorych, Ivan; Zimdars, David; Federici, John F.

    2007-04-01

    Experimental results of homodyne terahertz interferometric 2-D imaging of RDX are presented. Continuous waves at 0.25-0.6 THz are used to obtain images of a C-4 sample at several THz frequencies. The performance of an N element detector array is imitated by only one detector placed at N positions. The distance between the C-4 sample and the detector array is ~30 cm. By taking interferometric images at several THz frequencies RDX can be recognized by the spectral peak at 0.82 THz. Simulations of interferometric images of two point sources of spherical waves are presented. The terahertz interferometric imaging method can be used in defense and security applications to detect concealed weapons, explosives as well as chemical and biological agents.

  10. A SQUID based read-out of sub-attoNewton force sensor operating at millikelvin temperatures

    CERN Document Server

    Usenko, O; Wijts, G; Oosterkamp, T H

    2010-01-01

    An increasing number of experiments require the use of ultrasensitive nanomechanical resonators. Relevant examples are the investigation of quantum effects in mechanical systems [1] or the detection of exceedingly small forces as in Magnetic Resonance Force Microscopy (MRFM) [2]. The force sensitivity of a mechanical resonator is typically limited by thermal fluctuations, which calls for detection methods capable of operating at ultralow temperature. Commonly used interferometric techniques, despite their excellent sensitivity, may not be an optimal choice at millikelvin temperatures, because of unwanted resonator heating caused by photon absorption. Although alternative detection techniques based on microwave cavities [3] [4] [5] have shown to perform better at ultralow temperature, these techniques still suffer from the fact that the detection sensitivity decreases as the power input is decreased. Here, we present a measurement approach based on the detection, through a Superconducting Quantum Interference ...

  11. The minimization of ac phase noise in interferometric systems

    DEFF Research Database (Denmark)

    Filinski, Ignacy; Gordon, R A

    1994-01-01

    A simple step-by-step procedure, including several novel techniques discussed in the Appendices, is given for minimizing ac phase noise in typical interferometric systems such as two-beam interferometers, holographic setups, four-wave mixers, etc. Special attention is given to index of refraction...... fluctuations, direct mechanical coupling, and acoustic coupling, whose importance in determining ac phase noise in interferometric systems has not been adequately treated. The minimization procedure must be carried out while continuously monitoring the phase noise which can be done very simply by using...... with the optical table will also have to be carefully carried out regardless of the type of interferometric system employed.It is recommended that this be followed by a simple, inexpensive change to a novel type of interferometer discussed in Appendix A which is inherently less sensitive to mechanical vibration...

  12. Refractive Index Compensation in Over-Determined Interferometric Systems

    Directory of Open Access Journals (Sweden)

    Zdeněk Buchta

    2012-10-01

    Full Text Available We present an interferometric technique based on a differential interferometry setup for measurement under atmospheric conditions. The key limiting factor in any interferometric dimensional measurement are fluctuations of the refractive index of air representing a dominating source of uncertainty when evaluated indirectly from the physical parameters of the atmosphere. Our proposal is based on the concept of an over-determined interferometric setup where a reference length is derived from a mechanical frame made from a material with a very low thermal coefficient. The technique allows one to track the variations of the refractive index of air on-line directly in the line of the measuring beam and to compensate for the fluctuations. The optical setup consists of three interferometers sharing the same beam path where two measure differentially the displacement while the third evaluates the changes in the measuring range, acting as a tracking refractometer. The principle is demonstrated in an experimental setup.

  13. Added value of IP-10 as a read-out of Mycobacterium tuberculosis - specific immunity in young children

    DEFF Research Database (Denmark)

    Jenum, Synne; Dhanasekaran, Sivmakumaran; Ritz, Christian;

    2016-01-01

    , suggest a potential for fewer missed cases with a combined IFNγ/IP-10 read-out in a 4 generation IGRA.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share...

  14. Evaluación del equipo de interferometría óptica de coherencia parcial Lenstar en la biometría ocular Evaluation of Lenstar partial coherente optical interferometry device in the ocular biometry

    Directory of Open Access Journals (Sweden)

    Iramis Miranda Hernández

    2010-01-01

    Full Text Available OBJETIVOS: Comparar y evaluar la biometría ocular con el nuevo equipo de interferometría óptica de coherencia parcial (Lenstar con el equipo de interferometría óptica de baja coherencia IOL Master y también con los sistemas topográficos Galilei y Pentacam. MÉTODOS: Se realizó un estudio descriptivo, transversal, en 120 ojos de 60 pacientes. Para el cálculo del lente intraocular se tomaron mediciones con un nuevo biómetro Lenstar LS 900 (Haag Streit AG y con el IOL Master V.5 (Carl Zeiss Meditec AG. Se compararon mediante el análisis de regresión lineal y correlación de Pearson. También se compararon las medidas con las obtenidas por los equipos topógrafos Galilei y Pentacam. RESULTADOS: Existe una alta correspondencia en los valores biómetricos de longitud axial, queratometría y profundidad de la cámara anterior entre los equipos Lenstar e IOL Master. También se encontró una buena correspondencia entre las medidas de profundidad de cámara posterior y queratometría entre Lenstar y los topógrafos Galilei y Pentacam. CONCLUSIONES: El nuevo biómetro Lenstar, provee resultados que se correlacionan muy bien con aquellos obtenidos con los equipos IOL Master, Pentacam y Galilei. El equipo Lenstar es un equipo preciso que brinda información adicional por lo que es útil en la cirugía de catarata y la cirugía refractiva.OBJECTIVES: To compare and to evaluate the ocular biometry taken by a new optical partial coherence interferometry device (Lenstar,the low coherence optical interferometry equipment (ILO Master and the topographic systems Pentacam y Galilei. METHODS: A descriptive cross-sectional study was conducted in 120 eyes from 60 patients. For the IOL calculation, the necessary measurements were taken with the new optical biometer Lenstar LS 900 (Haig Streit AG and with the IOL Master V5 (Carl Zeiss Meditec AG. The results were evaluated using the linear regression analysis and Pearson´s correlation. The measures were

  15. Optical back-action in silicon nanowire resonators: bolometric versus radiation pressure effects

    Science.gov (United States)

    Gil-Santos, E.; Ramos, D.; Pini, V.; Llorens, J.; Fernández-Regúlez, M.; Calleja, M.; Tamayo, J.; San Paulo, A.

    2013-03-01

    We study optical back-action effects associated with confined electromagnetic modes in silicon nanowire resonators interacting with a laser beam used for interferometric read-out of the nanowire vibrations. Our analysis describes the resonance frequency shift produced in the nanowires by two different mechanisms: the temperature dependence of the nanowire's Young's modulus and the effect of radiation pressure. We find different regimes in which each effect dominates depending on the nanowire morphology and dimensions, resulting in either positive or negative frequency shifts. Our results also show that in some cases bolometric and radiation pressure effects can have opposite contributions so that their overall effect is greatly reduced. We conclude that Si nanowire resonators can be engineered for harnessing back-action effects for either optimizing frequency stability or exploiting dynamic phenomena such as parametric amplification.

  16. Common-Path Interferometric Wavefront Sensing for Space Telescopes

    Science.gov (United States)

    Wallace, James Kent

    2011-01-01

    This paper presents an optical configuration for a common-path phase-shifting interferometric wavefront sensor.1 2 This sensor has a host of attractive features which make it well suited for space-based adaptive optics. First, it is strictly reflective and therefore operates broadband, second it is common mode and therefore does not suffer from systematic errors (like vibration) that are typical in other interferometers, third it is a phase-shifting interferometer and therefore benefits from both the sensitivity of interferometric sensors as well as the noise rejection afforded by synchronous detection. Unlike the Shack-Hartman wavefront sensor, it has nearly uniform sensitivity to all pupil modes. Optical configuration, theory and simulations for such a system will be discussed along with predicted performance.

  17. MEMS Gyroscope with Interferometric Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is a novel MEMS gyroscope that uses micro-interferometric detection to measure the motion of the proof mass. Using an interferometric...

  18. Introduction to the 30m Ring Interferometric Telescope

    Science.gov (United States)

    Liu, Z.; Qian, S.-B.

    2007-08-01

    For the demand of astronomical limitation observations, such as exploring extra-terrestrial planets, black hole accretion disk and jet in the near-infrared and optical wave band, extremely large telescopes (optical and infrared) have become the principal ground-based astronomical instrumentation. With the maturation of interferometric imaging theory, the borderline between new generation ground-based extremely large telescope and interferometric array for aperture synthesis imaging is increasingly going blurring and the only differences in their technical methods and characteristics are also gradually disappearing. Based on the research result of interferometric imaging in Yunnan Observatory, we bring forward a new concept ground-based extremely large telescope -- 30m Ring Interferometric Telescope (30mRIT). It has the direct imaging ability and resolution like single aperture telescope, and it also can image with high resolution like the aperture synthesis imaging mode. The 30m RIT has a ring spherical primary mirror with 90 segmented mirrors, the width of the ring is 1 meter and the F/D ratio is about 0.8.This report also introduces some high resolution astronomical observe results by one meter ring which is 1 m diameter and 100 mm width. The 30mRIT project is remarkably different from the conventional ground-base ELT and its pivotal techniques have got the support of CAS and China NSF.

  19. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG) on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications.

    Science.gov (United States)

    Pérez, Ramón José; Álvarez, Ignacio; Enguita, José María

    2016-04-27

    This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG) prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h). This design presents two important properties: (1) an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2) a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM), so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type) realized by quadrupolar winding. The working wavelength will be

  20. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG) on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications

    Science.gov (United States)

    Pérez, Ramón José; Álvarez, Ignacio; Enguita, José María

    2016-01-01

    This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG) prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h). This design presents two important properties: (1) an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2) a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM), so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type) realized by quadrupolar winding. The working wavelength will be

  1. Theoretical Design of a Depolarized Interferometric Fiber-Optic Gyroscope (IFOG on SMF-28 Single-Mode Standard Optical Fiber Based on Closed-Loop Sinusoidal Phase Modulation with Serrodyne Feedback Phase Modulation Using Simulation Tools for Tactical and Industrial Grade Applications

    Directory of Open Access Journals (Sweden)

    Ramón José Pérez

    2016-04-01

    Full Text Available This article presents, by means of computational simulation tools, a full analysis and design of an Interferometric Fiber-Optic Gyroscope (IFOG prototype based on a closed-loop configuration with sinusoidal bias phase- modulation. The complete design of the different blocks, optical and electronic, is presented, including some novelties as the sinusoidal bias phase-modulation and the use of an integrator to generate the serrodyne phase-modulation signal. The paper includes detailed calculation of most parameter values, and the plots of the resulting signals obtained from simulation tools. The design is focused in the use of a standard single-mode optical fiber, allowing a cost competitive implementation compared to commercial IFOG, at the expense of reduced sensitivity. The design contains an IFOG model that accomplishes tactical and industrial grade applications (sensitivity ≤ 0.055 °/h. This design presents two important properties: (1 an optical subsystem with advanced conception: depolarization of the optical wave by means of Lyot depolarizers, which allows to use a sensing coil made by standard optical fiber, instead by polarization maintaining fiber, which supposes consequent cost savings and (2 a novel and simple electronic design that incorporates a linear analog integrator with reset in feedback chain, this integrator generating a serrodyne voltage-wave to apply to Phase-Modulator (PM, so that it will be obtained the interferometric phase cancellation. This particular feedback design with sawtooth-wave generated signal for a closed-loop configuration with sinusoidal bias phase modulation has not been reported till now in the scientific literature and supposes a considerable simplification with regard to previous designs based on similar configurations. The sensing coil consists of an 8 cm average diameter spool that contains 300 m of standard single-mode optical-fiber (SMF-28 type realized by quadrupolar winding. The working

  2. Canopy reconstruction from interferometric SAR

    NARCIS (Netherlands)

    Varekamp, C.

    2001-01-01

    Interferometric Synthetic Aperture Radar (InSAR) is investigated as a method for 3D tree mapping. When operational, the method may be important for monitoring forests with a persistent cloud cover such as tropical rain forests. The problem of crown displacement due to lay-over in a vegetation with a

  3. Improving the reliability of multiplexed fiber optic low-coherence interferometric sensors by use of novel twin-loop network topologies.

    Science.gov (United States)

    Yang, Jun; Yuan, Libo; Jin, Wei

    2007-05-01

    Novel twin-loop network topologies for multiplexing fiber optic low-coherence reflectometric sensors are proposed and theoretically analyzed. The sensing fibers are made by connecting segments of standard single-mode fibers with partial reflections at the fiber joints and are completely passive. Absolute length measurement can be made for each segment of the sensing fiber so that strain or temperature distribution along the entire sensing fiber can be derived. It is expected that novel topologies would help as to improve the reliability of the sensor network by providing multiple accesses to each of the sensing segment so that most of the sensing segments can still be interrogated even when one or more point breakages occur along the transmission fibers. A nine-sensor twin-loop sensing network was constructed and experimentally tested by use of a Michelson low-coherence interferometer, and the results obtained agree with our theoretical prediction. The novel network topologies may be used for large-scale smart structure applications where breakages of transmission fibers may occur during the stages of sensor imbedding, installation, and structure-in-service cycles.

  4. ZnO coated Fabry-Perot interferometric optical fiber for detection of gasoline blend vapors: Refractive index and fringe visibility manipulation studies

    Science.gov (United States)

    Pawar, Dnyandeo; Kitture, Rohini; Kale, S. N.

    2017-03-01

    ZnO nanoparticles-coated Fabry-Perot interferometer based optical fiber sensor is demonstrated to detect different gasoline blend concentrations in ethanol. Different gasoline blends (with ethanol varying from 0% (E0) to 100% (E100)) have been subjected to the sensor to observe the change in refractive index of the material that leads to the wavelength shift and fringe visibility change of the interference spectrum. The sensor shows the remarkable response with different gasoline blend mixtures within the time span of 0-60 s in terms of wavelength and Intensity (power) shift. The maximum wavelength shift of 12.1 nm is observed for E0 mixture and least of 3 nm for E100 in 60 s, respectively. A fast response time and recovery time of 5 s and 9 s, respectively, are obtained for E0 mixture. The results are related to the formation of interference pattern due the ZnO-mediated-Fabry-Perot cavity, changes in refractive index with the change in external gaseous environment, changes in fringe visibility of the spectrum and the interaction of oxygen vacancies on ZnO surface with the gasoline moieties. The rates of sensing and recovery times are related to the Reid vapor pressures of ethanol and gasoline. Hence a dual scale of sensing, both in terms of wavelength shift (refractive index) and intensity shift (fringe visibility) has been proposed for gasoline blend sensing.

  5. Quantitative read-out of Al2O3:C,Mg-based fluorescent nuclear track detectors using a commercial confocal microscope

    CERN Document Server

    Greilich, Steffen; Niklas, Martin; Lauer, Florian; Bestvater, Felix; Jäkel, Oliver

    2014-01-01

    Fluorescent nuclear track detectors (FNTD) show great potential for applications in ion-beam therapy research, such as dosimetry, advanced beam characterization, in-vivo use or as radiobiological assay. A essential feature of FNTDs is their ability to assess the energy loss of single ions yielding for example LET estimations. This article describes the basic characterisations of FNTDs and our read-out system (a Zeiss LSM710 confocal laser scanning microscope) to enable quantative measurements of energy loss.

  6. Development of a High Dynamic Range Read-out System Using Multi-photodiode for the Total Absorption Calorimeter of CALET

    Science.gov (United States)

    Katayose, Y.; Shibata, M.; Torii, S.; Shimizu, Y.; Tamura, T.; Hibino, K.; Okuno, S.; Yoshida, K.; Kitamura, H.; Uchihori, Y.; Murakami, H.

    We have been developing the CALET instrument, which is proposed to be launched on the Japanese Experiment Module (JEM), Exposed Facility (EF) of the ISS. CALET consists of an imaging calorimeter (IMC) and a total absorption calorimeter (TASC). The role of IMC is identification of the incident particle by imaging the shower tracks with scintillating fibers. TASC is used for observing the total development of shower particles with a stack of BGO scintillators. A read-out system using multi-photodiode and a front-end circuit including analog ASIC, 16 bit ADC, FPGA was developed to measure the energy deposit with the dynamic range from 1MIP(Minimum Ionization Particle) up to 106MIPs in a BGO bar of TASC. The output signal of 1 MIP was calibrated by cosmic ray muon. The dynamic range of the read-out system was measured with both LED pulser and heavy ions beam in the range from 1MIP to about 2400 MIPs . In this paper, the performance of the read-out system is described.

  7. The 2010 Interferometric Imaging Beauty Contest

    CERN Document Server

    Malbet, Fabien; Duvert, Gilles; Lawson, Peter; Chiavassa, Andrea; Young, John; Baron, Fabien; Buscher, David; Rengaswamy, Sridharan; Kloppenborg, Brian; Vannier, Martin; Mugnier, Laurent

    2010-01-01

    We present the results of the fourth Optical/IR Interferometry Imaging Beauty Contest. The contest consists of blind imaging of test data sets derived from model sources and distributed in the OI-FITS format. The test data consists of spectral data sets on an object "observed" in the infrared with spectral resolution. There were 4 different algorithms competing this time: BSMEM the Bispectrum Maximum Entropy Method by Young, Baron & Buscher; RPR the Recursive Phase Reconstruction by Rengaswamy; SQUEEZE a Markov Chain Monte Carlo algorithm by Baron, Monnier & Kloppenborg; and, WISARD the Weak-phase Interferometric Sample Alternating Reconstruction Device by Vannier & Mugnier. The contest model image, the data delivered to the contestants and the rules are described as well as the results of the image reconstruction obtained by each method. These results are discussed as well as the strengths and limitations of each algorithm.

  8. An interferometric view of hot star disks

    CERN Document Server

    Faes, Daniel Moser

    2015-01-01

    Optical long baseline interferometry was recently established as a technique capable of resolving stars and their circumstellar environments at the milliarcsecond (mas) resolution level. This high-resolution opens an entire new window to the study of astrophysical systems, providing information inaccessible by other techniques. Astrophysical disks are observed in a wide variety of systems, from galaxies up to planetary rings, commonly sharing similar physical processes. Two particular disk like systems are studied in the thesis: (i) B He-rich stars that exhibits magnetic fields in order of kG and that trap their winds in structures called magnetospheres; and (ii) Be stars, fast rotating stars that create circumstellar viscous disks. This study uses the interferometric technique to investigate both the photosphere proper and the circumstellar environment of these stars. The objective is to combine interferometry with other observational techniques (such as spectroscopy and polarimetry) to perform a complete an...

  9. Research on interferometric photonic crystal fiber hydrophone

    Science.gov (United States)

    Luo, Hong; Zhang, Zhen-hui; Wang, Fu-yin; Xiong, Shui-dong

    2013-08-01

    Current research on photonic crystal fiber (PCF) for acoustic sensing was focused on the PCF's pressure sensitivity enhancement. However, whether the enhancement of the PCF's pressure sensitivity can be actually realized is still controversial. Practical hydrophone, utilizing PCFs, to manifest its superior sensitivity to normal single mode fibers (SMFs) for acoustic sensing, should be made. Account to this point of view, actual hydrophone was fabricated. Index guiding PCF was used, the fiber core is solid silicon dioxide (SiO2), and the cladding is SiO2 filled with lots of periodical transverse circular air hollows. The PCF, mounted on an air-backed mandrel for structural sensitivity enhancement, was used as a sensing arm of the fiber Michelson interferometer. The other arm, so called reference arm, was made of SMF. Faraday rotator mirrors (FRM) were spliced in the end of each interferometric arm account for polarization induced phase fading, which is a common scheme in fiber interferometric sensing systems. A similar hydrophone, with all the same structure except that the PCF was exchanged into SMF, was also fabrication to make the contrast. The narrowlinewidth and frequency-tunable optical fiber laser was used to achieve high accuracy optical interferometric measurement. Meanwhile, the phase generated carrier (PGC) modulation-demodulation scheme was adopted to interrogate the measurand signal. Experiment was done by using acoustic standing-wave test apparatus. Linearity characteristics of the two hydrophones were measured at frequency 100Hz, 500Hz, and 1000Hz, experimental results showed that the maximum error of the linearity was 10%, a little larger than the theoretical results. Pressure sensitivities of the PCF hydrophone and the SMF hydrophone were measured using a reference standard PZT hydrophone in the frequency range from 20 Hz to 1600 Hz, the measurement data showed that the sensitivity of the PCF hydrophone was about -162.8 dB re. rad/μPa, with a

  10. Interferometric polarization control

    Science.gov (United States)

    Wollack, Edward J. (Inventor); Moseley, Samuel H. (Inventor); Novak, Giles A. (Inventor); Chuss, David T. (Inventor)

    2009-01-01

    A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

  11. Field Guide to Interferometric Optical Testing

    CERN Document Server

    Goodwin, Eric P

    2006-01-01

    A distillation of Dr. Wyant's course at the University of Arizona, this Field Guide covers the key fundamentals of interferometry, types of interferometers and interferograms, concepts of phase-shifting interferometry, long-wavelength interferometry, testing of aspheric surfaces, measurement of surface microstructure, flat and curved surface testing, and absolute measurements.

  12. SPIROC: design and performances of a dedicated very front-end electronics for an ILC Analog Hadronic CALorimeter (AHCAL) prototype with SiPM read-out

    Science.gov (United States)

    Conforti Di Lorenzo, S.; Callier, S.; Fleury, J.; Dulucq, F.; De la Taille, C.; Chassard, G. Martin; Raux, L.; Seguin-Moreau, N.

    2013-01-01

    For the future e+ e- International Linear Collider (ILC) the ASIC SPIROC (Silicon Photomultiplier Integrated Read-Out Chip) was designed to read out the Analog Hadronic Calorimeter (AHCAL) equipped with Silicon Photomultiplier (SiPM). It is an evolution of the FLC_SiPM chip designed by the OMEGA group in 2005. SPIROC2 [1] was realized in AMS SiGe 0.35 μm technology [2] and developed to match the requirements of large dynamic range, low noise, low consumption, high precision and large number of read-out channels. This ASIC is a very front-end read-out chip that integrates 36 self triggered channels with variable gain to achieve charge and time measurements. The charge measurement must be performed from 1 up to 2000 photo-electrons (p.e.) corresponding to 160 fC up to 320 pC for SiPM gain 106. The time measurement is performed with a coarse 12-bit counter related to the bunch crossing clock (up to 5 MHz) and a fine time ramp based on this clock (down to 200 ns) to achieve a resolution of 1 ns. An analog memory array with a depth of 16 for each channel is used to store the time information and the charge measurement. The analog memory content (time and charge) is digitized thanks to an internal 12-bit Wilkinson ADC. The data is then stored in a 4kbytes RAM. A complex digital part is necessary to manage all these features and to transfer the data to the DAQ. SPIROC2 is the second generation of the SPIROC ASIC family designed in 2008 by the OMEGA group. A very similar version (SPIROC2c) was submitted in February 2012 to improve the noise performance and also to integrate a new TDC (Time to Digital Converter) structure. This paper describes SPIROC2 and SPIROC2c ASICs and illustrates the main characteristics thank to a series of measurements.

  13. Oscillation of Angiogenesis and Vascular Dropout in Progressive Human Vascular Disease. [Vascular Pattern as Useful Read-Out of Complex Molecular Signaling

    Science.gov (United States)

    Parsons-Wingerter, Patricia

    2010-01-01

    When analyzed by VESsel GENeration Analysis (VESGEN) software, vascular patterns provide useful integrative read-outs of complex, interacting molecular signaling pathways. Using VESGEN, we recently discovered and published our innovative, surprising findings that angiogenesis oscillated with vascular dropout throughout progression of diabetic retinopathy, a blinding vascular disease. Our findings provide a potential paradigm shift in the current prevailing view on progression and treatment of this disease, and a new early-stage window of regenerative therapeutic opportunities. The findings also suggest that angiogenesis may oscillate with vascular disease in a homeostatic-like manner during early stages of other inflammatory progressive diseases such as cancer and coronary vascular disease.

  14. Digital signal processing for a thermal neutron detector using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs

    OpenAIRE

    Mosset, J. -B.; Stoykov, A.; Greuter, U.; Hildebrandt, M.; Schlumpf, N.

    2015-01-01

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC^4 filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC^4 filter has been emulated digitally. The dete...

  15. Digital signal processing for a thermal neutron detector using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs

    Science.gov (United States)

    Mosset, J.-B.; Stoykov, A.; Greuter, U.; Hildebrandt, M.; Schlumpf, N.

    2016-07-01

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC4 filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC4 filter has been emulated digitally. The detector performance obtained with this analog approach is compared with the one obtained with the best performing digital approach.

  16. Digital signal processing for a thermal neutron detector using ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs

    CERN Document Server

    Mosset, J -B; Greuter, U; Hildebrandt, M; Schlumpf, N

    2015-01-01

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):6LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC^4 filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC^4 filter has been emulated digitally. The detector performance obtained with this analog approach is compared with the one obtained with the best performing digital approach.

  17. A large acceptance scintillator detector with wavelength shifting fibre read-out for search of eta-nucleus bound states

    CERN Document Server

    Kilian, K; Kirillov, Da; Kirillov, Di; Kolev, D; Kravcikova, M; Kutsarova, T; Lesiak, M; Lieb, J; Machner, H; Magiera, A; Maier, R; Martinská, G; Nedev, S; Piskunov, N; Prasuhn, D; Prottic, D; Ritman, J; Von Rossen, P; Roy, B J; Shukla, P; Sitnik, I; Siudak, R; Tsenov, R; Ulicny, M; Urbán, J; Vankova, G

    2007-01-01

    A large acceptance scintillator detector with wavelength shifting optical fibre readout has been designed and built to detect the decay particles of $\\eta$-nucleus bound system (the so-called $\\eta$-mesic nuclei), namely, protons and pions. The detector, named as ENSTAR detector, consists of 122 pieces of plastic scintillator of various shapes and sizes, which are arranged in a cylindrical geometry to provide particle identification, energy loss and coarse position information for these particles. A solid angle coverage of $\\sim$95% of total 4$\\pi$ is obtained in the present design of the detector. Monte Carlo phase space calculations performed to simulate the formation and decay of $\\eta$-mesic nuclei suggest that its decay particles, the protons and pions are emitted with an opening angle of 150$^\\circ \\pm 20^\\circ$, and with energies in the range of 25 to 300 MeV and 225 to 450 MeV respectively. The detailed GEANT simulations show that $\\sim$ 80 % of the decay particles (protons and pions) can be detected ...

  18. The 2016 interferometric imaging beauty contest

    Science.gov (United States)

    Sanchez-Bermudez, J.; Thiébaut, E.; Hofmann, K.-H.; Heininger, M.; Schertl, D.; Weigelt, G.; Millour, F.; Schutz, A.; Ferrari, A.; Vannier, M.; Mary, D.; Young, J.

    2016-08-01

    Image reconstruction in optical interferometry has gained considerable importance for astrophysical studies during the last decade. This has been mainly due to improvements in the imaging capabilities of existing interferometers and the expectation of new facilities in the coming years. However, despite the advances made so far, image synthesis in optical interferometry is still an open field of research. Since 2004, the community has organized a biennial contest to formally test the different methods and algorithms for image reconstruction. In 2016, we celebrated the 7th edition of the "Interferometric Imaging Beauty Contest". This initiative represented an open call to participate in the reconstruction of a selected set of simulated targets with a wavelength-dependent morphology as they could be observed by the 2nd generation of VLTI instruments. This contest represents a unique opportunity to benchmark, in a systematic way, the current advances and limitations in the field, as well as to discuss possible future approaches. In this contribution, we summarize: (a) the rules of the 2016 contest; (b) the different data sets used and the selection procedure; (c) the methods and results obtained by each one of the participants; and (d) the metric used to select the best reconstructed images. Finally, we named Karl-Heinz Hofmann and the group of the Max-Planck-Institut f ur Radioastronomie as winners of this edition of the contest.

  19. A positron emission tomograph based on LSO-APD modules with a sampling ADC read-out system for a students' advanced laboratory course.

    Science.gov (United States)

    Schneider, Florian R; Mann, Alexander B; Konorov, Igor; Delso, Gaspar; Paul, Stephan; Ziegler, Sibylle I

    2012-06-01

    A one-day laboratory course on positron emission tomography (PET) for the education of physics students and PhD students in medical physics has been set up. In the course, the physical background and the principles of a PET scanner are introduced. Course attendees set the system in operation, calibrate it using a (22)Na point source and reconstruct different source geometries filled with (18)F. The PET scanner features an individual channel read-out of 96 lutetium oxyorthosilicate (LSO) scintillator crystals coupled to avalanche photodiodes (APD). The analog data of each APD are digitized by fast sampling analog to digital converters (SADC) and processed within field programmable gate arrays (FPGA) to extract amplitudes and time stamps. All SADCs are continuously sampling with a precise rate of 80MHz, which is synchronous for the whole system. The data is transmitted via USB to a Linux PC, where further processing and the image reconstruction are performed. The course attendees get an insight into detector techniques, modern read-out electronics, data acquisition and PET image reconstruction. In addition, a short introduction to some common software applications used in particle and high energy physics is part of the course.

  20. Optimisation of the Read-out Electronics of Muon Drift-Tube Chambers for Very High Background Rates at HL-LHC and Future Colliders

    CERN Document Server

    Nowak, Sebastian; Gadow, Philipp; Ecker, Katharina; Fink, David; Fras, Markus; Kortner, Oliver; Kroha, Hubert; Mueller, Felix; Richter, Robert; Schmid, Clemens; Schmidt-Sommerfeld, Korbinian; Zhao, Yazhou

    2016-01-01

    In the ATLAS Muon Spectrometer, Monitored Drift Tube (MDT) chambers and sMDT chambers with half of the tube diameter of the MDTs are used for precision muon track reconstruction. The sMDT chambers are designed for operation at high counting rates due to neutron and gamma background irradiation expected for the HL-LHC and future hadron colliders. The existing MDT read-out electronics uses bipolar signal shaping which causes an undershoot of opposite polarity and same charge after a signal pulse. At high counting rates and short electronics dead time used for the sMDTs, signal pulses pile up on the undershoot of preceding background pulses leading to a reduction of the signal amplitude and a jitter in the drift time measurement and, therefore, to a degradation of drift tube efficiency and spatial resolution. In order to further increase the rate capability of sMDT tubes, baseline restoration can be used in the read-out electronics to suppress the pile-up effects. A discrete bipolar shaping circuit with baseline...

  1. Development of the superconducting detectors and read-out for the X-IFU instrument on board of the X-ray observatory Athena

    Energy Technology Data Exchange (ETDEWEB)

    Gottardi, L., E-mail: l.gottardi@sron.nl [SRON Netherlands Institute for Space Research, Utrecht (Netherlands); Akamatsu, H.; Bruijn, M.P.; Hartog, R. den; Herder, J.-W. den; Jackson, B. [SRON Netherlands Institute for Space Research, Utrecht (Netherlands); Kiviranta, M. [VTT, Espoo (Finland); Kuur, J. van der; Weers, H. van [SRON Netherlands Institute for Space Research, Utrecht (Netherlands)

    2016-07-11

    The Advanced Telescope for High-Energy Astrophysics (Athena) has been selected by ESA as its second large-class mission. The future European X-ray observatory will study the hot and energetic Universe with its launch foreseen in 2028. Microcalorimeters based on superconducting Transition-edge sensor (TES) are the chosen technology for the detectors array of the X-ray Integral Field Unit (X-IFU) on board of Athena. The X-IFU is a 2-D imaging integral-field spectrometer operating in the soft X-ray band (0.3–12 keV). The detector consists of an array of 3840 TESs coupled to X-ray absorbers and read out in the MHz bandwidth using Frequency Domain Multiplexing (FDM) based on Superconducting QUantum Interference Devices (SQUIDs). The proposed design calls for devices with a high filling-factor, high quantum efficiency, relatively high count-rate capability and an energy resolution of 2.5 eV at 5.9 keV. The paper will review the basic principle and the physics of the TES-based microcalorimeters and present the state-of-the art of the FDM read-out.

  2. Development of the superconducting detectors and read-out for the X-IFU instrument on board of the X-ray observatory Athena

    Science.gov (United States)

    Gottardi, L.; Akamatsu, H.; Bruijn, M. P.; den Hartog, R.; den Herder, J.-W.; Jackson, B.; Kiviranta, M.; van der Kuur, J.; van Weers, H.

    2016-07-01

    The Advanced Telescope for High-Energy Astrophysics (Athena) has been selected by ESA as its second large-class mission. The future European X-ray observatory will study the hot and energetic Universe with its launch foreseen in 2028. Microcalorimeters based on superconducting Transition-edge sensor (TES) are the chosen technology for the detectors array of the X-ray Integral Field Unit (X-IFU) on board of Athena. The X-IFU is a 2-D imaging integral-field spectrometer operating in the soft X-ray band (0.3-12 keV). The detector consists of an array of 3840 TESs coupled to X-ray absorbers and read out in the MHz bandwidth using Frequency Domain Multiplexing (FDM) based on Superconducting QUantum Interference Devices (SQUIDs). The proposed design calls for devices with a high filling-factor, high quantum efficiency, relatively high count-rate capability and an energy resolution of 2.5 eV at 5.9 keV. The paper will review the basic principle and the physics of the TES-based microcalorimeters and present the state-of-the art of the FDM read-out.

  3. Interferometric Measurement Of Residual Stress

    Science.gov (United States)

    Danyluk, Steven; Andonian, A. T.

    1990-01-01

    Stress averaged through thickness of plate measured nondestructively. Theory of elasticity combined with laser interferometric technique into technique for measurement of residual stresses in solid objects - usually in thin, nominally-flat plates. Measurements particularly useful in inspection of wafers of single-crystal silicon for making solar cells or integrated circuits, because stresses remaining after crystal-growing process cause buckling or fracture. Used to predict deflections of plates caused by known applied loads under specified boundary condition, or to infer applied loads that cause known deflections. Also used to relate known deflections to residual stresses equivalent to stresses produced by fictitious applied loads.

  4. Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry

    Directory of Open Access Journals (Sweden)

    Sabina Merlo

    2017-02-01

    Full Text Available In this work, we have applied optical low-coherence reflectometry (OLCR, implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time.

  5. Testing of Piezo-Actuated Glass Micro-Membranes by Optical Low-Coherence Reflectometry.

    Science.gov (United States)

    Merlo, Sabina; Poma, Paolo; Crisà, Eleonora; Faralli, Dino; Soldo, Marco

    2017-02-25

    In this work, we have applied optical low-coherence reflectometry (OLCR), implemented with infra-red light propagating in fiberoptic paths, to perform static and dynamic analyses on piezo-actuated glass micro-membranes. The actuator was fabricated by means of thin-film piezoelectric MEMS technology and was employed for modifying the micro-membrane curvature, in view of its application in micro-optic devices, such as variable focus micro-lenses. We are here showing that OLCR incorporating a near-infrared superluminescent light emitting diode as the read-out source is suitable for measuring various parameters such as the micro-membrane optical path-length, the membrane displacement as a function of the applied voltage (yielding the piezo-actuator hysteresis) as well as the resonance curve of the fundamental vibration mode. The use of an optical source with short coherence-time allows performing interferometric measurements without spurious resonance effects due to multiple parallel interfaces of highly planar slabs, furthermore selecting the plane/layer to be monitored. We demonstrate that the same compact and flexible setup can be successfully employed to perform spot optical measurements for static and dynamic characterization of piezo-MEMS in real time.

  6. Influence of spatial temperature distribution on high accuracy interferometric metrology

    Science.gov (United States)

    Gu, Yongqiang; Miao, Erlong; Yan, Feng; Zhang, Jian; Yang, Huaijiang

    2010-10-01

    We calculate the influence of temperature change on the refractive index of air, establish a model of air temperature distribution and analyze the effect of different temperature distribution on the high accuracy interferometric metrology. First, a revised Edlen formula is employed to acquire the relation between temperature and refractive index of air, followed by introducing the fixed temperature gradient distribution among the spatial grid within the optical cavity between the reference flat and the test flat of the Fizeau interferometer, accompanied by a temperature change random function within each grid. Finally, all the rays through the air layer with different incident angles are traced by Matlab program in order to obtain the final output position, angle and OPD for each ray. The influence of different temperature distribution and the length of the optical cavity in on the testing accuracy can be analyzed through the RMS value that results from repeatable rays tracing. As a result, the horizontal distribution (vertical to optical axis) has a large effect on the testing accuracy. Thus, to realize the high accuracy figure metrology, the horizontal distribution of temperature must be rigorously controlled as well as to shorten the length of the optical cavity to a large extent. The results from our simulation are of great significant for the accuracy analysis of interferometric testing and the research of manufacturing a interferometer.

  7. DigiCam - Fully Digital Compact Read-out and Trigger Electronics for the SST-1M Telescope proposed for the Cherenkov Telescope Array

    CERN Document Server

    Rajda, P; Bilnik, W.; Błocki, J.; Bogacz, L.; Bulik, T.; Cadoux, F.; Christov, A.; Curyło, M.; della Volpe, D.; Dyrda, M.; Favre, Y.; Frankowski, A.; Grudnik, Ł.; Grudzińska, M.; Heller, M.; Idźkowski, B.; Jamrozy, M.; Janiak, M.; Kasperek, J.; Lalik, K.; Lyard, E.; Mach, E.; Mandat, D.; Marszałek, A.; Michałowski, J.; Moderski, R.; Rameez, M.; Montaruli, T.; Neronov, A.; Niemiec, J.; Ostrowski, M.; Paśko, P.; Pech, M.; Porcelli, A.; Prandini, E.; Schioppa, E. jr; Schovanek, P.; Seweryn, K.; Skowron, K.; Sliusar, V.; Sowiński, M.; Stawarz, Ł.; Stodulska, M.; Stodulski, M.; Toscano, S.; Pujadas, I. Troyano; Walter, R.; Więcek, M.; Zagdański, A.; Żychowski, P.

    2016-01-01

    The SST-1M is one of three prototype small-sized telescope designs proposed for the Cherenkov Telescope Array, and is built by a consortium of Polish and Swiss institutions. The SST-1M will operate with DigiCam - an innovative, compact camera with fully digital read-out and trigger electronics. A high level of integration will be achieved by massively deploying state-of-the-art multi-gigabit transmission channels, beginning from the ADC flash converters, through the internal data and trigger signals transmission over backplanes and cables, to the camera's server link. Such an approach makes it possible to design the camera to fit the size and weight requirements of the SST-1M exactly, and provide low power consumption, high reliability and long lifetime. The structure of the digital electronics will be presented, along with main physical building blocks and the internal architecture of FPGA functional subsystems.

  8. Development FD-SOI MOSFET Amplifiers for Integrated Read-Out Circuit of Superconducting-Tunnel-Junction Single-Photon-Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Kiuchi, Kenji; et al.

    2015-07-27

    We proposed a new high-resolution single-photon infrared spectrometer for search for radiative decay of cosmic neutrino background (CνB). The superconducting-tunnel-junctions(STJs) are used as a single-photon counting device. Each STJ consists of Nb/Al/AlxOy/Al/Nb layers, and their thicknesses are optimized for the operation temperature at 370 mK cooled by a 3He sorption refrigerator. Our STJs achieved the leak current 250 pA, and the measured data implies that a smaller area STJ fulfills our requirement. FD-SOI MOSFETs are employed to amplify the STJ signal current in order to increase signal-to-noise ratio (S/N). FD-SOI MOSFETs can be operated at cryogenic temperature of 370 mK, which reduces the noise of the signal amplification system. FD-SOI MOSFET characteristics are measured at cryogenic temperature. The Id-Vgs curve shows a sharper turn on with a higher threshold voltage and the Id-Vds curve shows a nonlinear shape in linear region at cryogenic temperature. Taking into account these effects, FD-SOI MOSFETs are available for read-out circuit of STJ detectors. The bias voltage for STJ detectors is 0.4 mV, and it must be well stabilized to deliver high performance. We proposed an FD-SOI MOSFET-based charge integrated amplifier design as a read-out circuit of STJ detectors. The requirements for an operational amplifier used in the amplifier is estimated using SPICE simulation. The op-amp is required to have a fast response (GBW ≥ 100 MHz), and it must have low power dissipation as compared to the cooling power of refrigerator.

  9. Michelsonův interferometr

    OpenAIRE

    Rýc, Jan

    2011-01-01

    Diplomová práce se zabývá bezkontaktními optickými metodami měření vzdálenosti a rychlosti (vibrací). Je zde uveden základní přehled a teoretická rešerže těchto metod. Podrobně je zde rozebrána zejména problematika interferometrických metod pro měření vibrací. Obsahuje rozdělení interferometrů, popis principu jejich funkce a rovněž obsahuje kapitoly zabývající se prvky, které se v interferometrech používají, jako lasery, fotodetektory a prvky v optické trase paprsku (polarizátory, retardéry a...

  10. Absolute Measurement of Quantum-Limited Interferometric Displacements

    CERN Document Server

    Thiel, Valérian; Treps, Nicolas; Roslund, Jonathan

    2016-01-01

    A methodology is introduced that enables an absolute, quantum-limited measurement of sub-wavelength interferometric displacements. The technique utilizes a high-frequency optical path modulation within an interferometer operated in a homodyne configuration. All of the information necessary to fully characterize the resultant path displacement is contained within the relative strengths of the various harmonics of the phase modulation. The method, which is straightforward and readily implementable, allows a direct measurement of the theoretical Cram\\'er-Rao limit of detection without any assumptions on the nature of the light source.

  11. Interferometric vibration sensor using phase-generated carrier method.

    Science.gov (United States)

    Li, Yang; Liu, Zhibo; Liu, Yan; Ma, Lin; Tan, Zhongwei; Jian, Shuisheng

    2013-09-01

    An interferometric fiber-optic vibration sensing system using the phase-generated carrier (PGC) method is proposed and experimentally demonstrated. The sensing section consists of a Sagnac interferometer combined with a Mach-Zehnder interferometer, a length of sensing fiber is shared between the two interferometers. The PGC demodulation scheme is used to demodulate the time-varying phase shifts induced by vibrations. Spatial information can be extracted from the demodulated results. A prototype sensing system with a 628 m long sensing fiber has been tested and a spatial resolution better than 12 m is successfully achieved.

  12. Introduction to the 30m Ringy Interferometric Telescope

    Science.gov (United States)

    Liu, Zhong; Jin, Zhe-Yu; Lin, Jing; Li, Yan; Xu, Jun

    2006-03-01

    In order to meet the demands of exploring extra-terrestrial planets, black holes and other astronomical utmost observation in the near infrared and optical regions, several extremely large telescopes (optical and infrared) with the aperture diameter larger than 30m and the long baseline optical synthetic aperture imaging arrays have been proposed. We advise to build a ringy shape telescope with a large primary mirror, and the telescope with such formation is called Ringy Interferometric Telescope - RIT. The form of the RIT is between the forms of a traditional ELT and an interferometric array. The paper also shows our research results about the ringy aperture. We propose to build a segmented RIT with outer diameter 30m and effective ring width 1m. Because of the whole spatial-frequency coverage characteristic, images photographed by RIT can have the same spatial resolution with a 30m full aperture telescope, need only some simple processes. The resolution (FWHM) of RIT can reach to 0.003 arcsec, its light-gathering area equivalent to that of a 10m full aperture telescope. Since its simple configuration, the cost of building the 30m RIT will not exceed that of a 10m segmented telescope a lot.

  13. A novel lightweight Fizeau infrared interferometric imaging system

    Science.gov (United States)

    Hope, Douglas A.; Hart, Michael; Warner, Steve; Durney, Oli; Romeo, Robert

    2016-05-01

    Aperture synthesis imaging techniques using an interferometer provide a means to achieve imagery with spatial resolution equivalent to a conventional filled aperture telescope at a significantly reduced size, weight and cost, an important implication for air- and space-borne persistent observing platforms. These concepts have been realized in SIRII (Space-based IR-imaging interferometer), a new light-weight, compact SWIR and MWIR imaging interferometer designed for space-based surveillance. The sensor design is configured as a six-element Fizeau interferometer; it is scalable, light-weight, and uses structural components and main optics made of carbon fiber replicated polymer (CFRP) that are easy to fabricate and inexpensive. A three-element prototype of the SIRII imager has been constructed. The optics, detectors, and interferometric signal processing principles draw on experience developed in ground-based astronomical applications designed to yield the highest sensitivity and resolution with cost-effective optical solutions. SIRII is being designed for technical intelligence from geo-stationary orbit. It has an instantaneous 6 x 6 mrad FOV and the ability to rapidly scan a 6x6 deg FOV, with a minimal SNR. The interferometric design can be scaled to larger equivalent filled aperture, while minimizing weight and costs when compared to a filled aperture telescope with equivalent resolution. This scalability in SIRII allows it address a range of IR-imaging scenarios.

  14. Evaluating mirror alignment systems using the optical sensing matrix

    Energy Technology Data Exchange (ETDEWEB)

    Mantovani, M [Universita di Siena, INFN Pisa (Italy); Freise, A [School of Physics and Astronomy, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom)], E-mail: mantovan@ego-gw.it

    2008-07-15

    The most sensitive gravitational-wave detectors today are based on large-scale laser interferometers whose optics are suspended from pendulums to decouple the instrument from seismic motion. Complex control systems are required to set and maintain the microscopic position of each mirror at a precisely defined value. Such control systems use the interferometer signals as input signals, and ideally it is designed such that the degrees of freedom (mirror positions) are well decoupled in the interferometer signals. However, this is not always feasible, in particular the mirror alignment control signals in interferometric gravitational wave detectors often show strong couplings between the different degrees of freedom. In this paper we will describe a simple and powerful method to quantify in advance the performances of an alignment control system by analyzing the optical matrix of the proposed read-out system. We will motivate the method using a Fabry-Perot cavity as an example, and we will further present results for the Virgo alignment system where this method was used to characterize and improve the alignment sensing scheme.

  15. Advanced Components For Fiber-Optical Systems

    Science.gov (United States)

    Depaula, Ramon; Stowe, David W.

    1989-01-01

    Paper reviews statuses of some advanced passive and active optical components for use with optical fibers. Emphasis on highly birefringent components controling polarization, because control of polarization critical in applications as fiber-optical gyroscopes, interferometric sensors, and coherent communications.

  16. Interferometric measurements of silicon carbide mirrors at liquid helium temperature

    Science.gov (United States)

    Robb, Paul N.; Huff, Lynn W.; Forney, Paul B.; Petrovsky, Gury T.; Ljubarsky, Sergey V.; Khimitch, Yuri P.

    1995-10-01

    This paper presents the results of interferometric tests of two silicon carbide mirrors tested at room temperature and 6 K. The first mirror has a spherical f/1.73 surface, a diameter of 170 mm, and is of solid, plano-concave construction. The other mirror, a plano measuring 308 mm by 210 mm, is of lightweighted, closed-back construction. The mirrors were manufactured by the Vavilov State Optical Institute, St. Petersburg, Russia, and were loaned to Lockheed for these tests. Optical tests on both mirrors were performed using the Lockheed cryogenic optical test facility at liquid helium temperature and a Zygo Mark II interferometer. There was no change in the surface figure of the mirrors, within the test uncertainty of approximately plus or minus 0.02 waves at 0.6328-micrometer wavelength.

  17. Cross-calibration of interferometric SAR data

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2003-01-01

    Generation of digital elevation models from interferometric synthetic aperture radar (SAR) data is a well established technique. Achieving a high geometric fidelity calls for a calibration accounting for inaccurate navigation data and system parameters as well as system imperfections. Fully...

  18. Time-resolved quantitative multiphase interferometric imaging of a highly focused ultrasound pulse

    CERN Document Server

    Souris, Fabien; Jacquier, Philippe; Dupont-Roc, Jacques; Arvengas, Arnaud; Caupin, Frédéric; 10.1364/AO.49.006127

    2010-01-01

    Interferometric imaging is a well established method to image phase objects by mixing the image wavefront with a reference one on a CCD camera. It has also been applied to fast transient phenomena, mostly through the analysis of single interferograms. It is shown that for repetitive phenomena multiphase acquisition brings significant advantages. A 1 MHz focused sound field emitted by a hemispherical piezotransducer in water is imaged as an example. Quantitative image analysis provides high resolution sound field profiles. Pressure at focus determined by this method agrees with measurements from a fiber-optic probe hydrophone. This confirms that multiphase interferometric imaging can indeed provide quantitative measurements.

  19. Pattern effects and noise accumulation in concatenated all-optical regenerators

    DEFF Research Database (Denmark)

    Lading, Brian; Mørk, Jesper; Bischoff, Svend

    2001-01-01

    In future high-speed networks, interferometric structures based on semiconductor optical amplifiers (SOAs) are strong candidates for wavelength conversion applications and signal regeneration. One of the latest reported interferometric devices is the semiconductor delayed-interference signal-wave...

  20. INTERFEROMETRIC VIEWS ON THE CEPHEIDS

    Directory of Open Access Journals (Sweden)

    A. Mérand

    2010-01-01

    Full Text Available El método de paralaje de pulsación, o método de Baade-Wesselink (BW, es una poderosa manera de medir distancias a Cefeidas en una manera pseudo-geométrica. En la búsqueda para obtener la más precisa distancia usando interferometría de gran línea de base (alcanzamos 1.5%, nosotros obtuvimos dos resultados quizás no tan insospechados. En primer lugar, nuestros estudios demuestran que alcanzamos un punto donde la suposición que la fotósfera que pulsa se puede aproximar usando modelos estáticos no es válida en el contexto del método BW. En segundo lugar, revelamos la presencia sistemática de envolturas circunestelares (CSE en escala de algunos diámetros estelares, como un leve exceso del infrarrojo cercano, que podría ser una indicación de que está ocurriendo una pérdida de masa. No sólo estos dos resultados representan un sesgo al método BW, y merece ser estudiado observacionalmente, sino también vierten nuevas luces a nuestro conocimiento de las cefeidas y requieren un extenso modelamiento.

  1. Fiberless Optical Gyroscope Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a radical new approach for to the design and fabrication of a fiber-less Interferometric Optical Gyroscope (IOG) that enables the production of a very...

  2. Fiberless Optical Gyroscope Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a radical new approach for to the design and fabrication of a fiber-less Interferometric Optical Gyroscope (IOG) that enables the production of a...

  3. The LINC-NIRVANA Fizeau interferometric imager: final lab integration, first light experiments and challenges

    Science.gov (United States)

    Herbst, T. M.; Ragazzoni, R.; Eckart, A.; Weigelt, G.

    2014-07-01

    LINC-NIRVANA (LN) is an innovative Fizeau interferometric imager for the Large Binocular Telescope (LBT). LN uses Multi-Conjugate Adaptive Optics (MCAO) for high-sky-coverage single-eye imagery and interferometric beam combination. The last two years have seen both successes and challenges. On the one hand, final integration is proceeding well in the lab. We also achieved First Light at the LBT with the Pathfinder experiment. On the other hand, funding constraints have forced a significant re-planning of the overall instrument implementation. These laboratory, observatory, and financial "events" provide lessons for builders of complex interferometric instruments on large telescopes. This paper presents our progress and plans for bringing the instrument online at the telescope.

  4. Test beam results of the first CMS double-sided strip module prototypes using the CBC2 read-out chip

    Science.gov (United States)

    Harb, Ali; Mussgiller, Andreas; Hauk, Johannes

    2017-02-01

    The CMS Binary Chip (CBC) is a prototype version of the front-end read-out ASIC to be used in the silicon strip modules of the CMS outer tracking detector during the high luminosity phase of the LHC. The CBC is produced in 130 nm CMOS technology and bump-bonded to the hybrid of a double layer silicon strip module, the so-called 2S-pT module. It has 254 input channels and is designed to provide on-board trigger information to the first level trigger system of CMS, with the capability of cluster-width discrimination and high-pT track identification. In November 2013 the first 2S-pT module prototypes equipped with the CBC chips were put to test at the DESY-II test beam facility. Data were collected exploiting a beam of positrons with an energy ranging from 2 to 4 GeV. In this paper the test setup and the results are presented.

  5. Development of the superconducting detectors and read-out for the X-IFU instrument on board of the X-ray observatory Athena

    CERN Document Server

    Gottardi, Luciano; Bruijn, Marcel P; Hartog, Roland den; Herder, Jan-Willem den; Jackson, Brian; Kiviranta, Mikko; van der Kuur, Jan; van Weers, Henk

    2016-01-01

    The Advanced Telescope for High-Energy Astrophysics (Athena) has been selected by ESA as its second large-class mission. The future European X-ray observatory will study the hot and energetic Universe with its launch foreseen in 2028. Microcalorimeters based on superconducting Transition-edge sensor (TES) are the chosen technology for the detectors array of the X-ray Integral Field Unit (X-IFU) on board of Athena. The X-IFU is a 2-D imaging integral-field spectrometer operating in the soft X-ray band (0.3 -12 keV). The detector consists of an array of 3840 TESs coupled to X-ray absorbers and read out in the MHz bandwidth using Frequency Domain Multiplexing (FDM) based on Superconducting QUantum Interference Devices (SQUIDs). The proposed design calls for devices with a high filling-factor, high quantum e?ciency, relatively high count-rate capability and an energy resolution of 2.5 eV at 5.9 keV. The paper will review the basic principle and the physics of the TES-based microcalorimeters and present the state-...

  6. Gossipo-3 A prototype of a Front-End Pixel Chip for Read-Out of Micro-Pattern Gas Detectors

    CERN Document Server

    Brezina, Christpoh; van der Graaf, Haryy; Gromov, Vladimir; Kluit, Ruud; Kruth, Andre; Zappon, Francesco

    2009-01-01

    In a joint effort of Nikhef (Amsterdam) and the University of Bonn, the Gossipo-3 integrated circuit (IC) has been developed. This circuit is a prototype of a chip dedicated for read-out of various types of position sensitive Micro-Pattern Gas detectors (MPGD). The Gossipo-3 is defined as a set of building blocks to be used in a future highly granulated (60 μm) chip. The pixel circuit can operate in two modes. In Time mode every readout pixel measures the hit arrival time and the charge deposit. For this purpose it has been equipped with a high resolution TDC (1.7 ns) covering dynamic range up to 102 μs. Charge collected by the pixel will be measured using Time-over- Threshold method in the range from 400 e- to 28000 e- with accuracy of 200 e- (standard deviation). In Counting mode every pixel operates as a 24-bit counter, counting the number of incoming hits. The circuit is also optimized to operate at low power consumption (100 mW/cm2) that is required to avoid the need for massive power transport and coo...

  7. Automated computational aberration correction method for broadband interferometric imaging techniques.

    Science.gov (United States)

    Pande, Paritosh; Liu, Yuan-Zhi; South, Fredrick A; Boppart, Stephen A

    2016-07-15

    Numerical correction of optical aberrations provides an inexpensive and simpler alternative to the traditionally used hardware-based adaptive optics techniques. In this Letter, we present an automated computational aberration correction method for broadband interferometric imaging techniques. In the proposed method, the process of aberration correction is modeled as a filtering operation on the aberrant image using a phase filter in the Fourier domain. The phase filter is expressed as a linear combination of Zernike polynomials with unknown coefficients, which are estimated through an iterative optimization scheme based on maximizing an image sharpness metric. The method is validated on both simulated data and experimental data obtained from a tissue phantom, an ex vivo tissue sample, and an in vivo photoreceptor layer of the human retina.

  8. Molecular Histopathology by Spectrally Reconstructed Nonlinear Interferometric Vibrational Imaging

    Science.gov (United States)

    Chowdary, Praveen D.; Jiang, Zhi; Chaney, Eric J.; Benalcazar, Wladimir A.; Marks, Daniel L.; Gruebele, Martin; Boppart, Stephen A.

    2011-01-01

    Sensitive assays for rapid quantitative analysis of histologic sections, resected tissue specimens, or in situ tissue are highly desired for early disease diagnosis. Stained histopathology is the gold standard but remains a subjective practice on processed tissue taking from hours to days. We describe a microscopy technique that obtains a sensitive and accurate color-coded image from intrinsic molecular markers. Spectrally reconstructed nonlinear interferometric vibrational imaging can differentiate cancer versus normal tissue sections with greater than 99% confidence interval in a preclinical rat breast cancer model and define cancer boundaries to ±100 μm with greater than 99% confidence interval, using fresh unstained tissue sections imaged in less than 5 minutes. By optimizing optical sources and beam delivery, this technique can potentially enable real-time point-of-care optical molecular imaging and diagnosis. PMID:21098699

  9. Introduction of GRPC Detectors With Semi-digital Read-Out%半数字读出式玻璃板阻抗室

    Institute of Scientific and Technical Information of China (English)

    韩然

    2013-01-01

    A large GRPC detector equipped with semi-digital electronics read-out with 1 cm2 lateral granularity was conceived to be used as a sensitive medium in the hadronic calorimeter of the future linear collider experiments. The GRPC detector was designed to provide high detection efficiency, excellent homogeneity and negligible dead zones. Using the ILD software, the energy resolutions under digital and semi-digital were analyzed and compared.%为提高探测器测量粒子流的能量分辨率,未来的国际直线对撞机(ILC)采用了高粒度的量能器和高精的径迹探测器相结合的方法.半数字读出式气体探测器是目前针对ILC上强子量能器所提出的预研之一,它由1 cm2高粒度性读出系统的玻璃板阻抗室组成,具有制作方便、高效率和精准定位等优势.读出系统采用半数字读出方式,具有并行度高,可分辨不同能量粒子等特点.经模拟分析验证,在高能量下,半数字读出方式比数字读出方式的探测器具有更高的能量分辨率.

  10. Precision Laser Development for Interferometric Space Missions NGO, SGO, and GRACE Follow-On

    Science.gov (United States)

    Numata, Kenji; Camp, Jordan

    2011-01-01

    Optical fiber and semiconductor laser technologies have evolved dramatically over the last decade due to the increased demands from optical communications. We are developing a laser (master oscillator) and optical amplifier based on those technologies for interferometric space missions, including the gravitational-wave missions NGO/SGO (formerly LISA) and the climate monitoring mission GRACE Follow-On, by fully utilizing the matured wave-guided optics technologies. In space, where simpler and more reliable system is preferred, the wave-guided components are advantageous over bulk, crystal-based, free-space laser, such as NPRO (Nonplanar Ring Oscillator) and bulk-crystal amplifier.

  11. Radio Interferometric Calibration Using a Riemannian Manifold

    CERN Document Server

    Yatawatta, Sarod

    2013-01-01

    In order to cope with the increased data volumes generated by modern radio interferometers such as LOFAR (Low Frequency Array) or SKA (Square Kilometre Array), fast and efficient calibration algorithms are essential. Traditional radio interferometric calibration is performed using nonlinear optimization techniques such as the Levenberg-Marquardt algorithm in Euclidean space. In this paper, we reformulate radio interferometric calibration as a nonlinear optimization problem on a Riemannian manifold. The reformulated calibration problem is solved using the Riemannian trust-region method. We show that calibration on a Riemannian manifold has faster convergence with reduced computational cost compared to conventional calibration in Euclidean space.

  12. Applications of interferometrically derived terrain slopes: Normalization of SAR backscatter and the interferometric correlation coefficient

    Science.gov (United States)

    Werner, Charles L.; Wegmueller, Urs; Small, David L.; Rosen, Paul A.

    1994-01-01

    Terrain slopes, which can be measured with Synthetic Aperture Radar (SAR) interferometry either from a height map or from the interferometric phase gradient, were used to calculate the local incidence angle and the correct pixel area. Both are required for correct thematic interpretation of SAR data. The interferometric correlation depends on the pixel area projected on a plane perpendicular to the look vector and requires correction for slope effects. Methods for normalization of the backscatter and interferometric correlation for ERS-1 SAR are presented.

  13. Interferometric Synthetic Aperture Microscopy: Computed Imaging for Scanned Coherent Microscopy

    Directory of Open Access Journals (Sweden)

    Stephen A. Boppart

    2008-06-01

    Full Text Available Three-dimensional image formation in microscopy is greatly enhanced by the use of computed imaging techniques. In particular, Interferometric Synthetic Aperture Microscopy (ISAM allows the removal of out-of-focus blur in broadband, coherent microscopy. Earlier methods, such as optical coherence tomography (OCT, utilize interferometric ranging, but do not apply computed imaging methods and therefore must scan the focal depth to acquire extended volumetric images. ISAM removes the need to scan the focus by allowing volumetric image reconstruction from data collected at a single focal depth. ISAM signal processing techniques are similar to the Fourier migration methods of seismology and the Fourier reconstruction methods of Synthetic Aperture Radar (SAR. In this article ISAM is described and the close ties between ISAM and SAR are explored. ISAM and a simple strip-map SAR system are placed in a common mathematical framework and compared to OCT and radar respectively. This article is intended to serve as a review of ISAM, and will be especially useful to readers with a background in SAR.

  14. White Light Interferometric Surface Profiler

    OpenAIRE

    Toal, Vincent; Bowe, Brian

    1998-01-01

    We describe an optical system for 3-D profilometry based on the white light interferometer. We detail a simple way to construct a profiler that uses two simple algorithms which deal efficiently and quickly with the data. The system has a theoretically unlimited range and can deal with rough and smooth surfaces

  15. Reversible Charge Trapping in Bis-Carbazole-Diimide Redox Polymers with Complete Luminescence Quenching Enabling Nondestructive Read-Out by Resonance Raman Spectroscopy

    Science.gov (United States)

    2017-01-01

    The coupling of substituted carbazole compounds through carbon–carbon bond formation upon one-electron oxidation is shown to be a highly versatile approach to the formation of redox polymer films. Although the polymerization of single carbazole units has been proposed earlier, we show that by tethering pairs of carbazoles double sequential dimerization allows for facile formation of redox polymer films with fine control over film thickness. We show that the design of the monomers and in particular the bridging units is key to polymer formation, with the diaminobenzene motif proving advantageous, in terms of the matching to the redox potentials of the monomer and polymer film and thereby avoiding limitations in film thickness (autoinsulation), but introduces unacceptable instability due to the intrinsic redox activity of this moiety. The use of a diimide protecting group both avoids complications due to p-diamino-benzene redox chemistry and provides for a redox polymer in which the photoluminescence of the bis-carbazole moiety can be switched reversibly (on/off) with redox control. The monomer design approach is versatile enabling facile incorporation of additional functional units, such as naphthalene. Here we show that a multicomponent carbazole/naphthalene containing monomer (APCNDI) can form redox polymer films showing both p- and n- conductivity under ambient conditions and allows access to five distinct redox states, and a complex electrochromic response covering the whole of the UV/vis–NIR spectral region. The highly effective quenching of the photoluminescence of both components in poly-APCNDI enables detailed characterization of the redox polymer films. The poly-APCNDI films show extensive charge trapping, which can be read out spectroscopically in the case of films and is characterized as kinetic rather than chemical in origin on the basis of UV/vis–NIR absorption and resonance Raman spectroscopic analyses. The strong resonantly enhanced Raman

  16. Fiscal 1998 research report. R and D on the nanometer-controlled optical disk system / Magnetic domain- response 3-D optical memory technology (Development of rational use technology of energy); 1998 nendo nanometa seigyo hikari disk system no kenkyu kaihatsu seika hokokusho (jiku oto sanjigen hikari memory gijutsu). Energy shiyo gorika gijutsu kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This report describes the fiscal 1998 result on the magnetic domain-response 3-D optical memory of the nanometer-controlled optical disk system. The magnetic domain response technology is a next-generation optical disk technology which copies fine bits recorded on a recording layer on a read-out layer while magnifying them, and detects the bit smaller than a read out optical spot as large signal level. Magnetic domain-response read out of a fine magnetic domain of 0.12{mu}m in mark length and 0.60{mu}m in track width recorded by optical pulse magnetic field modulation was attempted under the conditions of conventional wavelength (around 680nm) and NA (0.55), and succeeded in expanding unobservable signals up to saturated amplitudes. This is equivalent to a 2-D recording density of 10Gbit/in{sup 2}. Crosstalk-free read out was also verified. As for R and D on the magnetic circular polarization enhanced multiple read out system, the 2-wavelength read out system was fabricated by using 515nm Ar laser light and 780nm semiconductor laser light. It was verified in 2- wavelength read out test that the multi-wavelength read out system is reasonable theoretically. (NEDO)

  17. Interferometric correlator for acoustic radiation and underlying structural vibration

    Science.gov (United States)

    Apostol, Adela; Kilpatrick, James; Markov, Vladimir; Bendiksen, Oddvar O.

    2016-12-01

    In this paper we discuss the background and principles of an optical non-contact sensor fusion concept, the Interferometric Correlator for Acoustic Radiation and Underlying Structural Vibration (ICARUSV) and give practical example of its capabilities, focusing on its ability to simultaneously capture, visualize and quantitatively characterize full-field non-stationary structural dynamics and unsteady radiated sound fields or transient flow fields around the structure of interest. The ICARUSV's multi-sensor design is based on a parallel architecture and therefore the data capture is fast and inherently support a wide variety of spatio-temporal or spatio-spectral analysis methods which characterize the structural or acoustic/flow field dynamics as it occurs in real time, including short-lived transient events. No other technology available today offers this level of multi-parameter multi-dimensional data1.

  18. Modified Fabry-Perot interferometric method for waveguide loss measurement.

    Science.gov (United States)

    Taebi, Sareh; Khorasaninejad, Mohammadreza; Saini, Simarjeet Singh

    2008-12-10

    An extension to the Fabry-Perot interferometric method is demonstrated to calculate the optical loss and the reflectivity for optical waveguides simultaneously. The method uses an excitation of the waveguide with a broadband amplified spontaneous emission source (a superluminescent diode in our case) and curve fitting to account for the change of input power, thereby simplifying the measurement procedure. The use of a broadband source as opposed to tunable lasers allows for simultaneous measurements over multiple wavelengths and decreased sensitivity to reflections in the cavity. Further, waveguides of different lengths are measured to calculate the optical loss and the reflectivity simultaneously. It is shown that, if the value for reflectivity is assumed, there could be a large error in the measurement of loss especially for short waveguides. Optical loss for ridge waveguides is measured and compared by using a tunable laser as the input source. The method can be used for a generic case where it is suspected that the input power changes during the measurement.

  19. Fiber-interferometric detection of gun-launched projectiles

    Science.gov (United States)

    Goodwin, Peter M.; Marshall, Bruce R.; Gustavsen, Richard L.; Lang, John M.; Pacheco, Adam H.; Loomis, Eric N.; Dattelbaum, Dana M.

    2017-01-01

    We are developing a new diagnostic useful for the non-invasive detection of projectile passage in the launch tube of a gas gun. The sensing element consists of one or more turns of single-mode optical fiber that is epoxy-bonded around the external circumference of the launch tube. The hoop strain induced in the launch tube by the passage of the projectile causes a momentary expansion of the fiber loop. This transient change in path length is detected with high sensitivity using a fiber optic-based interferometer developed by the NSTec Special Technologies Laboratory. We have fielded this new diagnostic, along with fiber optic Bragg grating (FBG) strain gauges we previously used for this purpose, on a variety of gas guns used for shock compression studies at Los Alamos and Sandia National Laboratories. We anticipate that, when coupled with a broad-range analog demodulator circuit, the fiber optic interferometer will have improved dynamic range over that of the FBG strain gauge approach. Moreover, in contrast to the FBG strain gauge which is somewhat temperature sensitive, the interferometric approach requires no alignment immediately prior to the experiment and is therefore easier to implement. Both approaches provide early, pre-event signals useful for triggering high-latency diagnostics.

  20. Resolving phase ambiguities in the calibration of redundant interferometric arrays: implications for array design

    Science.gov (United States)

    Kurien, Binoy G.; Tarokh, Vahid; Rachlin, Yaron; Shah, Vinay N.; Ashcom, Jonathan B.

    2016-10-01

    We provide new results enabling robust interferometric image reconstruction in the presence of unknown aperture piston variation via the technique of redundant spacing calibration (RSC). The RSC technique uses redundant measurements of the same interferometric baseline with different pairs of apertures to reveal the piston variation among these pairs. In both optical and radio interferometry, the presence of phase-wrapping ambiguities in the measurements is a fundamental issue that needs to be addressed for reliable image reconstruction. In this paper, we show that these ambiguities affect recently developed RSC phasor-based reconstruction approaches operating on the complex visibilities, as well as traditional phase-based approaches operating on their logarithm. We also derive new sufficient conditions for an interferometric array to be immune to these ambiguities in the sense that their effect can be rendered benign in image reconstruction. This property, which we call wrap-invariance, has implications for the reliability of imaging via classical three-baseline phase closures as well as generalized closures. We show that wrap-invariance is conferred upon arrays whose interferometric graph satisfies a certain cycle-free condition. For cases in which this condition is not satisfied, a simple algorithm is provided for identifying those graph cycles which prevent its satisfaction. We apply this algorithm to diagnose and correct a member of a pattern family popular in the literature.

  1. Resolving phase ambiguities in the calibration of redundant interferometric arrays: implications for array design

    Science.gov (United States)

    2016-05-18

    2014)), and the Ooty Radio Telescope (ORT) in India (see Marthi & Chengalur (2014)). As will be shown below, N−3 independent redundant re- lations are...interferometric baseline with different pairs of apertures to reveal the piston variation among these pairs. In both optical and radio interferometry...In this paper, we show that these ambigu- ities affect recently- developed RSC phasor-based reconstruction approaches operating on the complex

  2. Computer simulations of interferometric imaging with the VLT interferometer and its AMBER instrument

    CERN Document Server

    Przygodda, F; Hofmann, Karl Heinrich; Weigelt, G

    2001-01-01

    We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO) and the Astronomical MultiBEam Recombiner (AMBER) phase-closure instrument. These simulations include both the astrophysical modelling of a stellar object by radiative transfer calculations and the simulation of light propagation from the object to the detector (through atmosphere, telescopes, and the AMBER instrument), simulation of photon noise and detector read-out noise, and finally data processing of the interferograms. The results show the dependence of the visibility error bars on the following observational parameters: different seeing during the observation of object and reference star (Fried parameters r_0,object and r_0,ref ranging between 0.9m and 1.2m), different residual tip-tilt error (delta_tt,object and delta_tt,ref ranging between 0.1% and 20% of the Airy disk diameter), and object brightness (K_object=0.7mag to 10.2mag, K_ref=0.7mag). Exem...

  3. Calibration of mixed-polarization interferometric observations

    CERN Document Server

    Marti-Vidal, Ivan; Conway, John; Zensus, Anton J

    2016-01-01

    Heterodyne receivers register the sky signal on either a circular polarization basis (where it is split into left-hand and right-hand circular polarization) or a linear polarization basis (where it is split into horizontal and vertical linear polarization). We study the problem of interferometric observations performed with telescopes that observe on different polarization bases, hence producing visibilities that we call "mixed basis" (i.e., linear in one telescope and circular in the other). We present novel algorithms for the proper calibration and treatment of such interferometric observations and test our algorithms with both simulations and real data. The use of our algorithms will be important for the optimum calibration of forthcoming observations with the Atacama Large mm/submm Array (ALMA) in very-long-baseline interferometry (VLBI) mode. Our algorithms will also allow us to optimally calibrate future VLBI observations at very high data rates (i.e., wide bandwidths), where linear-polarization feeds w...

  4. Analysis of the interferometric Ronchi test.

    Science.gov (United States)

    Malacara, D

    1990-09-01

    It is well known that the Ronchi test has two equivalent interpretations, Physical, as an interferometer, or geometrical, as if the fringes were just shadows from the fringes on the ruling. The second interpretation is nearly always used in practice because it is simpler. However, the disadvantage is that the irradiance profile of the fringes cannot be calculated with this theory. Here, the interferometric interpretation of the test will be used to obtain the irradiance profile and the sharpness of the fringes.

  5. Digital Detection of Exosomes by Interferometric Imaging

    OpenAIRE

    2016-01-01

    Exosomes, which are membranous nanovesicles, are actively released by cells and have been attributed to roles in cell-cell communication, cancer metastasis, and early disease diagnostics. The small size (30–100 nm) along with low refractive index contrast of exosomes makes direct characterization and phenotypical classification very difficult. In this work we present a method based on Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS) that allows multiplexed phenotyping and ...

  6. A high resolution, high frame rate detector based on a microchannel plate read out with the Medipix2 counting CMOS pixel chip.

    CERN Document Server

    Mikulec, Bettina; McPhate, J B; Tremsin, A S; Siegmund, O H W; Clark, Allan G; CERN. Geneva

    2005-01-01

    The future of ground-based optical astronomy lies with advancements in adaptive optics (AO) to overcome the limitations that the atmosphere places on high resolution imaging. A key technology for AO systems on future very large telescopes are the wavefront sensors (WFS) which detect the optical phase error and send corrections to deformable mirrors. Telescopes with >30 m diameters will require WFS detectors that have large pixel formats (512x512), low noise (<3 e-/pixel) and very high frame rates (~1 kHz). These requirements have led to the idea of a bare CMOS active pixel device (the Medipix2 chip) functioning in counting mode as an anode with noiseless readout for a microchannel plate (MCP) detector and at 1 kHz continuous frame rate. First measurement results obtained with this novel detector are presented both for UV photons and beta particles.

  7. Investigation of polarization-induced phase noise in interferometric optical fiber sensing system based on FRM%基于法拉第旋镜的干涉型光纤传感系统偏振相位噪声特性研究

    Institute of Scientific and Technical Information of China (English)

    王建飞; 王潇; 罗洪; 孟洲

    2012-01-01

    One of the key technologies of interferometric optical fiber sensing system is to overcome polarization-induced signal fading in interferometric fiber sensors.The theoretical and the experimental investigations of the residual polarization-induced phase noise (PIN) in single-mode optical fiber Michelson interferometer based on Faraday rotation mirror(FRM) are conducted in this paper.A theoretical model of the residual PIN based on Jones matrix is developed.Three leading influencing factors of the residual PIN are educed:the rotation deviation angle of FRM,the state of polarization of input light,and the birefrigent effect of the optical fiber.And three methods are proposed to overcome the residual PIN.The maximal PIN with its amplitude of 0.0815 rad possibly exists in the sensing system when the polarization modulation degree equals 1.84 rad.The correctness of the theoretical model is proved by the experimental results.%偏振诱导信号衰落现象的抑制是干涉型光纤传感系统的关键技术之一.针对法拉第旋镜(FRM)法抑制偏振诱导信号衰落技术的残留偏振相位噪声问题进行了深入的理论和实验研究.运用琼斯矩阵法建立了基于法拉第旋镜的干涉型光纤传感系统偏振相位噪声的理论模型;分析了影响系统偏振相位噪声的主要原因:法拉第旋镜的旋光角度偏差、入射光偏振态调制度、干涉仪两臂光纤双折射;提出了相应的抑制偏振相位噪声的方法.详细仿真分析了入射光偏振态调制度对干涉型光纤传感系统偏振相位噪声的影响,仿真分析得出若法拉第旋镜旋光角度偏差为最大工艺制造误差1°,当入射光偏振态调制度为1.84 rad时,系统可能出现的最大偏振相位噪声为0.0815 rad.最后,搭建了基于M-Z型偏振态调制器的偏振相位噪声测试系统,测试了在传输光纤受到外界偏振扰动的情况下,干涉传感系统存在的偏振相位噪声,实验测试结

  8. An Interferometric Study of the Post-AGB Binary 89 Herculis. 1: Spatially Resolving the Continuum Circumstellar Environment at Optical and Near-IR Wavelengths with the VLTI, NPOI, IOTA, PTI, and the CHARA Array

    Science.gov (United States)

    2013-01-01

    envelope situa- tion (see, e.g., Mastrodemos & Morris 1998; van Winckel 2003; Frankowski & Jorissen 2007). Due to the large and badly con- strained...atmospheres. We use the grid-based method of Degroote et al. (2011), which allows us to identify correlations between parameters and to take them into...discussions about this work and P. Degroote for his SED-fitting scripts. The Navy Precision Optical Interferometer is a joint project of the Naval Research

  9. Three-dimensional interferometric, spectrometric, and planetary views of Procyon

    CERN Document Server

    Chiavassa, A; Kervella, P; Matter, A; Lopez, B; Collet, R; Magic, Z; Asplund, M

    2012-01-01

    We used a new realistic 3D radiative-hydrodynamical model atmosphere of Procyon generated with the Stagger Code and synthetic spectra computed with the radiative transfer code Optim3D to re-analyze interferometric and spectroscopic data from the optical to the infrared of Procyon. We compute intensity maps in two optical filters centered at 500 and 800 nm (MARK III) and one infrared filter centered at 2200 nm (VINCI). We constructed stellar disk images accounting for the center-to-limb variations and used them to derive visibility amplitudes and closure phases. We provide 3D limb-darkening coefficients in the optical as well as in the infrared. We show that visibility curves and closure phases show clear deviations from circular symmetry from the 3rd lobe on. These deviations are detectable with current interferometers using closure phases. We derive new angular diameters at different wavelengths with two independent methods based on 3D simulations. We find a diameter_Vinci = 5.390 \\pm 0.03 mas that this is c...

  10. Improving terrain height estimates from RADARSAT interferometric measurements

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, P.A.; Eichel, P.H.; Calloway, T.M.

    1998-03-01

    The authors describe two methods of combining two-pass RADAR-SAT interferometric phase maps with existing DTED (digital terrain elevation data) to produce improved terrain height estimates. The first is a least-squares estimation procedure that fits the unwrapped phase data to a phase map computed from the DTED. The second is a filtering technique that combines the interferometric height map with the DTED map based on spatial frequency content. Both methods preserve the high fidelity of the interferometric data.

  11. Electronic speckle pattern interferometric testing of JWST primary mirror segment assembly

    Science.gov (United States)

    Smith, Koby Z.; Chaney, David M.; Saif, Babak N.

    2011-09-01

    The James Webb Space Telescope (JWST) Primary Mirror Segment Assembly (PMSA) was required to meet NASA Technology Readiness Level (TRL) 06 requirements in the summer of 2006. These TRL06 requirements included verifying all mirror technology systems level readiness in simulated end-to-end operating conditions. In order to support the aggressive development and technology readiness schedule for the JWST Primary Mirror Segment Assembly (PMSA), a novel approach was implemented to verify the nanometer surface figure distortion effects on an in-process non-polished beryllium mirror surface. At the time that the TRL06 requirements needed to be met, a polished mirror segment had not yet been produced that could have utilized the baselined interferometric optical test station. The only JWST mirror segment available was a finished machined segment with an acid-etched optical surface. Therefore an Electronic Speckle Pattern Interferometer (ESPI) was used in coordination with additional metrology techniques to perform interferometric level optical testing on a non-optical surface. An accelerated, rigorous certification program was quickly developed for the ESPI to be used with the unfinished optical surface of the primary mirror segment. The ESPI was quickly implemented into the PMSA test program and optical testing was very successful in quantifying the nanometer level surface figure deformation changes in the PMSA due to assembly, thermal cycling, vibration, and acoustic testing. As a result of the successful testing, the PMSA passed all NASA TRL06 readiness requirements.

  12. Determination of physical properties of the asteroid (41) Daphne from interferometric observations in the thermal infrared

    CERN Document Server

    Matter, Alexis; Ligori, Sebastiano; Crouzet, Nicolas; Tanga, Paolo

    2011-01-01

    We describe interferometric observations of the asteroid (41) Daphne in the thermal infrared obtained with the Mid-Infrared Interferometric Instrument (MIDI) of the Very Large Telescope Interferometer (VLTI). We derived the size and the surface thermal properties of (41) Daphne by means of a thermophysical model (TPM), which is used for the interpretation of interferometric data for the first time. From our TPM analysis, we derived a volume equivalent diameter for (41) Daphne of 189 km, using a non-convex 3-D shape model derived from optical lightcurves and adaptive optics images (B. Carry, private communication). On the other hand, when using the convex shape of Kaasalainen et al. (2002. Icarus 159, 369-395) in our TPM analysis, the resulting volume equivalent diameter of (41) Daphne is between 194 and 209 km, depending on the surface roughness. The shape of the asteroid is used as an a priori information in our TPM analysis. No attempt is made to adjust the shape to the data. Only the size of the asteroid a...

  13. High-resolution diffraction grating interferometric transducer of linear displacements

    Science.gov (United States)

    Shang, Ping; Xia, Haojie; Fei, Yetai

    2016-01-01

    A high-resolution transducer of linear displacements is presented. The system is based on semiconductor laser illumination and a diffraction grating applied as a length master. The theory of the optical method is formulated using Doppler description. The relationship model among the interference strips, measurement errors, grating deflection around the X, Y and Z axes and translation along the Z axis is built. The grating interference strips' direction and space is not changed with movement along the X (direction of grating movement), Y (direction of grating line), Z axis, and the direction and space has a great effect when rotating around the X axis. Moreover the space is little affected by deflection around the Z axis however the direction is changed dramatically. In addition, the strips' position shifted rightward or downwards respectively for deflection around the X or Y axis. Because the emitted beams are separated on the grating plane, the tilt around the X axis error of the stage during motion will lead to the optical path difference of the two beams resulting in phase shift. This study investigates the influence of the tilt around the X axis error. Experiments show that after yaw error compensation, the high-resolution diffraction grating interferometric transducer readings can be significantly improved. The error can be reduced from +/-80 nm to +/-30 nm in maximum.

  14. Improving the performance of interferometric imaging through the use of disturbance feedforward.

    Science.gov (United States)

    Böhm, Michael; Glück, Martin; Keck, Alexander; Pott, Jörg-Uwe; Sawodny, Oliver

    2017-05-01

    In this paper, we present a disturbance compensation technique to improve the performance of interferometric imaging for extremely large ground-based telescopes, e.g., the Large Binocular Telescope (LBT), which serves as the application example in this contribution. The most significant disturbance sources at ground-based telescopes are wind-induced mechanical vibrations in the range of 8-60 Hz. Traditionally, their optical effect is eliminated by feedback systems, such as the adaptive optics control loop combined with a fringe tracking system within the interferometric instrument. In this paper, accelerometers are used to measure the vibrations. These measurements are used to estimate the motion of the mirrors, i.e., tip, tilt and piston, with a dynamic estimator. Additional delay compensation methods are presented to cancel sensor network delays and actuator input delays, improving the estimation result even more, particularly at higher frequencies. Because various instruments benefit from the implementation of telescope vibration mitigation, the estimator is implemented as a separate, independent software on the telescope, publishing the estimated values via multicast on the telescope's ethernet. Every client capable of using and correcting the estimated disturbances can subscribe and use these values in a feedforward for its compensation device, e.g., the deformable mirror, the piston mirror of LINC-NIRVANA, or the fast path length corrector of the Large Binocular Telescope Interferometer. This easy-to-use approach eventually leveraged the presented technology for interferometric use at the LBT and now significantly improves the sky coverage, performance, and operational robustness of interferometric imaging on a regular basis.

  15. Speckle interferometric observations of close binary stars

    CERN Document Server

    Saha, S K; Yeswanth, L; Anbazhagan, P

    2002-01-01

    Speckle interferometric technique is employed to record a series of hundreds of short-exposure images of several close binary stars with sub-arcsecond separation through a narrow band filter at the Cassegrain focus of the 2.34 meter (m) Vainu Bappu telescope (VBT), situated at Vainu Bappu Observatory (VBO), Kavalur, India. The data are recorded sequentially by a Peltier-cooled intensified CCD camera with 10 ms exposure. The auto-correlation method is applied to determine the angular separations and position angles of these binary systems.

  16. The response of interferometric gravitational wave detectors

    CERN Document Server

    Finn, Lee Samuel

    2008-01-01

    The standard derivation of the response of interferometric gravitational wave detectors makes a series of erroneous approximations regarding the coordinate trajectory of the light and the parameterization of the null geodesic it travels along. These errors appear to have remained unrecognized for at least thirty five years. We provide, in full detail, a correct derivation of the response of a single-bounce Michelson interferometer to gravitational waves, compare it to the "standard", but incorrect, derivation, and show where the earlier mistakes were made. By a fortuitous set of circumstances, not generally so, the final result is the same.

  17. Interferometric Calibration with Natural Distributed Targets

    DEFF Research Database (Denmark)

    Dall, Jørgen; Christensen, Erik Lintz

    2002-01-01

    Cross-calibration is a fully automated algorithm for calibration of interferometric synthetic aperture radar (IFSAR) data. It has been developed for single-pass interferometry, but the principles may be applicable to multi-pass interferometry, too. The algorithm is based on natural distributed...... targets and it excels by neither requiring surveyed ground control points nor dedicated calibration scenes. However, the parameters to be calibrated must be stable during mapping. The algorithm has been applied to data from the Danish airborne SAR, EMISAR, and the performance has been assessed...

  18. Cross-calibration of interferometric SAR data

    DEFF Research Database (Denmark)

    Dall, Jørgen

    2003-01-01

    Generation of digital elevation models from interferometric synthetic aperture radar (SAR) data is a well established technique. Achieving a high geometric fidelity calls for a calibration accounting for inaccurate navigation data and system parameters as well as system imperfections. Fully......, but not necessarily from map to map. It is based on natural distributed targets for which no a priori knowledge is needed. In particular, no DEM is required as in calibration techniques based on dedicated calibration scenes. To achieve absolute calibration, i.e. elimination of a constant elevation offset, a single...

  19. Interferometric direct imaging properties of a BIGRE-DAM device in laboratory

    Science.gov (United States)

    Patru, Fabien; Antichi, Jacopo; Rabou, Patrick; Giro, Enrico; Farinato, Jacopo; Gratton, Raffaele; Vassallo, Daniele; Verinaud, Christophe; Mourard, Denis; Girard, Julien

    2016-08-01

    DAM (Discretized Aperture Mapping) is an original optical concept able to improve the performance in high angular resolution and high contrast imaging by the present class of large telescopes equipped with adaptive optics. By discretizing the entrance pupil of a large telescope into an array of many coherent sub-apertures, DAM provides unique imaging and filtering properties by means of spatial filtering and interferometric techniques. DAM can be achieved by means of single-mode fibers, integrated optic waveguides, pinholes, or simply with an innovative BIGRE optical device. BIGRE is formed of an afocal double micro-lenses array. In addition to the pupil discretization process by spatial filtering, BIGRE can also provide two other optical processes: the pupil densification or the pupil dilution. DAD (Discretized Aperture Densification) increase the sub-aperture sizes and is suitable to a hypertelescope, whereas DADI (Discretized Aperture Dilution Interferometry) reduces the sub-aperture sizes and turns a large telescope into a Fizeau interferometer. This paper deals with the first in-lab experiment at visible wavelength of BIGRE devices for the three configurations above. We study the point spread function (PSF) when observing a point-like object located either on-axis or at various off-axis positions across the field of view. Both interferometric and diffractive effects are described. The experimental measurements are in good agreement with the BIGRE theory. It results that BIGRE fulfils the requirements to carry out spatially filtered pupil discretization (DAM), with possible densification (DAD) or dilution (DADI).

  20. Interferometric interpolation of sparse marine data

    KAUST Repository

    Hanafy, Sherif M.

    2013-10-11

    We present the theory and numerical results for interferometrically interpolating 2D and 3D marine surface seismic profiles data. For the interpolation of seismic data we use the combination of a recorded Green\\'s function and a model-based Green\\'s function for a water-layer model. Synthetic (2D and 3D) and field (2D) results show that the seismic data with sparse receiver intervals can be accurately interpolated to smaller intervals using multiples in the data. An up- and downgoing separation of both recorded and model-based Green\\'s functions can help in minimizing artefacts in a virtual shot gather. If the up- and downgoing separation is not possible, noticeable artefacts will be generated in the virtual shot gather. As a partial remedy we iteratively use a non-stationary 1D multi-channel matching filter with the interpolated data. Results suggest that a sparse marine seismic survey can yield more information about reflectors if traces are interpolated by interferometry. Comparing our results to those of f-k interpolation shows that the synthetic example gives comparable results while the field example shows better interpolation quality for the interferometric method. © 2013 European Association of Geoscientists & Engineers.

  1. Digital Detection of Exosomes by Interferometric Imaging

    Science.gov (United States)

    Daaboul, George G.; Gagni, Paola; Benussi, Luisa; Bettotti, Paolo; Ciani, Miriam; Cretich, Marina; Freedman, David S.; Ghidoni, Roberta; Ozkumur, Ayca Yalcin; Piotto, Chiara; Prosperi, Davide; Santini, Benedetta; Ünlü, M. Selim; Chiari, Marcella

    2016-01-01

    Exosomes, which are membranous nanovesicles, are actively released by cells and have been attributed to roles in cell-cell communication, cancer metastasis, and early disease diagnostics. The small size (30–100 nm) along with low refractive index contrast of exosomes makes direct characterization and phenotypical classification very difficult. In this work we present a method based on Single Particle Interferometric Reflectance Imaging Sensor (SP-IRIS) that allows multiplexed phenotyping and digital counting of various populations of individual exosomes (>50 nm) captured on a microarray-based solid phase chip. We demonstrate these characterization concepts using purified exosomes from a HEK 293 cell culture. As a demonstration of clinical utility, we characterize exosomes directly from human cerebrospinal fluid (hCSF). Our interferometric imaging method could capture, from a very small hCSF volume (20 uL), nanoparticles that have a size compatible with exosomes, using antibodies directed against tetraspanins. With this unprecedented capability, we foresee revolutionary implications in the clinical field with improvements in diagnosis and stratification of patients affected by different disorders. PMID:27853258

  2. Miniaturized High Performance Optical Gyroscope Project

    Data.gov (United States)

    National Aeronautics and Space Administration — We propose a new approach for to the design and fabrication of miniaturized Interferometric Fiber Optical Gyroscope (FOG) that enables the production of smaller IRU...

  3. Interferometric source of multi-color, multi-beam entangled photons with mirror and mixer

    Science.gov (United States)

    Dress, William B.; Kisner, Roger A.; Richards, Roger K.

    2004-06-01

    53 Systems and methods are described for an interferometric source of multi-color, multi-beam entangled photons. An apparatus includes: a multi-refringent device optically coupled to a source of coherent energy, the multi-refringent device providing a beam of multi-color entangled photons; a condenser device optically coupled to the multi-refringent device, the condenser device i) including a mirror and a mixer and ii) converging two spatially resolved portions of the beam of multi-color entangled photons into a converged multi-color entangled photon beam; a tunable phase adjuster optically coupled to the condenser device, the tunable phase adjuster changing a phase of at least a portion of the converged multi-color entangled photon beam to generate a first interferometeric multi-color entangled photon beam; and a beam splitter optically coupled to the condenser device, the beam splitter combining the first interferometeric multi-color entangled photon beam with a second interferometric multi-color entangled photon beam.

  4. Dynamic measurements of flowing cells labeled by gold nanoparticles using full-field photothermal interferometric imaging

    Science.gov (United States)

    Turko, Nir A.; Roitshtain, Darina; Blum, Omry; Kemper, Björn; Shaked, Natan T.

    2017-06-01

    We present highly dynamic photothermal interferometric phase microscopy for quantitative, selective contrast imaging of live cells during flow. Gold nanoparticles can be biofunctionalized to bind to specific cells, and stimulated for local temperature increase due to plasmon resonance, causing a rapid change of the optical phase. These phase changes can be recorded by interferometric phase microscopy and analyzed to form an image of the binding sites of the nanoparticles in the cells, gaining molecular specificity. Since the nanoparticle excitation frequency might overlap with the sample dynamics frequencies, photothermal phase imaging was performed on stationary or slowly dynamic samples. Furthermore, the computational analysis of the photothermal signals is time consuming. This makes photothermal imaging unsuitable for applications requiring dynamic imaging or real-time analysis, such as analyzing and sorting cells during fast flow. To overcome these drawbacks, we utilized an external interferometric module and developed new algorithms, based on discrete Fourier transform variants, enabling fast analysis of photothermal signals in highly dynamic live cells. Due to the self-interference module, the cells are imaged with and without excitation in video-rate, effectively increasing signal-to-noise ratio. Our approach holds potential for using photothermal cell imaging and depletion in flow cytometry.

  5. Heterogeneous radio-over-fiber passive access network architecture to mitigate Rayleigh backscattering interferometric beat noise.

    Science.gov (United States)

    Yeh, C H; Chow, C W

    2011-03-28

    We propose and experimentally demonstrate a hybrid radio-over-fiber (ROF) wavelength division multiplexed and time division multiplexed passive optical network (WDM-TDM PON) architecture to mitigate Rayleigh backscattering (RB) interferometric beat noises. Here, only a single wavelength is needed at the central office (CO) to generate the downstream baseband data for optical wired application and optical millimeter-wave (mm-wave) signal for wireless application. The upstream signal is produced by remodulating the downstream signal. No optical filter is required at the optical network unit/remote antenna unit (ONU/RAU) to separate the optical wired and optical mm-wave signals. In the proposed network, 10 Gb/s differential phase shift keying (DPSK) signal is used for the downstream optical wired application and 2.5 Gb/s on-off keying (OOK) signal on 20 GHz carrier is used for the optical mm-wave signal. In each ONU, a reflective optical semiconductor amplifier (RSOA) is used to remodulate and produce a 2.5 Gb/s OOK format for upstream traffic. As the back-refection produced by the downstream DPSK signal and the upstream OOK signal is traveling in different fiber path, RB noise at the CO can be completely mitigated.

  6. Asynchronous rotation scan for synthetic aperture interferometric radiometer

    Institute of Scientific and Technical Information of China (English)

    WU Ji; ZHANG Cheng; LIU Hao; SUN WeiYing

    2009-01-01

    Synthetic aperture interferometric technique has wide applications in optics, radio astronomy and mi-crowave remote sensing areas. With the increasing demands of high resolution imaging observation, a new time-sharing sampling scheme of asynchronous rotation scan is proposed to meet the technical challenge of achieving a large equivalent aperture and overcome the operating barriers of space borne application. This configuration is basically composed by two asynchronously and concentrically ro-tating antenna groups, whose revolving radii and speeds are different. The synthetic aperture system with asynchronous rotation scanning scheme can effectively solve the trade-off problem of system complexity, and greatly simplify the system hardware at the cost of sacrificing a certain time resolution. The basic rules and design methods of asynchronous rotation scan are investigated The Gridding method is introduced to inverse the spiral sampling data for image reconstruction. The potential ap-plications of geostationary orbit (GEO) earth observation and solar polar orbit (SPO) plasma cloud observation are explored with numerical simulations to validate the significance and feasibility of this new imaging configuration.

  7. Interferometric measurement of many-body topological invariants using polarons

    Science.gov (United States)

    Grusdt, Fabian; Yao, Norman; Abanin, Dmitry; Demler, Eugene

    2014-05-01

    We present a scheme for the direct detection of many-body topological invariants in ultra cold quantum gases in optical lattices. We generalize single-particle interferometric schemes developed for the detection of topologically non-trivial band structures [Atala et al., Nature Physics 9, 795 (2013)] by coupling a spin-1/2 impurity to a (topological) excitation of an interacting many-body system. Performing Ramsey interferometry in combination with Bloch oscillations of the resulting polaronic particle allows to directly detect the many body-topological invariant. In particular we consider adiabatic Thouless pumps in the super-lattice Bose-Hubbard model, which transport a quantized amount of particles across a one-dimensional lattice. In the presence of inter-atomic interactions this quantized current is given by a many-body Chern number, which can be measured using our protocol. These systems also support symmetry-protected topological phases, the invariants of which can be obtained from our protocol as well.

  8. Controlling interferometric properties of nanoporous anodic aluminium oxide.

    Science.gov (United States)

    Kumeria, Tushar; Losic, Dusan

    2012-01-26

    A study of reflective interference spectroscopy [RIfS] properties of nanoporous anodic aluminium oxide [AAO] with the aim to develop a reliable substrate for label-free optical biosensing is presented. The influence of structural parameters of AAO including pore diameters, inter-pore distance, pore length, and surface modification by deposition of Au, Ag, Cr, Pt, Ni, and TiO2 on the RIfS signal (Fabry-Perot fringe) was explored. AAO with controlled pore dimensions was prepared by electrochemical anodization of aluminium using 0.3 M oxalic acid at different voltages (30 to 70 V) and anodization times (10 to 60 min). Results show the strong influence of pore structures and surface modifications on the interference signal and indicate the importance of optimisation of AAO pore structures for RIfS sensing. The pore length/pore diameter aspect ratio of AAO was identified as a suitable parameter to tune interferometric properties of AAO. Finally, the application of AAO with optimised pore structures for sensing of a surface binding reaction of alkanethiols (mercaptoundecanoic acid) on gold surface is demonstrated.

  9. Asynchronous rotation scan for synthetic aperture interferometric radiometer

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Synthetic aperture interferometric technique has wide applications in optics,radio astronomy and mi-crowave remote sensing areas.With the increasing demands of high resolution imaging observation,a new time-sharing sampling scheme of asynchronous rotation scan is proposed to meet the technical challenge of achieving a large equivalent aperture and overcome the operating barriers of space borne application.This configuration is basically composed by two asynchronously and concentrically ro-tating antenna groups,whose revolving radii and speeds are different.The synthetic aperture system with asynchronous rotation scanning scheme can effectively solve the trade-off problem of system complexity,and greatly simplify the system hardware at the cost of sacrificing a certain time resolution.The basic rules and design methods of asynchronous rotation scan are investigated The Gridding method is introduced to inverse the spiral sampling data for image reconstruction.The potential ap-plications of geostationary orbit(GEO)earth observation and solar polar orbit(SPO)plasma cloud observation are explored with numerical simulations to validate the significance and feasibility of this new imaging configuration.

  10. Interferometric Plasmonic Lensing with Nanohole Arrays

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Yu; Joly, Alan G.; El-Khoury, Patrick Z.; Hess, Wayne P.

    2014-12-18

    Nonlinear photoemission electron microscopy (PEEM) of nanohole arrays in gold films maps propagating surface plasmons (PSPs) launched from lithographically patterned structures. Strong near field photoemission patterns are observed in the PEEM images, recorded following low angle of incidence irradiation of nanohole arrays with sub-15 fs laser pulses centered at 780 nm. The recorded photoemission patterns are attributed to constructive and destructive interferences between PSPs launched from the individual nanoholes which comprise the array. By exploiting the wave nature of PSPs, we demonstrate how varying the array geometry (hole diameter, pitch, and number of rows/columns) ultimately yields intense localized photoemission. Through a combination of PEEM and finite-difference time-domain simulations, we identify the optimal array geometry for efficient light coupling and interferometric plasmonic lensing. We show a preliminary application of inteferometric plasmonic lensing by enhancing the photoemission from the vertex of a gold triangle using nanohole array.

  11. uvmcmcfit: Parametric models to interferometric data fitter

    Science.gov (United States)

    Bussmann, Shane; Leung, Tsz Kuk (Daisy); Conley, Alexander

    2016-06-01

    Uvmcmcfit fits parametric models to interferometric data. It is ideally suited to extract the maximum amount of information from marginally resolved observations with interferometers like the Atacama Large Millimeter Array (ALMA), Submillimeter Array (SMA), and Plateau de Bure Interferometer (PdBI). uvmcmcfit uses emcee (ascl:1303.002) to do Markov Chain Monte Carlo (MCMC) and can measure the goodness of fit from visibilities rather than deconvolved images, an advantage when there is strong gravitational lensing and in other situations. uvmcmcfit includes a pure-Python adaptation of Miriad’s (ascl:1106.007) uvmodel task to generate simulated visibilities given observed visibilities and a model image and a simple ray-tracing routine that allows it to account for both strongly lensed systems (where multiple images of the lensed galaxy are detected) and weakly lensed systems (where only a single image of the lensed galaxy is detected).

  12. The 2012 interferometric imaging beauty contest

    Science.gov (United States)

    Baron, Fabien; Cotton, William D.; Lawson, Peter R.; Ridgway, Steve T.; Aarnio, Alicia; Monnier, John D.; Hofmann, Karl-Heinz; Schertl, Dieter; Weigelt, Gerd; Thiébaut, Eric; Soulez, Férréol; Mary, David; Millour, Florentin; Vannier, Martin; Young, John; Elias, Nicholas M.; Schmitt, Henrique R.; Rengaswamy, Sridharan

    2012-07-01

    We present the results of the fifth Interferometric Imaging Beauty Contest. The contest consists in blind imaging of test data sets derived from model sources and distributed in the OIFITS format. Two scenarios of imaging with CHARA/MIRC-6T were offered for reconstruction: imaging a T Tauri disc and imaging a spotted red supergiant. There were eight different teams competing this time: Monnier with the software package MACIM; Hofmann, Schertl and Weigelt with IRS; Thiebaut and Soulez with MiRA ; Young with BSMEM; Mary and Vannier with MIROIRS; Millour and Vannier with independent BSMEM and MiRA entries; Rengaswamy with an original method; and Elias with the radio-astronomy package CASA. The contest model images, the data delivered to the contestants and the rules are described as well as the results of the image reconstruction obtained by each method. These results are discussed as well as the strengths and limitations of each algorithm.

  13. The 2012 Interferometric Imaging Beauty Contest

    CERN Document Server

    Baron, Fabien; Lawson, Peter R; Ridgway, Steve T; Aarnio, Alicia; Monnier, John D; Hofmann, Karl-Heinz; Schertl, Dieter; Weigelt, Gerd; Thiébaut, Eric; Soulez, Férréol; Mary, David; Millour, Florentin; Vannier, Martin; Young, John; Elias, Nicholas M; Schmitt, Henrique R; Rengaswamy, Sridharan

    2012-01-01

    We present the results of the fifth Interferometric Imaging Beauty Contest. The contest consists in blind imaging of test data sets derived from model sources and distributed in the OIFITS format. Two scenarios of imaging with CHARA/MIRC-6T were offered for reconstruction: imaging a T Tauri disc and imaging a spotted red supergiant. There were eight different teams competing this time: Monnier with the software package MACIM; Hofmann, Schertl and Weigelt with IRS; Thi\\'ebaut and Soulez with MiRA ; Young with BSMEM; Mary and Vannier with MIROIRS; Millour and Vannier with independent BSMEM and MiRA entries; Rengaswamy with an original method; and Elias with the radio-astronomy package CASA. The contest model images, the data delivered to the contestants and the rules are described as well as the results of the image reconstruction obtained by each method. These results are discussed as well as the strengths and limitations of each algorithm.

  14. Fundamentals of interferometric gravitational wave detectors

    CERN Document Server

    Saulson, Peter R

    2017-01-01

    LIGO's recent discovery of gravitational waves was headline news around the world. Many people will want to understand more about what a gravitational wave is, how LIGO works, and how LIGO functions as a detector of gravitational waves.This book aims to communicate the basic logic of interferometric gravitational wave detectors to students who are new to the field. It assumes that the reader has a basic knowledge of physics, but no special familiarity with gravitational waves, with general relativity, or with the special techniques of experimental physics. All of the necessary ideas are developed in the book.The first edition was published in 1994. Since the book is aimed at explaining the physical ideas behind the design of LIGO, it stands the test of time. For the second edition, an Epilogue has been added; it brings the treatment of technical details up to date, and provides references that would allow a student to become proficient with today's designs.

  15. Compression of interferometric radio-astronomical data

    CERN Document Server

    Offringa, A R

    2016-01-01

    The volume of radio-astronomical data is a considerable burden in the processing and storing of radio observations with high time and frequency resolutions and large bandwidths. Lossy compression of interferometric radio-astronomical data is considered to reduce the volume of visibility data and to speed up processing. A new compression technique named "Dysco" is introduced that consists of two steps: a normalization step, in which grouped visibilities are normalized to have a similar distribution; and a quantization and encoding step, which rounds values to a given quantization scheme using a dithering scheme. Several non-linear quantization schemes are tested and combined with different methods for normalizing the data. Four data sets with observations from the LOFAR and MWA telescopes are processed with different processing strategies and different combinations of normalization and quantization. The effects of compression are measured in image plane. The noise added by the lossy compression technique acts ...

  16. Interferometric Approach to Probing Fast Scrambling

    CERN Document Server

    Yao, Norman Y; Swingle, Brian; Lukin, Mikhail D; Stamper-Kurn, Dan M; Moore, Joel E; Demler, Eugene A

    2016-01-01

    Out-of-time-order correlation functions provide a proxy for diagnosing chaos in quantum systems. We propose and analyze an interferometric scheme for their measurement, using only local quantum control and no reverse time evolution. Our approach utilizes a combination of Ramsey interferometry and the recently demonstrated ability to directly measure Renyi entropies. To implement our scheme, we present a pair of cold-atom-based experimental blueprints; moreover, we demonstrate that within these systems, one can naturally realize the transverse-field Sherrington-Kirkpatrick (TFSK) model, which exhibits certain similarities with fast scrambling black holes. We perform a detailed numerical study of scrambling in the TFSK model, observing an interesting interplay between the fast scrambling bound and the onset of spin-glass order.

  17. Matched filtering with interferometric 21 cm experiments

    Science.gov (United States)

    White, Martin; Padmanabhan, Nikhil

    2017-10-01

    A new generation of interferometric instruments is emerging, which aims to use intensity mapping of redshifted 21 cm radiation to measure the large-scale structure of the Universe at z ≃ 1-2 over wide areas of the sky. While these instruments typically have limited angular resolution, they cover huge volumes and thus can be used to provide large samples of rare objects. In this paper we study how well such instruments could find spatially extended large-scale structures, such as cosmic voids, using a matched filter formalism. Such a formalism allows us to work in Fourier space, the natural space for interferometers, and to study the impact of finite u - v coverage, noise and foregrounds on our ability to recover voids. We find that in the absence of foregrounds, such instruments would provide enormous catalogs of voids, with high completeness, but that control of foregrounds is key to realizing this goal.

  18. The Space Infrared Interferometric Telescope (SPIRIT)

    Science.gov (United States)

    Leisawitz, David T.

    2014-01-01

    The far-infrared astrophysics community is eager to follow up Spitzer and Herschel observations with sensitive, high-resolution imaging and spectroscopy, for such measurements are needed to understand merger-driven star formation and chemical enrichment in galaxies, star and planetary system formation, and the development and prevalence of water-bearing planets. The Space Infrared Interferometric Telescope (SPIRIT) is a wide field-of-view space-based spatio-spectral interferometer designed to operate in the 25 to 400 micron wavelength range. This talk will summarize the SPIRIT mission concept, with a focus on the science that motivates it and the technology that enables it. Without mentioning SPIRIT by name, the astrophysics community through the NASA Astrophysics Roadmap Committee recently recommended this mission as the first in a series of space-based interferometers. Data from a laboratory testbed interferometer will be used to illustrate how the spatio-spectral interferometry technique works.

  19. Fiber optic sensing and imaging

    CERN Document Server

    2013-01-01

    This book is designed to highlight the basic principles of fiber optic imaging and sensing devices. The editor has organized the book to provide the reader with a solid foundation in fiber optic imaging and sensing devices. It begins with an introductory chapter that starts from Maxwell’s equations and ends with the derivation of the basic optical fiber characteristic equations and solutions (i.e. fiber modes). Chapter 2 reviews most common fiber optic interferometric devices and Chapter 3 discusses the basics of fiber optic imagers with emphasis on fiber optic confocal microscope. The fiber optic interferometric sensors are discussed in detail in chapter 4 and 5. Chapter 6 covers optical coherence tomography and goes into the details of signal processing and systems level approach of the real-time OCT implementation. Also useful forms of device characteristic equations are provided so that this book can be used as a reference for scientists and engineers in the optics and related fields.

  20. Detection and characterization of single nanoparticles by interferometric phase modulated ellipsometry

    Energy Technology Data Exchange (ETDEWEB)

    Barroso, F.; Bosch, S.; Tort, N.; Arteaga, O. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Sancho-Parramon, J. [Rudjer Boskovic Institute, Bijenicka c. 54, Zagreb 10002 (Croatia); Jover, E.; Bertran, E. [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain); Canillas, A., E-mail: acanillas@ub.ed [Universitat de Barcelona, IN2UB, Dep. Fisica Aplicada i Optica, c/Marti i Franques 1, 08028 (Spain)

    2011-02-28

    We introduce a new measurement system called Nanopolar interferometer devoted to monitor and characterize single nanoparticles which is based on the interferometric phase modulated ellipsometry technique. The system collects the backscattered light by the particles in the solid angle subtended by a microscope objective and then analyses its frequency components. The results for the detection of 2 {mu}m and 50 nm particles are explained in terms of a cross polarization effect of the polarization vectors when the beam converts from divergent to parallel in the microscope objective. This explanation is supported with the results of the optical modelling using the exact Mie theory for the light scattered by the particles.

  1. GRAVITY: the VLTI 4-beam combiner for narrow-angle astrometry and interferometric imaging

    CERN Document Server

    Blind, N; Gillessen, S; Kok, Y; Lippa, M; Perrin, G; Dembet, R; Fedou, P; Lacour, S; Perraut, K; Jocou, L; Burtscher, L; Hans, O; Haug, M; Haussmann, F; Huber, S; Janssen, A; Kellner, S; Ott, T; Pfuhl, O; Sturm, E; Weber, J; Wieprecht, E; Amorim, A; Brandner, W; Straubmeier, C

    2015-01-01

    GRAVITY is the second generation Very Large Telescope Interferometer instrument for precision narrow-angle astrometry and interferometric imaging in the Near Infra-Red (NIR). It shall provide precision astrometry of order 10 microarcseconds, and imaging capability at a few milliarcsecond resolution, and hence will revolutionise dynamical measurements of celestial objects. GRAVITY is currently in the last stages of its integration and tests in Garching at MPE, and will be delivered to the VLT Interferometer (VLTI) in 2015. We present here the instrument, with a particular focus on the components making use of fibres: integrated optics beam combiners, polarisation rotators, fibre differential delay lines, and the metrology.

  2. Ultrasonic evaluation of residual stresses in flat glass tempering by an original double interferometric detection.

    Science.gov (United States)

    Devos, D; Duquennoy, M; Roméro, E; Jenot, F; Lochegnies, D; Ouaftouh, M; Ourak, M

    2006-12-22

    In industrial thermal tempering of glass, the knowledge of the homogeneity of compressive residual stress field on the glass product is fundamental to guarantee the quality of the tempered glass product. In this paper, we use the acoustoelasticity phenomenon in order to estimate the residual stress distribution by using acoustic surface wave. We present an experimental setup based on a double interferometric detection in which an aspheric lens is associated with a beam splitter and a YAG laser whose power is 100 mW. This relative high power enables us to carry out measurements on surface flat glass although optical reflection coefficient is typically weak (glass tempering.

  3. Tunable mechanical monolithic sensor with interferometric readout for low frequency seismic noise measurement

    Science.gov (United States)

    Acernese, F.; De Rosa, R.; Giordano, G.; Romano, R.; Barone, F.

    2008-03-01

    This paper describes a mechanical monolithic sensor for geophysical applications developed at the University of Salerno. The instrument is basically a monolithic tunable folded pendulum, shaped with precision machining and electric-discharge-machining, that can be used both as seismometer and, in a force-feedback configuration, as accelerometer. The monolithic mechanical design and the introduction of laser interferometric techniques for the readout implementation make it a very compact instrument, very sensitive in the low-frequency seismic noise band, with a very good immunity to environmental noises. Many changes have been produced since last version (2007), mainly aimed to the improvement of the mechanics and of the optical readout of the instrument. In fact, we have developed and tested a prototype with elliptical hinges and mechanical tuning of the resonance frequency together with a laser optical lever and a new laser interferometer readout system. The theoretical sensitivity curve both for both laser optical lever and laser interferometric readouts, evaluated on the basis of suitable theoretical models, shows a very good agreement with the experimental measurements. Very interesting scientific result, for example, is that the measured natural resonance frequency of the instrument is 70 mHz with a Q = 140 in air without thermal stabilization, demonstrating the feasibility of a monolithic FP sensor with a natural resonance frequency of the order of mHz with a more refined mechanical tuning. Results on the readout system based on polarimetric homodyne Michelson interferometer is discussed.

  4. Scalable Engineering of Quantum Optical Information Processing Architectures (SEQUOIA)

    Science.gov (United States)

    2016-12-13

    interfacing with telecom quantum networks /qubit distribution 4. DV quantum computing using CV cluster Embed circuit model quantum computing into CV...linear-optics mode transformations Realizing scalable, high-fidelity interferometric networks is a central challenge to be addressed on the path...methods for characterizing these large interferometric networks . Figure 1:Photonic integrated circuit. Left: programmable PIC. Right: Transmission at

  5. Digital signal processing for a thermal neutron detector using ZnS(Ag):{sup 6}LiF scintillating layers read out with WLS fibers and SiPMs

    Energy Technology Data Exchange (ETDEWEB)

    Mosset, J.-B., E-mail: jean-baptiste.mosset@psi.ch; Stoykov, A.; Greuter, U.; Hildebrandt, M.; Schlumpf, N.

    2016-07-11

    We present a digital signal processing system based on a photon counting approach which we developed for a thermal neutron detector consisting of ZnS(Ag):{sup 6}LiF scintillating layers read out with WLS fibers and SiPMs. Three digital filters have been evaluated: a moving sum, a moving sum after differentiation and a digital CR-RC{sup 4} filter. The performances of the detector with these filters are presented. A full analog signal processing using a CR-RC{sup 4} filter has been emulated digitally. The detector performance obtained with this analog approach is compared with the one obtained with the best performing digital approach. - Highlights: • Application of digital signal processing for a SiPM-based ZnS:6LiF neutron detector. • Optimisation of detector performances with 3 different digital filters. • Comparison with detector performances with a full analog signal processing.

  6. Theoretical and experimental study on white light interferometric sensing network with double-ring topology

    Institute of Scientific and Technical Information of China (English)

    YANG Jun; YUAN Li-bo

    2006-01-01

    A white-light interferometric fiber-optic sensing network based on the double-ring topology is demonstrated,which can be applied to the measurements of quasidistributed strain and temperature in a smart structure.In order to increase the multiplexing capacity,decrease the measurement cost of each sensor,and improve the ability of reliability of the sensor network,a double-port interrogating technology was used.The double- ring fiber optical sensing network based on the space division multiplexing (SDM) is further developed,The low coherent multiplexing principle in the double-ring network structure is analyzed.Based on the optical path matching condition of SDM,the intensity characteristic of the interference signal in the sensor is deduced.The characteristics of the double-ring sensing network connecting 9 sensors and its property of robust resisting destruction are verified by experiments,and the results are analyzed and discussed.

  7. Weighted-elastic-wave interferometric imaging of microseismic source location

    Science.gov (United States)

    Li, Lei; Chen, Hao; Wang, Xiu-Ming

    2015-06-01

    Knowledge of the locations of seismic sources is critical for microseismic monitoring. Time-window-based elastic wave interferometric imaging and weighted-elastic-wave (WEW) interferometric imaging are proposed and used to locate modeled microseismic sources. The proposed method improves the precision and eliminates artifacts in location profiles. Numerical experiments based on a horizontally layered isotropic medium have shown that the method offers the following advantages: It can deal with low-SNR microseismic data with velocity perturbations as well as relatively sparse receivers and still maintain relatively high precision despite the errors in the velocity model. Furthermore, it is more efficient than conventional traveltime inversion methods because interferometric imaging does not require traveltime picking. Numerical results using a 2D fault model have also suggested that the weighted-elastic-wave interferometric imaging can locate multiple sources with higher location precision than the time-reverse imaging method.

  8. Benefits and limitations of imaging multiples: Interferometric and resonant migration

    KAUST Repository

    Guo, Bowen

    2015-07-01

    The benefits and limitations of imaging multiples are reviewed for interferometric migration and resonant migration. Synthetic and field data examples are used to characterize the effectiveness of the methods.

  9. Spectroscopic and Interferometric Measurements of Nine K Giant Stars

    CERN Document Server

    Baines, Ellyn K; Guenther, Eike W; Hatzes, Artie P; Hrudkovu, Marie; van Belle, Gerard T

    2016-01-01

    We present spectroscopic and interferometric measurements for a sample of nine K giant stars. These targets are of particular interest because they are slated for stellar oscillation observations. Our improved parameters will directly translate into reduced errors in the final masses for these stars when interferometric radii and asteroseismic densities are combined. Here we determine each star's limb-darkened angular diameter, physical radius, luminosity, bolometric flux, effective temperature, surface gravity, metallicity, and mass. When we compare our interferometric and spectroscopic results, we find no systematic offsets in the diameters and the values generally agree within the errors. Our interferometric temperatures for seven of the nine stars are hotter than those determined from spectroscopy with an average difference of about 380 K.

  10. Laser frequency stabilization based on Sagnac interferometric spectroscopy

    Institute of Scientific and Technical Information of China (English)

    Hui Yan; Guoqing Yang; Jin Wang; Mingsheng Zhan

    2008-01-01

    @@ A simple method based on Sagnac interferometric spectroscopy (SIS) is applied for frequency stabilization of diode lasers. Sagnac interferometric spectra of rubidium vapor are investigated both theoretically and experimentally. The interference signal at the output of the Sagnac interferometer displays a sharp dispersion feature near the atomic resonance. This dispersion curve is used as the feedback error signal to stabilize the laser frequency. Linewidth of a diode laser is stabilized down to 1 MHz by this modulation-free method.

  11. Interferometric SAR imaging by transmitting stepped frequency chaotic noise signals

    Science.gov (United States)

    Zhang, Yunhua; Gu, Xiang; Zhai, Wenshuai; Dong, Xiao; Shi, Xiaojin; Kang, Xueyan

    2015-10-01

    Noise radar has been applied in many fields since it was proposed more than 50 years ago. However, it has not been applied to interferometric SAR imaging yet as far as we know. This paper introduces our recent work on interferometric noise radar. An interferometric SAR system was developed which can transmit both chirp signal and chaotic noise signal (CNS) at multiple carrier frequencies. An airborne experiment with this system by transmitting both signals was carried out, and the data were processed to show the capability of interferometric SAR imaging with CNS. The results shows that although the interferometric phase quality of CNS is degraded due to the signal to noise ratio (SNR) is lower compared with that of chirp signal, we still can get satisfied DEM after multi-looking processing. Another work of this paper is to apply compressed sensing (CS) theory to the interferometric SAR imaging with CNS. The CS theory states that if a signal is sparse, then it can be accurately reconstructed with much less sampled data than that regularly required according to Nyquist Sampling Theory. To form a structured random matrix, if the transmitted signal is of fixed waveform, then random subsampling is needed. However, if the transmitted signal is of random waveform, then only uniform subsampling is needed. This is another advantage of noise signal. Both the interferometric phase images and the DEMs by regular method and by CS method are processed with results compared. It is shown that the degradation of interferometric phases due to subsampling is larger than that of amplitude image.

  12. Optical biosensors

    Science.gov (United States)

    Damborský, Pavel; Švitel, Juraj

    2016-01-01

    Optical biosensors represent the most common type of biosensor. Here we provide a brief classification, a description of underlying principles of operation and their bioanalytical applications. The main focus is placed on the most widely used optical biosensors which are surface plasmon resonance (SPR)-based biosensors including SPR imaging and localized SPR. In addition, other optical biosensor systems are described, such as evanescent wave fluorescence and bioluminescent optical fibre biosensors, as well as interferometric, ellipsometric and reflectometric interference spectroscopy and surface-enhanced Raman scattering biosensors. The optical biosensors discussed here allow the sensitive and selective detection of a wide range of analytes including viruses, toxins, drugs, antibodies, tumour biomarkers and tumour cells. PMID:27365039

  13. Understanding magnetic structures in permanent magnets via in situ Lorentz microscopy, interferometric and non-interferometric phase-reconstructions.

    Science.gov (United States)

    Zhu, Y; Volkov, V V; De Graef, M

    2001-01-01

    We present our observations of field- and orientation-dependence of magnetic domains and their reversal nucleation at grain boundaries in polycrystalline Nd2Fe14B, using Fresnel- and Foucault-Lorentz microscopy. The local magnetization associated with the domain and domain-wall in Nd2Fe14B and in precipitated Fe particles was mapped using an interferometric holography as well as a novel non-interferometric method based on the 'transport of intensity' equation.

  14. Acoustic vs Interferometric Measurements of Lightning

    Science.gov (United States)

    Arechiga, R. O.; Erives, H.; Sonnenfeld, R. G.; Stanley, M. A.; Rison, W.; Thomas, R. J.; Edens, H. E.; Lapierre, J. L.; Stock, M.; Jensen, D.; Morris, K.

    2015-12-01

    During the summer of 2015 we acquired acoustic and RF data on severalflashes from thunderstorms over Fort Morgan CO. and Langmuir Laboratoryin the Magdalena mountains of central New Mexico. The acoustic arrayswere located at a distance of roughly 150 m from the interferometers.Lightning mapping array and slow antenna data were also obtained. Theacoustic arrays consist of arrays of five audio-range and six infrasoundmicrophones operating at 50 KHz and 1 KHz respectively. The lightninginterferometer at Fort Morgan CO. consists of three flat-plate, 13" diameterantennas at the vertices of an equilateral 50 m per side triangle. Theinterferometer at Langmuir Laboratory consists of three 13" dishes separatedby about 15 m. Both interferometers, operating at 180 Megasamples persecond, use the analysis software and digitizer hardware pioneered byStanley, Stock et al. The high data rate allows for excellent spatialresolution of high speed (and typically high current) processes such asK-changes, return strokes and dart-leaders. In previous studies, we haveshown the usefulness of acoustic recordings to locate thunder sources aswell as infrasound pulses from lightning. This work will present acomparison of Acoustic and Interferometric measurements from lightning,using some interesting flashes, including a positive cloud to ground,that occurred in these campaigns.

  15. Airborne Radar Interferometric Repeat-Pass Processing

    Science.gov (United States)

    Hensley, Scott; Michel, Thierry R.; Jones, Cathleen E.; Muellerschoen, Ronald J.; Chapman, Bruce D.; Fore, Alexander; Simard, Marc; Zebker, Howard A.

    2011-01-01

    Earth science research often requires crustal deformation measurements at a variety of time scales, from seconds to decades. Although satellites have been used for repeat-track interferometric (RTI) synthetic-aperture-radar (SAR) mapping for close to 20 years, RTI is much more difficult to implement from an airborne platform owing to the irregular trajectory of the aircraft compared with microwave imaging radar wavelengths. Two basic requirements for robust airborne repeat-pass radar interferometry include the ability to fly the platform to a desired trajectory within a narrow tube and the ability to have the radar beam pointed in a desired direction to a fraction of a beam width. Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) is equipped with a precision auto pilot developed by NASA Dryden that allows the platform, a Gulfstream III, to nominally fly within a 5 m diameter tube and with an electronically scanned antenna to position the radar beam to a fraction of a beam width based on INU (inertial navigation unit) attitude angle measurements.

  16. An interferometric view of binary stars

    CERN Document Server

    Boffin, Henri M J

    2016-01-01

    The study of binary stars is critical to apprehend many of the most interesting classes of stars. Moreover, quite often, the study of stars in binary systems is our only mean to constrain stellar properties, such as masses and radii. Unfortunately, a great fraction of the most interesting binaries are so compact that they can only be apprehended by high-resolution techniques, mostly by interferometry. I present some results highlighting the use of interferometry in the study of binary stars, from finding companions and deriving orbits, determining the mass and radius of stars, to studying mass transfer in symbiotic stars, and tackling luminous blue variables. In particular, I show how interferometric studies using the PIONIER instrument have allowed us to confirm a dichotomy within symbiotic stars, obtain masses of stars with a precision better than 1%, and help us find a new Eta Carinae-like system. I will also illustrate the benefits for the study of binary stars one would get from upgrading the VLT Interfe...

  17. Calibration Errors in Interferometric Radio Polarimetry

    Science.gov (United States)

    Hales, Christopher A.

    2017-08-01

    Residual calibration errors are difficult to predict in interferometric radio polarimetry because they depend on the observational calibration strategy employed, encompassing the Stokes vector of the calibrator and parallactic angle coverage. This work presents analytic derivations and simulations that enable examination of residual on-axis instrumental leakage and position-angle errors for a suite of calibration strategies. The focus is on arrays comprising alt-azimuth antennas with common feeds over which parallactic angle is approximately uniform. The results indicate that calibration schemes requiring parallactic angle coverage in the linear feed basis (e.g., the Atacama Large Millimeter/submillimeter Array) need only observe over 30°, beyond which no significant improvements in calibration accuracy are obtained. In the circular feed basis (e.g., the Very Large Array above 1 GHz), 30° is also appropriate when the Stokes vector of the leakage calibrator is known a priori, but this rises to 90° when the Stokes vector is unknown. These findings illustrate and quantify concepts that were previously obscure rules of thumb.

  18. Interferometric phase reconstruction using simplified coherence network

    Science.gov (United States)

    Zhang, Kui; Song, Ruiqing; Wang, Hui; Wu, Di; Wang, Hua

    2016-09-01

    Interferometric time-series analysis techniques, which extend the traditional differential radar interferometry, have demonstrated a strong capability for monitoring ground surface displacement. Such techniques are able to obtain the temporal evolution of ground deformation within millimeter accuracy by using a stack of synthetic aperture radar (SAR) images. In order to minimize decorrelation between stacked SAR images, the phase reconstruction technique has been developed recently. The main idea of this technique is to reform phase observations along a SAR stack by taking advantage of a maximum likelihood estimator which is defined on the coherence matrix estimated from each target. However, the phase value of a coherence matrix element might be considerably biased when its corresponding coherence is low. In this case, it will turn to an outlying sample affecting the corresponding phase reconstruction process. In order to avoid this problem, a new approach is developed in this paper. This approach considers a coherence matrix element to be an arc in a network. A so-called simplified coherence network (SCN) is constructed to decrease the negative impact of outlying samples. Moreover, a pointed iterative strategy is designed to resolve the transformed phase reconstruction problem defined on a SCN. For validation purposes, the proposed method is applied to 29 real SAR images. The results demonstrate that the proposed method has an excellent computational efficiency and could obtain more reliable phase reconstruction solutions compared to the traditional method using phase triangulation algorithm.

  19. Wideband Interferometric Sensing and Imaging Polarimetry

    Science.gov (United States)

    Verdi, James Salvatore; Kessler, Otto; Boerner, Wolfgang-Martin

    1996-01-01

    Wideband Interferometric Sensing and Imaging Polarimetry (WISIP) has become an important, indispensible tool in wide area military surveillance and global environmental monitoring of the terrestrial and planetary covers. It enables dynamic, real time optimal feature extraction of significant characteristics of desirable targets and/or target sections with simultaneous suppression of undesirable background clutter and propagation path speckle at hitherto unknown clarity and never before achieved quality. WISIP may be adopted to the detection, recognition, and identification (DRI) of any stationary, moving or vibrating targets or distributed scatterer segments versus arbitrary stationary, dynamical changing and/or moving geo-physical/ecological environments, provided the instantaneous 2x2 phasor and 4x4 power density matrices for forward propagation/backward scattering, respectively, can be measured with sufficient accuracy. For example, the DRI of stealthy, dynamically moving inhomogeneous volumetric scatter environments such as precipitation scatter, the ocean/sea/lake surface boundary layers, the littoral coastal surf zones, pack ice and snow or vegetative canopies, dry sands and soils, etc. can now be successfully realized. A comprehensive overview is presented on how these modern high resolution/precision, complete polarimetric co-registered signature sensing and imaging techniques, complemented by full integration of novel navigational electronic tools, such as DGPS, will advance electromagnetic vector wave sensing and imaging towards the limits of physical realization. Various examples utilizing the most recent image data take sets of airborne, space shuttle, and satellite imaging systems demonstrate the utility of WISIP.

  20. Phase Referencing in Optical Interferometry

    OpenAIRE

    Mercedes E. Filho; Garcia, Paulo; Duvert, Gilles; Duchene, Gaspard; Thiebaut, Eric; Young, John; Absil, Olivier; Berger, Jean-Phillipe; Beckert, Thomas; Hoenig, Sebastian; Schertl, Dieter; Weigelt, Gerd; Testi, Leonardo; Tatuli, Eric; Borkowski, Virginie

    2008-01-01

    One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two extremes of phase corruption by the atmosphere. While in radio it is possible to obtain calibrated phases for the science objects, in the optical this is currently not possible. Instead, optical interferometry has relied on closure phase techniques to produce...

  1. Non-Interferometric Tomography of Phase Objects Using Spatial Light Modulators

    Directory of Open Access Journals (Sweden)

    Thanh Nguyen

    2016-10-01

    Full Text Available Quantitative 3D phase retrieval techniques are based on either interferometric techniques such as holography or noninterferometric intensity-based techniques such as the transport of intensity equation (TIE. Interferometric techniques are vibration-sensitive and often use a reference beam requiring complicated optical alignment. In this work we develop a simple, fast, and noninterferometric tomographic 3D phase retrieval technique based on the TIE which does not suffer from such drawbacks. The optical setup is a modified 4f TIE system which uses an SLM to replace the slow translation of the CCD required to record several diffraction patterns in a traditional TIE system. This novel TIE setup is suitable for dynamical events such as imaging biological processes. A rotating mechanical stage is constructed to obtain tomographic phase images of the object. The tomographic reconstruction algorithm is based on the Fourier slice theorem (backprojection algorithm which applies to objects with a small refractive index span. Simulation and experimental results are shown as part of this work. A graphical user interface is developed to perform the TIE tomographic reconstruction algorithm and to synchronize the captured intensities by the CCD, the phase patterns displayed on the SLM, and the Arduino controlled rotating stage assembly.

  2. Development of dynamic 3-D surface profilometry using stroboscopic interferometric measurement and vertical scanning techniques

    Energy Technology Data Exchange (ETDEWEB)

    Fan, K-C [Department of Mechanical Engineering, National Taiwan University, 1, Sec. 4 Roosevelt Rd, Taipei, Taiwan (China); Chen, L-C [Graduate Institute of Automation Technology, National Taipei University of Technology, 1 Sec. 3 Chung-Hsiao East Rd, Taipei, 106, Taiwan (China); Lin, C-D [Department of Mechanical Engineering, National Taiwan University, 1, Sec. 4 Roosevelt Rd, Taipei, Taiwan (China); Chang, Calvin C [Industrial Technology Research Institute, Centre for Measurement Standards, 321 Sec. 2, Kuang Fu Rd, Hsinchu, Taiwan, 300 (China); Kuo, C-F [Industrial Technology Research Institute, Centre for Measurement Standards, 321 Sec. 2, Kuang Fu Rd, Hsinchu, Taiwan, 300 (China); Chou, J-T [Industrial Technology Research Institute, Centre for Measurement Standards, 321 Sec. 2, Kuang Fu Rd, Hsinchu, Taiwan, 300 (China)

    2005-01-01

    The main objective of this technical advance is to provide a single optical interferometric framework and methodology to be capable of delivering both nano-scale static and dynamic surface profilometry. Microscopic interferometry is a powerful technique for static and dynamic characterization of micro (opto) electromechanical systems (M (O) EMS). In view of this need, a microscopic prototype based on white-light stroboscopic interferometry and the white light vertical scanning principle, was developed to achieve dynamic full-field profilometry and characterization of MEMS devices. The system primarily consists of an optical microscope, on which a Mirau interferometric objective embedded with a piezoelectric vertical translator, a high-power LED light module with dual operation modes and light synchronizing electronics unit are integrated. A micro cantilever beam used in AFM was measured to verify the system capability in accurate characterization of dynamic behaviours of the device. The full-field second-mode vibration at a vibratory frequency of 68.60 kHz can be fully characterized and 3-5 nm of vertical measurement resolution as well as tens of micrometers of vertical measurement range can be easily achieved.

  3. Semiconductor optical amplifier-based all-optical gates for high-speed optical processing

    DEFF Research Database (Denmark)

    Stubkjær, Kristian

    2000-01-01

    Semiconductor optical amplifiers are useful building blocks for all-optical gates as wavelength converters and OTDM demultiplexers. The paper reviews the progress from simple gates using cross-gain modulation and four-wave mixing to the integrated interferometric gates using cross-phase modulation....... These gates are very efficient for high-speed signal processing and open up interesting new areas, such as all-optical regeneration and high-speed all-optical logic functions...

  4. Small optic suspensions for Advanced LIGO input optics and other precision optical experiments

    CERN Document Server

    Ciani, G; Aston, S M; Feldbaum, D; Fulda, P; Gleason, J; Heintze, M; Martin, R M; Mueller, C L; Kumar, D M Nanda; Pele, A; Reitze, D H; Sainathan, P; Tanner, D B; Williams, L F; Mueller, G

    2016-01-01

    We report on the design and performance of small optic suspensions developed to suppress seismic motion of out-of-cavity optics in the Input Optics subsystem of the Advanced LIGO interferometric gravitational wave detector. These compact single stage suspensions provide isolation in all six degrees of freedom of the optic, local sensing and actuation in three of them, and passive damping for the other three.

  5. 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

  6. Resolution limits of extrinsic Fabry-Perot interferometric displacement sensors utilizing wavelength scanning interrogation.

    Science.gov (United States)

    Ushakov, Nikolai; Liokumovich, Leonid

    2014-08-10

    The factors limiting the resolution of displacement sensors based on the extrinsic Fabry-Perot interferometer were studied. An analytical model giving the dependency of extrinsic Fabry-Perot interferometric (EFPI) resolution on the parameters of an optical setup and a sensor interrogator was developed. The proposed model enables one to either estimate the limit of possible resolution achievable with a given setup, or derive the requirements for optical elements and/or a sensor interrogator necessary for attaining the desired sensor resolution. An experiment supporting the analytical derivations was performed, demonstrating a large dynamic measurement range (with cavity length from tens of microns to 5 mm), a high baseline resolution (from 14 pm), and good agreement with the model.

  7. Determine electric field directions at semiconductor surfaces by femtosecond frequency domain interferometric second harmonic (FDISH) generation

    Science.gov (United States)

    Nelson, C. A.; Zhu, X.-Y.

    2016-10-01

    Optical excitations at semiconductor surfaces or interfaces are accompanied by transient interfacial electric fields due to charge redistribution or transfer. While such transient fields may be probed by time-resolved second harmonic generation (TR-SHG), it is difficult to determine the field direction, which is invaluable to unveiling the underlying physics. Here we apply a time-resolved frequency domain interferometric second harmonic (TR-FDISH) generation technique to determine the phase relationship between the SH field emitted from bulk GaAs(1 0 0) and the transient SH field from the space charge region. The interference between these two SH fields allow us to unambiguously determine the directions of transient electric fields. Since SH fields from a static bulk contribution and a changing electric field contribution are present at most semiconductor surfaces or interfaces under optical excitation, the TR-FDISH technique is of general significance to probing the dynamics of interfacial charge transfer/redistribution.

  8. Atmospheric turbulence in phase-referenced and wide-field interferometric images: Application to the SKA

    CERN Document Server

    Marti-Vidal, I; Jimenez-Monferrer, S; Marcaide, J M

    2010-01-01

    Phase referencing is a standard calibration procedure in radio interferometry. It allows to detect weak sources by using quasi-simultaneous observations of closeby sources acting as calibrators. Therefore, it is assumed that, for each antenna, the optical paths of the signals from both sources are similar. However, atmospheric turbulence may introduce strong differences in the optical paths of the signals and affect, or even waste, phase referencing for cases of relatively large calibrator-to-target separations and/or bad weather. The situation is similar in wide-field observations, since the random deformations of the images, mostly caused by atmospheric turbulence, have essentially the same origin as the random astrometric variations of phase-referenced sources with respect to the phase center of their calibrators. In this paper, we present the results of a Monte Carlo study of the astrometric precision and sensitivity of an interferometric array (a realization of the Square Kilometre Array, SKA) in phase-r...

  9. Interferometric Reflectance Imaging Sensor (IRIS—A Platform Technology for Multiplexed Diagnostics and Digital Detection

    Directory of Open Access Journals (Sweden)

    Oguzhan Avci

    2015-07-01

    Full Text Available Over the last decade, the growing need in disease diagnostics has stimulated rapid development of new technologies with unprecedented capabilities. Recent emerging infectious diseases and epidemics have revealed the shortcomings of existing diagnostics tools, and the necessity for further improvements. Optical biosensors can lay the foundations for future generation diagnostics by providing means to detect biomarkers in a highly sensitive, specific, quantitative and multiplexed fashion. Here, we review an optical sensing technology, Interferometric Reflectance Imaging Sensor (IRIS, and the relevant features of this multifunctional platform for quantitative, label-free and dynamic detection. We discuss two distinct modalities for IRIS: (i low-magnification (ensemble biomolecular mass measurements and (ii high-magnification (digital detection of individual nanoparticles along with their applications, including label-free detection of multiplexed protein chips, measurement of single nucleotide polymorphism, quantification of transcription factor DNA binding, and high sensitivity digital sensing and characterization of nanoparticles and viruses.

  10. Characterization of the room temperature payload prototype for the cryogenic interferometric gravitational wave detector KAGRA.

    Science.gov (United States)

    Peña Arellano, Fabián Erasmo; Sekiguchi, Takanori; Fujii, Yoshinori; Takahashi, Ryutaro; Barton, Mark; Hirata, Naoatsu; Shoda, Ayaka; van Heijningen, Joris; Flaminio, Raffaele; DeSalvo, Riccardo; Okutumi, Koki; Akutsu, Tomotada; Aso, Yoichi; Ishizaki, Hideharu; Ohishi, Naoko; Yamamoto, Kazuhiro; Uchiyama, Takashi; Miyakawa, Osamu; Kamiizumi, Masahiro; Takamori, Akiteru; Majorana, Ettore; Agatsuma, Kazuhiro; Hennes, Eric; van den Brand, Jo; Bertolini, Alessandro

    2016-03-01

    KAGRA is a cryogenic interferometric gravitational wave detector currently under construction in the Kamioka mine in Japan. Besides the cryogenic test masses, KAGRA will also rely on room temperature optics which will hang at the bottom of vibration isolation chains. The payload of each chain comprises an optic, a system to align it, and an active feedback system to damp the resonant motion of the suspension itself. This article describes the performance of a payload prototype that was assembled and tested in vacuum at the TAMA300 site at the NAOJ in Mitaka, Tokyo. We describe the mechanical components of the payload prototype and their functionality. A description of the active components of the feedback system and their capabilities is also given. The performance of the active system is illustrated by measuring the quality factors of some of the resonances of the suspension. Finally, the alignment capabilities offered by the payload are reported.

  11. Pupil configurations for an interferometric TPF mission

    Science.gov (United States)

    Serabyn, G.; Mennesson, B.

    2003-01-01

    The primary goal of the proposed Terrestrial Planet Finder mission is the direct detection of radiation from potential terrestrial planets orbiting around nearby stars. However, the faintness of the expected signals leads to very stringent technical requirements on the optical performance. As a result, both of the candidate approaches currently under active development by the TPF project, infrared nulling interferometry with separated aperture telescopes, and optical coronagraphy with a large singl aperture telescope, require complex optical systems which push the state of the art.

  12. 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

  13. Evaluation of two thermal neutron detection units consisting of ZnS/${}^6$LiF scintillating layers with embedded WLS fibers read out with a SiPM

    CERN Document Server

    Mosset, J -B; Greuter, U; Hildebrandt, M; Schlumpf, N; Van Swygenhoven, H

    2014-01-01

    Two single channel detection units for thermal neutron detection are investigated in a neutron beam. They consist of two ZnS/${}^6$LiF scintillating layers sandwiching an array of WLS fibers. The pattern of this units can be repeated laterally and vertically in order to build up a one dimensional position sensitive multi-channel detector with the needed sensitive surface and with the required neutron absorption probability. The originality of this work arises from the fact that the WLS fibers are read out with SiPMs instead of the traditionally used PMTs or MaPMTs. The signal processing system is based on a photon counting approach. For SiPMs with a dark count rate as high as 0.7 MHz, a trigger efficiency of 80% is achieved together with a system background rate lower than ${10}^{-3}$ Hz and a dead time of 30 $\\mu$s. No change of performance is observed for neutron count rates of up to 3.6 kHz.

  14. Integrated optical readout for miniaturization of cantilever-based sensor system

    DEFF Research Database (Denmark)

    Nordström, Maria; Zauner, Dan; Calleja, Montserrat

    2007-01-01

    The authors present the fabrication and characterization of an integrated optical readout scheme based on single-mode waveguides for cantilever-based sensors. The cantilever bending is read out by monitoring changes in the optical intensity of light transmitted through the cantilever that also acts...

  15. UVMULTIFIT: A versatile tool for fitting astronomical radio interferometric data

    CERN Document Server

    Marti-Vidal, I; Muller, S; Casey, S

    2014-01-01

    The analysis of astronomical interferometric data is often performed on the images obtained after deconvolution of the interferometer's point spread function (PSF). This strategy can be understood (especially for cases of sparse arrays) as fitting models to models, since the deconvolved images are already non-unique model representations of the actual data (i.e., the visibilities). Indeed, the interferometric images may be affected by visibility gridding, weighting schemes (e.g., natural vs. uniform), and the particulars of the (non-linear) deconvolution algorithms. Fitting models to the direct interferometric observables (i.e., the visibilities) is preferable in the cases of simple (analytical) sky intensity distributions. In this paper, we present UVMULTIFIT, a versatile library for fitting visibility data, implemented in a Python-based framework. Our software is currently based on the CASA package, but can be easily adapted to other analysis packages, provided they have a Python API. We have tested the sof...

  16. Dynamics of laser interferometric gravitational wave detectors

    Science.gov (United States)

    Rakhmanov, Malik

    2000-11-01

    Dynamics of fields and mirrors in the new laser interferometric gravitational wave detectors is described. The dynamics of fields is formulated in terms of difference equations, which take into account the large delay due to the light transit time in the interferometer arm cavities. Solutions of these field equations are found in both transient and steady-state regimes. The solutions for fields in the transient regime can be used for the measurement of the parameters of Fabry-Perot cavities. The solutions for fields in the steady-state regime can be used for the analysis of noise performance of Fabry-Perot cavities. The dynamics of the mirrors is described in terms of two normal coordinates: the cavity length and its center of mass. Such dynamics is strongly affected by the radiation pressure of light circulating in the cavity. The forces of radiation pressure are nonlinear and nonconservative. These two effects introduce instabilities and give rise to a violation of conservation of energy for the motion of the suspended mirrors. Analytical calculations and numerical simulations of the dynamics are done with applications to the Laser Interferometer Gravitational-Wave Observatory (LIGO). The dynamics of signal recycling and power recycling interferometers is analyzed using the field equations. The response of the interferometers to the input laser field and motion of its mirrors is calculated. Several basic transfer functions are found. These correspond to either a single or a nested cavity. A nested cavity appears either in the dynamics of the differential mode in signal recycling interferometers or in the dynamics of the common mode of power recycling interferometers. The poles of transfer functions of these nested cavities are found. The response of the interferometers to gravitational waves is described: the analysis is done in the rest frame of a local observer which is a natural coordinate system of the detector. This response is given by the interferometer

  17. Compression of interferometric radio-astronomical data

    Science.gov (United States)

    Offringa, A. R.

    2016-11-01

    Context. The volume of radio-astronomical data is a considerable burden in the processing and storing of radio observations that have high time and frequency resolutions and large bandwidths. For future telescopes such as the Square Kilometre Array (SKA), the data volume will be even larger. Aims: Lossy compression of interferometric radio-astronomical data is considered to reduce the volume of visibility data and to speed up processing. Methods: A new compression technique named "Dysco" is introduced that consists of two steps: a normalization step, in which grouped visibilities are normalized to have a similar distribution; and a quantization and encoding step, which rounds values to a given quantization scheme using a dithering scheme. Several non-linear quantization schemes are tested and combined with different methods for normalizing the data. Four data sets with observations from the LOFAR and MWA telescopes are processed with different processing strategies and different combinations of normalization and quantization. The effects of compression are measured in image plane. Results: The noise added by the lossy compression technique acts similarly to normal system noise. The accuracy of Dysco is depending on the signal-to-noise ratio (S/N) of the data: noisy data can be compressed with a smaller loss of image quality. Data with typical correlator time and frequency resolutions can be compressed by a factor of 6.4 for LOFAR and 5.3 for MWA observations with less than 1% added system noise. An implementation of the compression technique is released that provides a Casacore storage manager and allows transparent encoding and decoding. Encoding and decoding is faster than the read/write speed of typical disks. Conclusions: The technique can be used for LOFAR and MWA to reduce the archival space requirements for storing observed data. Data from SKA-low will likely be compressible by the same amount as LOFAR. The same technique can be used to compress data from

  18. Optical Measurement Techniques for Optical Fiber and Waveguide Devices

    Institute of Scientific and Technical Information of China (English)

    D.Y.; Kim; Y.; Park; N.H.; Seong; Y.C.Youk; J.Y.; Lee; S.; Moon; I.H.; Shin; H.S.; Ryu

    2003-01-01

    We describe three major optical characterization methods for fiber and fiber devices. A simple servo controlled scanning fiber-optic confocal microscope is proposed for determining the refractive index profile of an optical fiber. To measure the chromatic dispersion of a short length fiber a Mach-Zehnder fiber interferometer with a novel interferometric distance meter is introduced. At the end, a tomographic method is demonstrated for determining the 2-D stress profile of a fiber.

  19. Validation of Orthorectified Interferometric Radar Imagery and Digital Elevation Models

    Science.gov (United States)

    Smith Charles M.

    2004-01-01

    This work was performed under NASA's Verification and Validation (V&V) Program as an independent check of data supplied by EarthWatch, Incorporated, through the Earth Science Enterprise Scientific Data Purchase (SDP) Program. This document serves as the basis of reporting results associated with validation of orthorectified interferometric interferometric radar imagery and digital elevation models (DEM). This validation covers all datasets provided under the first campaign (Central America & Virginia Beach) plus three earlier missions (Indonesia, Red River: and Denver) for a total of 13 missions.

  20. EQUIVALENT BASELINE AND INTERFEROMETRIC PHASE OF CLUSTER SATELLITE SAR

    Institute of Scientific and Technical Information of China (English)

    Gong Min; Zhang Chuanwu; Huang Shunji

    2005-01-01

    The change of the equivalent baseline and interferometric phase of cluster SAR satellites is analyzed when the constellation circles around the Earth and the satellites rotate around the center at the same time. The letter provides assessment of baseline error and phase error which influence the precision of height measurement in the across-track interferometric mode. The mathematical model of cluster satellite movement is built, simulation analyses and the curve of height error are presented. The simulation results show that height measurement error can be compensated by the formulae derived in this letter, therefore, the Digital Elevation Models (DEM's) are recovered accurately.

  1. Monitoring water level using Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) images

    Science.gov (United States)

    Stavroulaki, Eleni; Alexakis, Dimitrios D.; Tsanis, Ioannis K.

    2017-04-01

    Interferometric Synthetic Aperture Radar (SAR) methodology can successfully detect phase variations related to water level changes and produce corresponding water level maps. Two lakes located in Western Crete, Greece, namely Lake Kournas and Lake Agia were used as case studies to study water level change with means of SAR interferometry. The change of the water surface in the lake is examined over a period of two years, 2015-2016 using Sentinel 1 IW mode images and in situ water level data. Initially, all the SAR images were preprocessed in terms of atmospheric and radiometric corrections. Various interferograms were developed to study the multi-temporal regime of water level in both lakes. Optical satellite sensor data (Landsat 8) were used to study the vegetation regime and how this affect the interferogram processing. The results denoted the fact that the combination of SAR backscattering intensity and unwrapped phase water level data can provide additional insight into hydrological state. It is also shown that integrated analysis of the backscattering mechanism and interferometric characteristics can considerably enhance the reliability of the water-level retrieval scheme and optimize the capture of hydrological patterns spatial distribution. Keywords: Sentinel-1, interferogram, water level, Backscattering

  2. The ZpiM algorithm: a method for interferometric image reconstruction in SAR/SAS.

    Science.gov (United States)

    Dias, José M B; Leitao, José M N

    2002-01-01

    This paper presents an effective algorithm for absolute phase (not simply modulo-2-pi) estimation from incomplete, noisy and modulo-2pi observations in interferometric aperture radar and sonar (InSAR/InSAS). The adopted framework is also representative of other applications such as optical interferometry, magnetic resonance imaging and diffraction tomography. The Bayesian viewpoint is adopted; the observation density is 2-pi-periodic and accounts for the interferometric pair decorrelation and system noise; the a priori probability of the absolute phase is modeled by a compound Gauss-Markov random field (CGMRF) tailored to piecewise smooth absolute phase images. We propose an iterative scheme for the computation of the maximum a posteriori probability (MAP) absolute phase estimate. Each iteration embodies a discrete optimization step (Z-step), implemented by network programming techniques and an iterative conditional modes (ICM) step (pi-step). Accordingly, the algorithm is termed ZpiM, where the letter M stands for maximization. An important contribution of the paper is the simultaneous implementation of phase unwrapping (inference of the 2pi-multiples) and smoothing (denoising of the observations). This improves considerably the accuracy of the absolute phase estimates compared to methods in which the data is low-pass filtered prior to unwrapping. A set of experimental results, comparing the proposed algorithm with alternative methods, illustrates the effectiveness of our approach.

  3. Engineering of Surface Chemistry for Enhanced Sensitivity in Nanoporous Interferometric Sensing Platforms.

    Science.gov (United States)

    Law, Cheryl Suwen; Sylvia, Georgina M; Nemati, Madieh; Yu, Jingxian; Losic, Dusan; Abell, Andrew D; Santos, Abel

    2017-03-15

    We explore new approaches to engineering the surface chemistry of interferometric sensing platforms based on nanoporous anodic alumina (NAA) and reflectometric interference spectroscopy (RIfS). Two surface engineering strategies are presented, namely (i) selective chemical functionalization of the inner surface of NAA pores with amine-terminated thiol molecules and (ii) selective chemical functionalization of the top surface of NAA with dithiol molecules. The strong molecular interaction of Au(3+) ions with thiol-containing functional molecules of alkane chain or peptide character provides a model sensing system with which to assess the sensitivity of these NAA platforms by both molecular feature and surface engineering. Changes in the effective optical thickness of the functionalized NAA photonic films (i.e., sensing principle), in response to gold ions, are monitored in real-time by RIfS. 6-Amino-1-hexanethiol (inner surface) and 1,6-hexanedithiol (top surface), the most sensitive functional molecules from approaches i and ii, respectively, were combined into a third sensing strategy whereby the NAA platforms are functionalized on both the top and inner surfaces concurrently. Engineering of the surface according to this approach resulted in an additive enhancement in sensitivity of up to 5-fold compared to previously reported systems. This study advances the rational engineering of surface chemistry for interferometric sensing on nanoporous platforms with potential applications for real-time monitoring of multiple analytes in dynamic environments.

  4. The EDGE-CALIFA Survey: Interferometric Observations of 126 Galaxies with CARMA

    Science.gov (United States)

    Bolatto, Alberto D.; Wong, Tony; Utomo, Dyas; Blitz, Leo; Vogel, Stuart N.; Sánchez, Sebastián F.; Barrera-Ballesteros, Jorge; Cao, Yixian; Colombo, Dario; Dannerbauer, Helmut; García-Benito, Rubén; Herrera-Camus, Rodrigo; Husemann, Bernd; Kalinova, Veselina; Leroy, Adam K.; Leung, Gigi; Levy, Rebecca C.; Mast, Damián; Ostriker, Eve; Rosolowsky, Erik; Sandstrom, Karin M.; Teuben, Peter; van de Ven, Glenn; Walter, Fabian

    2017-09-01

    We present interferometric CO observations, made with the Combined Array for Millimeter-wave Astronomy (CARMA) interferometer, of galaxies from the Extragalactic Database for Galaxy Evolution survey (EDGE). These galaxies are selected from the Calar Alto Legacy Integral Field Area (CALIFA) sample, mapped with optical integral field spectroscopy. EDGE provides good-quality CO data (3σ sensitivity {{{Σ }}}{mol}∼ 11 {M}ȯ {{pc}}-2 before inclination correction, resolution ∼1.4 kpc) for 126 galaxies, constituting the largest interferometric CO survey of galaxies in the nearby universe. We describe the survey and data characteristics and products, then present initial science results. We find that the exponential scale lengths of the molecular, stellar, and star-forming disks are approximately equal, and galaxies that are more compact in molecular gas than in stars tend to show signs of interaction. We characterize the molecular-to-stellar ratio as a function of Hubble type and stellar mass and present preliminary results on the resolved relations between the molecular gas, stars, and star-formation rate. We then discuss the dependence of the resolved molecular depletion time on stellar surface density, nebular extinction, and gas metallicity. EDGE provides a key data set to address outstanding topics regarding gas and its role in star formation and galaxy evolution, which will be publicly available on completion of the quality assessment.

  5. Stimulated Brillouin scattering-induced phase noise in an interferometric fiber sensing system

    Institute of Scientific and Technical Information of China (English)

    Chen Wei; Meng Zhou; Zhou Hui-Juan; Luo Hong

    2012-01-01

    Stimulated Brillouin scattering-induced phase noise is harmful to interferometric fiber sensing systems. Thelocalized fluctuating model is used to study the intensity noise caused by the stimulated Brillouin scattering in a single-mode fiber.The phase noise structure is analyzed for an interferometric fiber sensing system,and an unbalanced Michelson interferometer with an optical path difference of 1 m,as well as the phase-generated carrier technique,is used to measure the phase noise.It is found that the phase noise is small when the input power is below the stimulated Brillouin scattering threshold,increases dramatically at first and then gradually becomes fiat when the input power is above the threshold,which is similar to the variation in relative intensity noise.It can be inferred that the increase in phase noise is mainly due to the broadening of the laser linewidth caused by stimulated Brillouin scattering,which is verified through linewidth measurements in the absence and presence of the stimulated Brillouin scattering.

  6. Squeezed Light for the Interferometric Detection of High Frequency Gravitational Waves

    CERN Document Server

    Schnabel, R; Strain, K A; Danzmann, K

    2004-01-01

    The quantum noise of the light field is a fundamental noise source in interferometric gravitational wave detectors. Injected squeezed light is capable of reducing the quantum noise contribution to the detector noise floor to values that surpass the so-called Standard-Quantum-Limit (SQL). In particular, squeezed light is useful for the detection of gravitational waves at high frequencies where interferometers are typically shot-noise limited, although the SQL might not be beaten in this case. We theoretically analyze the quantum noise of the signal-recycled laser interferometric gravitational-wave detector GEO600 with additional input and output optics, namely frequency-dependent squeezing of the vacuum state of light entering the dark port and frequency-dependent homodyne detection. We focus on the frequency range between 1 kHz and 10 kHz, where, although signal recycled, the detector is still shot-noise limited. It is found that the GEO600 detector with present design parameters will benefit from frequency d...

  7. Interferometric laser cooling of atomic rubidium

    CERN Document Server

    Dunning, Alexander; Bateman, James; Himsworth, Matthew; Freegarde, Tim

    2014-01-01

    We report the 1-D cooling of atoms using a velocity-dependent optical force based upon Ramsey matter-wave interferometry. The interferometer is realised with stimulated Raman transitions between ground hyperfine states, and after 12 cycles of the cooling sequence, we observe a reduction in the temperature of a freely moving cloud of magneto-optically cooled $^{85}$Rb atoms from 20 $\\mu$K to 4 $\\mu$K, accompanied in this first demonstration by an acceleration of the centre of mass of the atom cloud. This pulse-based laser cooling technique could in principle be extended to molecules and atoms that lack a closed radiative transition.

  8. Interferometric characterization of few-mode fibers (FMF) for mode-division multiplexing (MDM)

    Science.gov (United States)

    Muliar, O.; Usuga, M. A.; Rottwitt, K.; Lægsgaard, J.

    2015-03-01

    The rapid growth of global data traffic demands the continuous search for new technologies and systems that could increase transmission capacity in optical links and recent experiments show that to do so, it is advantageous to explore new degrees of freedom such as polarization, wavelength or optical modes. Mode division multiplexing (MDM) appears in this context as a promising and viable solution for such capacity increase, since it utilizes multiple spatial modes of an optical fiber as individual communication channels for data transmission. In order to evaluate its performance, a MDM system requires advanced characterization methods with regard to the modal content of its photonics components and in particular of the fibers involved for data transmission. In this contribution we present a time-domain interferometric technique for a full modal characterization of few mode fibers (FMF), commonly used in a MDM scenario. This experimental technique requires the use of a Mach-Zehnder interferometer, where the reference's path length is controlled by an optical delay line. The interference between the output beams of reference and fiber under test (FUT) is recorded on a CCD camera and a careful evaluation of the resulting interferograms allows us to have full access to key parameters such as number of modes, modal weight, differential time delay between propagating modes and intensity profiles. In this work, we apply this simple and complete characterization method to the case of a short link with two optical modes propagating in a FMF, which illustrates its potential as a diagnostic tool for MDM systems.

  9. Optical trapping and optical binding using cylindrical vector beams

    Directory of Open Access Journals (Sweden)

    S. E. Skelton

    2011-09-01

    Full Text Available We report on the use of cylindrical vector beams for optical manipulation of micron and sub-micron sized particles using the methods of a single-beam gradient force trap (optical tweezers and an evanescent-field surface trap (optical binding. We have demonstrated a stable interferometric method for the synthesis of cylindrical vector beams (CVBs, and present measurements demonstrating polarization-controlled focal volume shaping using CVBs in an optical tweezers. Furthermore we show how appropriate combinations of CVBs corresponding to superpositions of optical fibre modes can be used for controlled trapping and trafficking of micro- and nanoparticles along a tapered optical fibre.

  10. Apparatus and Method for Elimination of Polarization-Induced Fading in Fiber-optic Sensor System

    Science.gov (United States)

    Chan, Hon Man (Inventor); Parker, Jr., Allen R. (Inventor)

    2015-01-01

    The invention is an apparatus and method of eliminating polarization-induced fading in interferometric fiber-optic sensor system having a wavelength-swept laser optical signal. The interferometric return signal from the sensor arms are combined and provided to a multi-optical path detector assembly and ultimately to a data acquisition and processing unit by way of a switch that is time synchronized with the laser scan sweep cycle.

  11. Robust radio interferometric calibration using the t-distribution

    NARCIS (Netherlands)

    Kazemi, S.; Yatawatta, S.

    2013-01-01

    A major stage of radio interferometric data processing is calibration or the estimation of systematic errors in the data and the correction for such errors. A stochastic error (noise) model is assumed, and in most cases, this underlying model is assumed to be Gaussian. However, outliers in the data

  12. An error prediction framework for interferometric SAR data

    DEFF Research Database (Denmark)

    Mohr, Johan Jacob; Merryman Boncori, John Peter

    2008-01-01

    Three of the major error sources in interferometric synthetic aperture radar measurements of terrain elevation and displacement are baseline errors, atmospheric path length errors, and phase unwrapping errors. In many processing schemes, these errors are calibrated out by using ground control poi...

  13. Theory, analysis and design of RF interferometric sensors

    CERN Document Server

    Nguyen, Cam

    2012-01-01

    Theory, Analysis and Design of RF Interferometric Sensors presents the theory, analysis and design of RF interferometric sensors. RF interferometric sensors are attractive for various sensing applications that require every fine resolution and accuracy as well as fast speed. The book also presents two millimeter-wave interferometric sensors realized using RF integrated circuits. The developed millimeter-wave homodyne sensor shows sub-millimeter resolution in the order of 0.05 mm without correction for the non-linear phase response of the sensor's quadrature mixer. The designed millimeter-wave double-channel homodyne sensor provides a resolution of only 0.01 mm, or 1/840th of the operating wavelength, and can inherently suppress the non-linearity of the sensor's quadrature mixer. The experimental results of displacement and velocity measurement are presented as a way to demonstrate the sensing ability of the RF interferometry and to illustrate its many possible applications in sensing. The book is succinct, ye...

  14. High data rate atom interferometric device

    Science.gov (United States)

    Biedermann, Grant; McGuinness, Hayden James Evans; Rakholia, Akash

    2015-07-21

    A light-pulse atomic interferometry (LPAI) apparatus is provided. The LPAI apparatus comprises a vessel, two sets of magnetic coils configured to magnetically confine an atomic vapor in two respective magneto-optical traps (MOTs) within the vessel when activated, and an optical system configured to irradiate the atomic vapor within the vessel with laser radiation that, when suitably tuned, can launch atoms previously confined in each of the MOTs toward the other MOT. In embodiments, the magnetic coils are configured to produce a magnetic field that is non-zero at the midpoint between the traps. In embodiments, the time-of-flight of the launched atoms from one MOT to the other is 12 ms or less. In embodiments, the MOTs are situated approximately 36 mm apart. In embodiments, the apparatus is configured to activate the magnetic coils according to a particular temporal magnetic field gradient profile.

  15. Ring-Resonator/Sol-Gel Interferometric Immunosensor

    Science.gov (United States)

    Bearman, Gregory; Cohen, David

    2007-01-01

    A proposed biosensing system would be based on a combination of (1) a sensing volume containing antibodies immobilized in a sol-gel matrix and (2) an optical interferometer having a ring resonator configuration. The antibodies would be specific to an antigen species that one seeks to detect. In the ring resonator of the proposed system, light would make multiple passes through the sensing volume, affording greater interaction length and, hence, greater antibody- detection sensitivity.

  16. Broadband, Common-path, Interferometric Wavefront Sensor

    Science.gov (United States)

    Wallace, James Kent (Inventor)

    2015-01-01

    Hybrid sensors comprising Shack-Hartmann Wavefront Sensor (S-HWFS) and Zernike Wavefront Sensor (Z-WFS) capabilities are presented. The hybrid sensor includes a Z-WFS optically arranged in-line with a S-HWFS such that the combined wavefront sensor operates across a wide dynamic range and noise conditions. The Z-WFS may include the ability to introduce a dynamic phase shift in both transmissive and reflective modes.

  17. Precision frequency measurements with interferometric weak values

    CERN Document Server

    Starling, David J; Jordan, Andrew N; Howell, John C; 10.1103/PhysRevA.82.063822

    2011-01-01

    We demonstrate an experiment which utilizes a Sagnac interferometer to measure a change in optical frequency of 129 kHz per root Hz with only 2 mW of continuous wave, single mode input power. We describe the measurement of a weak value and show how even higher frequency sensitivities may be obtained over a bandwidth of several nanometers. This technique has many possible applications, such as precision relative frequency measurements and laser locking without the use of atomic lines.

  18. Interferometric characterization of few-mode fibers (FMF) for mode-division multiplexing (MDM)

    DEFF Research Database (Denmark)

    Muliar, Olena; Usuga Castaneda, Mario A.; Rottwitt, Karsten;

    2015-01-01

    The rapid growth of global data traffic demands the continuous search for new technologies and systems that could increase transmission capacity in optical links and recent experiments show that to do so, it is advantageous to explore new degrees of freedom such as polarization, wavelength...... requires advanced characterization methods with regard to the modal content of its photonics components and in particular of the fibers involved for data transmission. In this contribution we present a time-domain interferometric technique for a full modal characterization of few mode fibers (FMF...... and a careful evaluation of the resulting interferograms allows us to have full access to key parameters such as number of modes, modal weight, differential time delay between propagating modes and intensity profiles. In this work, we apply this simple and complete characterization method to the case of a short...

  19. Mach-Zehnder interferometric photonic crystal fiber for low acoustic frequency detections

    Energy Technology Data Exchange (ETDEWEB)

    Pawar, Dnyandeo; Rao, Ch. N.; Kale, S. N., E-mail: sangeetakale2004@gmail.com [Department of Applied Physics, Defence Institute of Advanced Technology (DU), Girinagar, Pune 411 025, Maharashtra (India); Choubey, Ravi Kant [Department of Applied Physics, Amity Institute of Applied Sciences, Amity University, Noida 201 313 (India)

    2016-01-25

    Low frequency under-water acoustic signal detections are challenging, especially for marine applications. A Mach-Zehnder interferometric hydrophone is demonstrated using polarization-maintaining photonic-crystal-fiber (PM-PCF), spliced between two single-mode-fibers, operated at 1550 nm source. These data are compared with standard hydrophone, single-mode and multimode fiber. The PM-PCF sensor shows the highest response with a power shift (2.32 dBm) and a wavelength shift (392.8 pm) at 200 Hz. High birefringence values and the effect of the imparted acoustic pressure on this fiber, introducing the difference between the fast and slow axis changes, owing to the phase change in the propagation waves, demonstrate the strain-optic properties of the sensor.

  20. Detection strategies for a supernova gravitational wave burst in a network of interferometric detectors

    CERN Document Server

    Arnaud, N; Bizouard, M A; Brisson, V; Cavalier, F; Davier, M; Hello, P; Kreckelberg, S; Porter, E K; Arnaud, Nicolas; Barsuglia, Matteo; Bizouard, Marie-Anne; Brisson, Violette; Cavalier, Fabien; Davier, Michel; Hello, Patrice; Kreckelberg, Stephane; Porter, Edward K.

    2003-01-01

    Trying to detect the gravitational wave (GW) signal emitted by a type II supernova is a main challenge for the GW community. Indeed, the corresponding waveform is not accurately modeled as the supernova physics is very complex; in addition, all the existing numerical simulations agree on the weakness of the GW emission, thus restraining the number of sources potentially detectable. Consequently, triggering the GW signal with a confidence level high enough to conclude directly to a detection is very difficult, even with the use of a network of interferometric detectors. On the other hand, one can hope to take benefit from the neutrino and optical emissions associated to the supernova explosion, in order to discover and study GW radiation in an event already detected independently. This article aims at presenting some realistic scenarii for the search of the supernova GW bursts, based on the present knowledge of the emitted signals and on the results of network data analysis simulations. Both the direct search ...

  1. Interferometric detection of edge magnetoplasmons in AlGaAs/GaAs heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Hashisaka, Masayuki [Research Center for Low Temperature Physics, Tokyo Institute of Technology, 2-12-1-H81, Meguro, Tokyo 152-8551 (Japan); Department of Physics, Tokyo Institute of Technology, 2-12-1-H81, Meguro, Tokyo 152-8551 (Japan); Washio, Kazuhisa; Fujisawa, Toshimasa [Research Center for Low Temperature Physics, Tokyo Institute of Technology, 2-12-1-H81, Meguro, Tokyo 152-8551 (Japan); Kamata, Hiroshi [Research Center for Low Temperature Physics, Tokyo Institute of Technology, 2-12-1-H81, Meguro, Tokyo 152-8551 (Japan); NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi 243-0198 (Japan); Muraki, Koji [NTT Basic Research Laboratories, NTT Corporation, 3-1, Morinosato-Wakamiya, Atsugi 243-0198 (Japan)

    2011-02-15

    We propose and demonstrate an interferometric detection scheme for edge magnetoplasmons (EMPs) propagating in two dimensional electron gas systems. Analogous to homodyne detection of electromagnetic wave in quantum optics, we apply reference microwaves to interfere with EMPs. Tuning the delay time, hence the phase, of the reference wave and analyzing the interference signal allow us to extract the amplitude and the phase of the original EMP at the detection point. The magnetic field dependence of the amplitude and the group velocity of EMPs are investigated by the detection scheme. This detection scheme is performed with a gate electrode as well as an Ohmic contact, which will be useful in evaluating spatial distribution of EMPs (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  2. Mach-Zehnder interferometric photonic crystal fiber for low acoustic frequency detections

    Science.gov (United States)

    Pawar, Dnyandeo; Rao, Ch. N.; Choubey, Ravi Kant; Kale, S. N.

    2016-01-01

    Low frequency under-water acoustic signal detections are challenging, especially for marine applications. A Mach-Zehnder interferometric hydrophone is demonstrated using polarization-maintaining photonic-crystal-fiber (PM-PCF), spliced between two single-mode-fibers, operated at 1550 nm source. These data are compared with standard hydrophone, single-mode and multimode fiber. The PM-PCF sensor shows the highest response with a power shift (2.32 dBm) and a wavelength shift (392.8 pm) at 200 Hz. High birefringence values and the effect of the imparted acoustic pressure on this fiber, introducing the difference between the fast and slow axis changes, owing to the phase change in the propagation waves, demonstrate the strain-optic properties of the sensor.

  3. Interferometric windows characterization up to 450 K for shock wave experiments: Hugoniot curves and refractive index

    Directory of Open Access Journals (Sweden)

    Godefroit J.-L.

    2012-08-01

    Full Text Available Conventional shock wave experiments need interferometric windows in order to determine the equation of state of a large variety of metals. Lithium fluoride (LiF and sapphire are extensively used for that purpose because their optical transparencies enable the optical diagnostics at interfaces under a given range of shock pressure. In order to simulate and analyse the experiments it is necessary to gather a correct knowledge of the optical and mechanical properties of these windows. Therefore, our window supplies are systematically characterized and an experimental campaign under shock loading is conducted. Our preliminary work on LiF windows at 532 nm is in good agreement with literature data at room temperature and the new characterization at 450 K enables a better interpretation of our preheated target experiments. It confirms the predominant effect of density on optical properties under pressure and temperature. The present work demonstrates that the initial density determination is a key point and that the uncertainties need to be improved. For that purpose, complementary experiments are conducted on LiF windows with simplified target designs and enriched diagnostics, coupling VISAR (532 nm and PdV (1550 nm diagnostics. Furthermore, a similar campaign is conducted on sapphire windows with symmetric impact configuration.

  4. Method and apparatus for white-light dispersed-fringe interferometric measurement of corneal topography

    Science.gov (United States)

    Hochberg, Eric B. (Inventor); Baroth, Edmund C. (Inventor)

    1994-01-01

    An novel interferometric apparatus and method for measuring the topography of aspheric surfaces, without requiring any form of scanning or phase shifting. The apparatus and method of the present invention utilize a white-light interferometer, such as a white-light Twyman-Green interferometer, combined with a means for dispersing a polychromatic interference pattern, using a fiber-optic bundle and a disperser such as a prism for determining the monochromatic spectral intensities of the polychromatic interference pattern which intensities uniquely define the optical path differences or OPD between the surface under test and a reference surface such as a reference sphere. Consequently, the present invention comprises a snapshot approach to measuring aspheric surface topographies such as the human cornea, thereby obviating vibration sensitive scanning which would otherwise reduce the accuracy of the measurement. The invention utilizes a polychromatic interference pattern in the pupil image plane, which is dispersed on a point-wise basis, by using a special area-to-line fiber-optic manifold, onto a CCD or other type detector comprising a plurality of columns of pixels. Each such column is dedicated to a single point of the fringe pattern for enabling determination of the spectral content of the pattern. The auto-correlation of the dispersed spectrum of the fringe pattern is uniquely characteristic of a particular optical path difference between the surface under test and a reference surface.

  5. Extrinsic Fabry-Perot interferometric sensor using a polarization-switched phase interrogator

    Science.gov (United States)

    Xia, Ji; Wang, Fuyin; Yang, Yangyang; Xiong, Shuidong; Luo, Hong; Wei, Wenjian

    2016-10-01

    In this paper, a phase variation tracking method for the extrinsic Fabry-Perot interferometric (EFPI) voice sensing system is designed and experimentally demonstrated through a polarization-switched unit based on the combination of polarization-maintaining fiber Bragg grating (PMFBG). The measurements at two operation wavelengths are firstly achieved in one total-optical path, which eliminates the imbalance of optical power from the external disturbances, optical source fluctuation, different detecting response of photoelectric detector and different background noise. Two operation wavelengths reflected from a PMFBG for interference phase tracking are switched via an electro-optic modulator at a high switching speed of 10 kHz. Besides, an ellipse fitting-differential cross multiplication (EF-DCM) algorithm is proposed and illustrated for interrogating the variation of EFPI cavity gap length of the EFPI voice sensor effectively. Preliminary experimental results have proven that the polarization-switched system based on the EF-DCM algorithm could find potential applications in the fields of marine acoustic, medical science measurements, etc.

  6. Chromatic aberration measurement for transmission interferometric testing.

    Science.gov (United States)

    Seong, Kibyung; Greivenkamp, John E

    2008-12-10

    A method of chromatic aberration measurement is described based on the transmitted wavefront of an optical element obtained from a Mach-Zehnder interferometer. The chromatic aberration is derived from transmitted wavefronts measured at five different wavelengths. Reverse ray tracing is used to remove induced aberrations associated with the interferometer from the measurement. In the interferometer, the wavefront transmitted through the sample is tested against a plano reference, allowing for the absolute determination of the wavefront radius of curvature. The chromatic aberrations of a singlet and a doublet have been measured.

  7. Precision frequency measurements with interferometric weak values

    Science.gov (United States)

    Starling, David J.; Dixon, P. Ben; Jordan, Andrew N.; Howell, John C.

    2010-12-01

    We demonstrate an experiment which utilizes a Sagnac interferometer to measure a change in optical frequency of 129 ± 7 kHz/Hz with only 2 mW of continuous-wave, single-mode input power. We describe the measurement of a weak value and show how even higher-frequency sensitivities may be obtained over a bandwidth of several nanometers. This technique has many possible applications, such as precision relative frequency measurements and laser locking without the use of atomic lines.

  8. Speckle interferometric system to measure ocular microtremor

    Science.gov (United States)

    Ryle, James P.; Al-Kalbani, Mohammed; Collins, Niamh; Gopinathan, Unnikrishnan; Boyle, Gerard; Coakley, Davis; Sheridan, John T.

    2008-04-01

    Ocular microtremor (OMT) is a biological high frequency (up to 150Hz) low amplitude (25-2500nm peak to peak) involuntary motion of the human eye. Clinical OMT investigations to date have used eye-contacting mechanical piezoelectric probes or piezoelectric strain gauges. Before contact can be made, the eye must first be anaesthetized. In some cases, this eyelid spasms occur making it impossible to measure OMT. Using the contact probe method, the eye motion is mechanically loaded. Results from clinical studies with this method to date have given electrical signal amplitudes from the probe proportional to the displacement, but not the exact displacement information. Recent studies suggest a number of clinical applications for OMT, these include monitoring the depth of anesthesia of a patient in surgery, prediction of outcome in coma, diagnosis of brain stem death. In addition to this, in patients with neurological disorders such as Multiple Sclerosis and Parkinson's disease, abnormal OMT frequency content is present. In this paper, we design a compact non-contact phase modulating optical fiber speckle interferometer to measure eye motions. We simulate OMT motion using a calibrated piezoelectric vibration simulator and compare results produced using a contact method with those using our optical non-contact method.

  9. Quantum optics for engineers

    CERN Document Server

    Duarte, FJ

    2013-01-01

    Quantum Optics for Engineers provides a transparent and methodical introduction to quantum optics via the Dirac's bra-ket notation with an emphasis on practical applications and basic aspects of quantum mechanics such as Heisenberg's uncertainty principle and Schrodinger's equation. Self-contained and using mainly first-year calculus and algebra tools, the book:Illustrates the interferometric quantum origin of fundamental optical principles such as diffraction, refraction, and reflectionProvides a transparent introduction, via Dirac's notation, to the probability amplitude of quantum entanglem

  10. Influence of intensity loss in the cavity of a folded Fabry-Perot interferometer on interferometric signals.

    Science.gov (United States)

    Shyu, Lih-Horng; Chang, Chung-Ping; Wang, Yung-Cheng

    2011-06-01

    Fabry-Perot interferometer is often used for the micro-displacement, because of its common optical path structure being insensitive to the environmental disturbances. Recently, the folded Fabry-Perot interferometer has been investigated for displacement measurements in large ranges. The advantages of a folded Fabry-Perot interferometer are insensitive to the tilt angle and higher optical resolution. But the design of the optical cavity has become more and more complicated. For this reason, the intensity loss in the cavity will be an important parameter for the distribution of the interferometric intensity. To obtain a more accurate result of such interferometer utilized for displacement measurements, the intensity loss of the cavity in the fabricated folded Fabry-Perot interferometer and the modified equation of the folded Fabry-Perot interferometer will be described. According to the theoretical and experimental results, the presented model is available for the analysis of displacement measurements by a folded Fabry-Perot interferometer.

  11. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)

    Yun-Jiang Rao; Jian Jiang; Zheng-Lin Ran

    2003-01-01

    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  12. A Novel Extrinsic Fiber-Optic Fabry-Perot Strain Sensor System Based on Optical Amplification

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel extrinsic fiber-optic Fabry-Perot interferometric strain sensor system is demonstrated based on the simultaneous use of the amplified spontaneous emission and optical amplification. The improvement of 3~4 orders of magnitude in signal level can be achieved.

  13. Detection of fast transients with radio interferometric arrays

    CERN Document Server

    Bhat, N D R; Cox, P J; Gupta, Y; Prasad, J; Roy, J; Bailes, M; Burke-Spolaor, S; Kudale, S S; van Straten, W

    2013-01-01

    Next-generation radio arrays, including the SKA and its pathfinders, will open up new avenues for exciting transient science at radio wavelengths. Their innovative designs, comprising a large number of small elements, pose several challenges in digital processing and optimal observing strategies. The Giant Metre-wave Radio Telescope (GMRT)presents an excellent test-bed for developing and validating suitable observing modes and strategies for transient experiments with future arrays. Here we describe the first phase of the ongoing development of a transient detection system for GMRT that is planned to eventually function in a commensal mode with other observing programs. It capitalizes on the GMRT's interferometric and sub-array capabilities, and the versatility of a new software backend. We outline considerations in the plan and design of transient exploration programs with interferometric arrays, and describe a pilot survey that was undertaken to aid in the development of algorithms and associated analysis s...

  14. Synchronous interferometric demodulation of Placido mires applied to corneal topography

    CERN Document Server

    Servin, Manuel

    2012-01-01

    This paper presents a novel digital interferometric method to demodulate Placido fringe patterns. This is a synchronous method which uses a computer-stored conic-wavefront as demodulating reference. Here we focuses on the experimental aspects to phase-demodulate Placido mires applied to corneal topography. This synchronous method is applied to two topographic Placido images and their de-modulated corneal-slope deformation is estimated. This conic-interferometric method is highly robust against typical "noisy" signals in Placido topography such as: reflected eyelashes and iris structures. That is because the eyelashes and the iris structure are high frequency "noisy" signals corrupting the reflected Placido mire, so they are filtered-out by this method. Digital synchronous interferometry is here applied for the first time to demodulate corneal topographic concentric-rings images (Patent pending at the USPTO).

  15. Robust sparse image reconstruction of radio interferometric observations with PURIFY

    CERN Document Server

    Pratley, Luke; d'Avezac, Mayeul; Carrillo, Rafael E; Onose, Alexandru; Wiaux, Yves

    2016-01-01

    Next-generation radio interferometers, such as the Square Kilometre Array (SKA), will revolutionise our understanding of the universe through their unprecedented sensitivity and resolution. However, to realise these goals significant challenges in image and data processing need to be overcome. The standard methods in radio interferometry for reconstructing images, such as CLEAN and its variants, have served the community well over the last few decades and have survived largely because they are pragmatic. However, they produce reconstructed interferometric images that are limited in quality and they are not scalable for big data. In this work we apply and evaluate alternative interferometric reconstruction methods that make use of state-of-the-art sparse image reconstruction algorithms motivated by compressive sensing, which have been implemented in the PURIFY software package. In particular, we implement and apply the proximal alternating direction method of multipliers (P-ADMM) algorithm presented in a recen...

  16. Rapid interferometric imaging of printed drug laden multilayer structures

    DEFF Research Database (Denmark)

    Sandler, Niklas; Kassamakov, Ivan; Ehlers, Henrik

    2014-01-01

    /and active pharmaceutical ingredients (API) adhere to each other. This is crucial in order to have predetermined drug release profiles. We also demonstrate non-invasive measurement of a polymer structure in a microfluidic channel. It shown that traceable interferometric 3D microscopy is a viable technique......The developments in printing technologies allow fabrication of micron-size nano-layered delivery systems to personal specifications. In this study we fabricated layered polymer structures for drug-delivery into a microfluidic channel and aimed to interferometrically assure their topography...... and adherence to each other. We present a scanning white light interferometer (SWLI) method for quantitative assurance of the topography of the embedded structure. We determined rapidly in non-destructive manner the thickness and roughness of the structures and whether the printed layers containing polymers or...

  17. Rapid Development of Interferometric Software Using MIRIAD and Python

    CERN Document Server

    Williams, Peter K G; Bower, Geoffrey C

    2012-01-01

    New and upgraded radio interferometers produce data at massive rates and will require significant improvements in analysis techniques to reach their promised levels of performance in a routine manner. Until these techniques are fully developed, productivity and accessibility in scientific programming environments will be key bottlenecks in the pipeline leading from data-taking to research results. We present an open-source software package, miriad-python, that allows access to the MIRIAD interferometric reduction system in the Python programming language. The modular design of MIRIAD and the high productivity and accessibility of Python provide an excellent foundation for rapid development of interferometric software. Several other projects with similar goals exist and we describe them and compare miriad-python to them in detail. Along with an overview of the package design, we present sample code and applications, including the detection of millisecond astrophysical transients, determination and application ...

  18. A detector interferometric calibration experiment for high precision astrometry

    CERN Document Server

    Crouzier, A; Henault, F; Leger, A; Cara, C; LeDuigou, J M; Preis, O; Kern, P; Delboulbe, A; Martin, G; Feautrier, P; Stadler, E; Lafrasse, S; Rochat, S; Ketchazo, C; Donati, M; Doumayrou, E; Lagage, P O; Shao, M; Goullioud, R; Nemati, B; Zhai, C; Behar, E; Potin, S; Saint-Pe, M; Dupont, J

    2016-01-01

    Context: Exoplanet science has made staggering progress in the last two decades, due to the relentless exploration of new detection methods and refinement of existing ones. Yet astrometry offers a unique and untapped potential of discovery of habitable-zone low-mass planets around all the solar-like stars of the solar neighborhood. To fulfill this goal, astrometry must be paired with high precision calibration of the detector. Aims: We present a way to calibrate a detector for high accuracy astrometry. An experimental testbed combining an astrometric simulator and an interferometric calibration system is used to validate both the hardware needed for the calibration and the signal processing methods. The objective is an accuracy of 5e-6 pixel on the location of a Nyquist sampled polychromatic point spread function. Methods: The interferometric calibration system produced modulated Young fringes on the detector. The Young fringes were parametrized as products of time and space dependent functions, based on vari...

  19. rtpipe: Searching for Fast Radio Transients in Interferometric Data

    Science.gov (United States)

    Law, Casey J.

    2017-06-01

    rtpipe (real-time pipeline) analyzes radio interferometric data with an emphasis on searching for transient or variable astrophysical sources. The package combines single-dish concepts such as dedispersion and filters with interferometric concepts, including images and the uv-plane. In contrast to time-domain data recorded with large single-dish telescopes, visibilities from interferometers can precisely localize sources anywhere in the entire field of view. rtpipe opens interferometers to the study of fast transient sky, including sources like pulsars, stellar flares, rotating radio transients, and fast radio bursts. Key portions of the search pipeline, such as image generation and dedispersion, have been accelerated. That, in combination with its multi-threaded, multi-node design, makes rtpipe capable of searching millisecond timescale data in real time on small compute clusters.

  20. Rapid interferometric imaging of printed drug laden multilayer structures

    DEFF Research Database (Denmark)

    Sandler, Niklas; Kassamakov, Ivan; Ehlers, Henrik

    2014-01-01

    /and active pharmaceutical ingredients (API) adhere to each other. This is crucial in order to have predetermined drug release profiles. We also demonstrate non-invasive measurement of a polymer structure in a microfluidic channel. It shown that traceable interferometric 3D microscopy is a viable technique......The developments in printing technologies allow fabrication of micron-size nano-layered delivery systems to personal specifications. In this study we fabricated layered polymer structures for drug-delivery into a microfluidic channel and aimed to interferometrically assure their topography...... and adherence to each other. We present a scanning white light interferometer (SWLI) method for quantitative assurance of the topography of the embedded structure. We determined rapidly in non-destructive manner the thickness and roughness of the structures and whether the printed layers containing polymers or...

  1. Nanohertz gravitational wave searches with interferometric pulsar timing experiments.

    Science.gov (United States)

    Tinto, Massimo

    2011-05-13

    We estimate the sensitivity to nano-Hertz gravitational waves of pulsar timing experiments in which two highly stable millisecond pulsars are tracked simultaneously with two neighboring radio telescopes that are referenced to the same timekeeping subsystem (i.e., "the clock"). By taking the difference of the two time-of-arrival residual data streams we can exactly cancel the clock noise in the combined data set, thereby enhancing the sensitivity to gravitational waves. We estimate that, in the band (10(-9)-10(-8))  Hz, this "interferometric" pulsar timing technique can potentially improve the sensitivity to gravitational radiation by almost 2 orders of magnitude over that of single-telescopes. Interferometric pulsar timing experiments could be performed with neighboring pairs of antennas of the NASA's Deep Space Network and the forthcoming large arraying projects.

  2. Interferometric key readable security holograms with secrete-codes

    Indian Academy of Sciences (India)

    Raj Kumar; D Mohan; A K Aggarwal

    2007-03-01

    A new method is described to create secrete-codes in the security holograms for enhancing their anti-counterfeiting characteristics. To imitate these codes is difficult as pure phase objects having complex phase distribution function are used to modulate the object beam that is recorded in conjunction with an encoded interferometric reference beam derived from a key hologram. Lloyd's folding mirror interferometer is used to convert phase variations of the reconstructed wave-front into an intensity pattern for hologram authenticity verification. Creating the secrete-codes through an interferometric reference beam from the key hologram facilitates a multi-stage authenticity verification as well as easy repositioning of the security hologram through a specific Moiré pattern generated during the verification process.

  3. UVMULTIFIT: A versatile tool for fitting astronomical radio interferometric data

    Science.gov (United States)

    Martí-Vidal, I.; Vlemmings, W. H. T.; Muller, S.; Casey, S.

    2014-03-01

    Context. The analysis of astronomical interferometric data is often performed on the images obtained after deconvolving the interferometer's point spread function. This strategy can be understood (especially for cases of sparse arrays) as fitting models to models, since the deconvolved images are already non-unique model representations of the actual data (i.e., the visibilities). Indeed, the interferometric images may be affected by visibility gridding, weighting schemes (e.g., natural vs. uniform), and the particulars of the (non-linear) deconvolution algorithms. Fitting models to the direct interferometric observables (i.e., the visibilities) is preferable in the cases of simple (analytical) sky intensity distributions. Aims: We present UVMULTIFIT, a versatile library for fitting visibility data, implemented in a Python-based framework. Our software is currently based on the CASA package, but can be easily adapted to other analysis packages, provided they have a Python API. Methods: The user can simultaneously fit an indefinite number of source components to the data, each of which depend on any algebraic combination of fitting parameters. Fits to individual spectral-line channels or simultaneous fits to all frequency channels are allowed. Results: We have tested the software with synthetic data and with real observations. In some cases (e.g., sources with sizes smaller than the diffraction limit of the interferometer), the results from the fit to the visibilities (e.g., spectra of close by sources) are far superior to the output obtained from the mere analysis of the deconvolved images. Conclusions: UVMULTIFIT is a powerful improvement of existing tasks to extract the maximum amount of information from visibility data, especially in cases close to the sensitivity/resolution limits of interferometric observations.

  4. Radar Interferometric Imaging of Near-Earth Asteroids

    Science.gov (United States)

    Margot, J. L.; Nolan, M. C.

    1999-09-01

    High resolution imagery and a three-dimensional characterization of Near-Earth Asteroids (NEAs) can be obtained with ground-based radars. The Arecibo and Goldstone radar systems yield data at spatial resolutions comparable to the highest resolution spacecraft images of asteroids obtained to date. The use of radar interferometry techniques can further improve imaging and shape reconstruction algorithms [1],[2] and may allow direct measurements of the topography of NEAs. A two-element radar interferometer of appropriate baseline provides an observable, the interferometric phase, which can be used to extract three-dimensional information about the target [3], hence giving additional control in shape modeling procedures. The measurement of interferometric phase also opens the possibility of mapping the topography of an asteroid, in a manner similar to that applied recently to the Moon [4]. Simulations show that this is feasible when potential ambiguities in range-Doppler imaging are avoided, for instance when elongated objects are in a favorable orientation. Radar interferometric imaging of 6489 Golevka was attempted during its June 1999 close approach to Earth [5]. The Arecibo 305 m telescope was used to transmit, and the DSN 70 m antenna in Madrid formed the second element of the interferometer. The Arecibo-Madrid baseline defined an ideal fringe pattern for interferometric mapping, but technical difficulties prevented imaging of the Madrid data. Radar interferometry concepts and simulation results will be presented, as well as any new data acquired before the meeting. [1] R. S. Hudson and S. J. Ostro (1994). Science, 263, 940. [2] R. S. Hudson and S. J. Ostro (1995). Science, 270, 84. [3] I. I. Shapiro et al. (1972). Science, 178, 939. [4] J. L. Margot et al. (1999). Science, 284, 1658. [5] J. L. Margot and M. C. Nolan (1999). ACM Meeting, July 26-30, Cornell University, Ithaca, NY.

  5. Passive millimeter-wave camera with interferometric processing

    Science.gov (United States)

    Nohmi, Hitoshi; Ohnishi, Seiki; Kujubu, Osamu

    2006-05-01

    A proto-type passive millimeter-wave (MMW) camera with interferometric processing has been developed. The purpose is to confirm the feasibility of the interferometric MMW camera and to study the characteristics of MMW images. In this paper, the principle and the feature of the interferometric MMW camera is described. Also, the hardware configuration and the image processing algorithm are presented. This proto-type camera is comprised of the minimum configuration as an interferometric imager which consists of two sets of a W-band front end with a horn antenna, a receiver, and an A/D converter, a high-speed processing hardware, and a computer. The position of these two antennas with W-band front-end moves on the precision linear slider in horizontal and vertical axis. The coherently amplified two channel signals are digitized and processed in the hardware processor. The process is comprised of phase error compensation, correlation of all combination of each axis data, and integration to improve the signal to noise ratio. The computer input the integrated data to make an image by matched filter processing. The integration time is from 1mS to 10S depending on required integration gain. The maximum synthesized antenna aperture size is 1m for horizontal axis and 50cm for vertical axis. Because it takes certain time to receive by the moving antennas, only the targets without motion are imaged by this proto-type camera. The processed images will be shown. Also, future plan for a real-time camera using this technique is presented.

  6. Potential of sinkhole precursor detection through interferometric SAR

    CSIR Research Space (South Africa)

    Theron, Andre

    2016-08-01

    Full Text Available detection through interferometric SAR Theron, A.1, 2, Engelbrecht, J.1 and Kemp, J.2 1 Remote Sensing Research Unit, CSIR Meraka Institute, ATheron1@csir.co.za 2 Department of Geography and Environmental Sciences, Stellenbosch University...]. However, the location and timing of sinkholes is typically unpredictable. The in situ monitoring of large areas for small scale subsidence is therefore not feasible. Satellite remote sensing, specifically Synthetic aperture radar (SAR), is a unique...

  7. Magnonic interferometric switch for multi-valued logic circuits

    Science.gov (United States)

    Balynsky, Michael; Kozhevnikov, Alexander; Khivintsev, Yuri; Bhowmick, Tonmoy; Gutierrez, David; Chiang, Howard; Dudko, Galina; Filimonov, Yuri; Liu, Guanxiong; Jiang, Chenglong; Balandin, Alexander A.; Lake, Roger; Khitun, Alexander

    2017-01-01

    We investigated a possible use of the magnonic interferometric switches in multi-valued logic circuits. The switch is a three-terminal device consisting of two spin channels where input, control, and output signals are spin waves. Signal modulation is achieved via the interference between the source and gate spin waves. We report experimental data on a micrometer scale prototype based on the Y3Fe2(FeO4)3 structure. The output characteristics are measured at different angles of the bias magnetic field. The On/Off ratio of the prototype exceeds 13 dB at room temperature. Experimental data are complemented by the theoretical analysis and the results of micro magnetic simulations showing spin wave propagation in a micrometer size magnetic junction. We also present the results of numerical modeling illustrating the operation of a nanometer-size switch consisting of just 20 spins in the source-drain channel. The utilization of spin wave interference as a switching mechanism makes it possible to build nanometer-scale logic gates, and minimize energy per operation, which is limited only by the noise margin. The utilization of phase in addition to amplitude for information encoding offers an innovative route towards multi-state logic circuits. We describe possible implementation of the three-value logic circuits based on the magnonic interferometric switches. The advantages and shortcomings inherent in interferometric switches are also discussed.

  8. Relating Sentinel-1 Interferometric Coherence to Mowing Events on Grasslands

    Directory of Open Access Journals (Sweden)

    Tanel Tamm

    2016-09-01

    Full Text Available In this study, the interferometric coherence calculated from 12-day Sentinel-1 image pairs was analysed in relation to mowing events on agricultural grasslands. Results showed that after a mowing event, median VH (vertical transmit, horizontal receive and VV (vertical transmit, vertical receive polarisation coherence values were statistically significantly higher than those from before the event. The shorter the time interval after the mowing event and the first interferometric acquisition, the higher the coherence. The coherence tended to stay higher, even 24 to 36 days after a mowing event. Precipitation caused the coherence to decrease, impeding the detection of a mowing event. Given the three analysed acquisition geometries, it was concluded that afternoon acquisitions and steeper incidence angles were more useful in the context of this study. In the case of morning acquisitions, dew might have caused a decrease of coherence for mowed and unmowed grasslands. Additionally, an increase of coherence after a mowing event was not evident during the rapid growth phase, due to the 12-day separation between the interferometric acquisitions. In future studies, six-day pairs utilising Sentinel-1A and 1B acquisitions should be considered.

  9. Interferometric synthetic aperture radar imagery of the Gulf Stream

    Science.gov (United States)

    Ainsworth, T. L.; Cannella, M. E.; Jansen, R. W.; Chubb, S. R.; Carande, R. E.; Foley, E. W.; Goldstein, R. M.; Valenzuela, G. R.

    1993-01-01

    The advent of interferometric synthetic aperture radar (INSAR) imagery brought to the ocean remote sensing field techniques used in radio astronomy. Whilst details of the interferometry differ between the two fields, the basic idea is the same: Use the phase information arising from positional differences of the radar receivers and/or transmitters to probe remote structures. The interferometric image is formed from two complex synthetic aperture radar (SAR) images. These two images are of the same area but separated in time. Typically the time between these images is very short -- approximately 50 msec for the L-band AIRSAR (Airborne SAR). During this short period the radar scatterers on the ocean surface do not have time to significantly decorrelate. Hence the two SAR images will have the same amplitude, since both obtain the radar backscatter from essentially the same object. Although the ocean surface structure does not significantly decorrelate in 50 msec, surface features do have time to move. It is precisely the translation of scattering features across the ocean surface which gives rise to phase differences between the two SAR images. This phase difference is directly proportional to the range velocity of surface scatterers. The constant of proportionality is dependent upon the interferometric mode of operation.

  10. Interferometric Phase Improvement Based on Polarimetric Data Fusion

    Directory of Open Access Journals (Sweden)

    Tao Xiong

    2008-11-01

    Full Text Available In this paper, a method is proposed to improve the interferometric phase quality, based on fusing data from different polarimetric channels. Since lower amplitude implies less reliable phase in general, the phase quality of polarimetric interferometric data can be improved by seeking optimal fusion of data from different polarizations to maximize the resulting amplitude. In the proposed approach, for each pixel, two coherent polarimetric scattering vectors are synchronously projected onto a same optimum direction, maximizing the lower amplitude of the two projections. In the single-look case, the fused phase is equivalent to the weighted average of phases in all polarimetric channels. It provides a good physical explanation of the proposed approach. Without any filtering, the phase noise and the number of residue points are significantly reduced, and the interferometric phase quality is greatly improved. It is a useful tool to preprocess the phase ahead of phase unwrapping. The Cloude’s coherence optimization method is used for a comparison. Using the data collected by SIR-C/X-SAR, the authors demonstrate the effectiveness and the robustness of the proposed approach.

  11. Iterated unscented Kalman filter for phase unwrapping of interferometric fringes.

    Science.gov (United States)

    Xie, Xianming

    2016-08-22

    A fresh phase unwrapping algorithm based on iterated unscented Kalman filter is proposed to estimate unambiguous unwrapped phase of interferometric fringes. This method is the result of combining an iterated unscented Kalman filter with a robust phase gradient estimator based on amended matrix pencil model, and an efficient quality-guided strategy based on heap sort. The iterated unscented Kalman filter that is one of the most robust methods under the Bayesian theorem frame in non-linear signal processing so far, is applied to perform simultaneously noise suppression and phase unwrapping of interferometric fringes for the first time, which can simplify the complexity and the difficulty of pre-filtering procedure followed by phase unwrapping procedure, and even can remove the pre-filtering procedure. The robust phase gradient estimator is used to efficiently and accurately obtain phase gradient information from interferometric fringes, which is needed for the iterated unscented Kalman filtering phase unwrapping model. The efficient quality-guided strategy is able to ensure that the proposed method fast unwraps wrapped pixels along the path from the high-quality area to the low-quality area of wrapped phase images, which can greatly improve the efficiency of phase unwrapping. Results obtained from synthetic data and real data show that the proposed method can obtain better solutions with an acceptable time consumption, with respect to some of the most used algorithms.

  12. Lensless single-exposure super-resolved interferometric microscopy

    Science.gov (United States)

    Granero, Luis; Ferreira, Carlos; García, Javier; Micó, Vicente

    2013-04-01

    Single Exposure Super Resolved Interferometric Microscopy (SESRIM) has been recently proposed as a way to achieve one dimensional super resolved imaging in digital holographic microscopy. SESRIM uses Red-Green-Blue (RGB) multiplexing for illuminating the sample having different propagation angles for each one of the three illumination wavelengths and it has been experimentally validated considering color (A. Calabuig, V. Mico, J. Garcia, Z. Zalevsky, and C. Ferreira, "Single-exposure super-resolved interferometric microscopy by red-green-blue multiplexing," Opt. Lett. 36, 885-887, 2011) and monochrome (A. Calabuig, J. Garcia, C. Ferreira, Z. Zalevsky, and V. Mico, "Resolution improvement by single-exposure superresolved interferometric microscopy with a monochrome sensor," J. Opt. Soc. Am. A 28, 2346-2358, 2011) digital sensors for holographic recording. In this contribution, we will first review some of the characteristics of the previously reported SESRIM approaches and second, we will present preliminary results for the extension of SESRIM to the field of lensless holographic microscopy. Experimental results are reported validating this new kind of superresolution imaging method named as lensless SESRIM (L-SESRIM).

  13. Remote access to an interferometric fringes stabilization active system via RENATA

    Science.gov (United States)

    Espitia-Gómez, Javier; Ángel-Toro, Luciano

    2013-11-01

    The Advanced Technology National Network (RENATA, for its acronym in Spanish) is a Colombian, collaborative work tool, linked to other networks worldwide, in which take participation researchers, teachers and students, by sharing laboratory resources located in different universities, institutes and research centers throughout the country. In the Universidad EAFIT (Medellín, Colombia) it has been designed an interferometric fringes stabilization active system, which can be accessed remotely via the RENATA network. A Mach-Zehnder interferometer was implemented, with independent piezoelectric actuators in each arm, with which the lengths of optical path of light that goes over in each of them can be modified. Using these actuators, one can simultaneously perturb the system and compensate the phase differences caused by that perturbation. This allows us to experiment with different disturbs, and analyze the system response to each one of them. This can be made from any location worldwide, and especially from those regions in which optical and optoelectronic components required for the implementation of the interferometer or for the stabilization system are not available. The device can also be used as a platform in order to conduct diverse experiments, involving optical and controlling aspects, constituting with this in a pedagogic tool. For the future, it can be predicted that remote access to available applications would be possible, as well as modifications of the implemented code in labVIEW™, so that researchers and teachers can adapt and improve their functionalities or develop new applications, based on the collaborative work.

  14. Coherent optics in students' laboratories

    Science.gov (United States)

    Senderáková, Dagmar; Mesaros, Vladimir; Drzik, Milan

    2014-12-01

    Lasers provide us with unique kind of light - coherent light. Besides being the keystone of historical interferometric measuring methods, coherent waves, now accessible in a very easy way, become a base of new optical measuring and information processing methods. Moreover, holographic recording seems today to have become a common term, even among common, not especially optically educated people. The presentation deals with our attempt to take our students' interest in the coherence of light and getting them familiar with the phenomenon, indeed.

  15. Mirror Prescription Regression: A Differential Interferometric Technique

    Directory of Open Access Journals (Sweden)

    Brian M. Robinson

    2010-01-01

    Full Text Available We present a remote, differential method for measuring the prescription of aspheric mirrors using null interferometry in the center-of-curvature configuration. The method requires no equipment beyond that used in a basic interferometery setup (i.e., there are no shearing elements or absolute distance meters. We chose this configuration because of its widespread use. However, the method is generalizable to other configurations with an adjustment of the governing equation. The method involves taking a series of interferograms before and after small, known misalignments are applied to the mirror in the interferometry setup and calculating the prescription (e.g., radius of curvature and conic constant of the mirror, based on these differential measurements, using a nonlinear regression. We apply this method successfully to the testing of a Space Optics Research Lab off-axis parabola with a known focal length of 152.4 mm, a diameter of 76.2 mm, and an off-axis angle of 12°.

  16. Interferometric Laser Scanner for Direction Determination.

    Science.gov (United States)

    Kaloshin, Gennady; Lukin, Igor

    2016-01-21

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5-10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  17. Interferometric Laser Scanner for Direction Determination

    Directory of Open Access Journals (Sweden)

    Gennady Kaloshin

    2016-01-01

    Full Text Available In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  18. Research Progress on F-P Interference—Based Fiber-Optic Sensors

    Science.gov (United States)

    Huang, Yi Wen; Tao, Jin; Huang, Xu Guang

    2016-01-01

    We review our works on Fabry-Perot (F-P) interferometric fiber-optic sensors with various applications. We give a general model of F-P interferometric optical fiber sensors including diffraction loss caused by the beam divergence and the Gouy phase shift. Based on different structures of an F-P cavity formed on the end of a single-mode fiber, the F-P interferometric optical sensor has been extended to measurements of the refractive index (RI) of liquids and solids, temperature as well as small displacement. The RI of liquids and solids can be obtained by monitoring the fringe contrast related to Fresnel reflections, while the ambient temperature and small displacement can be obtained by monitoring the wavelength shift of the interference fringes. The F-P interferometric fiber-optic sensors can be used for many scientific and technological applications. PMID:27598173

  19. Research Progress on F-P Interference-Based Fiber-Optic Sensors.

    Science.gov (United States)

    Huang, Yi Wen; Tao, Jin; Huang, Xu Guang

    2016-01-01

    We review our works on Fabry-Perot (F-P) interferometric fiber-optic sensors with various applications. We give a general model of F-P interferometric optical fiber sensors including diffraction loss caused by the beam divergence and the Gouy phase shift. Based on different structures of an F-P cavity formed on the end of a single-mode fiber, the F-P interferometric optical sensor has been extended to measurements of the refractive index (RI) of liquids and solids, temperature as well as small displacement. The RI of liquids and solids can be obtained by monitoring the fringe contrast related to Fresnel reflections, while the ambient temperature and small displacement can be obtained by monitoring the wavelength shift of the interference fringes. The F-P interferometric fiber-optic sensors can be used for many scientific and technological applications.

  20. Robust interferometric imaging via prior-less phase recovery: redundant spacing calibration with generalized closure phases

    Science.gov (United States)

    Kurien, Binoy G.; Ashcom, Jonathan B.; Shah, Vinay N.; Rachlin, Yaron; Tarokh, Vahid

    2016-09-01

    Atmospheric turbulence presents a fundamental challenge to Fourier phase recovery in optical interferometry. Typical reconstruction algorithms employ Bayesian inference techniques which rely on prior knowledge of the scene under observation. In contrast, Redundant Spacing Calibration (RSC) algorithms employ redundancy in the baselines of the interferometric array to directly expose the contribution of turbulence, thereby enabling phase recovery for targets of arbitrary and unknown complexity. Traditionally RSC algorithms have been applied directly to single-exposure measurements, which are reliable only at high photon flux in general. In scenarios of low photon flux, such as those arising in the observation of dim objects in space, one must instead rely on time-averaged, atmosphere-invariant quantities such as the bispectrum. In this paper, we develop a novel RSC-based algorithm for prior-less phase recovery in which we generalize the bispectrum to higher-order atmosphere-invariants (n-spectra) for improved sensitivity. We provide a strategy for selection of a high-SNR set of n-spectra using the graph-theoretic notion of the minimum cycle basis. We also discuss a key property of this set (wrap-invariance), which then enables reliable application of standard linear estimation techniques to recover the Fourier phases from the 2π-wrapped n-spectra phases. For validation, we analyze the expected shot-noise-limited performance of our algorithm for both pairwise and Fizeau interferometric architectures, and corroborate this analysis with simulation results showing performance near an atmosphere-oracle Cramer-Rao bound. Lastly, we apply techniques from the field of compressed sensing to perform image reconstruction from the estimated complex visibilities.

  1. Imaging capabilities of the VLTI/MATISSE spectro-interferometric instrument

    Science.gov (United States)

    Sanchez-Bermudez, J.; Pott, J.-U.; van Boekel, R.; Henning, T.; Baron, F.; Matter, A.; Lopez, B.; Millour, F.; Weigelt, G.; Hofmann, K.-H.; Schertl, D.

    2016-08-01

    During the last decade, the first generation of beam combiners at the Very Large Telescope Interferometer has proved the importance of optical interferometry for high-angular resolution astrophysical studies in the nearand mid-infrared. With the advent of 4-beam combiners at the VLTI, the u - v coverage per pointing increases significantly, providing an opportunity to use reconstructed images as powerful scientific tools. Here, we present our ongoing studies to characterize the imaging capabilities of the Multi-AperTure mid-infrared SpectroScopic Experiment (MATISSE), a second-generation instrument for the Very Large Telescope Interferometer (VLTI). By providing simultaneous observations with 6 baselines and spectral resolutions up to R 5000. MATISSE will deliver, for the first time, thermal-IR interferometric data with enough u-v coverage and phase information for imaging. In this work, we report detailed image reconstruction studies carried out with the image reconstruction package SQUEEZE. For our studies, we use realistic simulated MATISSE data from radiative transfer simulations of a proto-planetary disk. In particular, we will discuss the role of the regularization function and of the initial brightness distribution. MATISSE will perform observations at three different mid-infrared bands: L, M and N. Hence, due to its large bandwidth, chromatic effects should be taken into account when image reconstruction is attempted. We also discuss the capabilities of SQUEEZE to perform multi-wavelength image reconstruction. Finally, we perform an analysis of the image quality and present our future line of research. The work here presented is being carried out within the Opticon FP7-2 joint research activity on interferometric imaging.

  2. Multiplexed optical operation of distributed nanoelectromechanical systems arrays.

    Science.gov (United States)

    Sampathkumar, A; Ekinci, K L; Murray, T W

    2011-03-09

    We report a versatile all optical technique to excite and read-out a distributed nanoelectromechanical systems (NEMS) array. The NEMS array is driven by a distributed, intensity modulated optical pump through the photothermal effect. The ensuing vibrational response of the array is multiplexed onto a single probe beam in the form of a high frequency phase modulation. The phase modulation is optically down converted to a low frequency intensity modulation using an adaptive full-field interferometer, and subsequently detected using a CCD array. Rapid and single step mechanical characterization of ∼44 nominally identical high-frequency resonators is demonstrated. The technique may enable sensitivity improvements over single NEMS resonators by averaging signals coming from a multitude of devices in the array. In addition, the diffraction limited spatial resolution may allow for position-dependent read-out of NEMS sensor chips for sensing multiple analytes or spatially inhomogeneous forces.

  3. Demonstration of Interferometric SAR Onboard Processing for Planetary Mapping Missions Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This task will enable future planetary mapping missions through a technique called interferometric synthetic aperture radar, using microwave and triangulation to...

  4. Validation of the Read Out Electronics for the CMS Muon Drift Chambers at Tests Beam in CERN/GIF; Validacion en el Test Beam del CERN/GIF de la electronica de Lectura de las Camaras de Muones del Experimento CMS

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, C.; Fouz, M. c.; Marin, J.; Oller, J. C.; Willmott, C.; Amigo, L. J.

    2002-07-01

    Part of the readout system for the CMS muon drift chambers has been tested in test beams at CERN/GIF. Read Out Board (ROB) and HPTD have been validated with signals from a real muon beam, with an structure and flux similar to LHC operating conditions and using one of the chambers produced in CIEMAT already located in the test beam area under normal gas and voltage conditions. (Author) 5 refs.

  5. A near-infrared interferometric survey of debris disc stars. II. CHARA/FLUOR observations of six early-type dwarfs

    CERN Document Server

    Absil, O; Merand, A; Augereau, J -C; Foresto, V Coude du; Defrere, D; Kervella, P; Aufdenberg, J P; Desort, M; Ehrenreich, D; Lagrange, A -M; Montagnier, G; Olofsson, J; Brummelaar, T A ten; McAlister, H A; Sturmann, J; Sturmann, L; Turner, N H

    2008-01-01

    High-precision interferometric observations of six early-type main sequence stars known to harbour cold debris discs have been obtained in the near-infrared K band with the FLUOR instrument at the CHARA Array. The measured squared visibilities are compared to the expected visibility of the stellar photospheres based on theoretical photospheric models taking into account rotational distortion, searching for potential visibility reduction at short baselines due to circumstellar emission. Our observations bring to light the presence of resolved circumstellar emission around one of the six target stars (zeta Aql) at the 5 sigma level. The morphology of the emission source cannot be directly constrained because of the sparse spatial frequency sampling of our interferometric data. Using complementary adaptive optics observations and radial velocity measurements, we find that the presence of a low-mass companion is a likely origin for the excess emission. The potential companion has a K-band contrast of four magnitu...

  6. Integrated optics for astronomical interferometry; 1, Concept and astronomical applications

    CERN Document Server

    Malbet, M; Schanen-Duport, J P; Berger, J P; Rousselet-Perraut, K; Benech, P

    1999-01-01

    We propose a new instrumental concept for long-baseline optical single-mode interferometry using integrated optics which were developed for telecommunication. Visible and infrared multi-aperture interferometry requires many optical functions (spatial filtering, beam combination, photometric calibration, polarization control) to detect astronomical signals at very high angular resolution. Since the 80's, integrated optics on planar substrate have become available for telecommunication applications with multiple optical functions like power dividing, coupling, multiplexing, etc. We present the concept of an optical / infrared interferometric instrument based on this new technology. The main advantage is to provide an interferometric combination unit on a single optical chip. Integrated optics are compact, provide stability, low sensitivity to external constrains like temperature, pressure or mechanical stresses, no optical alignment except for coupling, simplicity and intrinsic polarization control. The integra...

  7. Interferometric synthetic aperture microscopy implementation on a floating point multi-core digital signal processer

    Science.gov (United States)

    Ahmad, Adeel; Ali, Murtaza; South, Fredrick; Monroy, Guillermo L.; Adie, Steven G.; Shemonski, Nathan; Carney, P. Scott; Boppart, Stephen A.

    2013-03-01

    The transition of optical coherence tomography (OCT) technology from the lab environment towards the more challenging clinical and point-of-care settings is continuing at a rapid pace. On one hand this translation opens new opportunities and avenues for growth, while on the other hand it also presents a new set of challenges and constraints under which OCT systems have to operate. OCT systems in the clinical environment are not only required to be user friendly and easy to operate, but should also be portable, have a smaller form factor coupled with low cost and reduced power consumption. Digital signal processors (DSP) are in a unique position to satisfy the computational requirements for OCT at a much lower cost and power consumption compared to the existing platforms such as CPU and graphics processing units (GPUs). In this work, we describe the implementation of optical coherence tomography (OCT) and interferometric synthetic aperture microscopy (ISAM) processing on a floating point multi-core DSP (C6678, Texas Instruments). ISAM is a computationally intensive data processing technique that is based on the re-sampling of the Fourier space of the data to yield spatially invariant transverse resolution in OCT. Preliminary results indicate that 2DISAM processing at 70,000 A-lines/sec and OCT at 180,000 A-lines/sec can be achieved with the current implementation using available DSP hardware.

  8. Quantum noise limited interferometric measurement of atomic noise: towards spin squeezing on the Cs clock transition

    CERN Document Server

    Oblak, D; Tittel, W; Vershovski, A K; Sørensen, J L; Petrov, P G; Alzar, C L G; Polzik, E S; Oblak, Daniel; Mikkelsen, Jens K.; Tittel, Wolfgang; Vershovski, Anton K.; Sorensen, Jens L.; Petrov, Plamen G.; Alzar, Carlos L. Garrido; Polzik, Eugene S.

    2003-01-01

    We investigate theoretically and experimentally a nondestructive interferometric measurement of the state population of an ensemble of laser cooled and trapped atoms. This study is a step towards generation of (quasi-) spin squeezing of cold atoms targeted at the improvement of the Caesium clock performance beyond the limit set by the quantum projection noise of atoms. We propose a protocol for the sequence of operations required to generate and utilize spin squeezing for the improved microwave clock performance via a quantum nondemolition measurement (qnd) on the probe light. We calculate the phase shift and the quantum noise of a near resonant optical probe pulse propagating through a cloud of cold 133Cs atoms. We analyze the figure of merit for a qnd measurement of the collective quasi-spin and show that it can be expressed simply as a product of the ensemble optical depth and the probability of the spontaneous emission caused by the off-resonant probe light. In the experimental part we report on the preli...

  9. Wavelength-switched phase interrogator for extrinsic Fabry-Perot interferometric sensors.

    Science.gov (United States)

    Xia, Ji; Xiong, Shuidong; Wang, Fuyin; Luo, Hong

    2016-07-01

    We report on phase interrogation of extrinsic Fabry-Perot interferometric (EFPI) sensors through a wavelength-switched unit with a polarization-maintaining fiber Bragg grating (PMFBG). The measurements at two wavelengths are first achieved in one total-optical path. The reflected peaks of the PMFBG with two natural wavelengths are in mutually perpendicular polarization detection, and they are switched through an electro-optic modulator at a high switching speed of 10 kHz. An ellipse fitting differential cross multiplication (EF-DCM) algorithm is proposed for interrogating the variation of the gap length of the EFPI sensors. The phase demodulation system has been demonstrated to recover a minimum phase of 0.42  μrad/Hz at the test frequency of 100 Hz with a stable intensity fluctuation level of ±0.8  dB. Three EFPI sensors with different cavity lengths are tested at the test frequency of 200 Hz, and the results indicate that the system can achieve the demodulation of EFPI sensors with different cavity lengths stably.

  10. Optical fiber rotation sensing

    CERN Document Server

    Burns, William K; Kelley, Paul

    1993-01-01

    Optical Fiber Rotation Sensing is the first book devoted to Interferometric Fiber Optic Gyros (IFOG). This book provides a complete overview of IFOGs, beginning with a historical review of IFOG development and including a fundamental exposition of basic principles, a discussion of devices and components, and concluding with industry reports on state-of-the-art activity. With several chapters contributed by principal developers of this solid-state device, the result is an authoritative work which will serve as the resource for researchers, students, and users of IFOGs.* * State-of-t

  11. Optical information storage

    Energy Technology Data Exchange (ETDEWEB)

    Woike, T. [Koeln Univ., Inst. fuer Kristallography, Koeln (Germany)

    1996-11-01

    In order to increase storage capacity and data transfer velocity by about three orders of magnitude compared to CD or magnetic disc it is necessary to work with optical techniques, especially with holography. About 100 TByte can be stored in a waver of an area of 50 cm{sup 2} via holograms which corresponds to a density of 2.10{sup 9} Byte/mm{sup 2}. Every hologram contains data of 1 MByte, so that parallel-processing is possible for read-out. Using high-speed CCD-arrays a read-out velocity of 1 MByte/{mu}sec can be reached. Further, holographic technics are very important in solid state physics. We will discuss the existence of a space charge field in Sr{sub 1-x}Ba{sub x}Nb{sub 2}O{sub 6} doped with cerium and the physical properties of metastable states, which are suited for information storage. (author) 19 figs., 9 refs.

  12. Interferometric detection of mode splitting for whispering gallery mode biosensors

    CERN Document Server

    Knittel, Joachim; Lee, Kwan H; Bowen, Warwick P

    2010-01-01

    Sensors based on whispering gallery mode resonators can detect single nanoparticles and even single molecules. Particles attaching to the resonator induce a doublet in the transmission spectrum which provides a self-referenced detection signal. However, in practice this spectral feature is often obscured by the width of the resonance line which hides the doublet structure. This happens particularly in liquid environments that reduce the effective Q factor of the resonator. In this paper we demonstrate an interferometric set-up that allows the direct detection of the hidden doublet and thus provides a pathway for developing practical sensor applications.

  13. On the GNSS-R Interferometric Complex Field Coherence Time

    CERN Document Server

    Ruffini, G

    2004-01-01

    In this paper we focus on the microwave bistatic scattering process, with the aim of deriving an expression for the interferometric complex field auto-correlation function from a static platform. We start from the Fresnel integral and derive the auto-correlation function in the Fraunhofer and Modified Fraunhofer regime. The autocorrelation function at short times can be expressed as a Gaussian with a direction dependent time scale. The directional modulation is a function of the angle between the scattering direction and the wave direction. The obtained relation can be used for directional sea state estimation using one or more GNSS-R coastal receivers.

  14. Data Quality Studies of Enhanced Interferometric Gravitational Wave Detectors

    CERN Document Server

    McIver, Jessica

    2012-01-01

    Data quality assessment plays an essential role in the quest to detect gravitational wave signals in data from the LIGO and Virgo interferometric gravitational wave detectors. Interferometer data contains a high rate of noise transients from the environment, the detector hardware, and the detector control systems. These transients severely limit the statistical significance of gravitational wave candidates of short duration and/or poorly modeled waveforms. This paper describes the data quality studies that have been performed in recent LIGO and Virgo observing runs to mitigate the impact of transient detector artifacts on the gravitational wave searches.

  15. Interferometric millimeter wave and THz wave doppler radar

    Science.gov (United States)

    Liao, Shaolin; Gopalsami, Nachappa; Bakhtiari, Sasan; Raptis, Apostolos C.; Elmer, Thomas

    2015-08-11

    A mixerless high frequency interferometric Doppler radar system and methods has been invented, numerically validated and experimentally tested. A continuous wave source, phase modulator (e.g., a continuously oscillating reference mirror) and intensity detector are utilized. The intensity detector measures the intensity of the combined reflected Doppler signal and the modulated reference beam. Rigorous mathematics formulas have been developed to extract bot amplitude and phase from the measured intensity signal. Software in Matlab has been developed and used to extract such amplitude and phase information from the experimental data. Both amplitude and phase are calculated and the Doppler frequency signature of the object is determined.

  16. Interferometric full-waveform inversion of time-lapse data

    KAUST Repository

    Sinha, Mrinal

    2017-08-17

    One of the key challenges associated with time-lapse surveys is ensuring the repeatability between the baseline and monitor surveys. Non-repeatability between the surveys is caused by varying environmental conditions over the course of different surveys. To overcome this challenge, we propose the use of interferometric full waveform inversion (IFWI) for inverting the velocity model from data recorded by baseline and monitor surveys. A known reflector is used as the reference reflector for IFWI, and the data are naturally redatumed to this reference reflector using natural reflections as the redatuming operator. This natural redatuming mitigates the artifacts introduced by the repeatability errors that originate above the reference reflector.

  17. New orbital elements of 5 interferometric double stars

    Directory of Open Access Journals (Sweden)

    Olević D.

    1999-01-01

    Full Text Available In this paper, for the first time, are presented elliptical and Thiel- Innes orbitatal elements for the following interferometric pairs: WDS 00416+2438 = WRH, WDS 03271+1845 = CHARA 10, WDS 04044+2406 = McA 13 Aa, WDS 17095+4047 = McA 45 and WDS 23019+4219 = o And Aa. For the pairs WDS 03271+1845 = CHARA 10 andWDS 04044+2406 = McA 13 Aa are calculated total masses and dynamical parallaxes which are compared with corresponding Hipparcos parallaxes.

  18. The Deep Interferometric VSOP--Arecibo Survey (DIVAS)

    Science.gov (United States)

    Edwards, P. G.; Hirabayashi, H.; Ulvestad, J. S.; Salter, C.; Ghosh, T.; Gurvits, L. I.; Fomalont, E. B.

    2009-08-01

    The Deep Interferometric VSOP-Arecibo Survey (DIVAS) program used space VLBI observations of a faint sample of flat-spectrum sources made with the HALCA satellite and the Arecibo telescope to provide the highest possible space VLBI sensitivity at 5 GHz. The main aim of the survey is to compare statistical results on the source structures (e.g., brightness temperatures, sizes, visibilities) with results from the VLBI Space Observatory Programme (VSOP) Survey, to determine whether there are systematic differences in the compact structures of sources selected from samples with limiting flux densities differing by over an order of magnitude.

  19. An All Fiber White Light Interferometric Absolute Temperature Measurement System

    Directory of Open Access Journals (Sweden)

    Jeonggon Harrison Kim

    2008-11-01

    Full Text Available Recently the author of this article proposed a new signal processing algorithm for an all fiber white light interferometer. In this article, an all fiber white light interferometric absolute temperature measurement system is presented using the previously proposed signal processing algorithm. Stability and absolute temperature measurement were demonstrated. These two tests demonstrated the feasibility of absolute temperature measurement with an accuracy of 0.015 fringe and 0.0005 fringe, respectively. A hysteresis test from 373K to 873K was also presented. Finally, robustness of the sensor system towards laser diode temperature drift, AFMZI temperature drift and PZT non-linearity was demonstrated.

  20. INTERFEROMETRIC STUDIES OF HOT STARS AT SYDNEY UNIVERSITY

    OpenAIRE

    Robertson, J. G.; Davis, J.; Ireland, M.J.; Tuthill, P. G.; Tango, W. J.; Jacob, A. P.; North, J. R.; ten Brummelaar, T. A.

    2010-01-01

    La Universidad de Sydney tiene una larga historia en interferometrÍa estelar óptica. El primer proyecto, en los aÑos 60, fue el interferómetro de intensidad estelar de Narrabri, que midió los di ametros angulares de 32 estrellas calientes y estableció la escala de temperatura para las clases espectrales O-F. Ese instrumento fue seguido por el interferómetro estelar de la Universidad de Sydney (SUSI), que ahora está experimentando una mejora de tercera generación, para utilizar el combinador d...

  1. Twin mirrors for laser interferometric gravitational-wave detectors.

    Science.gov (United States)

    Sassolas, Benoît; Benoît, Quentin; Flaminio, Raffaele; Forest, Danièle; Franc, Janyce; Galimberti, Massimo; Lacoudre, Aline; Michel, Christophe; Montorio, Jean-Luc; Morgado, Nazario; Pinard, Laurent

    2011-05-01

    Gravitational-wave detectors such as Virgo and the laser interferometric gravitational-wave observatory (LIGO) use a long-baseline Michelson interferometer with Fabry-Perot cavities in the arms to search for gravitational waves. The symmetry between the two Fabry-Perot cavities is crucial to reduce the interferometer's sensitivity to the laser amplitude and frequency noise. To this purpose, the transmittance of the mirrors in both cavities should be as close as possible. This paper describes the realization and the characterization of the first twin large low-loss mirrors with transmissions differing by less than 0.01%.

  2. Optically sensitive Medipix2 detector for adaptive optics wavefront sensing

    CERN Document Server

    Vallerga, John; Tremsina, Anton; Siegmund, Oswald; Mikulec, Bettina; Clark, Allan G; CERN. Geneva

    2005-01-01

    A new hybrid optical detector is described that has many of the attributes desired for the next generation adaptive optics (AO) wavefront sensors. The detector consists of a proximity focused microchannel plate (MCP) read out by multi-pixel application specific integrated circuit (ASIC) chips developed at CERN ("Medipix2") with individual pixels that amplify, discriminate and count input events. The detector has 256 x 256 pixels, zero readout noise (photon counting), can be read out at 1 kHz frame rates and is abutable on 3 sides. The Medipix2 readout chips can be electronically shuttered down to a temporal window of a few microseconds with an accuracy of 10 ns. When used in a Shack-Hartmann style wavefront sensor, a detector with 4 Medipix chips should be able to centroid approximately 5000 spots using 7 x 7 pixel sub-apertures resulting in very linear, off-null error correction terms. The quantum efficiency depends on the optical photocathode chosen for the bandpass of interest.

  3. Design of an interferometric system for piston measurements in segmented primary mirrors

    Science.gov (United States)

    Arasa, Josep; Laguarta, Ferran; Pizarro, Carlos; Tomas, Nuria; Pinto, Agusti

    2000-10-01

    Recently, telescopes with segmented primary mirrors are becoming increasingly popular due to their ability of achieving large apertures without the inconveniences caused by the fabrication and handling of monolithic surfaces with 8m (or over) in diameter. The difference in position of each pair of adjacent segments along the local normal of their interface (called piston hereafter), however, needs to be precisely measured in order to provide a diffraction- limited image. If a system yielding the nanometric accuracy required in piston measurements worked in daylight hours, the resultant saving in observation time would be an important advance on a majority of the state-of-the-art piston measurement systems. An interferometric piston measurement instrument accomplishing such objectives has been designed starting from the usual Michelson configuration at the CD6 (Terrassa, Spain), and its final test has been carried out in the test workbench of the Instituto de Astrofisica de Canarias (IAC, Canary Islands, Spain). Its optical layout relies on projecting the reference arm of the interferometer onto one of the segments of the pair considered, along the direction of the local normal to the surface while the measurement arm is projected onto the interface which divides the pair of segments considered. The field of view and its illumination are calculated to be equivalent in both segments. The lateral shift of the fringes in both interferograms determines the piston error present. A combination of monochromatic and white light is used, in order to remove the (lambda) /2 phase ambiguities present in piston measurements without losing the required resolution in the measurement. In this paper, the optical design of this interferometric piston measurement instrument will be presented. The particular configuration used in the interferometer, the implementation of an imaging system allowing to see both the interface of the segments and the interference fringes, the effect of the

  4. Interferometric SAR Persistent Scatterer Analysis of Mayon volcano, Albay, Philippines

    Science.gov (United States)

    Bato, M. P.; Lagmay, A. A.; Paguican, E. R.

    2011-12-01

    Persistent Scatterer Interferometry (PSInSAR) is a new method of interferometric processing that overcomes the limitations of conventional Synthetic Aperture Radar differential interferometry (DInSAR) and is capable of detecting millimeter scale ground displacements. PSInSAR eliminate anomalies due to atmospheric delays and temporal and geometric decorrelation eminent in tropical regions by exploiting the temporal and spatial characteristics of radar interferometric signatures derived from time-coherent point-wise targets. In this study, PSInSAR conducted in Mayon Volcano, Albay Province, Bicol, Philippines, reveal tectonic deformation passing underneath the volcano. Using 47 combined ERS and ENVISAT ascending and descending imageries, differential movement between the northern horst and graben on which Mayon volcano lies, is as much as 2.5 cm/year in terms of the line-of-sight (LOS) change in the radar signal. The northern horst moves in the northwest direction whereas the graben moves mostly downward. PSInSAR results when coupled with morphological interpretation suggest left-lateral oblique-slip movement of the northern bounding fault of the Oas graben. The PSInSAR results are validated with dGPS measurements. This work presents the functionality of PSInSAR in a humid tropical environment and highlights the probable landslide hazards associated with an oversteepened volcano that may have been further deformed by tectonic activity.

  5. Regional landslide forecasting model using interferometric SAR images

    Institute of Scientific and Technical Information of China (English)

    董育烦; 张发明; 高正夏; 蒯志要

    2008-01-01

    Method of obtaining landslide evaluating information by using Interferometric Synthetic Aperture Radar (InSAR) technique was discussed. More precision landslide surface deformation data extracted from InSAR image need take suitable SAR interferometric data selecting, path tracking, phase unwrapping processes. Then, the DEM model of scope and surface shape of the landslide was built. Combining with geological property of landslide and sliding displacements obtained from InSAR/D-InSAR images, a new landslide forecasting model called equal central angle slice method for those not obviously deformed landslides was put forward. This model breaks the limits of traditional research methods of geology. In this model, the landslide safety factor was calculated by equal central angle slice method, then considering the persistence ratio of the sliding surface based on plastic theory, the minimum safety factor was the phase when plastic area were complete persistence. This new model makes the application of InSAR/D-InSAR technology become more practical in geology hazard research.

  6. Super-virtual interferometric diffractions as guide stars

    KAUST Repository

    Dai, Wei

    2011-01-01

    A significant problem in seismic imaging is seismically seeing below salt structures: large velocity contrasts and the irregular geometry of the salt-sediment interface strongly defocus both the downgoing and upgoing seismic wavefields. This can result in severely defocused migration images so as to seismically render some subsalt reserves invisible. The potential cure is a good estimate of the subsalt and salt velocity distributions, but that is also the problem: severe velocity contrasts prevent the appearance of coherent subsalt reflections in the surface records so that MVA or tomographic methods can become ineffective. We now present an interferometric method for extracting the diffraction signals that emanate from diffractors, also denoted as seismic guide stars. The signal-to-noise ratio of these interferometric diffractions is enhanced by N, where N is the number of source points coincident with the receiver points. Thus, diffractions from subsalt guide stars can then be rendered visible and so can be used for velocity analysis, migration, and focusing of subsalt reflections. Both synthetic and field data records are used to demonstrate the benefits and limitations of this method. © 2011 Society of Exploration Geophysicists.

  7. Rapid interferometric imaging of printed drug laden multilayer structures.

    Science.gov (United States)

    Sandler, Niklas; Kassamakov, Ivan; Ehlers, Henrik; Genina, Natalja; Ylitalo, Tuomo; Haeggstrom, Edward

    2014-01-01

    The developments in printing technologies allow fabrication of micron-size nano-layered delivery systems to personal specifications. In this study we fabricated layered polymer structures for drug-delivery into a microfluidic channel and aimed to interferometrically assure their topography and adherence to each other. We present a scanning white light interferometer (SWLI) method for quantitative assurance of the topography of the embedded structure. We determined rapidly in non-destructive manner the thickness and roughness of the structures and whether the printed layers containing polymers or/and active pharmaceutical ingredients (API) adhere to each other. This is crucial in order to have predetermined drug release profiles. We also demonstrate non-invasive measurement of a polymer structure in a microfluidic channel. It shown that traceable interferometric 3D microscopy is a viable technique for detailed structural quality assurance of layered drug-delivery systems. The approach can have impact and find use in a much broader setting within and outside life sciences.

  8. Interferometric estimation of ice sheet motion and topography

    Science.gov (United States)

    Joughlin, Ian; Kwok, Ron; Fahnestock, Mark; Winebrenner, Dale; Tulaczyk, Slawek; Gogenini, Prasad

    1997-01-01

    With ERS-1/2 satellite radar interferometry, it is possible to make measurements of glacier motion with high accuracy and fine spatial resolution. Interferometric techniques were applied to map velocity and topography for several outlet glaciers in Greenland. For the Humboldt and Petermann glaciers, data from several adjacent tracks were combined to make a wide-area map that includes the enhanced flow regions of both glaciers. The discharge flux of the Petermann glacier upstream of the grounding line was estimated, thereby establishing the potential use of ERS-1/2 interferometric data for monitoring ice-sheet discharge. Interferograms collected along a single track are sensitive to only one component of motion. By utilizing data from ascending and descending passes and by making a surface-parallel flow assumption, it is possible to measure the full three-dimensional vector flow field. The application of this technique for an area on the Ryder glacier is demonstrated. Finally, ERS-1/2 interferograms were used to observe a mini-surge on the Ryder glacier that occurred in autumn of 1995.

  9. Secure space-to-space interferometric communications and its nexus to the physics of quantum entanglement

    Science.gov (United States)

    Duarte, F. J.

    2016-12-01

    The history of the probability amplitude equation |ψ>=(|x ,y >-|y ,x >) applicable to quanta pairs, propagating in different directions with entangled polarizations, is reviewed and traced back to the 1947-1949 period. The interferometric Dirac foundations common to |ψ>=(|x ,y >-|y ,x >) and the generalized N-slit interferometric equation, for indistinguishable quanta, are also described. The results from a series of experiments on N-slit laser interferometers, with intra interferometric propagation paths up to 527 m, are reviewed. Particular attention is given to explain the generation of interferometric characters, for secure space-to-space communications, which immediately collapse on attempts of interception. The design of a low divergence N-slit laser interferometer for low Earth orbit-low Earth orbit (LEO-LEO), and LEO-geostationary Earth orbit (LEO-GEO), secure interferometric communications is described and a weight assessment is provided.

  10. All-Optical Terahertz Optical Asymmetric Demultiplexer (toad) Based Binary Comparator:. a Proposal

    Science.gov (United States)

    Chattopadhyay, Tanay

    Comparator determines whether a number is greater than, equals to or less than another number. It plays a significant role in fast central processing unit in all-optical scheme. In all-optical scheme here 1-bit binary comparator is proposed and described by Terahertz Optical Asymmetric Demultiplexer (TOAD) based interferometric switch. Simulation result by Mathcad-7 is also given. Cascading technique of building up the n-bit binary comparator with this 1-bit comparator block is also proposed here.

  11. Fiber optic and laser sensors VIII; Proceedings of the Meeting, San Jose, CA, Sept. 17-19, 1990

    Science.gov (United States)

    Depaula, Ramon P. (Editor); Udd, Eric (Editor)

    1991-01-01

    This issue presents topics on the advances in fiber-optic sensor technology, fiber-optic gyroscope, fiber-optic position and pressure sensors, fiber-optic magnetic and temperature sensors, and generic fiber-optic sensors. Papers included are on a novel analog phase tracker for interferometric fiber-optic sensor applications, recent development status of fiber-optic sensors in China, the magnetic-field sensitivity of depolarized fiber-optic gyros, a depolarized fiber-optic gyro for future tactical applications, fiber-optic position transducers for aircraft controls, and a metal embedded optical-fiber pressure sensor. Attention is also given to a fiber-optic magnetic field sensor using spectral modulation encoding, a bare-fiber temperature sensor, an interferometric fiber-optic accelerometer, improvement of specular reflection pyrometer, a theoretical analysis of two-mode elliptical-core optical fiber sensors, and a fiber probe for ring pattern.

  12. Three-dimensional hydrodynamical simulations of red giant stars: semi-global models for the interpretation of interferometric observations

    CERN Document Server

    Chiavassa, A; Casagrande, L; Asplund, M

    2010-01-01

    Context. Theoretical predictions from models of red giant branch stars are a valuable tool for various applications in astrophysics ranging from galactic chemical evolution to studies of exoplanetary systems. Aims. We use the radiative transfer code OPTIM3D and realistic 3D radiative-hydrodynamical (RHD) surface convection simulations of red giants to explore the impact of granulation on interferometric observables. Methods. We compute intensity maps for the 3D simulation snapshots in two filters: in the optical at 5000 \\pm 300 {\\AA} and in the K band 2.14 $\\pm$ 0.26 {\\mu}m FLUOR filter, corresponding to the wavelength-range of instruments mounted on the CHARA interferometer. From the intensity maps, we construct images of the stellar disks, accounting for center-to-limb variations. We then derive interferometric visibility amplitudes and phases. We study their behavior with position angle and wavelength. Results. We provide average limb-darkening coefficients for different metallicities and wavelength-ranges...

  13. Cryogenic optical performance of a lightweighted mirror assembly for future space astronomical telescopes: correlating optical test results and thermal optical model

    Science.gov (United States)

    Eng, Ron; Arnold, William R.; Baker, Markus A.; Bevan, Ryan M.; Burdick, Gregory; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Hanson, Craig; Hogue, William D.; Kegley, Jeffrey R.; Kirk, Charlie; Maffett, Steven P.; Matthews, Gary W.; Siler, Richard D.; Smith, W. Scott; Stahl, H. Philip; Tucker, John M.; Wright, Ernest R.

    2013-09-01

    A 43cm diameter stacked core mirror demonstrator was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two CNC pocket milled face sheets. The 93% lightweighted Corning ULE® mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model.

  14. Cryogenic Optical Performance of a Lightweighted Mirror Assembly for Future Space Astronomical Telescopes: Correlating Optical Test Results and Thermal Optical Model

    Science.gov (United States)

    Eng, Ron; Arnold, William R.; Baker, Marcus A.; Bevan, Ryan M.; Burdick, Gregory; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Hanson, Craig; Hogue, William D.; Kegley, Jeffrey R.; Kirk, Charlie; Maffett, Steven P.; Matthews, Gary W.; Siler, Richard D.; Smith, W. Scott; Stahl, H. Philip; Tucker, John M.; Wright, Ernest R.

    2013-01-01

    A 43cm diameter stacked core mirror demonstrator was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two CNC pocket milled face sheets. The 93% lightweighted Corning ULE® mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model.

  15. Cryogenic Optical Performance of a Light-weight Mirror Assembly for Future Space Astronomical Telescopes: Optical Test Results and Thermal Optical Model

    Science.gov (United States)

    Eng, Ron; Arnold, William; Baker, Markus A.; Bevan, Ryan M.; Carpenter, James R.; Effinger, Michael R.; Gaddy, Darrell E.; Goode, Brian K.; Kegley, Jeffrey R.; Hogue, William D.; Siler, Richard D.; Smith, W. Scott; Stahl. H. Philip; Tucker, John M.; Wright, Ernest R.; Kirk, Charles S.; Hanson, Craig; Burdick, Gregory; Maffett, Steven

    2013-01-01

    A 40 cm diameter mirror assembly was interferometrically tested at room temperature down to 250 degrees Kelvin for thermal deformation. The 2.5 m radius of curvature spherical mirror assembly was constructed by low temperature fusing three abrasive waterjet core sections between two face sheets. The 93% lightweighted Corning ULE mirror assembly represents the current state of the art for future UV, optical, near IR space telescopes. During the multiple thermal test cycles, test results of interferometric test, thermal IR images of the front face were recorded in order to validate thermal optical model.

  16. Fiber-Optic Temperature Sensor

    Science.gov (United States)

    Maram, Jonathan M.

    1987-01-01

    Proposed sensor measures temperatures over wide range, from cryogenic liquids to burning gases. Made in part of optical fibers, sensor lighter in weight than thermocouple and immune to electromagnetic interference. Device does not respond to temperatures elsewhere than at sensing tip. Thermal expansion and contraction of distance between fiber end and mirror alters interference between light reflected from those two surfaces, thereby giving interferometric indication of temperatures.

  17. Interferometric observations of the supergiant stars alpha Orionis and alpha Herculis with FLUOR at IOTA

    CERN Document Server

    Perrin, G; Foresto, V C; Mennesson, B; Traub, W A; Lacasse, M G

    2004-01-01

    We report the observations in the K band of the red supergiant star alpha Orionis and of the bright giant star alpha Herculis with the FLUOR beamcombiner at the IOTA interferometer. The high quality of the data allows us to estimate limb-darkening and derive precise diameters in the K band which combined with bolometric fluxes yield effective temperatures. In the case of Betelgeuse, data collected at high spatial frequency although sparse are compatible with circular symmetry and there is no clear evidence for departure from circular symmetry. We have combined the K band data with interferometric measurements in the L band and at 11.15 micron. The full set of data can be explained if a 2055 K layer with optical depths $\\tau_{K}=0.060\\pm0.003$, $\\tau_{L}=0.026\\pm0.002$ and $\\tau_{11.15\\mu m}=2.33\\pm0.23$ is added 0.33 $R_{\\star}$ above the photosphere providing a first consistent view of the star in this range of wavelengths. This layer provides a consistent explanation for at least three otherwise puzzling ob...

  18. Long-Baseline Interferometric Multiplicity Survey of the Sco-Cen OB Association

    CERN Document Server

    Rizzuto, A C; Robertson, J G; Kok, Y; Tuthill, P G; Warrington, B A; Haubois, X; Tango, W J; Norris, B; Brummelaar, T ten; Kraus, A L; Jacob, A; Laliberte-Houdeville, C

    2013-01-01

    We present the first multiplicity-dedicated long baseline optical interferometric survey of the Scorpius-Centaurus-Lupus-Crux association. We used the Sydney University Stellar Interferometer to undertake a survey for new companions to 58 Sco-Cen B- type stars and have detected 24 companions at separations ranging from 7-130mas, 14 of which are new detections. Furthermore, we use a Bayesian analysis and all available information in the literature to determine the multiplicity distribution of the 58 stars in our sample, showing that the companion frequency is F = 1.35 and the mass ratio distribution is best described as a power law with exponent equal to -0.46, agreeing with previous Sco-Cen high mass work and differing significantly from lower-mass stars in Tau-Aur. Based on our analysis, we estimate that among young B-type stars in moving groups, up to 23% are apparently single stars. This has strong implications for the understanding of high-mass star formation, which requires angular momentum dispersal thr...

  19. LINC-NIRVANA, integration of an interferometric and cryogenic camera: first verification results

    Science.gov (United States)

    Bizenberger, Peter; Baumeister, Harald; Böhm, Armin; Herbst, Tom; Huber, Armin; Laun, Werner; Mall, Ulrich; Mohr, Lars; Naranjo, Vianak; Storz, Clemens; Trowitzsch, Jan

    2012-09-01

    LINC-NIRVANA is an interferometric imaging camera, which combines the two 8.4 m telescopes of the Large Binocular Telescope (LBT). The instrument operates in the wavelength range from 1.1 μm to 2.4 μm, covering the J, H and K-bands. The beam combining camera (NIRCS) offers the possibility to achieve diffraction limited images with the spatial resolution of a 23 m telescope. This camera, which combines the AO corrected beams of both telescopes, is designed to deliver a 10 arcsec x 10 arcsec diffraction limited field of view. The optics and cryo-mechanics are designed for operation at 60 Kelvin. Equipped with a HAWAII-2 detector mounted on a rotation stage in order to compensate for the sky rotation, a filter wheel and a dichroic wheel to split the light into the science channel and the fringe tracking channel, the camera is fairly large and complex and requires certain features to be considered and tested. The verification of all these components follows a challenging AIV plan. We describe this AIV phase from initial integration of individual units to the final verification tests of the complete system. We report the performance of the cryogenic opto-mechanics and of the science detector. We also demonstrate the functionality of the cryo-mechanics and the cryo-cooling at sub-system level, which represents the current state of integration. Finally, we discuss key elements of our design and potential pros and cons.

  20. Differential Radiometers Using Fabry-Perot Interferometric Technique for Remote Sensing of Greenhouse Gases

    Science.gov (United States)

    Georgieva, Elena M.; Heaps,William S.; Wilson, Emily L.

    2007-01-01

    A new type of remote sensing radiometer based upon the Fabry-Perot interferometric technique has been developed at NASA's Goddard Space Flight Center and tested from both ground and aircraft platform. The sensor uses direct or reflected sunlight and has channels for measuring column concentration of carbon dioxide at 1570 nm, oxygen lines sensitive to pressure and temperature at 762 and 768 nm, and water vapor (940 nm). A solid Fabry-Perot etalon is used as a tunable narrow bandpass filter to restrict the measurement to the gas of interest's absorption bands. By adjusting the temperature of the etalon, which changes the index of refraction of its material, the transmission fringes can be brought into nearly exact correspondence with absorption lines of the particular species. With this alignment between absorption lines and fringes, changes in the amount of a species in the atmosphere strongly affect the amount of light transmitted by the etalon and can be related to gas concentration. The technique is applicable to different chemical species. We have performed simulations and instrument design studies for CH4, "Cot isotope, and CO detection. Index Terms- Absorbing media, Atmospheric measurements, Fabry-Perot interferometers, Optical interferometry, Remote sensing.

  1. Simultaneous refractive index and thickness measurement with the transmission interferometric adsorption sensor

    Energy Technology Data Exchange (ETDEWEB)

    Sannomiya, Takumi; Voeroes, Janos [Laboratory of Biosensors and Bioelectronics, Department of Information Technology and Electrical Engineering, ETH Zurich, 8092, Zurich (Switzerland); Balmer, Tobias E [Materials Research Center, ETH Zurich, 8093, Zurich (Switzerland); Heuberger, Manfred, E-mail: sannomiya@biomed.ee.ethz.c, E-mail: tobias.balmer@mat.ethz.c, E-mail: manfred.heuberger@empa.c, E-mail: janos.voros@biomed.ee.ethz.c [Laboratory for Surface Science and Technology, Department of Materials, ETH Zurich, 8093, Zurich (Switzerland)

    2010-10-13

    Refractive index and thickness of the adlayer are determined simultaneously using the transmission interferometric adsorption sensor (TInAS). Optical biosensors, where both refractive index and thickness of a homogeneous adlayer (thus the adsorbed mass) are determined simultaneously, so-called model-free biosensors, are important tools to investigate the adsorbed mass of biomolecules with unknown conformation. Our proposed calculation method enables model-free biosensing from a single spectrum acquired by a simple TInAS setup, namely using information of peak/dip positions as well as peak/dip intensities. The feasibility of this method was experimentally tested by adsorbing polyelectrolyte multilayer as well as biomolecules. To validate the new method also for the more intricate heterogeneous adlayer, the apparent refractive index and thickness were assessed theoretically by simulating a selection of different adsorbate configurations with the multiple multipole program (MMP). We found that a lateral inhomogeneity of the adsorbate (e.g. islands or adsorbed colloids) results in correct thickness and in reduced refractive index averaged in proportion to their density while vertically inhomogeneous density caused more complex responses. However, the apparent mass was always correct. Measurement errors can lead to significant errors in the apparent refractive index, particularly when the adlayer is very thin (<5 nm). This model-free TInAS technique would be useful not only for the measurement of adsorbed mass but also for the conformational analysis of the adsorbed molecules.

  2. Air temperature measurements based on the speed of sound to compensate long distance interferometric measurements

    Directory of Open Access Journals (Sweden)

    Astrua Milena

    2014-01-01

    Full Text Available A method to measure the real time temperature distribution along an interferometer path based on the propagation of acoustic waves is presented. It exploits the high sensitivity of the speed of sound in air to the air temperature. In particular, it takes advantage of a special set-up where the generation of the acoustic waves is synchronous with the amplitude modulation of a laser source. A photodetector converts the laser light to an electronic signal considered as reference, while the incoming acoustic waves are focused on a microphone and generate a second signal. In this condition, the phase difference between the two signals substantially depends on the temperature of the air volume interposed between the sources and the receivers. The comparison with the traditional temperature sensors highlighted the limit of the latter in case of fast temperature variations and the advantage of a measurement integrated along the optical path instead of a sampling measurement. The capability of the acoustic method to compensate the interferometric distance measurements due to air temperature variations has been demonstrated for distances up to 27 m.

  3. Laser interferometric vibration measurements of the middle ear in healthy humans

    Science.gov (United States)

    Jorge, J. Rodriguez; Hemmert, Werner; Burkhardt, Claus; Zenner, Hans-Peter; Gummer, Anthony W.

    1996-01-01

    The use of spontaneous and evoked otacoustic emissions is now a standard clinical tool for diagnosis of the function of the inner ear. However, it is not possible to extract this information over the entire, functionally relevant frequency range because of imperfect coupling of: (1) stapedial to ear-drum vibrations through the ossicular chain of the middle ear and (2) ear-drum vibrations to air in the external auditory meatus. The problem could be circumvented if it were possible to measure the vibration of the stapes and ear drum. The ear drum can be visualized non-invasively, whereas the stapes is only accessible intra-operatively. Therefore, we designed a laser-interferometric system to non-invasively measure the vibration of the human ear drum. Vibrations were measured with a laser Doppler velocimeter (Polytec OFV-302) coupled into the side arm of an operating microscope (Zeiss OPMI MDM). The wavelength was 633 nm and emitted power was less than 1 mW. Direct coupling through the optics of the operating microscope, instead of through glass fibers, enabled a larger signal-to- noise ratio (20 - 30 dB) due to collection of more reflected light. This coupling scheme avoids the problems associated with having to place a reflecting material on the ear drum. The developed vibration measurement system allows non-invasive, fast and reproducible characterization of the dynamics of the human ear drum and as such can be used for clinical diagnostics.

  4. Non-thermal emission from high-energy binaries through interferometric radio observations

    CERN Document Server

    Marcote, B

    2016-01-01

    High-mass binary systems involve extreme environments that produce non-thermal emission from radio to gamma rays. Only three types of these systems are known to emit persistent gamma-ray emission: colliding-wind binaries, high-mass X-ray binaries and gamma-ray binaries. This thesis is focused on the radio emission of high-mass binary systems through interferometric observations, and we have explored several of these sources with low- and high-frequency radio observations, and very high-resolution VLBI ones. We have studied two gamma-ray binaries, LS 5039 and LS I +61 303, at low frequencies. We have obtained their light-curves and spectra, and we have determined the physical properties of their radio emitting regions. We have also studied the gamma-ray binary HESS J0632+057 through VLBI observations. A new colliding wind binary, HD 93129A, has been discovered through VLBI and optical observations. Finally, we have conducted radio observations of two sources that were candidates to be gamma-ray binaries.

  5. The Age of the Directly-Imaged Planet Host Star $\\kappa$ Andromedae Determined From Interferometric Observations

    CERN Document Server

    Jones, Jeremy; Quinn, S; Ireland, M; Boyajian, T; Schaefer, G; Baines, E K

    2016-01-01

    $\\kappa$ Andromedae, an early type star that hosts a directly imaged low mass companion, is expected to be oblate due to its rapid rotational velocity ($v\\sin i$ = $\\sim$162 $\\mathrm{km~s^{-1}}$). We observed the star with the CHARA Array's optical beam combiner, PAVO, measuring its size at multiple orientations and determining its oblateness. The interferometric measurements, combined with photometry and this $v\\sin i$ value are used to constrain an oblate star model that yields the fundamental properties of the star and finds a rotation speed that is $\\sim$85\\% of the critical rate and a low inclination of $\\sim$30$^\\circ$. Three modeled properties (the average radius, bolometric luminosity, and equatorial velocity) are compared to MESA evolution models to determine an age and mass for the star. In doing so, we determine an age for the system of 47$^{+27}_{-40}$ Myr. Based on this age and previous measurements of the companion's temperature, the BHAC15 evolution models imply a mass for the companion of 22$^...

  6. Interferometric Scattering Microscopy for the Study of Molecular Motors.

    Science.gov (United States)

    Andrecka, J; Takagi, Y; Mickolajczyk, K J; Lippert, L G; Sellers, J R; Hancock, W O; Goldman, Y E; Kukura, P

    2016-01-01

    Our understanding of molecular motor function has been greatly improved by the development of imaging modalities, which enable real-time observation of their motion at the single-molecule level. Here, we describe the use of a new method, interferometric scattering microscopy, for the investigation of motor protein dynamics by attaching and tracking the motion of metallic nanoparticle labels as small as 20nm diameter. Using myosin-5, kinesin-1, and dynein as examples, we describe the basic assays, labeling strategies, and principles of data analysis. Our approach is relevant not only for motor protein dynamics but also provides a general tool for single-particle tracking with high spatiotemporal precision, which overcomes the limitations of single-molecule fluorescence methods.

  7. Fine tuning consensus optimization for distributed radio interferometric calibration

    CERN Document Server

    Yatawatta, Sarod

    2016-01-01

    We recently proposed the use of consensus optimization as a viable and effective way to improve the quality of calibration of radio interferometric data. We showed that it is possible to obtain far more accurate calibration solutions and also to distribute the compute load across a network of computers by using this technique. A crucial aspect in any consensus optimization problem is the selection of the penalty parameter used in the alternating direction method of multipliers (ADMM) iterations. This affects the convergence speed as well as the accuracy. In this paper, we use the Hessian of the cost function used in calibration to appropriately select this penalty. We extend our results to a multi-directional calibration setting, where we propose to use a penalty scaled by the squared intensity of each direction.

  8. Plasmonic propagations distances for interferometric surface plasmon resonance biosensing

    Directory of Open Access Journals (Sweden)

    Lepage Dominic

    2011-01-01

    Full Text Available Abstract A surface plasmon resonance (SPR scheme is proposed in which the local phase modulations of the coupled plasmons can interfere and yield phase-sensitive intensity modulations in the measured signal. The result is an increased traceability of the SPR shifts for biosensing applications. The main system limitation is the propagation distance of the coupled plasmon modes. This aspect is therefore studied for thin film microstructures operating in the visible and near-infrared spectral regions. The surface roughness of the substrate layer is examined for different dielectrics and deposition methods. The Au layer, on which the plasmonic modes are propagating and the biosensing occurs, is also examined. The surface roughness and dielectric values for various deposition rates of very thin Au films are measured. We also investigate an interferometric SPR setup where, due to the power flux transfer between plasmon modes, the specific choice of grating coupler can either decrease or increase the plasmon propagation length.

  9. Plasmonic propagations distances for interferometric surface plasmon resonance biosensing.

    Science.gov (United States)

    Lepage, Dominic; Carrier, Dominic; Jiménez, Alvaro; Beauvais, Jacques; Dubowski, Jan J

    2011-05-17

    A surface plasmon resonance (SPR) scheme is proposed in which the local phase modulations of the coupled plasmons can interfere and yield phase-sensitive intensity modulations in the measured signal. The result is an increased traceability of the SPR shifts for biosensing applications. The main system limitation is the propagation distance of the coupled plasmon modes. This aspect is therefore studied for thin film microstructures operating in the visible and near-infrared spectral regions. The surface roughness of the substrate layer is examined for different dielectrics and deposition methods. The Au layer, on which the plasmonic modes are propagating and the biosensing occurs, is also examined. The surface roughness and dielectric values for various deposition rates of very thin Au films are measured. We also investigate an interferometric SPR setup where, due to the power flux transfer between plasmon modes, the specific choice of grating coupler can either decrease or increase the plasmon propagation length.

  10. Radio interferometric gain calibration as a complex optimization problem

    CERN Document Server

    Smirnov, Oleg

    2015-01-01

    Recent developments in optimization theory have extended some traditional algorithms for least-squares optimization of real-valued functions (Gauss-Newton, Levenberg-Marquardt, etc.) into the domain of complex functions of a complex variable. This employs a formalism called the Wirtinger derivative, and derives a full-complex Jacobian counterpart to the conventional real Jacobian. We apply these developments to the problem of radio interferometric gain calibration, and show how the general complex Jacobian formalism, when combined with conventional optimization approaches, yields a whole new family of calibration algorithms, including those for the polarized and direction-dependent gain regime. We further extend the Wirtinger calculus to an operator-based matrix calculus for describing the polarized calibration regime. Using approximate matrix inversion results in computationally efficient implementations; we show that some recently proposed calibration algorithms such as StefCal and peeling can be understood...

  11. Differentiating surface and bulk interactions in nanoplasmonic interferometric sensor arrays

    CERN Document Server

    Zeng, Beibei; Bartoli, Filbert J

    2014-01-01

    Detecting specific target analytes and differentiating them from interfering background effects is a crucial but challenging task in complex multi-component solutions commonly encountered in environmental, chemical, biological, and medical sensing applications. Here we present a simple nanoplasmonic interferometric sensor platform that can differentiate the adsorption of a thin protein layer on the sensor surface (surface effects) from bulk refractive index changes (interfering background effects) at a single sensing spot, exploiting the different penetration depths of multiple propagating surface plasmon polaritons excited in the ring-hole nanostructures. A monolayer of bovine serum albumin (BSA) molecules with an effective thickness of 1.91nm is detected and differentiated from a 10-3 change in the bulk refractive index unit of the solution. The noise level of the retrieved real-time sensor output compares favorably with traditional prism-based surface plasmon resonance sensors, but is achieved using a sign...

  12. Interferometric control of the photon-number distribution

    Directory of Open Access Journals (Sweden)

    H. Esat Kondakci

    2017-07-01

    Full Text Available We demonstrate deterministic control over the photon-number distribution by interfering two coherent beams within a disordered photonic lattice. By sweeping a relative phase between two equal-amplitude coherent fields with Poissonian statistics that excite adjacent sites in a lattice endowed with disorder-immune chiral symmetry, we measure an output photon-number distribution that changes periodically between super-thermal and sub-thermal photon statistics upon ensemble averaging. Thus, the photon-bunching level is controlled interferometrically at a fixed mean photon-number by gradually activating the excitation symmetry of the chiral-mode pairs with structured coherent illumination and without modifying the disorder level of the random system itself.

  13. Spin-polarizing interferometric beam splitter for free electrons

    CERN Document Server

    Dellweg, Matthias M

    2016-01-01

    A spin-polarizing electron beam splitter is described which relies on an arrangement of linearly polarized laser waves of nonrelativistic intensity. An incident electron beam is first coherently scattered off a bichromatic laser field, splitting the beam into two portions, with electron spin and momentum being entangled. Afterwards, the partial beams are coherently superposed in an interferometric setup formed by standing laser waves. As a result, the outgoing electron beam is separated into its spin components along the laser magnetic field, which is shown by both analytical and numerical solutions of Pauli's equation. The proposed laser field configuration thus exerts the same effect on free electrons like an ordinary Stern-Gerlach magnet does on atoms.

  14. Hierarchical model-based interferometric synthetic aperture radar image registration

    Science.gov (United States)

    Wang, Yang; Huang, Haifeng; Dong, Zhen; Wu, Manqing

    2014-01-01

    With the rapid development of spaceborne interferometric synthetic aperture radar technology, classical image registration methods are incompetent for high-efficiency and high-accuracy masses of real data processing. Based on this fact, we propose a new method. This method consists of two steps: coarse registration that is realized by cross-correlation algorithm and fine registration that is realized by hierarchical model-based algorithm. Hierarchical model-based algorithm is a high-efficiency optimization algorithm. The key features of this algorithm are a global model that constrains the overall structure of the motion estimated, a local model that is used in the estimation process, and a coarse-to-fine refinement strategy. Experimental results from different kinds of simulated and real data have confirmed that the proposed method is very fast and has high accuracy. Comparing with a conventional cross-correlation method, the proposed method provides markedly improved performance.

  15. Advanced Virgo: a 2nd generation interferometric gravitational wave detector

    CERN Document Server

    ,

    2014-01-01

    Advanced Virgo is the project to upgrade the Virgo interferometric detector of gravitational waves, with the aim of increasing the number of observable galaxies (and thus the detection rate) by three orders of magnitude. The project is now in an advanced construction phase and the assembly and integration will be completed by the end of 2015. Advanced Virgo will be part of a network with the two Advanced LIGO detectors in the US and GEO HF in Germany, with the goal of contributing to the early detections of gravitational waves and to opening a new observation window on the universe. In this paper we describe the main features of the Advanced Virgo detector and outline the status of the construction.

  16. Interferometric SAR for observation of glacier motion and firn penetration

    Science.gov (United States)

    Winebrenner, Dale P.; Joughlin, Ian R.; Fahnestock, Mark A.

    1997-01-01

    A digital elevation model (DEM) for a swath in west Greenland above Jakobshavn Isbrae derived from a number ERS-1 interferograms combined so as to reduce phase errors and other problems is presented. The DEM shows a wealth of kilometer-scale, dynamically supported topography, which arises from ice sheet flow over the rough bed. A correlation is shown between topography and interferometric phase due solely to ice sheet motion, which clearly shows the translations of scatterers in the surface up and downslope in the topography. Finally, the low correlation in interferograms of ice sheet dry snow zones motivates investigation on the depth-locus of backscattering. A scattering model is presented, including realistic firn grain size distributions and layering, which shows that layering helps to localize backscattering from dry firn to shallower depths than would otherwise be expected.

  17. Interferometric array design optimizing the locations of the antenna pads

    CERN Document Server

    Boone, F

    2001-01-01

    The design of an interferometric array should allow optimal instrumental response regarding all possible source positions, times of integration and scientific goals. It should also take into account constraints such as forbidden regions on the ground due to impracticable topography. The complexity of the problem requires one to proceed by steps. A possible approach is to first consider a single observation and a single scientific purpose. A new algorithm is introduced to solve efficiently this particular problem called the configuration problem. It is based on the computation of pressure forces related to the discrepancies between the model (as determined by the scientific purpose) and the actual distribution of Fourier samples. The flexibility and rapidity of the method are well adapted to the full array design. A software named APO that can be used for the design of new generation interferometers such as ALMA and ATA has been developed.

  18. INTERFEROMETRIC SYNTHETIC APERTURE RADAR (INSAR TECHNOLOGY AND GEOMORPHOLOGY INTERPRETATION

    Directory of Open Access Journals (Sweden)

    M. Maghsoudi

    2013-09-01

    Full Text Available Geomorphology is briefly the study of landforms and their formative processes on the surface of the planet earth as human habitat. The landforms evolution and the formative processes can best be studied by technologies with main application in study of elevation. Interferometric Synthetic Aperture Radar (InSAR is the appropriate technology for this application. With phase differences calculations in radar waves, the results of this technology can extensively be interpreted for geomorphologic researches. The purpose of the study is to review the geomorphologic studies using InSAR and also the technical studies about InSAR with geomorphologic interpretations. This study states that the InSAR technology can be recommended to be employed as a fundamental for geomorphology researches.

  19. Geometrical model fitting for interferometric data: GEM-FIND

    CERN Document Server

    Klotz, D; Paladini, C; Hron, J; Wachter, G

    2012-01-01

    We developed the tool GEM-FIND that allows to constrain the morphology and brightness distribution of objects. The software fits geometrical models to spectrally dispersed interferometric visibility measurements in the N-band using the Levenberg-Marquardt minimization method. Each geometrical model describes the brightness distribution of the object in the Fourier space using a set of wavelength-independent and/or wavelength-dependent parameters. In this contribution we numerically analyze the stability of our nonlinear fitting approach by applying it to sets of synthetic visibilities with statistically applied errors, answering the following questions: How stable is the parameter determination with respect to (i) the number of uv-points, (ii) the distribution of points in the uv-plane, (iii) the noise level of the observations?

  20. A detector interferometric calibration experiment for high precision astrometry

    Science.gov (United States)

    Crouzier, A.; Malbet, F.; Henault, F.; Léger, A.; Cara, C.; LeDuigou, J. M.; Preis, O.; Kern, P.; Delboulbe, A.; Martin, G.; Feautrier, P.; Stadler, E.; Lafrasse, S.; Rochat, S.; Ketchazo, C.; Donati, M.; Doumayrou, E.; Lagage, P. O.; Shao, M.; Goullioud, R.; Nemati, B.; Zhai, C.; Behar, E.; Potin, S.; Saint-Pe, M.; Dupont, J.

    2016-11-01

    Context. Exoplanet science has made staggering progress in the last two decades, due to the relentless exploration of new detection methods and refinement of existing ones. Yet astrometry offers a unique and untapped potential of discovery of habitable-zone low-mass planets around all the solar-like stars of the solar neighborhood. To fulfill this goal, astrometry must be paired with high precision calibration of the detector. Aims: We present a way to calibrate a detector for high accuracy astrometry. An experimental testbed combining an astrometric simulator and an interferometric calibration system is used to validate both the hardware needed for the calibration and the signal processing methods. The objective is an accuracy of 5 × 10-6 pixel on the location of a Nyquist sampled polychromatic point spread function. Methods: The interferometric calibration system produced modulated Young fringes on the detector. The Young fringes were parametrized as products of time and space dependent functions, based on various pixel parameters. The minimization of function parameters was done iteratively, until convergence was obtained, revealing the pixel information needed for the calibration of astrometric measurements. Results: The calibration system yielded the pixel positions to an accuracy estimated at 4 × 10-4 pixel. After including the pixel position information, an astrometric accuracy of 6 × 10-5 pixel was obtained, for a PSF motion over more than five pixels. In the static mode (small jitter motion of less than 1 × 10-3 pixel), a photon noise limited precision of 3 × 10-5 pixel was reached.