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Sample records for mach-zehnder interferometric vibration

  1. Vibration induced phase noise in Mach-Zehnder atom interferometers

    CERN Document Server

    Miffre, A; Büchner, M; Trénec, G; Vigué, J; Miffre, Alain; Jacquey, Marion; B\\"{u}chner, Matthias; Vigu\\'{e}, Jacques

    2006-01-01

    The high inertial sensitivity of atom interferometers has been used to build accelerometers and gyrometers but this sensitivity makes these interferometers very sensitive to the laboratory seismic noise. This seismic noise induces a phase noise which is large enough to reduce the fringe visibility in many cases. We develop here a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are thus able to explain the observed dependence of the fringe visibility with the diffraction order. The dynamical model developed in the present paper should be very useful to further reduce this phase noise in atom interferometers and this reduction should open the way to improved interferometers.

  2. 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.

  3. 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.

  4. Vibration sensing using a tapered bend-insensitive fiber based Mach-Zehnder interferometer.

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Qin, Zengguang; Harris, Jeremie; Baset, Farhana; Lu, Ping; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2013-02-11

    In this study, a novel fiber-optic sensor consisting of a tapered bend-insensitive fiber based Mach-Zehnder interferometer is presented to realize damped and continuous vibration measurement. The double cladding structure and the central coating region of the in-fiber interferometer ensure an enhanced mechanical strength, reduced external disturbance, and a more uniform spectrum. A damped vibration frequency range of 29-60 Hz as well as continuous vibration disturbances ranging from 1 Hz up to 500 kHz are successfully demonstrated.

  5. Phase noise due to vibrations in Mach-Zehnder atom interferometers

    CERN Document Server

    Miffre, A; Büchner, M; Trénec, G; Vigué, J

    2006-01-01

    Atom interferometers are very sensitive to accelerations and rotations. This property, which has some very interesting applications, induces a deleterious phase noise due to the seismic noise of the laboratory and this phase noise is sufficiently large to reduce the fringe visibility in many experiments. We develop a model calculation of this phase noise in the case of Mach-Zehnder atom interferometers and we apply this model to our thermal lithium interferometer. We are able to explain the observed phase noise which has been detected through the rapid dependence of the fringe visibility with the diffraction order. We think that the dynamical model developed in the present paper should be very useful to reduce the vibration induced phase noise in atom interferometers, making many new experiments feasible.

  6. Sensitivity distribution of a vibration sensor based on Mach-Zehnder interferometer designed inside the window system

    Science.gov (United States)

    Zboril, Ondrej; Nedoma, Jan; Cubik, Jakub; Novak, Martin; Bednarek, Lukas; Fajkus, Marcel; Vasinek, Vladimir

    2016-04-01

    Interferometric sensors are very accurate and sensitive sensors that due to the extreme sensitivity allow sensing vibration and acoustic signals. This paper describes a new method of implementation of Mach-Zehnder interferometer for sensing of vibrations caused by touching on the window panes. Window panes are part of plastic windows, in which the reference arm of the interferometer is mounted and isolated inside the frame, a measuring arm of the interferometer is fixed to the window pane and it is mounted under the cover of the window frame. It prevents visibility of the optical fiber and this arrangement is the basis for the safety system. For the construction of the vibration sensor standard elements of communication networks are used - optical fiber according to G.652D and 1x2 splitters with dividing ratio 1:1. Interferometer operated at a wavelength of 1550 nm. The paper analyses the sensitivity of the window in a 12x12 measuring points matrix, there is specified sensitivity distribution of the window pane.

  7. A distributed fiber vibration sensor utilizing dispersion induced walk-off effect in a unidirectional Mach-Zehnder interferometer.

    Science.gov (United States)

    Chen, Qingming; Jin, Chao; Bao, Yuan; Li, Zhaohui; Li, Jianping; Lu, Chao; Yang, Liang; Li, Guifang

    2014-02-10

    We propose and experimentally demonstrate a novel ultra-long range and sensitive distributed fiber vibration sensor. Only one unidirectional Mach-Zehnder interferometer (MZI) is employed in this scheme as the sensing element. In this sensor structure, we utilize chromatic dispersion-induced walk-off effect between the vibration signals sensed by two distributed feedback (DFB) lasers at different wavelengths to locate the vibration position. Vibration signals with frequencies up to 9 MHz can be detected and the spatial resolution of 31 m is achieved over 320 km of the standard single mode fiber. Monitoring multiple vibration sources can also be realized using this scheme.

  8. Imaging and chemical surface analysis of biomolecular functionalization of monolithically integrated on silicon Mach-Zehnder interferometric immunosensors

    Science.gov (United States)

    Gajos, Katarzyna; Angelopoulou, Michailia; Petrou, Panagiota; Awsiuk, Kamil; Kakabakos, Sotirios; Haasnoot, Willem; Bernasik, Andrzej; Rysz, Jakub; Marzec, Mateusz M.; Misiakos, Konstantinos; Raptis, Ioannis; Budkowski, Andrzej

    2016-11-01

    Time-of-flight secondary ion mass spectrometry (imaging, micro-analysis) has been employed to evaluate biofunctionalization of the sensing arm areas of Mach-Zehnder interferometers monolithically integrated on silicon chips for the immunochemical (competitive) detection of bovine κ-casein in goat milk. Biosensor surfaces are examined after: modification with (3-aminopropyl)triethoxysilane, application of multiple overlapping spots of κ-casein solutions, blocking with 100-times diluted goat milk, and reaction with monoclonal mouse anti-κ-casein antibodies in blocking solution. The areas spotted with κ-casein solutions of different concentrations are examined and optimum concentration providing homogeneous coverage is determined. Coverage of biosensor surfaces with biomolecules after each of the sequential steps employed in immunodetection is also evaluated with TOF-SIMS, supplemented by Atomic force microscopy and X-ray photoelectron spectroscopy. Uniform molecular distributions are observed on the sensing arm areas after spotting with optimum κ-casein concentration, blocking and immunoreaction. The corresponding biomolecular compositions are determined with a Principal Component Analysis that distinguished between protein amino acids and milk glycerides, as well as between amino acids characteristic for Mabs and κ-casein, respectively. Use of the optimum conditions (κ-casein concentration) for functionalization of chips with arrays of ten Mach-Zehnder interferometers provided on-chips assays with dramatically improved both intra-chip response repeatability and assay detection sensitivity.

  9. Imaging and chemical surface analysis of biomolecular functionalization of monolithically integrated on silicon Mach-Zehnder interferometric immunosensors

    Energy Technology Data Exchange (ETDEWEB)

    Gajos, Katarzyna, E-mail: kasia.fornal@uj.edu.pl [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland); Angelopoulou, Michailia; Petrou, Panagiota [Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR Demokritos, P. Grigoriou & Neapoleos St, Aghia Paraksevi 15310, Athens (Greece); Awsiuk, Kamil [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland); Kakabakos, Sotirios [Institute of Nuclear & Radiological Sciences & Technology, Energy & Safety, NCSR Demokritos, P. Grigoriou & Neapoleos St, Aghia Paraksevi 15310, Athens (Greece); Haasnoot, Willem [RIKILT Wageningen UR, Akkermaalsbos 2, 6708 WB Wageningen (Netherlands); Bernasik, Andrzej [Faculty of Physics and Applied Computer Science, AGH University of Science and Technology, Mickiewicza 30, 30-059 Kraków (Poland); Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Mickiewicza 30, 30-059 Kraków (Poland); Rysz, Jakub [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland); Marzec, Mateusz M. [Academic Centre for Materials and Nanotechnology, AGH University of Science and Technology, Mickiewicza 30, 30-059 Kraków (Poland); Misiakos, Konstantinos; Raptis, Ioannis [Department of Microelectronics, Institute of Nanoscience and Nanotechnology, NCSR Demokritos, P. Grigoriou & Neapoleos St, Aghia Paraksevi 15310, Athens (Greece); Budkowski, Andrzej [M. Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków (Poland)

    2016-11-01

    Highlights: • Optimization of probe immobilization with robotic spotter printing overlapping spots. • In-situ inspection of microstructured surfaces of biosensors integrated on silicon. • Imaging and chemical analysis of immobilization, surface blocking and immunoreaction. • Insight with molecular discrimination into step-by-step sensor surface modifications. • Optimized biofunctionalization improves sensor sensitivity and response repeatability. - Abstract: Time-of-flight secondary ion mass spectrometry (imaging, micro-analysis) has been employed to evaluate biofunctionalization of the sensing arm areas of Mach-Zehnder interferometers monolithically integrated on silicon chips for the immunochemical (competitive) detection of bovine κ-casein in goat milk. Biosensor surfaces are examined after: modification with (3-aminopropyl)triethoxysilane, application of multiple overlapping spots of κ-casein solutions, blocking with 100-times diluted goat milk, and reaction with monoclonal mouse anti-κ-casein antibodies in blocking solution. The areas spotted with κ-casein solutions of different concentrations are examined and optimum concentration providing homogeneous coverage is determined. Coverage of biosensor surfaces with biomolecules after each of the sequential steps employed in immunodetection is also evaluated with TOF-SIMS, supplemented by Atomic force microscopy and X-ray photoelectron spectroscopy. Uniform molecular distributions are observed on the sensing arm areas after spotting with optimum κ-casein concentration, blocking and immunoreaction. The corresponding biomolecular compositions are determined with a Principal Component Analysis that distinguished between protein amino acids and milk glycerides, as well as between amino acids characteristic for Mabs and κ-casein, respectively. Use of the optimum conditions (κ-casein concentration) for functionalization of chips with arrays of ten Mach-Zehnder interferometers provided on-chips assays

  10. 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.

  11. Mach-Zehnder interferometer for movement monitoring

    Science.gov (United States)

    Vasinek, Vladimir; Cubik, Jakub; Kepak, Stanislav; Doricak, Jan; Latal, Jan; Koudelka, Petr

    2012-06-01

    Fiber optical interferometers belong to highly sensitive equipments that are able to measure slight changes like distortion of shape, temperature and electric field variation and etc. Their great advantage is that they are insensitive on ageing component, from which they are composed of. It is in virtue of herewith, that there are evaluated no changes in optical signal intensity but number interference fringes. To monitor the movement of persons, eventually to analyze the changes in state of motion we developed method based on analysis the dynamic changes in interferometric pattern. We have used Mach- Zehnder interferometer with conventional SM fibers excited with the DFB laser at wavelength of 1550 nm. It was terminated with optical receiver containing InGaAs PIN photodiode. Its output was brought into measuring card module that performs on FFT of the received interferometer signal. The signal rises with the composition of two waves passing through single interferometer arm. The optical fiber SMF 28e in one arm is referential; the second one is positioned on measuring slab at dimensions of 1x2m. A movement of persons around the slab was monitored, signal processed with FFT and frequency spectra were evaluated. They rose owing to dynamic changes of interferometric pattern. The results reflect that the individual subjects passing through slab embody characteristic frequency spectra, which are individual for particular persons. The scope of measuring frequencies proceeded from zero to 10 kHz. It was also displayed in experiments that the experimental subjects, who walked around the slab and at the same time they have had changed their state of motion (knee joint fixation), embodied characteristic changes in their frequency spectra. At experiments the stability of interferometric patterns was evaluated as from time aspects, so from the view of repeated identical experiments. Two kinds of balls (tennis and ping-pong) were used to plot the repeatability measurements and

  12. Positioning approach based on Mach-Zehnder fiber sensors and a DSP processor

    Science.gov (United States)

    Wan, Xiong; Du, Tingting; Zhang, Zhimin; Zhang, Huaming; Wang, Peng

    2013-12-01

    A positioning system based on Mach-Zehnder optical fiber interferometer is proposed, which can sense vibration information along the circumference of the fiber sensor and hence be applied to positioning invasions as a safe-guard system in residence communities. A cross-correlation algorithm fulfilled with a DSP processor has been adopted to calculate the time difference of two channels of the Mach-Zehnder optical fiber interferometer. A signal identification algorithm is proposed to decrease the workload of the DSP when no vibration occurs. An experiment with 11.28 kilometers sensing fiber has been carried out, whose results show the Mach-Zehnder positioning system identifies the position of vibration instantaneously and has a 44 meters positioning error within the total sensing distance.

  13. Slow light Mach-Zehnder fiber interferometer

    Institute of Scientific and Technical Information of China (English)

    Yundong Zhang; Jinfang Wang; Xuenan Zhang; Hao Wu; Yuanxue Cai; Jing Zhang; Ping Yuan

    2012-01-01

    A slow light structure Mach-Zehnder fiber interferometer is theoretically demonstrated.The sensitivity of the interferometer is significantly enhanced by the dispersion of the slow light structure.The numerical results show that the sensitivity enhancement factor varies with the coupling coefficient and reaches its maximum under critical coupling conditions.Interferometers have been investigated in relation to their applications in fields such as metrology[1],optical sensing[2],optical communication[3,4],quantum information processing[5],and biomedical engineering[6].A number of schemes have been proposed to improve the performance of interferometers[7],such as using photonic crystal structures to minimize the size of on-chip devices[8],utilizing the dispersive property of semiconductor to enhance the spectral sensitivity of interferometers[9,10],utilizing slow light medium to enhance the resolution of Fourier transform interferometer[11],exploiting fast light medium or slow light structure to increase the rotation sensitivity of a Sagnac interferometer[12,13],enhancing the transmittance of the Mach-Zehnder interferometer (MZI) in the slow light region by gratings[14],and using liquid crystal light valve to derive high sensitivity interferometers[15].%A slow light structure Mach-Zehnder fiber interferometer is theoretically demonstrated. The sensitivity of the interferometer is significantly enhanced by the dispersion of the slow light structure. The numerical results show that the sensitivity enhancement factor varies with the coupling coefficient and reaches its maximum under critical coupling conditions.

  14. Distributed optical fiber perturbation sensing system based on Mach-Zehnder interferometer

    Institute of Scientific and Technical Information of China (English)

    Wengang WANG; Deming LIU; Hairong LIU; Qizhen SUN; Zhifeng SUN; Xu ZHANG; Ziheng XU

    2009-01-01

    A novel distributed optical fiber vibration-sensing system based on Mach-Zehnder interferometer has been designed and experimentally demonstrated. Firstly, the principle of Mach-Zehnder optical path interferometer technique is clarified. The output of the Mach-Zehnder interferometer is proportional to the phase shift induced by the perturbation. Secondly, the system consists of the laser diode (LD) as the light source, fiber, Mach-Zehnder optical interferometers as the sensing units, a 1×N star fiber-optic coupler, an N×1 fiber-optic coupler, a photodiode (PD) detector, and a computer used in signal processing. The entire monitoring region of this system is divided into several small zones, and each small monitoring zone is independent from each other. All of the small monitoring zones have their own sensing unit, which is defined by Mach-Zehnder optical interferometer. A series of sensing units are connected by the star fiber-optic couplers to form a whole sensing net. Thirdly, signal-processing techniques are subsequently used to calculate the phase shift to estimate whether intruders appear. The sensing system is able to locate the vibration signal simultaneously, includ-ing multiple vibrations at different positions, by employing the time-division multiplexed (TDM) technique. Finally, the operation performance of the proposed system is tested in the experiment lab with the conditions as follows: the number of the sensing units is 3, the length of the sensing fiber is 50 m, and the wavelength of the light diode is 1550nm. Based on these investigations, the fiber surrounding alert system is achieved. We have experimen-tally demonstrated that the sensing system can measure both the frequency and position of the vibration in real time, with a spatial positional resolution better than 50 m in an area of 1 km2.

  15. Investigation on characteristics of self-organization in Mach-Zehnder erbium-doped fiber laser cavity

    Institute of Scientific and Technical Information of China (English)

    Fengnian Liu; Bo Liu; Bangcai Huang; Guiyun Kai; Shuzhong Yuan; Xiaoyi Dong

    2008-01-01

    The characteristics of coherent coupling in Mach-Zehnder erbium-doped fiber laser cavity are experimentally studied.By virtue of a seemly controlling of length difference between two interferometric arms,the obtained comb-like spectrum of interferometer resonator with a period of 0.06 nm commendably agrees with the theory of self-organization coherence The coherent output exits from the output mirror of a fiber Bragg grating with 4.5% reflectivity.A high coherent combining efficiency of 94% is obtained.Investigation on characteristics of the leak power opens out self-organization mechanism in Mach-Zehnder composite cavity.

  16. Mach-Zehnder Fiber-Optic Links for ICF Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E. K., Hermann, H. W.

    2012-11-01

    This article describes the operation and evolution of Mach-Zehnder links for single-point detectors in inertial confinement fusion experimental facilities, based on the Gamma Reaction History (GRH) diagnostic at the National Ignition Facility.

  17. Mach-Zehnder Phasing Sensor for Elts

    Science.gov (United States)

    Dohlen, Kjetil; Montoya-Martinez, Luzma

    Segmented mirror technology has been successfully applied to 10m class telescopes (Keck HET GTC) and its application to future extremely large telescopes (20m NG-CFHT 30m CELT 50m EURO50 100m OWL) is required. Extensive use of adaptive optics in these telescopes puts stringent specifications on wavefront error allowing typically of the order of lambda/20 to segmentation errors. Several phasing metrology schemes adaptable to these giant telescopes are under development. We investigate a novel technique based on the Mach-Zehnder interferometer with a spatial filter in one arm. Atmospheric turbulence is tolerated in this setup if the spatial filter has the size similar to that of the seeing disk. The resulting interference pattern only contains the high-frequency spatial information including information about the piston step height. We describe the theoretical analysis of this system and show simulated and experimatal results. Different error sources are analyzed in order to provide a preliminary idea of the merits of this technique compared with other phasing techniques.

  18. Mach-Zehnder recording systems for pulsed power diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E. K.; Abbott, R. Q.; McKenna, I.; Macrum, G.; Baker, D.; Tran, V.; Rodriguez, E.; Kaufman, M. I.; Tibbits, A.; Silbernagel, C. T.; Waltman, T. B. [National Security Technologies, LLC, Santa Barbara and Livermore, California 93111 (United States); National Security Technologies, LLC, Los Alamos, New Mexico 87544 (United States); and National Security Technologies, LLC, North Las Vegas, Nevada 89193 (United States); Herrmann, H. W.; Kim, Y. H.; Mack, J. M.; Young, C. S.; Caldwell, S. E.; Evans, S. C.; Sedillo, T. J. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Stoeffl, W.; Grafil, E. [Lawrence Livermore National Laboratory, Livermore, California (United States); and others

    2012-10-15

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as the Z accelerator at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History diagnostic at the OMEGA laser and at NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  19. Mach-Zehnder recording systems for pulsed power diagnostics.

    Science.gov (United States)

    Miller, E K; Abbott, R Q; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A; Smelser, R M

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as the Z accelerator at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History diagnostic at the OMEGA laser and at NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  20. Mach-Zehnder Recording Systems for Pulsed Power Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Miller, E K; McKenna, I; Macrum, G; Baker, D; Tran, V; Rodriguez, E; Kaufman, M I; Tibbits, A; Silbernagel, C T; Waltman, T B; Herrmann, H W; Kim, Y H; Mack, J M; Young, C S; Caldwell, S E; Evans, S C; Sedillo, T J; Stoeffl, W; Grafil, E; Liebman, J; Beeman, B; Watts, P; Carpenter, A; Horsfied, C J; Rubery, M S; Chandler, G A; Torres, J A

    2012-10-01

    Fiber-optic transmission and recording systems, based on Mach-Zehnder modulators, have been developed and installed at the National Ignition Facility (NIF), and are being developed for other pulsed-power facilities such as Z-R at Sandia, with different requirements. We present the design and performance characteristics for the mature analog links, based on the system developed for the Gamma Reaction History (GRH) diagnostic at OMEGA and NIF. For a single detector channel, two Mach-Zehnders are used to provide high dynamic range at the full recording bandwidth with no gaps in the coverage. We present laboratory and shot data to estimate upper limits on the radiation effects as they impact recorded data quality. Finally, we will assess the technology readiness level for mature and developing implementations of Mach-Zehnder links for these environments.

  1. Quantum heat engines based on electronic Mach-Zehnder interferometers

    Science.gov (United States)

    Hofer, Patrick P.; Sothmann, Björn

    2015-05-01

    We theoretically investigate the thermoelectric properties of heat engines based on Mach-Zehnder interferometers. The energy dependence of the transmission amplitudes in such setups arises from a difference in the interferometer arm lengths. Any thermoelectric response is thus of purely quantum-mechanical origin. In addition to an experimentally established three-terminal setup, we also consider a two-terminal geometry as well as a four-terminal setup consisting of two interferometers. We find that Mach-Zehnder interferometers can be used as powerful and efficient heat engines which perform well under realistic conditions.

  2. Mach-Zehnder fiber interferometer for people monitoring

    Science.gov (United States)

    Vasinek, Vladimir; Latal, Jan; Koudelka, Petr; Siska, Petr; Vitasek, Jan; Skapa, Jan

    2010-10-01

    Fiber optical interferometers belong to highly sensitive equipments that are able to measure slight changes like distortion of shape, temperature and electric field variation and etc. Their great advantage is that they are insensitive on ageing component, from which they are composed of. It is in virtue of herewith, that there are evaluated no changes in optical signal intensity but number interference fringes. To monitor the movement of persons, eventually to analyze the changes in state of motion we developed method based on analysis the dynamic changes in interferometric pattern. We have used Mach- Zehnder interferometer with conventional SM fibers excited with the DFB laser at wavelength of 1550 nm. It was terminated with optical receiver containing InGaAs PIN photodiode. Its output was brought into measuring card module that performs on FFT of the received interferometer signal. The signal rises with the composition of two waves passing through single interferometer arm. The optical fiber SMF 28e in one arm is referential; the second one is positioned on measuring slab at dimensions of 1x2m. A movement of persons over the slab was monitored, signal processed with FFT and frequency spectra were evaluated. They rose owing to dynamic changes of interferometric pattern. The results reflect that the individual subjects passing through slab embody characteristic frequency spectra, which are individual for particular persons. The scope of measuring frequencies proceeded from zero to 10 KHz. It was also displayed in experiments that the experimental subjects, who walked around the slab and at the same time they have had changed their state of motion (knee joint fixation), embodied characteristic changes in their frequency spectra. At experiments the stability of interferometric patterns was evaluated as from time aspects, so from the view of repeated identical experiments. Two kinds of balls (tennis and ping-pong) were used to plot the repeatability measurements and

  3. Quantum interference in an asymmetric Mach-Zehnder interferometer

    Science.gov (United States)

    Trenti, A.; Borghi, M.; Mancinelli, M.; Price, H. M.; Fontana, G.; Pavesi, L.

    2016-08-01

    A re-visitation of the well known free space Mach-Zehnder interferometer is reported here. The coexistence between one-photon and two-photons interference from collinear color entangled photon pairs is investigated. Thisarises from an arbitrarily small unbalance in the arm transmittance. The tuning of such asymmetry is reflected in dramatic changes in the coincidence detection, revealing beatings between one particle and two particle interference patterns. In particular, the role of the losses and of the intrinsic phase imperfectness of the lossy beamsplitter are explored in a single-port excited Mach-Zehnder interferometer. This configuration is especially useful for quantum optics on a chip, where the guiding geometry forces photons to travel in the same spatial mode.

  4. Spatial heterodyne spectrometer based on the Mach-Zehnder interferometer

    Science.gov (United States)

    Cai, Qisheng; Xiangli, Bin; Du, Shusong

    2015-11-01

    Spatial heterodyne spectroscopy (SHS) is a new kind of Fourier-transform spectroscopic technique capable of very high spectral resolution. In this paper, a spatial heterodyne spectrometer based on the Mach-Zehnder interferometer (MZ-SHS) is proposed. It is modified by replacing one mirror in the Mach-Zehnder interferometer with a diffraction grating. This technique retains many of the advantages of traditional SHS. Moreover, the spatial frequency of the interferogram is strictly linear with wavenumber. We describe the concept of the new MZ-SHS and elaborate the exact expression of the interferogram. Also, a design example and two kinds of imitated interferograms are presented in this paper. One is simulated in MATLAB and the other is generated in ZEMAX using ray tracing method. The retrieved spectra from these two interferograms show a good agreement with the theoretical results.

  5. 60dB high-extinction auto-configured Mach--Zehnder interferometer

    CERN Document Server

    Wilkes, Callum M; Wang, Jianwei; Santagati, Raffaele; Paesani, Stefano; Zhou, Xiaoqi; Miller, David A B; Marshall, Graham D; Thompson, Mark G; O'Brien, Jeremy L

    2016-01-01

    Imperfections in integrated photonics manufacturing have a detrimental effect on the maximal achievable visibility in interferometric architectures. These limits have profound implications for further photonics technological developments and in particular for quantum photonics technologies. Active optimisation approaches, together with reconfigurable photonics, have been proposed as a solution to overcome this. In this paper, we demonstrate an ultra-high (>60 dB) extinction ratio in a silicon photonic device consisting of cascaded Mach-Zehnder interferometers, in which additional interferometers function as variable beamsplitters. The imperfections of fabricated beamsplitters are compensated using an automated progressive optimization algorithm with no requirement for pre-calibration. This work shows the possibility of integrating and accurately controlling linear-optical components for large-scale quantum information processing and other applications.

  6. Photonic crystal fiber in-line Mach-Zehnder interferometer for explosive detection.

    Science.gov (United States)

    Tao, Chuanyi; Wei, Heming; Feng, Wenlin

    2016-02-08

    We report a photonic crystal fiber (PCF) in-line Mach-Zehnder interferometer used as a gas sensor device which exhibits high sensitivity to the explosive trinitrotoluene (TNT). The interferometric sensor head is formed by embedding a segment of large-mode-area/grapefruit PCF between standard single-mode fibers via butt coupling, which produces two small air gaps in between terminated fiber ends with ceramic ferrule connectors as coupling regions, which also serve as inlet/outlet for the gas. The spectral response of the interferometer is investigated in terms of its wavelength spectrum. The selectivity to TNT vapor is achieved by immobilizing a molecular recognition ployallylamine layer on the inner surface of the holey region of the PCF. The TNT-induced variations of the interference fringes are measured and the sensing capability of the proposed sensor is demonstrated experimentally.

  7. 60 dB high-extinction auto-configured Mach-Zehnder interferometer

    Science.gov (United States)

    Wilkes, C. M.; Qiang, X.; Wang, J.; Santagati, R.; Paesani, S.; Zhou, X.; Miller, D. A. B.; Marshall, G. D.; Thompson, M. G.; O'Brien, J. L.

    2016-11-01

    Imperfections in integrated photonics manufacturing have a detrimental effect on the maximal achievable visibility in interferometric architectures. These limits have profound implications for further photonics technological developments and in particular for quantum photonics technologies. Active optimisation approaches, together with reconfigurable photonics, have been proposed as a solution to overcome this. In this paper, we demonstrate an ultra-high (>60 dB) extinction ratio in a silicon photonic device consisting of cascaded Mach-Zehnder interferometers, in which additional interferometers function as variable beamsplitters. The imperfections of fabricated beamsplitters are compensated using an automated progressive optimization algorithm with no requirement for pre-calibration. This work shows the possibility of integrating and accurately controlling linear-optical components for large-scale quantum information processing and other applications.

  8. Temperature sensitivity of waveguide Mach-Zehnder interferometer

    OpenAIRE

    Sokolov, Viktor

    2013-01-01

    This thesis is part of a project that aims to develop a sensor for the detection of methane in the air and in water based on a waveguide Mach-Zehnder interferometer. The main application of this sensor is monitoring the environment and the ability to detect a leakage of methane. The development of a sensor includes analysis of operational conditions. In this project one of the greatest concerns is temperature. The temperature difference can reach several tens of degrees in the air, and severa...

  9. Quantum logic processor: Implementation with electronic Mach-Zehnder interferometer

    Science.gov (United States)

    Sarkar, Angik; Bhattacharyya, T. K.; Patwardhan, Ajay

    2006-05-01

    An approach for implementation of quantum logic in electronic Mach-Zehnder interferometer (MZI) has been described in this letter. All single qubit gates can be achieved by electron spin manipulation using Rashba spin-orbit coupling. Double qubit gates can also be implemented using the orbital degree of freedom of the electron. The MZI can be realized with intertwined ballistic nanowires. Spin injection and detection in the system can be done by a mesoscopic Stern-Gerlach apparatus. The system can be coupled in an array to form the quantum logic processor.

  10. A new magnetic sensor with Mach-Zehnder/Sagnac optical fiber interferometer

    Institute of Scientific and Technical Information of China (English)

    Shuguang LI; Xinwan LI; Xin WANG; Jianping CHEN

    2009-01-01

    This paper presents a new structure for magnetic sensor with Mach-Zehnder/Sagnac optical fiber interferometer. The magnetostrictive optical fiber sensor is placed in one of the two arms of the Mach-Zehnder interferometer, which can detect the optic phase shift by testing the length difference of the arm caused by environmental magnetic field. Because of forward and backward transmission in the arms, the Mach-Zehnder/ Sagnac optical fiber interferometer can deduce twice exactly of the phase shift proportional to the length difference as Mach-Zehnder interferometer. Theoretically, description of the Mach-Zehnder/Sagnac interferometer is given, and some main issues in the magnetic field sensor with optical fiber interferometer are demonstrated with experiments. The magnetic sensors are implemented using the proposed methods.

  11. Density Measurement of Compact Toroid with Mach-Zehnder Interferometer

    Science.gov (United States)

    Laufman-Wollitzer, Lauren; Endrizzi, Doug; Brookhart, Matt; Flanagan, Ken; Forest, Cary

    2016-10-01

    Utilizing a magnetized coaxial plasma gun (MCPG) built by Tri Alpha Energy, a dense compact toroid (CT) is created and injected at high speed into the Wisconsin Plasma Astrophysics Laboratory (WiPAL) vessel. A modified Mach-Zehnder interferometer from the Line-Tied Reconnection Experiment (LTRX) provides an absolute measurement of electron density. The interferometer is located such that the beam intersects the plasma across the diameter of the MCPG drift region before the CT enters the vessel. This placement ensures that the measurement is taken before the CT expand. Results presented will be used to further analyze characteristics of the CT. Funding provided by DoE, NSF, and WISE Summer Research.

  12. Structure optimization of polymeric Mach-Zehnder rib waveguide

    Institute of Scientific and Technical Information of China (English)

    LU Rong-guo; LiU Yong-zhi; LIAO Jin-kun; LIAO Yi-tao; HAN Wen-jie

    2007-01-01

    A systematic analysis of the polymeric Mach-Zehnder rib waveguide is presented based on the calculation and optimization. The simulation is carried out with the Effective Index Method (EIM) and two-dimensional (2-D)Finite Difference Beam Propagation Method (FD-BPM). The large refractive index step between the consecutive polymer layers is reduced by using EIM and thus the precision of the calculation is ensured. The important parameters of the waveguide such as Y-junction angle and the separation gap are discussed and their relationships with the optical power propagation and the loss characteristics are investigated in this paper. The total loss of the optimized structure is 0.258 dB.

  13. Mach-Zehnder Interferometer Based on Coupled Dielectric Pillars

    Institute of Scientific and Technical Information of China (English)

    GAO Ding-Shan; HAO Ran; ZHOU Zhi-Ping

    2007-01-01

    We propose a Mach-Zehnder interferometer (MZI) based on coupled dielectric pillars. It is composed of single-row pillar coupled waveguide modulating arms and three-row pillar waveguide 3 dB couplers. The slow light property and transmission loss of the single-row pillar modulating arm are optimized by the plane wave expansion method. A short 3dB coupler is designed based on the modes transformation in three-row pillar waveguide. Finite difference time domain simulations prove the validity of this MZI and show that it has low insertion loss of<1.1 dB and high extinction ratio of>12 dB.

  14. Theoretical and experimental study on white light interferometric fiber optic sensors network configuring by tandem of Michelson and Mach-Zehnder interferometers%级联式光纤白光干涉传感网络拓扑结构理论与实验研究

    Institute of Scientific and Technical Information of China (English)

    姜海丽; 苑勇贵; 杨军; 苑立波

    2011-01-01

    In order to improve the multiplexing ability of optical sensors, based on the low interferential optic fiber sensing technology, a novel combination interferometer of Mach-Zehnder and Michelson system has been proposed and demonstrated. It consists of a Michelson interferometer and a series of tandem Mach-Zehnder interferometers which are linked with one arm of the Michelson intefferometer, forming a multi-fiber optic sensors measuring network. It can be used to measure the distribution strain or temperature, especially suitable for monitoring large scale structural deformation due to its sensing gauge length could be chosen as long as tens of meters. It also could be used in the temperature compensation mode, in which one arm of the Mach-Zehnder interferometer measures strain caused by the variation of deformation and temperature, the other arm only measures the ambient temperature for eliminating the apparent strain caused by temperature.%为了提高传感器的多路复用能力,基于低相干光纤传感技术,提出一种新型干涉仪组合拓扑结构.该结构由Michelson干涉仪的一个臂与若干个Mach-Zehnder干涉仪混合级联而成,构成了可以同时实现多传感器测量的传感网络.构建了实验系统,对传感特性进行了分析.实验结果表明:该拓扑结构可以实现一个解调干涉仪对网络系统中多个传感器的问询,可以实现应变和温度的测量.该系统中传感器的长度可自由选取,能用于大尺度结构形变的检测;也叮以配对使用,并自动补偿应变测量过程中环境温度变化带来的影响.

  15. Wavelength conversion based on cross-phase modulation in a semiconductor Mach-Zehnder modulator

    DEFF Research Database (Denmark)

    Liu, Fenghai; Zheng, Xueyan; Oxenløwe, Leif Katsuo

    2001-01-01

    Wavelength conversion based on cross-phase modulation in a reversely biased semiconductor Mach-Zehnder modulator is proposed and successfully demonstrated in a commercial device. The converted signals exhibit extinction ratio >13 dB and penalty......Wavelength conversion based on cross-phase modulation in a reversely biased semiconductor Mach-Zehnder modulator is proposed and successfully demonstrated in a commercial device. The converted signals exhibit extinction ratio >13 dB and penalty...

  16. Integrated Mach-Zehnder interferometer for Bose-Einstein condensates.

    Science.gov (United States)

    Berrada, T; van Frank, S; Bücker, R; Schumm, T; Schaff, J-F; Schmiedmayer, J

    2013-01-01

    Particle-wave duality enables the construction of interferometers for matter waves, which complement optical interferometers in precision measurement devices. This requires the development of atom-optics analogues to beam splitters, phase shifters and recombiners. Integrating these elements into a single device has been a long-standing goal. Here we demonstrate a full Mach-Zehnder sequence with trapped Bose-Einstein condensates confined on an atom chip. Particle interactions in our Bose-Einstein condensate matter waves lead to a nonlinearity, absent in photon optics. We exploit it to generate a non-classical state having reduced number fluctuations inside the interferometer. Making use of spatially separated wave packets, a controlled phase shift is applied and read out by a non-adiabatic matter-wave recombiner. We demonstrate coherence times a factor of three beyond what is expected for coherent states, highlighting the potential of entanglement as a resource for metrology. Our results pave the way for integrated quantum-enhanced matter-wave sensors.

  17. Highly stable polarization independent Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Mičuda, Michal, E-mail: micuda@optics.upol.cz; Doláková, Ester; Straka, Ivo; Miková, Martina; Dušek, Miloslav; Fiurášek, Jaromír; Ježek, Miroslav, E-mail: jezek@optics.upol.cz [Department of Optics, Faculty of Science, Palacký University, 17. listopadu 1192/12, 77146 Olomouc (Czech Republic)

    2014-08-15

    We experimentally demonstrate optical Mach-Zehnder interferometer utilizing displaced Sagnac configuration to enhance its phase stability. The interferometer with footprint of 27×40 cm offers individually accessible paths and shows phase deviation less than 0.4° during a 250 s long measurement. The phase drift, evaluated by means of Allan deviation, stays below 3° or 7 nm for 1.5 h without any active stabilization. The polarization insensitive design is verified by measuring interference visibility as a function of input polarization. For both interferometer's output ports and all tested polarization states the visibility stays above 93%. The discrepancy in visibility for horizontal and vertical polarization about 3.5% is caused mainly by undesired polarization dependence of splitting ratio of the beam splitter used. The presented interferometer device is suitable for quantum-information and other sensitive applications where active stabilization is complicated and common-mode interferometer is not an option as both the interferometer arms have to be accessible individually.

  18. Ultra-Abrupt Tapered Fiber Mach-Zehnder Interferometer Sensors

    Directory of Open Access Journals (Sweden)

    Lanying Zhou

    2011-05-01

    Full Text Available A fiber inline Mach-Zehnder interferometer (MZI consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10 made by stretching. The proposed fabrication method is very low cost, 1/20–1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30–350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3–5 fold by fabricating an inline micro–trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N2 is tested by the MZI sensor coated with MFI–type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.

  19. Ultra-abrupt tapered fiber Mach-Zehnder interferometer sensors.

    Science.gov (United States)

    Li, Benye; Jiang, Lan; Wang, Sumei; Zhou, Lanying; Xiao, Hai; Tsai, Hai-Lung

    2011-01-01

    A fiber inline Mach-Zehnder interferometer (MZI) consisting of ultra-abrupt fiber tapers was fabricated through a new fusion-splicing method. By fusion-splicing, the taper diameter-length ratio is around 1:1, which is much greater than those (1:10) made by stretching. The proposed fabrication method is very low cost, 1/20-1/50 of those of LPFG pair MZI sensors. The fabricated MZIs are applied to measure refractive index, temperature and rotation angle changes. The temperature sensitivity of the MZI at a length of 30 mm is 0.061 nm/°C from 30-350 °C. The proposed MZI is also used to measure rotation angles ranging from 0° to 0.55°; the sensitivity is 54.98 nm/°. The refractive index sensitivity is improved by 3-5 fold by fabricating an inline micro-trench on the fiber cladding using a femtosecond laser. Acetone vapor of 50 ppm in N(2) is tested by the MZI sensor coated with MFI-type zeolite thin film. The proposed MZI sensors are capable of in situ detection in many areas of interest such as environmental management, industrial process control, and public health.

  20. 160 Gb/s all-optical AND gate using bulk SOA turbo-switched Mach-Zehnder interferometer

    Science.gov (United States)

    Rendón-Salgado, I.; Gutiérrez-Castrejón, R.

    2017-09-01

    A novel architecture to implement an all-optical AND gate that relies on the use of a bulk semiconductor optical amplifier-based active Mach-Zehnder interferometer and the turbo-switch effect is presented. Its performance is analyzed in terms of relevant physical parameters and its power consumption calculated. Error-free operation at 160 Gb/s is numerically demonstrated, thus becoming the fastest AND gate of its kind. Accurate simulations using a well-tested design suite predict a 2.7 dB improvement in terms of quality factor when compared to a conventional scheme. The performance advantages of the proposed architecture remain when combined with a turbo-switched XOR gate: the resulting all-optical half-adder also operates error-free at 160 Gb/s. Our research work boosts the potential of interferometric turbo-switched photonic structures as ultra-fast all-optical processing elements.

  1. Mach-Zehnder Modulator Performance on the NIF South Pole Bang Time Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Beeman, B.; MacPhee, A. G.; Kimbrough, J. R.; Chow, R.; Carpenter, A.; Bond, E.; Zayas-Rivera, Z.; Bell, P.; Celeste, J.; Clancy, T.; Miller, E. K.; Edgell, D.; Donaldson, W. R.

    2013-09-01

    We present performance data for Mach-Zehnder optical modulators fielded on the National Ignition Facility (NIF) as a potential signal path upgrade for the South Pole Bang Time diagnostic. A single channel demonstration system has been deployed utilizing two modulators operating in a 90-degree In phase and Quadrature (I/Q) configuration. X-ray target emission signals are split and fed into two recording systems: a reference CRT based oscilloscope, Greenfield FTD10000, and the dual Mach-Zehnder system. Results of X-ray implosion time (bang time) determination from these two recording systems are compared and presented.

  2. Event-based simulation of single-photon beam splitters and Mach-Zehnder interferometers

    NARCIS (Netherlands)

    De Raedt, H; De Raedt, K; Michielsen, K

    2005-01-01

    We demonstrate that networks of locally connected processing units with a primitive learning capability exhibit a behavior that is usually only attributed to quantum systems. We describe networks that simulate single-photon beam splitter and Mach-Zehnder interferometer experiments on a causal, event

  3. Analysing surface plasmon resonance phase sensor based on Mach-Zehnder interferometer technique using glycerin

    Science.gov (United States)

    Kashif, Muhammad; Bakar, A. Ashrif A.; Hashim, Fazida Hanim

    2016-12-01

    Surface Plasmon Resonance (SPR) based on Mach-Zehnder interferometer (MZI) is a very accurate tool for the detection and analysis of molecular interactions. The performance of the proposed SPR phase sensor is dependent upon multiple performance parameters that include sensitivity, repeatability, drift and the induction speed of fluid into the flow cell. The SPR Mach-Zehnder interferometer is tested for different glycerin-water concentrations to check its performance based on the different parameters. This paper highlights the enhancement of the performance of SPR phase technique based on MZI that is influenced by different parameters, measured using glycerin solutions. These four performance parameters can affect the performance of SPR based on MZI and have a particular impact on the sensor output. It also provides us information about suitable working conditions for the SPR Mach-Zehnder interferometer sensor. The experiment data shows that the sensor's sensitivity is high for small concentrations of glycerin-water mixtures. Also, any change in drift as well as in induction speed of fluid can affect the performance of SPR Mach-Zehnder interferometer. The sensitivity of SPR phase sensor is high as it can measure glycerin concentration as low as 0.05%.

  4. All optical wavelength conversion by SOA's in a Mach-Zehnder configuration

    DEFF Research Database (Denmark)

    Durhuus, T.; Jørgensen, C.; Mikkelsen, Benny

    1994-01-01

    Penalty free wavelength conversion is demonstrated at 2.5 Gbit/s over a wavelength span of 12 nm by the use of semiconductor optical amplifier (SOA)'s in a Mach-Zehnder configuration. An increase in the extinction ratio is measured for the converted signal compared to the input signal implying si...... signal regeneration as well as wavelength conversion...

  5. A versatile all-optical modulator based on nonlinear Mach-Zehnder interferometers

    NARCIS (Netherlands)

    Krijnen, G.J.M.; Villeneuve, A.; Stegeman, G.I.; Lambeck, P.V.; Hoekstra, H.J.W.M.

    1994-01-01

    A device based on a Nonlinear Mach-Zehnder interferometer (NMI) which exploits cross-phase modulation of two co-propagating modes in bimodal branches has been described in this paper. The advantage of this device is that it becomes polarisation independent while keeping phase insensitive by using di

  6. The realization of an integrated Mach-Zehnder waveguide immunosensor in silicon technology

    NARCIS (Netherlands)

    Schipper, E.F.; Brugman, A.M.; Lechuga, L.M.; Kooyman, R.P.H.; Greve, J.; Dominguez, C.

    1997-01-01

    We describe the realization of a symmetric integrated channel waveguide Mach-Zehnder sensor which uses the evanescent field to detect small refractive-index changes (¿nmin ¿ 1 × 10¿4) near the guiding-layer surface. This guiding layer consists of ridge structures with a height of 3 nm and a width of

  7. On the Use of a Virtual Mach-Zehnder Interferometer in the Teaching of Quantum Mechanics

    Science.gov (United States)

    Pereira, Alexsandro; Ostermann, Fernanda; Cavalcanti, Claudio

    2009-01-01

    For many students, the conceptual learning of quantum mechanics can be rather painful owing to the counter-intuitive nature of quantum phenomena. In order to enhance students' understanding of the odd behaviour of photons and electrons, we introduce a computational simulation of the Mach-Zehnder interferometer, developed by our research group. An…

  8. On the Use of a Virtual Mach-Zehnder Interferometer in the Teaching of Quantum Mechanics

    Science.gov (United States)

    Pereira, Alexsandro; Ostermann, Fernanda; Cavalcanti, Claudio

    2009-01-01

    For many students, the conceptual learning of quantum mechanics can be rather painful owing to the counter-intuitive nature of quantum phenomena. In order to enhance students' understanding of the odd behaviour of photons and electrons, we introduce a computational simulation of the Mach-Zehnder interferometer, developed by our research group. An…

  9. Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

    Energy Technology Data Exchange (ETDEWEB)

    Mosquera, L; Osorio, Jonas H; Hayashi, Juliano G; Cordeiro, Cristiano M B, E-mail: lmosquera@uni.edu.pe [Instituto de Fisica ' Gleb Wataghin' , UNICAMP, Campinas - Sao Paulo (Brazil)

    2011-01-01

    A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zehnder interferometer and its application to measure ethanol concentration in gasoline.

  10. High Accuracy Microwave Frequency Measurement Based on Single-Drive Dual-Parallel Mach-Zehnder Modulator

    DEFF Research Database (Denmark)

    Zhao, Ying; Deng, Lei; Pang, Xiaodan

    2011-01-01

    A novel approach for broadband microwave frequency measurement based on bias manipulation of a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. A 10-3 relative error verifies a significant accuracy improvement by this method.......A novel approach for broadband microwave frequency measurement based on bias manipulation of a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. A 10-3 relative error verifies a significant accuracy improvement by this method....

  11. Stabilized fiber-optic Mach-Zehnder interferometer for carrier-frequency rejection

    CERN Document Server

    Cooper, Nathan; Bateman, James; Dunning, Alexander; Freegarde, Tim

    2013-01-01

    We have demonstrated stabilization of a fiber-optic Mach-Zehnder interferometer, with a centimeter-scale path difference, to the transmission minimum for the carrier wave of a frequency-modulated laser beam. A time-averaged extinction of 32 dB, limited by the bandwidth of the feedback, was maintained over several hours. The interferometer was used to remove the carrier wave from a 780 nm laser beam that had been phase modulated at 2.7 GHz.

  12. Mach-Zehnder-based five-port silicon router for optical interconnects.

    Science.gov (United States)

    Li, Xianyao; Xiao, Xi; Xu, Hao; Li, Zhiyong; Chu, Tao; Yu, Jinzhong; Yu, Yude

    2013-05-15

    We propose and fabricate a five-port silicon optical router based on Mach-Zehnder interferometer switches. Only 10 switching elements and five low-loss waveguide crossings are required in our design. Through thermal control of the switching network, we successfully demonstrate 20 possible I/O paths of the five-port optical router at a data transmission rate of 32 Gb/s. The results here show great potential for application in ultrahigh-capacity optical interconnects.

  13. Electro-optic metal-insulator-semiconductor-insulator-metal Mach-Zehnder plasmonic modulator

    Science.gov (United States)

    Thomas, Roney; Ikonic, Zoran; Kelsall, Robert W.

    2012-01-01

    The performance of a CMOS-compatible electro-optic Mach-Zehnder plasmonic modulator is investigated using electromagnetic and carrier transport simulations. Each arm of the Mach-Zehnder device comprises a metal-insulator-semiconductor-insulator-metal (MISIM) structure on a buried oxide substrate. Quantum mechanical effects at the oxide/semiconductor interfaces were considered in the calculation of electron density profiles across the structure, in order to determine the refractive index distribution and its dependence on applied bias. This information was used in finite element simulations of the electromagnetic modes within the MISIM structure in order to determine the Mach-Zehnder arm lengths required to achieve destructive interference and the corresponding propagation loss incurred by the device. Both inversion and accumulation mode devices were investigated, and the layer thicknesses and height were adjusted to optimise the device performance. A device loss of <8 dB is predicted for a MISIM structure with a 25 nm thick silicon layer, for which the device length is <3 μm, and <5 dB loss is predicted for the limiting case of a 5 nm thick silicon layer in a 1.2 μm long device: in both cases, the maximum operating voltage is 7.5 V.

  14. Tunable multiwavelength erbium-doped fiber laser based on an in-line Mach Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Han, Young-Geun [Hanyang University, Seoul (Korea, Republic of)

    2010-12-15

    A tunable multiwavelength erbium-doped fiber laser based on an in-line Mach Zehnder interferometer is proposed and experimentally demonstrated. The in-line Mach Zehnder interferometer is realized by using cascaded long-period fiber gratings. The long-period fiber gratings can couple the guided core mode to several cladding modes. If two identical long-period fiber gratings are concatenated, an interference pattern can be generated, which results from an interaction of the core and the cladding modes in the second long-period fiber grating. Therefore, a simple multichannel filter based on an in-line Mach Zehnder interferometer can be realized. The wavelength spacing of the proposed multichannel filter is controlled by the number of long-period fiber gratings. We apply the proposed multichannel fiber to the generation of a multiwavelength erbium-doped fiber laser with a tunability on the order of the wavelength spacing. An erbium-doped fiber amplifier is implemented as a gain medium. The gain competition of erbium ions is suppressed by soaking the erbium-doped fiber in liquid nitrogen. The power fluctuation of the proposed multiwavelength fiber laser is measured to be less than 0.5 dB. A high-quality multiwavelength output with a high extinction ratio of more than 40 dB is achieved. The wavelength spacing of the proposed multiwavelength fiber laser is controlled by increasing the number of long-period fiber gratings. The wavelength spacing is changed from 0.8 nm to 1.6 nm discretely.

  15. Using a Mach-Zehnder interferometer to deduce nitrogen density mapping

    Science.gov (United States)

    Boudaoud, F.; Lemerini, M.

    2015-07-01

    This work presents an optical method using the Mach-Zehnder interferometer. We especially diagnose a pure nitrogen gas subjected to a point to plane corona discharge, and visualize the density spatial map. The interelectrode distance equals 6 mm and the variation of the optical path has been measured at different pressures: 220 Torr, 400 Torr, and 760 Torr. The interferograms are recorded with a CCD camera, and the numerical analysis of these interferograms is assured by the inverse Abel transformation. The nitrogen density is extracted through the Gladstone-Dale relation. The obtained results are in close agreement with values available in the literature.

  16. A Novel Method to Monitor OSNR Using a Mach-Zehnder Interferometer

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A novel method to monitor optical signal to noise ratio using a Mach-Zehnder interferometer is introduced. The OSNR meter is composed of two 3dB couplers, one phase tuner and one power meter which are of low cost. The experiments show that the error of our novel method is less than 0.5dB and the dynamic range is from 10dB to 25dB. They also show that the method works well under different cases of bit rates.

  17. Lateral-shearing, delay-dithering Mach-Zehnder interferometer for spatial coherence measurement.

    Science.gov (United States)

    Efimov, Anatoly

    2013-11-15

    An image-shearing interferometer of Mach-Zehnder type with corner cubes is introduced for the purpose of measuring spatial coherence at the output of inhomogeneous optical sources, such as multimode fibers (MMFs). One arm of the interferometer is modulated in optical delay to produce dynamic interference fringes. Fringe visibility and the two individual intensities are measured nearly simultaneously to allow direct calculation of the modulus of the complex degree of coherence as a function of the lateral shear between the two interferometer arms. Spatial degree of coherence is measured for a step-index MMF pumped with monochromatic and broadband optical sources.

  18. Developing an Interactive Tutorial on a Mach-Zehnder Interferometer with Single Photons

    CERN Document Server

    Singh, Chandralekha

    2015-01-01

    We are developing a Quantum Interactive Learning Tutorial (QuILT) on a Mach-Zehnder Interferometer with single photons to expose upper-level students in quantum mechanics courses to contemporary applications. The QuILT strives to help students develop the ability to apply fundamental quantum principles to physical situations and explore differences between classical and quantum ideas. The QuILT adapts visualization tools to help students build physical intuition about quantum phenomena and focuses on helping them integrate qualitative and quantitative understanding. We also discuss findings from a preliminary in-class evaluation.

  19. Linearization of Mach-Zehnder modulator using microring-based all-pass filter

    Institute of Scientific and Technical Information of China (English)

    Jianyi Yang; Fan Wang; Xiaoqing Jiang; Hongchang Qu; Yaming Wu; Minghua Wang; Yuelin Wang

    2005-01-01

    @@ By applying the microring resonator to the Mach-Zehnder (MZ) optical modulator and employing the super-linear phase change characteristic of the all-pass filter, the sublinear modulation curve of the conventional MZ modulator is highly linearized. With properly controlled power coupling between the microring and the arm of the MZ modulator, the third-order distortion can be suppressed. If the transmission coefficient is set between 0.25 and 0.42, the linearity range larger than 90% can be easily achieved. The maximum linearity range is even up to 99.5%.

  20. Integrated optical displacement sensor based on asymmetric Mach-Zehnder interferometer chip

    Science.gov (United States)

    Zhao, Ning; Qian, Guang; Fu, Xing-Chang; Zhang, Li-Jiang; Hu, Wei; Li, Ruo-Zhou; Zhang, Tong

    2017-02-01

    Displacement sensor is one of the most important measuring instruments in many automated systems. We demonstrated an integrated optical displacement sensor based on an asymmetric Mach-Zehnder interferometer chip on a flexible substrate. The sensing chip was made of polymer materials and fabricated by lithography and lift-off techniques. Measured results show that the device has a loss of less than 5 dB and a potential sensitivity of about 0.105 rad/μm with quite a large space for promotion. The sensor has advantages of antielectromagnetic interference, high reliability and stability, simple preparing process, and low cost; it will occupy an important place in displacement sensors.

  1. Asymmetric Mach-Zehnder Interferometer Based Biosensors for Aflatoxin M1 Detection.

    Science.gov (United States)

    Chalyan, Tatevik; Guider, Romain; Pasquardini, Laura; Zanetti, Manuela; Falke, Floris; Schreuder, Erik; Heideman, Rene G; Pederzolli, Cecilia; Pavesi, Lorenzo

    2016-01-06

    In this work, we present a study of Aflatoxin M1 detection by photonic biosensors based on Si₃N₄ Asymmetric Mach-Zehnder Interferometer (aMZI) functionalized with antibodies fragments (Fab'). We measured a best volumetric sensitivity of 10⁴ rad/RIU, leading to a Limit of Detection below 5 × 10(-7) RIU. On sensors functionalized with Fab', we performed specific and non-specific sensing measurements at various toxin concentrations. Reproducibility of the measurements and re-usability of the sensor were also investigated.

  2. Theoretical Analysis and Experiment of Temperature Stability for Fiber-optic Mach-Zehnder Interferometer Filter

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Fiber-optic Mach-Zehnder interferometer(MZI) can be used as wavelength-multiplexers and demultiplexers. The △L and △φ directly influence the properties of MZI. To lengthen the △L can demultiplex much more wavelengths, but when the △L is longer, the temperature will influence MZI more seriously. A method to solve this problem is proposed, which enables MZI to work stably. The wavelength distance is 0.8nm, and the extinction ratio is high.

  3. Analisis Perbandingan Kinerja Mach-Zehnder berdasarkan Ragam Format Modulasi pada Jaringan FTTH

    Directory of Open Access Journals (Sweden)

    ZULIA NURUL KARIMAH

    2017-01-01

    Full Text Available ABSTRAKPada jurnal ini dibuat pemodelan link FTTH pada software Optisystem 7.0 untuk mengetahui pengaruh dari Kerr effect dengan membandingkan performansi serat optik kaca dan serat optik plastik berdasarkan format modulasi berupa NRZ, RZ, RZ-DPSK, RZ-DQPSK dan CSRZ. Terdapat dua skenario, dengan skenario pertama, variabel input yang diubah adalah format modulasi pada Mach-zehnder, sedangkan pada skenario kedua, variabel yang diubah adalah pemakaian serat optik yang dipakai, yaitu serat optik bahan kaca, plastik dan hybrid kaca plastik. Hasil simulasi menunjukkan dengan efek linier dan non-linier pada kabel kaca yang menghasilkan performansi jaringan dari yang terbaik, dengan Q factor di atas 6 dan BER di bawah 10-9 adalah NRZ, RZ, RZ-DPSK, CSRZ dan RZ-DQPSK. Sedangkan dengan penggunaan kabel PMMA, yang menunjukkan performansi jaringan yang baik adalah dengan konfigurasi G652D-G652D-PMMA pada format modulasi NRZ, RZ, RZ-DPSK dan RZ-DQPSK. Efek non-linier yang terjadi pada jaringan ini hanya SPM dan XPM.Kata kunci: FTTH, mach-zehnder, format modulasi, efek non-linier, GOF, POF.ABSTRACTIn this journal is creating a FTTH link on Optisystem software 7.0 to determine the effect of Kerr effect by comparing the performance of fiber optic glass and plastic optical fiber based on modulation formats such as NRZ, RZ, RZ-DPSK, RZ-DQPSK and CSRZ. There are two scenarios, first, input variables are changed based on format in Mach-zehnder modulator, while in the second scenario, the changed variable is the material of optical fiber, the materials are optical fiber glass, plastic and hybrid plastic and glass. The simulation results based on comparison with linear and nonlinear effects on glass optical fiber, which produce Q factor above 6 and BER below 10-9 are NRZ, RZ, RZ-DPSK, CSRZ and RZ-DQPSK. While the use of PMMA cable, which indicates good network performance is the configuration G652D-G652D-PMMA on the modulation format NRZ, RZ, RZ-DPSK and RZ

  4. Optical Coupling Structures of Fiber-Optic Mach-Zehnder Interferometers Using CO2 Laser Irradiation

    Directory of Open Access Journals (Sweden)

    Chien-Hsing Chen

    2014-01-01

    Full Text Available The Mach-Zehnder interferometer (MZI can be used to test changes in the refractive index of sucrose solutions at different concentrations. However, the popularity of this measurement tool is limited by its substantial size and portability. Therefore, the MZI was integrated with a small fiber-optic waveguide component to develop an interferometer with fiber-optic characteristics, specifically a fiber-optic Mach-Zehnder interferometer (FO-MZI. Optical fiber must be processed to fabricate two optical coupling structures. The two optical coupling structures are a duplicate of the beam splitter, an optical component of the interferometer. Therefore, when the sensor length and the two optical coupling structures vary, the time or path for optical transmission in the sensor changes, thereby influencing the back-end interference signals. The researchers successfully developed an asymmetrical FO-MZI with sensing abilities. The spacing value between the troughs of the sensor length and interference signal exhibited an inverse relationship. In addition, image analysis was employed to examine the size-matching relationship between various sensor lengths and the coupling and decoupling structure. Furthermore, the spectral wavelength shift results measured using a refractive index sensor indicate that FO-MZIs with a sensor length of 38 mm exhibited excellent sensitivity, measuring 59.7 nm/RIU.

  5. Gain Flattening Filter for Hybrid Sb-Doped EDFA Using All-Fiber Mach-Zehnder Interferometers

    Institute of Scientific and Technical Information of China (English)

    Manjung Han; Youngeun Im; Woojin Shin; Uh-Chan Ryu; K. Oh

    2003-01-01

    We demonstrate a novel gain-flattening filter based on all fiber Mach-Zehnder interferometers for Sb-doped silica hybrid EDFA. A gain flatness of better than 0.9dB has been achieved for three concatenated filters in C-band.

  6. High extinction ratio multiplexer/demultiplexer with a Mach-Zehnder interferometer and a fiber loop mirror

    Institute of Scientific and Technical Information of China (English)

    Yonglin Huang(黄勇林); Jie Li(李杰); Guiyun Kai(开桂云); Xiaoyi Dong(董孝义)

    2003-01-01

    A novel structure of high extinction ratio multiplexer/demultiplexer with a Mach-Zehnder interferometer (MZI) and a fiber loop mirror (FLM) is proposed. The experimental results show that the extinction ratio can be enhanced about two times in comparison with the conventional MZI.

  7. Ultrafast optical reversible double Feynman logic gate using electro-optic effect in lithium-niobate based Mach Zehnder interferometers

    Science.gov (United States)

    Chauhan, Chanderkanta; Bedi, Amna; Kumar, Santosh

    2017-02-01

    In this ultra fast computing era power optimization is a major technological challenge that requires new computing paradigms. Conservative and reversible logic opens up the possibility of ultralow power computing. In this paper, basic reversible logic gate (double Feynman gate) using the lithium-niobate based Mach-Zehnder interferometer is proposed. The results are verified using beam propagation method and MATLAB simulations.

  8. Label-free detection in a lab-on-a-chip with a three-dimensional Mach-Zehnder interferometer

    NARCIS (Netherlands)

    Crespi, A.; Gu, Y.; Ngamson, B.; Dongre, C.; Hoekstra, H.J.W.M.; Vlekkert, van den H.H.; Watts, P.; Pollnau, M.; Cerullo, G.; Osellame, R.

    2010-01-01

    A Mach-Zehnder refractive index sensor is inscribed in a microfluidic lab-on-a-chip by exploiting the unique three-dimensional capabilities of femtosecond laser fabrication. This enables high sensitivity and spatially resolved label-free detection of biomolecules.

  9. A Thermally Annealed Mach-Zehnder Interferometer for High Temperature Measurement

    Directory of Open Access Journals (Sweden)

    Zhongyao Feng

    2014-08-01

    Full Text Available An in-fiber Mach-Zehnder interferometer (MZI for high temperature measurement is proposed and experimentally demonstrated. The device is constructed of a piece of thin-core fiber (TCF sandwiched between two short sections of multimode fiber (MMF, i.e., a MMF-TCF-MMF structure. A well-defined interference spectrum is obtained owing to the core-mismatch, and the interference dips are sensitive to the ambient temperature. The experimental results show that the proposed interferometer is capable of high temperature measurement up to 875 °C with a sensitivity of 92 pm/°C over repeated measurements. The explored wavelength drop point may limit the measurement range, which can be improved by repeated thermal annealing.

  10. Manipulation of quantum states in a memory cell: controllable Mach-Zehnder interferometer

    Science.gov (United States)

    Losev, A. S.; Golubeva, T. Yu; Golubev, Yu M.

    2017-05-01

    In this article, we consider the possibility of manipulation of quantum signals, ensured by the use of the tripod-type atomic memory cell. We show that depending on a configuration of driving fields at the writing and reading, such a cell allows the signal to both be stored and transformed. It is possible to provide the operation of the memory cell in a Mach-Zehnder interferometer mode passing two successive pulses at the input. We proposed a procedure of partial signal readout that provides entanglement between the retrieved light and the atomic ensemble. Thus, we have shown that a tripod atomic cell is a promising candidate to implement quantum logical operations, including two-qubit ones, which can be performed on the basis of only one cell.

  11. Interactive tutorial to improve student understanding of single photon experiments involving a Mach-Zehnder interferometer

    Science.gov (United States)

    Marshman, Emily; Singh, Chandralekha

    2016-03-01

    We have developed and evaluated a quantum interactive learning tutorial (QuILT) on a Mach-Zehnder interferometer with single photons to expose upper-level students in quantum mechanics courses to contemporary quantum optics applications. The QuILT strives to help students develop the ability to apply fundamental quantum principles to physical situations in quantum optics and explore the differences between classical and quantum ideas. The QuILT adapts visualization tools to help students build physical intuition about counter-intuitive quantum optics phenomena with single photons including a quantum eraser setup and focuses on helping them integrate qualitative and quantitative understanding. We discuss findings from in-class evaluations.

  12. Temperature characterization of integrated optical all-polymer Mach-Zehnder interferometers

    Science.gov (United States)

    Xiao, Yanfen; Hofmann, Meike; Wang, Ziyu; Langenecker, Alexa; Shermann, Stanislav; Gleissner, Uwe; Zappe, Hans

    2016-04-01

    Two new design concepts for all-polymer-based integrated optical Mach-Zehnder interferometers in foil as chemical or bio-chemical sensors are presented. Fabricated with hot-embossing and printing techniques, these all polymer optical components are designed for low-cost fabrication and yield highly sensitive response to external refractive index changes. Compared to traditional semiconductor based systems, these polymer sensors do not need the interaction window and do not require a cleanroom for fabrication. The optical response of the asymmetric interferometers to temperature variations is determined theoretically and compared for two designs. Using the designed asymmetric interferometer, a chemical micro-fluidic test system with temperature controller experimentally demonstrates the sensors' temperature characteristics.

  13. High-speed carrier-depletion silicon Mach-Zehnder optical modulators with lateral PN junctions

    Directory of Open Access Journals (Sweden)

    Graham Trevor Reed

    2014-12-01

    Full Text Available This paper presents new experimental data from a lateral PN junction silicon Mach-Zehnder optical modulator. Efficiencies in the 1.4V.cm to 1.9V.cm range are demonstrated for drive voltages between 0V and 6V. High speed operation up to 52Gbit/s is also presented. The performance of the device which has its PN junction positioned in the centre of the waveguide is then compared to previously reported data from a lateral PN junction device with the junction self-aligned to the edge of the waveguide rib. An improvement in modulation efficiency is demonstrated when the junction is positioned in the centre of the waveguide. Finally we propose schemes for achieving high modulation efficiency whilst retaining self-aligned formation of the PN junction.

  14. Simulation of acousto-optical interaction in a Mach-Zehnder interferometer

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Sigmund, Ole; Jensen, Jakob Søndergaard

    ]. In [3] it is explained how a SAW can be employed to modulate the output light of a GaAs Mach-Zehnder interferometer (MZI) and experimental results with a relative modulation depth of 40 % are presented. To modulate the light using a MZI a SAW is transmitted perpendicularly to the two waveguide arms...... in waveguide structures is to let the light interact with surface acoustic waves (SAW) [1]. SAWs are elastic waves that propagate along a material surface, they consist of a longitudinal and a shear component and they have most of their energy density concentrated within one wavelength of the surface [2...... and the elastic stress field from the SAW results in a periodic change of the refractive index and therefore a periodical phase change in the waveguide arms. At a wave crest the refractive index will increase and at a trough it will decrease. Thus, if the distance between the arms is chosen as an unequal multiple...

  15. Interactive tutorial to improve student understanding of single photon experiments involving a Mach-Zehnder Interferometer

    CERN Document Server

    Marshman, Emily

    2016-01-01

    We have developed and evaluated a Quantum Interactive Learning Tutorial (QuILT) on a Mach-Zehnder Interferometer with single photons to expose upper-level students in quantum mechanics courses to contemporary quantum optics applications. The QuILT strives to help students develop the ability to apply fundamental quantum principles to physical situations in quantum optics and explore the differences between classical and quantum ideas. The QuILT adapts visualization tools to help students build physical intuition about counter-intuitive quantum optics phenomena with single photons including a quantum eraser setup and focuses on helping them integrate qualitative and quantitative understanding. We discuss findings from in-class evaluations.

  16. Terahertz Detection Based on Spectral-Domain Interferometry Using Mach-Zehnder Interferometer

    Science.gov (United States)

    Ibrahim, Akram; Sharma, Gargi; Singh, Kanwarpal; Ozaki, Tsuneyuki

    2016-09-01

    We demonstrate the use of a Mach-Zehnder interferometer (MZI) to improve the performance of terahertz electric field measurements based on spectral-domain interferometry. The interferometer is introduced into the probe beam line to improve the temporal overlap between the two probe pulses. The probe pulse in the sample arm of the interferometer passes through the detection crystal and overlaps with the terahertz pulse, while the probe pulse in the reference arm does not. We measure the phase change between spectral components of these two pulses using spectral-domain interferometry. Using this new technique, we enable an unlimited temporal scanning window without the loss in the signal-to-noise ratio, thus overcoming the major limitation of conventional spectral-domain interferometry techniques for terahertz electric field detection.

  17. Pass-through Mach-Zehnder topologies for macroscopic quantum measurements

    CERN Document Server

    Khalili, F Ya

    2011-01-01

    Several relatively small-scale experimental setups aimed on prototyping of future laser gravitational-wave detectors and testing of new methods of quantum measurements with macroscopic mechanical objects, are under development now. In these devices, not devoted directly to the gravitational-wave detection, Mach-Zehnder interferometer with pass-through Fabry-Perot cavities in the arms can be used instead of the standard Michelson/Fabry-Perot one. The advantage of this topology is that it does not contain high-reflectivity end mirrors with multilayer coatings, which Brownian noise could constitute the major part of the noise budget of the Michelson/Fabry-Perot interferometers. We consider here two variants of this topology: the "ordinary" position meter scheme, and a new variant of the quantum speed meter.

  18. Optical waveguide biosensor based on cascaded Mach-Zehnder interferometer and ring resonator with Vernier effect

    Science.gov (United States)

    Jiang, Xianxin; Tang, Longhua; Song, Jinyan; Li, Mingyu; He, Jian-Jun

    2014-03-01

    Optical waveguide biosensors based on silicon-on-insulator (SOI) have been extensively investigated owing to its various advantages and many potential applications. In this article, we demonstrate a novel highly sensitive biosensor based on cascaded Mach-Zehnder interferometer (MZI) and ring resonator with the Vernier effect using wavelength interrogation. The experimental results show that the sensitivity reached 1,960 nm/RIU and 19,100 nm/RIU for sensors based on MZI alone and cascaded MZI-ring with Vernier effect, respectively. A biosensing application was also demonstrated by monitoring the interaction between goat and antigoat immunoglobulin G (IgG) pairs. This integrated high sensitivity biosensor has great potential for medical diagnostic applications.

  19. Mach-Zehnder fiber-optic links for reaction history measurements at the National Ignition Facility

    Science.gov (United States)

    Miller, E. Kirk; Herrmann, H. W.; Stoeffl, W.; Horsfield, C. J.

    2010-08-01

    We present the details of the analog fiber-optic data link that will be used in the chamber-mounted Gamma Reaction History (GRH) diagnostic at the National Ignition Facility (NIF) located at the Lawrence Livermore Laboratory in Livermore, California. The system is based on Mach-Zehnder (MZ) modulators integrated into the diagnostic, with the source lasers and bias control electronics located remotely to protect the active electronics. A complete recording system for a single GRH channel comprises two MZ modulators, with the fiber signals split onto four channels on a single digitizer. By carefully selecting the attenuation, the photoreceiver, and the digitizer settings, the dynamic range achievable is greater than 1000:1 at the full system bandwidth of greater than 10 GHz. The system is designed to minimize electrical reflections and mitigate the effects of transient radiation darkening on the fibers.

  20. Vortex array laser beam generation from a Dove prism-embedded unbalanced Mach-Zehnder interferometer.

    Science.gov (United States)

    Chu, Shu-Chun; Yang, Chao-Shun; Otsuka, Kenju

    2008-11-24

    This paper proposes a new scheme for generating vortex laser beams from a laser. The proposed system consists of a Dove prism embedded in an unbalanced Mach-Zehnder interferometer configuration. This configuration allows controlled construction of p x p vortex array beams from Ince-Gaussian modes, IG(e) (p,p) modes. An incident IG(e)(p,p) laser beam of variety order p can easily be generated from an end-pumped solid-state laser system with an off-axis pumping mechanism. This study simulates this type of vortex array laser beam generation, analytically derives the vortex positions of the resulting vortex array laser beams, and discusses beam propagation effects. The resulting vortex array laser beam can be applied to optical tweezers and atom traps in the form of two-dimensional arrays, or used to study the transfer of angular momentum to micro particles or atoms (Bose-Einstein condensate).

  1. Mach-zehnder based optical marker/comb generator for streak camera calibration

    Science.gov (United States)

    Miller, Edward Kirk

    2015-03-03

    This disclosure is directed to a method and apparatus for generating marker and comb indicia in an optical environment using a Mach-Zehnder (M-Z) modulator. High speed recording devices are configured to record image or other data defining a high speed event. To calibrate and establish time reference, the markers or combs are indicia which serve as timing pulses (markers) or a constant-frequency train of optical pulses (comb) to be imaged on a streak camera for accurate time based calibration and time reference. The system includes a camera, an optic signal generator which provides an optic signal to an M-Z modulator and biasing and modulation signal generators configured to provide input to the M-Z modulator. An optical reference signal is provided to the M-Z modulator. The M-Z modulator modulates the reference signal to a higher frequency optical signal which is output through a fiber coupled link to the streak camera.

  2. Migrating the Mach-Zehnder chemical and bio-sensor to the mid-infrared region

    Science.gov (United States)

    Leidner, L.; Ewald, M.; Sieger, M.; Mizaikoff, B.; Gauglitz, G.

    2013-05-01

    The properties of integrated optical phase-modulated Mach-Zehnder interferometers (IO-MZI) are used to set up a new generation of chemical and biochemical sensors working in the mid-infrared. First applications of the MZI principle were introduced in the beginning 1990s. They range from a gas sensor to monitor organic solvent concentrations1 to setting up an immunoassay for the detection of the herbicide simazine2. Most if not all sensors of MZI type operate at wavelengths of the visible or near infrared spectrum. There are several reasons to change this strategy and move into the mid-infrared spectral range (MIR): higher manufacturing tolerances, increased evanescent field penetration depth, signal amplification by surface enhanced infrared absorption effect (SEIRA), species identification by MIR fingerprints. The basis of the planned MIR-MZI is a GaAs waveguide pattern epitaxially grown on a substrate3. As a first step towards nanostructuring the waveguide surface, chemical deposition of Au nanoparticles on GaAs transducers was established. For the use of MIR-MZI sensors in bioanalytical assay development, chemical immobilization of molecular recognition elements on GaAs transducers was carried out. The modified surfaces were characterized by atomic force microscopy (AFM), dark field microscopy, contact angle measurements and ellipsometric data as well as by a modified version of Reflectometric Interference Spectroscopy (RIfS)4. It was possible to monitor both the immobilization of gold nanoparticles and time-resolved specific binding using a model antibody antigen assay. After successful setup of relevant assays with RIfS, e.g. the detection of bacteria or endocrine disruptors, the assays are designed to be transferred onto the mid-infrared Mach-Zehnder interferometer.

  3. High accuracy microwave frequency measurement based on single-drive dual-parallel Mach-Zehnder modulator

    DEFF Research Database (Denmark)

    Zhao, Ying; Pang, Xiaodan; Deng, Lei

    2011-01-01

    A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing a...... 10−3 relative error. This high accuracy frequency measurement technique is a promising candidate for high-speed electronic warfare and defense applications.......A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing...... a two-stage frequency measurement cooperating with digital signal processing. In the experiment, 10GHz measurement range is guaranteed and the average uncertainty of estimated microwave frequency is 5.4MHz, which verifies the measurement accuracy is significantly improved by achieving an unprecedented...

  4. Hybrid InGaAsP-InP Mach-Zehnder Racetrack Resonator for Thermooptic Switching and Coupling Control.

    Science.gov (United States)

    Green, William; Lee, Reginald; Derose, Guy; Scherer, Axel; Yariv, Amnon

    2005-03-07

    An InGaAsP-InP optical switch geometry based on electrical control of waveguide-resonator coupling is demonstrated. Thermooptic tuning of a Mach-Zehnder interferometer integrated with a racetrack resonator is shown to result in switching with ON-OFF contrast up to 18.5 dB. The optical characteristics of this unique design enable a substantial reduction of the switching power, to a value of 26 mW in comparison with 40 mW for a conventional Mach-Zehnder interferometer switch. Modulation response measurements reveal a 3 dB bandwidth of 400 kHz and a rise time of 1.8 micros, comparing favorably with current state-of-the-art thermooptic switches.

  5. Ultra-compact and temperature-insensitive Mach-Zehnder interferometer based on one multimode waveguide on silicon.

    Science.gov (United States)

    Yang, Huizhan; Zhang, Jianhao; Zhu, Yuntao; Zhou, Xuan; He, Sailing; Liu, Liu

    2017-02-01

    An ultra-compact and temperature-insensitive Mach-Zehnder interferometer device is introduced on the silicon-on-insulator platform. The device is constructed through one straight multimode waveguide, which consists of two densely packed silicon wires with a narrow gap of varying positions along the device. The total width of the proposed Mach-Zehnder interferometer is only about 1 μm. Interference patterns with extinction ratios of better than 20 dB are achieved. Temperature insensitive operation of the proposed device is also demonstrated for both global and local temperature changes. The shift rate of the wavelength response with respect to the substrate temperature change is within ±10  pm/K in a 30 nm wavelength range.

  6. High dynamic range microwave photonic down-conversion based on dual-parallel Mach-Zehnder modulator

    Science.gov (United States)

    Li, Hongli; Wang, Yunxin; Wang, Dayong; Rong, Lu; Jia, Yupeng; Li, Jingnan; Zhong, Xin; Yang, Dengcai; Zhou, Tao

    2016-10-01

    In order to enhance conversion efficiency and spurious free dynamic range of microwave photonic link, we present a microwave photonic down-conversion system based on an integrated dual-parallel Mach Zehnder modulator (DPMZM) and microwave photonic filter. The principle of frequency down conversion is analyzed. We demonstrate the conversion efficiency of system through theoretical derivation and simulation. The performance of the microwave photonic link is tested experimentally. It is found that the spurious free dynamic range of the proposed method is up to 102.5dB/Hz2/3 and the conversion efficiency is up to -22.01dB. The integrated dual-parallel Mach-Zehnder modulator link can serve as a good alternative to improve the conversion efficiency and spurious free dynamic range.

  7. Design of 1-bit and 2-bit magnitude comparators using electro-optic effect in Mach-Zehnder interferometers

    Science.gov (United States)

    Kumar, Santosh; Bisht, Ashish; Singh, Gurdeep; Choudhary, Kuldeep; Raina, K. K.; Amphawan, Angela

    2015-12-01

    The Mach-Zehnder interferometer (MZI) structures collectively show powerful capability in switching an input optical signal to a desired output port from a collection of output ports. Hence, it is possible to construct complex optical combinational digital circuits using the electro-optic effect constituting MZI structure as a basic building block. Optical switches have been designed for 1-bit and 2-bit magnitude comparators based on electro-optic effect using Mach-Zehnder interferometers. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. Analysis of some factors influencing the performances of proposed device has been discussed properly. The study is verified using beam propagation method.

  8. Radiation Hard Silicon Photonics Mach-Zehnder Modulator for HEP applications: all-Synopsys Sentaurus™ Pre-Irradiation Simulation

    CERN Document Server

    Cammarata, Simone

    2017-01-01

    Silicon Photonics may well provide the opportunity for new levels of integration between detectors and their readout electronics. This technology is thus being evaluated at CERN in order to assess its suitability for use in particle physics experiments. In order to check the agreement with measurements and the validity of previous device simulations, a pure Synopsys Sentaurus™ simulation of an un-irradiated Mach-Zehnder silicon modulator has been carried out during the Summer Student project.

  9. Mach-Zehnder Type Annealed Proton Exchange Waveguide and Coplanar Waveguide Modulation Electrode LiNbO3 Intensity Modulator

    Institute of Scientific and Technical Information of China (English)

    HE Jian; ZHU Xue-jun

    2007-01-01

    The characteristics of a conventional LiNbO3 intensity modulator made up of a Mach-Zehnder(MZ) type annealed proton exchange(APE) waveguide and coplanar waveguide(CPW) modulation electrode are presented. The APE waveguide characteristics and their relations with process parameters are analyzed. At the same time, the electrical characteristics of modulation electrode, such as modulation voltage, microwave effective index associated with modulation bandwidth, characteristics impedance, are also investigated in detail.

  10. 40-Gb/s star 16-QAM transmitter based on single dual-drive Mach-Zehnder modulator

    Institute of Scientific and Technical Information of China (English)

    Junming Gao; Xinyu Xu; Qingjiang Chang; Yikai Su

    2009-01-01

    We propose a 40-Gb/s star 16-ary quadrature amplitude modulation (16-QAM) transmitter using a single dual-drive Mach-Zehnder modulator (DDMZM). This transmitter is demonstrated through experiment and simulation and shows the advantage of simplicity for implementation. Simulation results indicate that error free performance could be achieved for the generated signal after 80-km standard single-mode fiber (SSMF) transmission with coherent detection scheme.

  11. Thermo-optic control of dielectric-loaded plasmonic Mach-Zehnder interferometers and directional coupler switches

    DEFF Research Database (Denmark)

    Gosciniak, J.; Markey, L.; Dereux, A.

    2012-01-01

    We report detailed experimental studies of compact fiber-coupled dielectric-loaded plasmonic waveguide components-Mach-Zehnder interferometers (MZIs) and directional couplers (DCs)-whose operation at telecom wavelengths is controlled via the thermo-optic effect by electrically heating the gold st......, and wavelength dependent low power (similar to 0.92 mW) rerouting is achieved with DC switches. Furthermore, simulations were performed to confirm the switching characteristics of the components....

  12. On-chip modulation for rotating sensing of gyroscope based on ring resonator coupled with Mach-Zehnder interferometer.

    Science.gov (United States)

    Zhang, Hao; Chen, Jiayang; Jin, Junjie; Lin, Jian; Zhao, Long; Bi, Zhuanfang; Huang, Anping; Xiao, Zhisong

    2016-01-01

    An improving structure for resonance optical gyro inserting a Mach-Zehnder Interferomete (MZI) into coupler region between ring resonator and straight waveguide was proposed. The different reference phase shift parameters in the MZI arms are tunable by thermo-optic effect and can be optimized at every rotation angular rate point without additional phase bias. Four optimum paths are formed to make the gyroscope to work always at the highest sensitivity.

  13. Design and analysis of various multifunctional operations at ultrahigh speed by using a semiconductor optical amplifier-Mach-Zehnder interferometer

    Science.gov (United States)

    Lovkesh; Marwaha, Anupma

    2016-03-01

    Various multifunctional operations are performed by proposing designs of optical adder, subtractor, comparator, and decoder at 60 Gb/s. In all operations, constructive interference is produced by choosing optimized parameters, i.e., optical pulse generator power, input power, semiconductor optical amplifier-Mach-Zehnder interferometer parameters, and so on, for delivering a true output signal. An optical pulse-generated signal is required for all operations except addition, subtraction and equal to in a comparator.

  14. Characteristics of an add-drop filter composed of a Mach-Zehnder interferometer and double ring resonators

    Institute of Scientific and Technical Information of China (English)

    Fufei Pang; Xiuyou Han; Haiwen Cai; Ronghui Qu; Zujie Fang

    2005-01-01

    @@ A planar lightwave circuit (PLC) add-drop filter is proposed and analyzed, which consists of a symmetric Mach-Zehnder interferometer (MZI) combined with double microring resonators. A critical coupling condition is derived for a better box-like drop spectrum. Comparisons of its characteristics with other schemes,such as a MZI with a single ring resonator, are presented, and some of the issues about device design and fabrication are also discussed.

  15. Optical directional coupler and Mach-Zehnder interferometer enhanced via 4H-SiC phonons

    Science.gov (United States)

    Finch, Michael F.; Saunders Filho, Claudio A. B.; Lail, Brian A.

    2016-09-01

    Surface phonon polaritons (SPhPs), similar to it cousin phenomenon surface plasmon polaitons (SPPs), are quasi-neutral particles resulting from light-matter coupling that can provide high modal confinement and long propagation in the mid to long infrared (IR). Mach-Zehnder interferometer (MZI) is a combination of two connected optical directional couplers (ODC). With the use of SPhPs, sub-wavelength feature sizes and modal areas can be achieved and to this end a hybrid SPhP waveguide, where propagation length and modal area can be trade-off, will be employed in the design of an ODC and MZI. This endeavor analyzes and characteristics both an ODC and MZI using commercially available numerical simulation software employing finite element method (FEM). The ODC and MZI are design using a novel SPhP hybrid waveguide design where a 4H-SiC substrate provides the polariton mode. The output ports power and relative phase difference between ports are investigated. SPhP enhanced ODC and MZI has applications including, but not limited to, next-generation ultra-compact photonic integrated circuits and waveguide based IR sensing.

  16. Design of all-optical multi-level regenerators based on Mach-Zehnder interferometer

    Science.gov (United States)

    Kong, Xiangjian; Wu, Baojian; Zhou, Xingyu; Wan, Qingyao; Jiang, Shanglong; Wen, Feng; Qiu, Kun

    2016-12-01

    We propose a design method for all-optical multi-level regenerators by mimicking the normalized power transfer function (PTF) in the first-order approximation to the ideal step-like PTF, in which a key step is to appropriately select the amplitude and phase conditions of Mach-Zehnder-interferometer (MZI)-based regenerators. As an example, we describe the design process of the self-phase-modulation (SPM)-based MZI regenerator constructed by a section of nonlinear fiber and an optical phase shifter (OPS). It is shown that the parameter of reference power level (RPL) can be regarded as the upper limit of input power, which is useful for the measure of the multi-level regeneration performance. The number of regenerative power levels increases with the RPL parameter. For 4-level pulse amplitude modulated (4PAM) optical signals degraded by the Gaussian noises with the standard deviation of 0.02, the SPM-based MZI regenerator has an average noise reduction ratio (NRR) of 6.5 dB, better than that of 1st-order regenerator by about 5 dB.

  17. An innovative single development process for integrated optical Mach-Zehnder interferometer pattern transfer

    Science.gov (United States)

    Idris, NurulBariah; Lau, Kuen Yau; Khor, Kang Nan; Abdul Wahid, Mohamad Halim; Ahmad Hambali, Nor Azura Malini; Retnasamy, Vithyacharan; Mohamad Shahimin, Mukhzeer

    2017-02-01

    Integrated optical Mach-Zehnder interferometer (IO-MZI) has been widely researched for various usage including for biosensor application. However, the success rate of IO-MZI pattern transfer has been low using the conventional multidevelopment process. One of the main factors is the particle contamination due to the practice of reused developer bath. In this work, an innovative single development process had been proposed with the utilization of the same conventional set-up but with a different protocol. The concept of this method is the estimation of total development time based on the calculated development rate. By doing so, the development process can be completed with only one immersion of the substrate in the developer bath. Besides, the manipulation of development rate by varying exposure time in this work also had revealed the possibility of manipulation of line-width based on the exposure time. In short, the proposed single development process has increased the success rate of IO-MZI pattern transfer from 30% (multi-development method) to 90%.

  18. A Mach-Zehnder interferometer based on orbital angular momentum for improved vortex coronagraph efficiency

    CERN Document Server

    Piron, P; Huby, E; Mawet, D; Ruane, M Karlsson ad G; Habraken, S; Absil, O; Surdej, J

    2016-01-01

    The Annular Groove Phase Mask (AGPM) is a vectorial vortex phase mask. It acts as a half-wave plate with a radial fast axis orientation operating in the mid infrared domain. When placed at the focus of a telescope element provides a continuous helical phase ramp for an on axis sources, which creates the orbital angular momentum. Thanks to that phase, the intensity of the central source is canceled by a down-stream pupil stop, while the off axis sources are not affected. However due to experimental conditions the nulling is hardly perfect. To improve the null, a Mach-Zehnder interferometer containing Dove prisms differently oriented can be proposed to sort out light based on its orbital angular momentum (OAM). Thanks to the differential rotation of the beam, a {\\pi} phase shift is achieved for the on axis light affected by a non zero OAM. Therefore the contrast between the star and its faint companion is enhanced. Nevertheless, due the Dove prisms birefringence, the performance of the interferometer is relativ...

  19. Optimization design of optical waveguide in Mach-Zehnder electro-optical polymer modulator

    Institute of Scientific and Technical Information of China (English)

    GAO Yuan; ZHANG Xiao-xia; LIAO Jin-kun

    2011-01-01

    @@ In order to reduce transmission loss of the optical waveguide in Mach-Zehnder (M-Z) electro-optical (EO) polymer modulator,the basic iterative formula of semi-vector finite-difference beam propagation method (FD-BPM) is obtained from the scalar wave equation.The transition waveguide is combined with S-type bend branch waveguide for the M-Z EO modulator in the branch waveguide.The effects of structure parameters such as ridge width, length of the branch waveguide and interferometer spacing on the transmission loss are systematically studied by using the semi-vector FD-BPM method.The structure is optimized as an S-sine bend branch waveguide, with rib width w=7 μm, length of branch waveguide L=1200μm and interferometer spacing G=22 μm.The results show that the optimized structure can reduce transmission loss to 0.083 dB,which have a certain reference value to the design of optical waveguide in M-Z polymer modulator.

  20. Silicon photonics athermal Mach-Zehnder interferometer with wide thermal and spectral operating range

    Science.gov (United States)

    Xing, Peng; Viegas, Jaime

    2015-02-01

    In the context of 3D-integrated circuit (3DIC) integration of photonic and electronic components on vertical stacks covering different domains (digital, analog, RF, optical and MEMS), the control and minimization of adverse thermal effects on the behavior of the different parts of the microsystem is a major concern. Solutions based on passive athermal design are good candidates for enabling operation of optical components over electronic ICs with variable temporal and spatial thermal load while at the same time, minimizing energy loss on thermal biasing resistive loads. In this work, an improved athermal design method and the corresponding validating fabricated prototype are presented with the aim of extending the spectral athermal operating range of a Mach-Zehnder interferometer (MZI) over a wide thermal range with minimal temperature sensitivity. The proposed approach is demonstrated with a CMOS compatible silicon-on-insulator process flow fabrication run. The fabricated MZIs have a temperature sensitivity of around 20 pm/K over a spectral range larger than 60 nm for operating temperatures in the range of 20°C to 60°C. These devices are suitable for future optical and electronic 3D IC integration.

  1. Photonic crystal fiber Mach-Zehnder interferometer for refractive index sensing.

    Science.gov (United States)

    Wang, Jian-Neng; Tang, Jaw-Luen

    2012-01-01

    We report on a refractive index sensor using a photonic crystal fiber (PCF) interferometer which was realized by fusion splicing a short section of PCF (Blaze Photonics, LMA-10) between two standard single mode fibers. The fully collapsed air holes of the PCF at the spice regions allow the coupling of PCF core and cladding modes that makes a Mach-Zehnder interferometer. The transmission spectrum exhibits sinusoidal interference pattern which shifts differently when the cladding/core surface of the PCF is immersed with different RI of the surrounding medium. Experimental results using wavelength-shift interrogation for sensing different concentrations of sucrose solution show that a resolution of 1.62 × 10(-4)-8.88 × 10(-4) RIU or 1.02 × 10(-4)-9.04 × 10(-4) RIU (sensing length for 3.50 or 5.00 cm, respectively) was achieved for refractive indices in the range of 1.333 to 1.422, suggesting that the PCF interferometer are attractive for chemical, biological, biochemical sensing with aqueous solutions, as well as for civil engineering and environmental monitoring applications.

  2. Silicon photonic Mach Zehnder modulators for next-generation short-reach optical communication networks

    Science.gov (United States)

    Lacava, C.; Liu, Z.; Thomson, D.; Ke, Li; Fedeli, J. M.; Richardson, D. J.; Reed, G. T.; Petropoulos, P.

    2016-02-01

    Communication traffic grows relentlessly in today's networks, and with ever more machines connected to the network, this trend is set to continue for the foreseeable future. It is widely accepted that increasingly faster communications are required at the point of the end users, and consequently optical transmission plays a progressively greater role even in short- and medium-reach networks. Silicon photonic technologies are becoming increasingly attractive for such networks, due to their potential for low cost, energetically efficient, high-speed optical components. A representative example is the silicon-based optical modulator, which has been actively studied. Researchers have demonstrated silicon modulators in different types of structures, such as ring resonators or slow light based devices. These approaches have shown remarkably good performance in terms of modulation efficiency, however their operation could be severely affected by temperature drifts or fabrication errors. Mach-Zehnder modulators (MZM), on the other hand, show good performance and resilience to different environmental conditions. In this paper we present a CMOS-compatible compact silicon MZM. We study the application of the modulator to short-reach interconnects by realizing data modulation using some relevant advanced modulation formats, such as 4-level Pulse Amplitude Modulation (PAM-4) and Discrete Multi-Tone (DMT) modulation and compare the performance of the different systems in transmission.

  3. Mach-Zehnder modulator modulated radio-over-fiber transmission system using dual wavelength linearization

    Science.gov (United States)

    Zhu, Ran; Hui, Ming; Shen, Dongya; Zhang, Xiupu

    2017-02-01

    In this paper, dual wavelength linearization (DWL) technique is studied to suppress odd and even order nonlinearities simultaneously in a Mach-Zehnder modulator (MZM) modulated radio-over-fiber (RoF) transmission system. A theoretical model is given to analyze the DWL employed for MZM. In a single-tone test, the suppressions of the second order harmonic distortion (HD2) and third order harmonic distortion (HD3) at the same time are experimentally verified at different bias voltages of the MZM. The measured spurious-free dynamic ranges (SFDRs) with respect to the HD2 and HD3 are improved simultaneously compared to using a single laser. The output P1 dB is also improved by the DWL technique. Moreover, a WiFi signal is transmitted in the RoF system to test the linearization for broadband signal. The result shows that more than 1 dB improvement of the error vector magnitude (EVM) is obtained by the DWL technique.

  4. Investigation on Nyquist pulse generation using a single dual-parallel Mach-Zehnder modulator.

    Science.gov (United States)

    Wu, Jian; Zang, Jizhao; Li, Yan; Kong, Deming; Qiu, Jifang; Zhou, Siyuan; Shi, Jindan; Lin, Jintong

    2014-08-25

    The generation of Nyquist pulses with a dual parallel Mach-Zehnder modulator (DPMZM) driven by a single RF signal is demonstrated theoretically and experimentally. A complete theoretical analysis is developed and the limitation of the proposed scheme is also discussed. It is theoretically proved that Nyquist pulses with a spectrum of 5 flat comb lines can be generated using a single DPMZM, which is also verified with simulation. 7 flat comb lines in frequency domain can also be obtained if a large RF driving voltage is applied to DPMZM but the generated waveforms won't present a sinc-shape. This scheme is further investigated experimentally. 40 GHz Nyquist pulses with full-width-at-half-maximum (FWHM) less than 4.65 ps, signal-to-noise ratio (SNR) better than 29.5 dB, and normalized root-mean-square error (NRMSE) less than 2.4% are generated. It is found that a tradeoff exists between the insertion loss of the DPMZM and the deviation of generated pulses. The tunability of repetition rate is experimentally verified by generation of 1 GHz to 40 GHz Nyquist pulses with SNR better than 28.4 dB and NRMSE less than 6.15%.

  5. Biosensors based on Si3N4 asymmetric Mach-Zehnder interferometers

    Science.gov (United States)

    Chalyan, Tatevik; Pasquardini, Laura; Falke, Floris; Zanetti, Manuela; Guider, Romain; Gandolfi, Davide; Schreuder, Eric; Pederzolli, Cecilia; Heideman, René G.; Pavesi, Lorenzo

    2016-04-01

    In this work, we present a study on photonic biosensors based on Si3N4 asymmetric Mach-Zehnder Interferometers (aMZI) for Aflatoxin M1 (AFM1) detection. AFM1 is an hepatotoxic and a carcinogenic toxin present in milk. The biosensor is based on an array of four Si3N4 aMZI that are optimized for 850nm wavelength. We measure the bulk Sensitivity (S) and the Limit of Detection (LOD) of our devices. In the array, three devices are exposed and have very similar sensitivities. The fourth aMZI, which is covered by SiO2, is used as an internal reference for laser (a VCSEL) and temperature fluctuations. We measured a phase sensitivity of 14300+/-400 rad/RIU. To characterize the LOD of the sensors, we measure the uncertainty of the experimental readout system. From the measurements on three aMZI, we observe the same value of LOD, which is ≍ 4.5×10-7 RIU. After the sensor characterization on homogeneous sensing, we test the surface sensing performances by flowing specific Aflatoxin M1 and non-specific Ochratoxin in 50 mM MES pH 6.6 buffer on the top of the sensors functionalized with Antigen-Recognising Fragments (Fab'). The difference between specific and non-specific signals shows the specificity of our sensors. A moderate regeneration of the sensors is obtained by using glycine solution.

  6. Tunable Photonic Crystal Mach-Zehnder Interferometer Based on Self-collimation Effect

    Institute of Scientific and Technical Information of China (English)

    CHEN Xi-Yao; LI Hui; QIU Yi-Shen; WANG Yu-Fei; NI Bo

    2008-01-01

    @@ A theoretical model for tunable Mach-Zehnder interferometers (TMZIs) constructed in a two-dimensional pho-tonic crystal (2D PhC) is proposed.The 2D PhC consists of a square lattice of cylindric air holes in silicon.The TMZI includes two mirrors and two splitters.Light propagates between them employing a sell-collimation effect.The two interferometer branches have different path lengths.Parts of the longer branch are infiltrated with a kind of liquid crystal (LC) with ordinary and extraordinary refractive indices 1.522 and I.706, respectively.The transmission spectra at two TMZI output ports are in the shape of sinusoidal carves and have a uniform peak spacing 0.0017c/a in the frequency range from 0.26c/a to 0.27c/a.When the effective refractive index neff of the liquid crystal is increased from 1.522 to 1.706, the peaks shift to the lower frequencies over 0.0017c/a while the peak spacing is almost kept unchanged.Thus this TMZI can work as a tunable power splitter or an optical switch.For the central operating wavelength around 1550nm, its dimensions are only about tens of micron.Thus this device may be applied to photonic integrated circuits.

  7. Temperature sensing setup based on an aluminum coated Mach-Zehnder Interferometer

    Science.gov (United States)

    Pacheco-Chacón, Eliana I.; Gallegos-Arellano, E.; Sierra-Hernandez, Juan M.; Rojas-Laguna, Roberto; Estudillo-Ayala, Julian M.; Hernandez, Emmanuel; Jauregui-Vazquez, D.; Hernandez-Garcia, J. C.

    2017-05-01

    In this paper a temperature sensing setup based on a Photonic Crystal Fiber (PCF) Mach-Zehnder Interferometer (MZI), coated with aluminum is proposed. Here, this interferometer is fabricated through the concatenation of two sections of Single Mode Fiber (SMF) with a segment of PCF between them. The SMF-PCF joint acts as beam splitter causing the excitement of PCF's, both cladding and fundamental core modes. In the PCF-SMF union, the cladding modes couple again to the core of the SMF, and interfere with the fundamental core mode, this interaction results in an interference pattern spectrum. Moreover, the MZI was coated with aluminum, using the evaporation technique. By adding a thin metal layer to the PCF section, the general thermal coefficient of the structure changes, enhancing the sensitivity of the device. Experimental results show that a visibility of 13 dBm can be obtained and a sensitivity of 250 pm/°C. Finally, the proposed structure is simple, cost effective and easy to fabricate.

  8. Stochastic dual-plane on-axis digital holography based on Mach-Zehnder interferometer

    Science.gov (United States)

    Wang, Fengpeng; Wang, Dayong; Rong, Lu; Wang, Yunxin; Zhao, Jie

    2016-09-01

    For traditional dual-plane on-axis digital holography, the robustness is lower because it is difficult to maintain the stability of the phase difference between the object beam and the reference beam, and it may be invalid when the objects are on the surface of a medium with uneven thickness. An improved dual-plane digital holographic method based on Mach-Zehnder interferometer is presented to address these problems. Two holograms are recorded at two different planes separated by a small distance. Then, the zero-order image and conjugated image are eliminated by Fourier domain processing. In order to enhance the robustness of the system, the object is illuminated by a stochastic beam that is a speckle wave produced by a diffuser. Simulated and experimental results are shown to demonstrate that the proposed method has greater robustness than the traditional dual-plane on-axis digital holography and it can be used to imaging on the irregular surface of a transparent medium.

  9. Microfiber Mach-Zehnder interferometer based on long period grating for sensing applications.

    Science.gov (United States)

    Tan, Yanzhen; Sun, Li-Peng; Jin, Long; Li, Jie; Guan, Bai-Ou

    2013-01-14

    A Mach-Zehnder interferometer (MZI) composed by a pair of long period gratings (LPGs) fabricated in silica microfiber for sensing applications is demonstrated. Each LPG is fabricated with a pulsed CO2 laser by creating six periodical deformations along fiber length with only one scanning cycle. The length of the MZI can reach as short as 8.84 mm when the diameter of the microfiber is 9.5 μm. Compared with the ones fabricated in single-mode fibers, the present MZI is much shorter owing to the large effective-index difference between the fundamental and higher order modes. The microfiber MZI exhibits a sensitivity to surrounding refractive index (RI) of 2225 nm per refractive index unit and the temperature sensitivity of only 11.7 pm/°C. Theoretical analysis suggests that the performances of the MZI sensor can be improved by using thinner microfibers with a diameter down to 3.5 μm: The sensitivity can be greatly enhanced due to the stronger evanescent-field interaction and reduced dispersion factor; the transmission dips become narrower which benefits high-resolution measurement; the thinner fiber also allows further reduction in device length. The present device has great potential in biochemical and medical sensing due to the advantages including easy fabrication, excellent compactness and high sensitivity.

  10. 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.

  11. 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.

  12. Label-free in-situ real-time DNA hybridization kinetics detection employing microfiber-assisted Mach-Zehnder interferometer.

    Science.gov (United States)

    Song, Binbin; Zhang, Hao; Liu, Bo; Lin, Wei; Wu, Jixuan

    2016-07-15

    A label-free DNA biosensor based on microfiber-assisted Mach-Zehnder interferometer (MAMZI) for in-situ real-time DNA hybridization kinetics detection has been proposed and experimentally demonstrated. A microfiber of hundreds of microns in length is fabricated by tapering a segment of standard single-mode fiber (SMF) to construct the U-shaped microcavity between the lead-in and lead-out SMFs. Thanks to the mode field mismatching between the SMF and microfiber, the incident guided mode light would separate into two beams that respectively propagate in the air microcavity and the microfiber. Consequently, interference between different light modes would occur at the joint between the microfiber and the lead-out SMF. Experimental results indicate that owing to the participation of opening cavity modes in the modal interference process, the interferometric spectrum of our proposed microcavity sensor is highly sensitive to the variation of environmental refractive index (RI), especially for the RI range around 1.34 which is useful for most biological applications. The microfiber functionalization is achieved by stepwise modifying the microfiber with monolayer Poly-l-lysine (PLL) and single-stranded DNA (ssDNA) probes to produce the sensitive surface that could uniquely attach specific target ssDNAs. The fiber surface functionalization as well as DNA hybridization processes have been experimentally investigated for different target ssDNA solutions in real time. The interferometric transmission spectrum shows large wavelength shift for different biological phases, and a detection limit conservatively down to 0.0001pmol/μL has been acquired by employing the U-shaped microcavity of 176.88μm in length. Our proposed DNA biosensor possesses several advantages such as compact size, ease of fabrication, and strong response for DNA hybridization, which make it a promising candidate for potential applications in such rapidly expanding areas as medical diagnosis, cancer

  13. Integrated all-polymer Mach-Zehnder interferometers without interaction window in asymmetric configuration

    Science.gov (United States)

    Xiao, Yanfen; Hofmann, Meike; Wang, Ziyu; Sherman, Stanislav; Li, Pei; Zappe, Hans

    2016-02-01

    Integrated Mach-Zehnder interferometers (MZI) based on semiconductors or glasses have been widely used as evanescent field sensors for the monitoring of liquid or gas concentrations. In these systems the upper cladding of the sensing arm is removed partially to form an interaction window by means of subtractive fabrication techniques like etching. The use of polymer materials implicates new options and challenges. Polymers are tunable in terms of refractive index and viscosity offering a great flexibility in design and fabrication in a certain range. They enable a cost-efficient and large-scale roll-to-roll manufacturing of integrated optics on flexible foils as substrate material. The foils can be pre-patterned for example by hot-embossing. Additive steps such as printing a pattern or dispensing a homogeneous layer of liquid monomer material followed by a UV induced polymerization can be used to define the optical structure. However, when a large scale fabrication is required, the reliable production of small lateral structures and thin layers is challenging. Thus the fabrication according to the classical MZI design including an interaction window is difficult so that new design approaches are required. We present here the design and systematic evaluation of MZI sensors without interaction window based on polymer materials. The phase shift at the recombining Y-splitter of the MZI upon a refractive index change of an analyte, which serves as upper cladding of the entire system, is generated by a geometrical asymmetricity of the MZI. The waveguides in the sensing and the reference arm have different width leading to different effective refractive indices and sensitivities. We consider theoretically the expected interference signal and show results from numerical simulations of the whole system using commercial software. The simulations include the material as well as propagation losses and give an overall optimal system length.

  14. Binary to Octal and Octal to Binary Code Converter Using Mach-Zehnder Interferometer for High Speed Communication

    Science.gov (United States)

    Pal, Amrindra; Kumar, Santosh; Sharma, Sandeep

    2017-05-01

    Binary to octal and octal to binary code converter is a device that allows placing digital information from many inputs to many outputs. Any application of combinational logic circuit can be implemented by using external gates. In this paper, binary to octal and octal to binary code converter is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).

  15. Reconfigurable nonblocking 4-port silicon thermo-optic optical router based on Mach-Zehnder optical switches.

    Science.gov (United States)

    Yang, Lin; Xia, Yuhao; Zhang, Fanfan; Chen, Qiaoshan; Ding, Jianfeng; Zhou, Ping; Zhang, Lei

    2015-04-01

    We demonstrate a reconfigurable nonblocking 4-port silicon thermo-optic optical router based on Mach-Zehnder optical switches. For all optical links in its 9 routing states, the optical signal-to-noise ratios are larger than 15 dB in the wavelength range from 1525 to 1565 nm. Each optical link of the optical router can manipulate 50 wavelength-division-multiplexing channels with the data rate of 32 Gbps for each channel in the same wavelength range. Its average energy efficiency is about 16.3 fJ/bit, and its response time is about 19 μs.

  16. Design of reversible sequential circuits using electro-optic effect of lithium-niobate-based Mach-Zehnder interferometers

    Science.gov (United States)

    Kumar, Santosh; Chauhan, Chanderkanta; Bedi, Amna

    2016-12-01

    In recent years, it has been shown that reversible logic can play an important role in power optimization for computer design. The various reversible logic gates such as Feynman, Fredkin, Peres, and Toffoli gates have been discussed by researchers, but very little work has been done on reversible sequential circuits. Design of reversible sequential circuits using lithium-niobate-based Mach-Zehnder interferometers is proposed. Here, flip-flops are designed with the help of basic reversible logic gates such as Feynman, Fredkin, and Peres gates. Theoretical descriptions along with mathematical formulation of the devices are provided. The devices are also analyzed through finite difference-beam propagation method and MATLAB® simulation.

  17. An all-optical switch of Mach-Zehnder interferometer type using an active fibre ring resonator

    Institute of Scientific and Technical Information of China (English)

    Li Jun-Qing; Alireza Bananej; Li Qiang-Hua; Chen Qiang; Li Chun-Fei

    2004-01-01

    We propose an all-optical switch of the Mach-Zehnder interferometer type using an active nonlinear ring resonatorand analyse the significance of the parameter A, a product of gain and total loss, for performing an ideal 1 by 2switch. We found that in the range of 1 - κ≤ A ≤√/1 - k, the increment of A can compensate the losses insidethe ring, therefore increase the finesse of the ring and enhance the nonlinearity contribution to reduce the switchingpower threshold effectively. We also emphasize the importance of the initial switching point and discuss the feasibilityof utilizing a high-nonlinear fibre in the ring.

  18. A 2×2 SOI mach-zehnder thermo-optical switch based on strongly guided paired multimode interference couplers

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A silicon-on-insulator 2×2 Mach-Zehnder thermo-optical switch is developed based on strongly guided paired multimode interference couplers. The multimode-interference couplers were etched deeply for improving coupler characteristics such as self-imaging quality, uniformity and fabrication tolerance. The proposed switch achieves good performances, including a low insertion loss of -11 .OdB, a fiber-waveguide coupling loss of -4.3dB and a fast response speed measured to be 3.5 and 8.8 μs for raise and fall switching time, respectively.

  19. Mach-Zehnder Interferometers with Asymmetric Modulation Arms in Applications of High Speed Silicon-on-Insulator Based Optical Switches

    Institute of Scientific and Technical Information of China (English)

    SUN Fei; YU Jin-Zhong

    2006-01-01

    @@ Modulation arms with different widths are introduced to Mach-Zehnder interferometers (MZIs) to obtain improved performance. Theoretical analysis and numerical simulation have shown that when the widths of the two arms are properly designed to achieve an inherent mπ/2 (m is an odd integer) optical phase difference between the arms, the asymmetric MZI presents higher modulation speed. Furthermore, the carrier-absorption induced divergence of insertion losses in silicon-on-insulator (SOI) based MZI optical switches can be obviously improved.

  20. Compact silicon-on-insulator-based 2 × 2 Mach-Zehnder interferometer electro-optic switch with low crosstalk

    Institute of Scientific and Technical Information of China (English)

    Jiejiang Xing; Zhiyong Li; Peiji Zhou; Yuanhao Gong; Yude Yu; Manqing Tan; Jinzhong Yu

    2015-01-01

    We report a compact 2 × 2 Mach-Zehnder interferometer (MZI) electro-optic switch fabricated on a siliconon-insulator using standard complementary metal-oxide semiconductor (CMOS) processes.With a short modulation arm length of 200 μm,the crosstalk is reduced to-22 dB by the new modulation scheme of push-pull modulation with a pre-biased π/2 phase shift.The new modulation scheme can also work with a fast switching time of about 5.4 ns.

  1. Design of 4 to 2 line encoder using lithium niobate based Mach Zehnder Interferometers for high speed communication

    Science.gov (United States)

    Pal, Amrindra; Kumar, Santosh; Sharma, Sandeep; Raghuwanshi, Sanjeev K.

    2016-04-01

    Encoder is a device that allows placing digital information from many inputs to many outputs. Any application of combinational logic circuit can be implemented by using encoder and external gates. In this paper, 4 to 2 line encoder is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).

  2. Radiation Hard Silicon Photonics Mach-Zehnder Modulator for HEP applications: all-Synopsys SentaurusTM Pre-Irradiation Simulation

    CERN Document Server

    Cammarata, Simone

    2017-01-01

    Silicon Photonics may well provide the opportunity for new levels of integration between detectors and their readout electronics. This technology is thus being evaluated at CERN in order to assess its suitability for use in particle physics experiments. In order to check the agreement with measurements and the validity of previous device simulations, a pure Synopsys SentaurusTM simulation of an un-irradiated Mach-Zehnder silicon modulator has been carried out during the Summer Student project. Index Terms—Silicon Photonics, Mach-Zehnder modulator, electro-optic simulation, Synopsys SentaurusTM, electro-optic measurement, HEP.

  3. Versatile photonic microwave waveforms generation using a dual-parallel Mach-Zehnder modulator without other dispersive elements

    Science.gov (United States)

    Bai, Guang-Fu; Hu, Lin; Jiang, Yang; Tian, Jing; Zi, Yue-Jiao; Wu, Ting-Wei; Huang, Feng-Qin

    2017-08-01

    In this paper, a photonic microwave waveform generator based on a dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. In this reported scheme, only one radio frequency signal is used to drive the dual-parallel Mach-Zehnder modulator. Meanwhile, dispersive elements or filters are not required in the proposed scheme, which make the scheme simpler and more stable. In this way, six variables can be adjusted. Through the different combinations of these variables, basic waveforms with full duty and small duty cycle can be generated. Tunability of the generator can be achieved by adjusting the frequency of the RF signal and the optical carrier. The corresponding theoretical analysis and simulation have been conducted. With guidance of theory and simulation, proof-of-concept experiments are carried out. The basic waveforms, including Gaussian, saw-up, and saw-down waveforms, with full duty and small duty cycle are generated at the repetition rate of 2 GHz. The theoretical and simulation results agree with the experimental results very well.

  4. On-chip integrated mid-infrared GaAs/AlGaAs Mach-Zehnder interferometer.

    Science.gov (United States)

    Sieger, Markus; Balluff, Franz; Wang, Xiaofeng; Kim, Seong-Soo; Leidner, Lothar; Gauglitz, Guenter; Mizaikoff, Boris

    2013-03-19

    We report the design, fabrication, and first functional verification of mid-infrared (MIR; 3-12 μm) Mach-Zehnder interferometers (MZIs). The developed MIR-MZIs are entirely chip-integrated solid-state devices based on GaAs/AlGaAs technology waveguide fabricated via conventional optical lithography and reactive ion etching (RIE). Thus, fabricated MIR-MZIs were combined with a broadly tunable quantum cascade laser (tQCL) providing a wavelength coverage of 5.78-6.35 μm. MIR-MZIs have been designed with a waveguide width of 5 μm to ensure single mode behavior, avoiding optically undefined interference patterns. Several structures with different opening angles of the Y-junction were fabricated and tested for maximizing IR radiation throughput. This study demonstrates the feasibility of the very first chip-integrated mid-infrared Mach-Zehnder structures via interference patterns produced by minute amounts of water deposited at different positions of the MIR-MZI structure.

  5. Comparisons of multi-wavelength oscillations using Sagnac loop mirror and Mach-Zehnder interferometer for ytterbium doped fiber lasers

    Science.gov (United States)

    Moghaddam, M. R. A.; Harun, S. W.; Shahi, S.; Lim, K. S.; Ahmad, H.

    2010-02-01

    A multiwavelength Ytterbium-doped fiber ring laser operating at 1030 nm region is demonstrated using a Sagnac loop mirror and a Mach-Zehnder interferometer. We report the Performance comparisons of multi-wavelength oscillations in Yb3+ doped fiber lasers (YDFL) with typical commercial ytterbium doped silica fibers. By adjusting the polarization controller (PC), a widely tunable laser range of 22 nm from 1030 nm to 1050 nm is obtained. The Mach-Zehnder interferometer (MZI) design has exhibited simplicity in the operation for controlling the smallest wavelength spacing compared to Sagnac loop mirror method. In our observations, the smallest achieved stable wavelength spacing in Sagnac loop mirror setup and MZI setup were 2.1 nm and 0.7 nm, respectively. In case of nine-wavelength operation with a MZI setup, the stability, Full Width at Half Maximum (FWHM) and side mode suppression ratio (SMSR) of laser lines are not affected by increasing pump power, While for above four wavelength operation, the laser stability with Sagnac loop mirror becomes worse specially for higher input pump power and the power fluctuation among the wave-lengths would be also slightly larger.

  6. Laser frequency stabilisation via quasi-monolithic, unequal arm-length Mach-Zehnder interferometer with balanced DC readout

    CERN Document Server

    Gerberding, Oliver; Mehmet, Moritz; Danzmann, Karsten; Heinzel, Gerhard

    2016-01-01

    Low frequency high precision laser interferometry is subject to excess laser frequency noise coupling via arm-length differences which is commonly mitigated by locking the frequency to a stable reference system. This is crucial to achieve picometer level sensitivities in the 0.1 mHz to 1 Hz regime, where laser frequency noise is usually high and couples into the measurement phase via arm-length mismatches in the interferometers. Here we describe the results achieved by frequency stabilising an external cavity diode laser to a quasi-monolithic unequal arm-length Mach-Zehnder interferometer read out at mid-fringe via balanced detection. This stabilisation scheme has been found to be an elegant solution combining a minimal number of optical components, no additional laser modulations and relatively low frequency noise levels. The Mach-Zehnder interferometer has been designed and constructed to minimise the influence of thermal couplings and to reduce undesired stray light using the optical simulation tool IfoCAD...

  7. All-optical clear/drop optimisation for a 4x40 Gbit/s signal in Mach-Zehnder Interferometers Based on Semiconductor Optical Amplifiers

    DEFF Research Database (Denmark)

    Bischoff, Svend; Mørk, Jesper

    2000-01-01

    Optimisation of the all-optical clear and drop functionality using a Mach-Zehnder Interferometer is investigated for 2, 4 and 8x40 Gbit/s signals. The performance of different devices is compared, and critical design issues are discussed....

  8. A system-level model for high-speed, radiation-hard optical links in HEP experiments based on silicon Mach-Zehnder modulators

    Science.gov (United States)

    Zeiler, M.; Detraz, S.; Olantera, L.; Sigaud, C.; Soos, C.; Troska, J.; Vasey, F.

    2016-12-01

    Silicon Mach-Zehnder modulators have been shown to be relatively insensitive to displacement damage beyond a 1-MeV-equivalent neutron fluence of 3ṡ1016n/cm2. Recent investigations on optimized device designs have also led to a high resistance against total ionizing dose levels of above 1 MGy. Such devices could potentially replace electrical and/or optical links close to the particle interaction points in future high energy physics experiments. Since they require an external continuous-wave light source, radiation-hard optical links based on silicon Mach-Zehnder modulators need to have a different system design when compared to existing directly modulated laser-based optical links. 10 Gb/s eye diagrams of irradiated Mach-Zehnder modulators were measured. The outcomes demonstrate the suitability for using these components in harsh radiation environments. A proposal for the implementation of silicon Mach-Zehnder modulators in CERN's particle detectors was developed and a model to calculate the system performance is presented. The optical power budget and the electrical power dissipation of the proposed link is compared to that of the upcoming Versatile Link system that will be installed in 2018.

  9. All-Optical Regenerative OTDM Add-Drop Multiplexing at 40 Gb/s using Monolithic InP Mach-Zehnder Interferometer

    DEFF Research Database (Denmark)

    Fischer, St.; Dülk, M.; Gamper, E.;

    2000-01-01

    We present a novel method for all-optical add-drop multiplexing having regenerative capability for 40-Gb/s optical time-division multiplexed (OTDM) data using a semiconductor optical amplifier (SOA) based, monolithic Mach-Zehnder interferometer (MZI). Simultaneous dropping of one 10-Gb/s channel ...

  10. Novel wideband microwave polarization network using a fully-reconfigurable photonic waveguide interleaver with a two-ring resonator-assisted asymmetric Mach-Zehnder structure

    NARCIS (Netherlands)

    Zhuang, Leimeng; Beeker, Willem; Leinse, Arne; Heideman, René; Dijk, van Paulus; Roeloffzen, Chris

    2013-01-01

    We propose and demonstrate a novel wideband microwave photonic polarization network for dual linear-polarized antennas. The polarization network is based on a waveguide-implemented fully-reconfigurable optical interleaver using a two-ring resonator-assisted asymmetric Mach-Zehnder structure. For mic

  11. Effect of Radiation on a Mach-Zehnder Interferometer Silicon Modulator for HL-LHC data Transmission Applications

    CERN Document Server

    El Nasr-Storey, Sarah Seif; Baudot, Charles; Detraz, Stephane; Fedeli, Jean Marc; Marris-Morini, Delphine; Olantera, Lauri; Pezzullo, Giuseppe; Sigaud, Christophe; Soos, Csaba; Troska, Jan; Vasey, Francois; Vivien, Laurent; Zeiler, Marcel; Ziebell, Melissa

    2015-01-01

    High-speed Mach-Zehnder interferometer silicon modulators were irradiated with neutrons and X-rays in two separate radiation tests. The devices were exposed to a total fluence of 1.2 x 10$^{15}$ neutrons/cm$^2$ and a total ionizing dose of 1.3 MGy; levels comparable to the worst radiation levels for a tracking detector after 10 years of operation at the High- Luminosity LHC. Our measurements indicate that the devices performance does not significantly degrade after exposure to nonionizing radiation and begins to be affected by ionizing radiation after a dose of a few hundred kGy; the phase-shift for an applied reverse bias of 1 V is 10% of its pre-irradiated value after 600 kGy of received ionizing dose.

  12. Refractive index sensing performance analysis of photonic crystal Mach-Zehnder interferometer based on BP neural network optimization

    Science.gov (United States)

    Chen, Ying; Liu, Teng; Wang, Wenyue; Zhu, Qiguang; Bi, Weihong

    2015-04-01

    According to the band gap and photon localization characteristics, the single-arm notching and the double-arm notching Mach-Zehnder interferometer (MZI) structures based on 2D triangular lattice air hole-typed photonic crystal waveguide are proposed. The back-propagation (BP) neural network is introduced to optimize the structural parameters of the photonic crystal MZI structure, which results in the normalized transmission peak increasing from 85.3% to 97.1%. The sensitivity performances of the two structures are compared and analyzed using the Salmonella solution samples with different concentrations in the numerical simulation. The results show that the sensitivity of the double-arm notching structure is 4583 nm/RIU, which is about 6.4 times of the single-arm notching structure, which can provide some references for the optimization of the photonic devices and the design of high-sensitivity biosensors.

  13. Low-voltage, high-extinction-ratio, Mach-Zehnder silicon optical modulator for CMOS-compatible integration.

    Science.gov (United States)

    Ding, Jianfeng; Chen, Hongtao; Yang, Lin; Zhang, Lei; Ji, Ruiqiang; Tian, Yonghui; Zhu, Weiwei; Lu, Yangyang; Zhou, Ping; Min, Rui

    2012-01-30

    We demonstrate a carrier-depletion Mach-Zehnder silicon optical modulator, which is compatible with CMOS fabrication process and works well at a low driving voltage. This is achieved by the optimization of the coplanar waveguide electrode to reduce the electrical signal transmission loss. At the same time, the velocity and impedance matching are both considered. The 12.5 Gbit/s data transmission experiment of the fabricated device with a 2-mm-long phase shifter is performed. The driving voltages with the swing amplitudes of 1 V and 2 V and the reverse bias voltages of 0.5 V and 0.8 V are applied to the device, respectively. The corresponding extinction ratios are 7.67 and 12.79 dB.

  14. Polarization independent thermally tunable erbium-doped fiber amplifier gain equalizer using a cascaded Mach-Zehnder coupler.

    Science.gov (United States)

    Sahu, P P

    2008-02-10

    A thermally tunable erbium-doped fiber amplifier (EDFA) gain equalizer filter based on compact point symmetric cascaded Mach-Zehnder (CMZ) coupler is presented with its mathematical model and is found to be polarization dependent due to stress anisotropy caused by local heating for thermo-optic phase change from its mathematical analysis. A thermo-optic delay line structure with a stress releasing groove is proposed and designed for the reduction of polarization dependent characteristics of the high index contrast point symmetric delay line structure of the device. It is found from thermal analysis by using an implicit finite difference method that temperature gradients of the proposed structure, which mainly causes the release of stress anisotropy, is approximately nine times more than that of the conventional structure. It is also seen that the EDFA gain equalized spectrum by using the point symmetric CMZ device based on the proposed structure is almost polarization independent.

  15. Highly sensitive strain sensor based on helical structure combined with Mach-Zehnder interferometer in multicore fiber.

    Science.gov (United States)

    Zhang, Hailiang; Wu, Zhifang; Shum, Perry Ping; Dinh, Xuan Quyen; Low, Chun Wah; Xu, Zhilin; Wang, Ruoxu; Shao, Xuguang; Fu, Songnian; Tong, Weijun; Tang, Ming

    2017-04-18

    Optical fiber sensors for strain measurement have been playing important roles in structural health monitoring for buildings, tunnels, pipelines, aircrafts, and so on. A highly sensitive strain sensor based on helical structures (HSs) assisted Mach-Zehnder interference in an all-solid heterogeneous multicore fiber (MCF) is proposed and experimentally demonstrated. Due to the HSs, a maximum strain sensitivity as high as -61.8 pm/με was experimentally achieved. This is the highest sensitivity among interferometer-based strain sensors reported so far, to the best of our knowledge. Moreover, the proposed sensor has the ability to discriminate axial strain and temperature, and offers several advantages such as repeatability of fabrication, robust structure and compact size, which further benefits its practical sensing applications.

  16. Grazing angle Mach-Zehnder interferometer using reflective phase gratings and a polychromatic, un-collimated light source.

    Science.gov (United States)

    Kemble, Camille K; Auxier, Julie; Lynch, Susanna K; Bennett, Eric E; Morgan, Nicole Y; Wen, Han

    2010-12-20

    Normal incidence Talbot-Lau interferometers in x-ray applications have the drawbacks of low fringe visibility with polychromatic sources when the wave propagation distance is increased to achieve higher phase sensitivity, and when fabrication limits the attainable grating density. In contrast, reflective gratings illuminated at grazing angles have dramatically higher effective densities than their physical values. However, new designs are needed for far field interferometers using grazing angle geometry with incoherent light sources. We show that, with the appropriate design and choice of reflective phase gratings, there exist pairs of interfering pathways of exactly equal lengths independent of the incoming beam's incidence angle and wavelength. With a visible light grazing angle Mach-Zehnder interferometer, we show the conditions for achieving near ideal fringe visibility and demonstrate both absolute and differential phase-contrast imaging. We also describe the design parameters of an x-ray interferometer and key factors for its implementation.

  17. A recirculating delayed self-heterodyne method using a Mach-Zehnder modulator for kHz-linewidth measurement

    Science.gov (United States)

    Deng, Shuo; Li, Min; Gao, Hongyun; Dai, Yawen

    2016-09-01

    A laser linewidth measurement method which uses a Mach-Zehnder electro-optic modulator (MZM) is proposed in a loss-compensated recirculating delayed self-heterodyne interferometer (LC-RDSHI). Compared with the traditional acousto-optic modulator (AOM), the electro-optic modulator has the merits of broader bandwidth, lower insertion loss, higher extinction ratio and thus, a wider application. A theoretical analysis shows that the power spectrum curve of the novel measurement system is a Lorentzian line, which fits well with experiment. The linewidth is measured to be 137 ± 7 kHz at a frequency shift of 4 GHz. Measurement of a distributed feedback Bragg (DFB) laser has manifested that the linewidth broadens from 98.5 kHz to 137.4 kHz as the operating temperature changes by 16 °C. This work will allow investigation of narrow linewidth semiconductor and fiber laser stability.

  18. A comparison of delayed self-heterodyne interference measurement of laser linewidth using Mach-Zehnder and Michelson interferometers.

    Science.gov (United States)

    Canagasabey, Albert; Michie, Andrew; Canning, John; Holdsworth, John; Fleming, Simon; Wang, Hsiao-Chuan; Aslund, Mattias L

    2011-01-01

    Linewidth measurements of a distributed feedback (DFB) fibre laser are made using delayed self heterodyne interferometry (DHSI) with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are w(L) (MZI) = (1.6 ± 0.2) kHz and w(L) (MI) = (1.4 ± 0.1) kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

  19. Twist and temperature characteristics of the PD-NSN fiber structure based on in-line Mach-Zehnder interferometer

    Science.gov (United States)

    Dong, Yue; Sun, Chunran; Xiao, Han; Dong, Changbin; Jian, Shuisheng

    2017-01-01

    A novel polarization-dependent (PD) no core-single mode-no core (NSN) fiber structure for twist and temperature sensing has been experimentally investigated. The proposed structure simply involves a section of polarization maintain fiber sandwiched into NSN fiber structure, only using the splicing method. We have analyzed and demonstrated the transmission characteristics of the no core fiber (NCF) with the different lengths. Experimental results indicate that the extinction ratio of the PD-NSN fiber structure comb spectrum based on Mach-Zehnder interferometer (MZI) various with twist rate. The maximum sensitivity of 0.33904 dB/(rad/m) for range from -240° to 360° is achieved. The temperature sensitivity of the proposed structure reaches 41.89 pm/°C for temperature ranging from 20 to 70 °C in the experiment. By using the peak-wavelength discrimination method, the proposed sensor can overcome the temperature and twist cross-sensitivity effects.

  20. W-band OFDM photonic vector signal generation employing a single Mach-Zehnder modulator and precoding.

    Science.gov (United States)

    Xiao, Jiangnan; Li, Xinying; Xu, Yuming; Zhang, Ziran; Chen, Long; Yu, Jianjun

    2015-09-07

    We present a simple radio-over-fiber (RoF) link architecture for millimeter-wave orthogonal frequency division multiplexing (OFDM) transmission using only one Mach-Zehnder modulator (MZM) and precoding technique. In the transmission system, the amplitudes and the phase of the driving radio-frequency (RF) OFDM signal on each sub-carrier are precoded, to ensure that the OFDM signal after photodetector (PD) can be restored to original OFDM signal. The experimental results show that the bit-error ratios (BERs) of the transmission system are less than the forward-error-correction (FEC) threshold of 3.8 × 10(-3), which demonstrates that the generation of OFDM vector signal based on our proposed scheme can be employed in our system architecture.

  1. A Comparison of Delayed Self-Heterodyne Interference Measurement of Laser Linewidth Using Mach-Zehnder and Michelson Interferometers

    Directory of Open Access Journals (Sweden)

    Simon Fleming

    2011-09-01

    Full Text Available Linewidth measurements of a distributed feedback (DFB fibre laser are made using delayed self heterodyne interferometry (DHSI with both Mach-Zehnder and Michelson interferometer configurations. Voigt fitting is used to extract and compare the Lorentzian and Gaussian linewidths and associated sources of noise. The respective measurements are wL (MZI = (1.6 ± 0.2 kHz and wL (MI = (1.4 ± 0.1 kHz. The Michelson with Faraday rotator mirrors gives a slightly narrower linewidth with significantly reduced error. This is explained by the unscrambling of polarisation drift using the Faraday rotator mirrors, confirmed by comparing with non-rotating standard gold coated fibre end mirrors.

  2. Temperature effects of Mach-Zehnder interferometer using a liquid crystal-filled fiber

    DEFF Research Database (Denmark)

    Ho, Bo-Yan; Su, Hsien-Pin; Tseng, Yu-Pei;

    2015-01-01

    with a maximum interferometric contrast over 35dB. The temperature-induced resonant wavelength blue-shifts 70.4 nm for the MZI with an LC length of 9.79 mm and the wavelength temperature sensitivity of -1.55 nm/degrees C is easily achieved as the temperature increases from 25 degrees C to 77 degrees C. (C)2015...

  3. N-port strictly non-blocking optical router based on Mach-Zehnder optical switch for photonic networks-on-chip

    Science.gov (United States)

    Geng, Minming; Tang, Zhenhua; Chang, Kan; Huang, Xufang; Zheng, Jiali

    2017-01-01

    A universal method for constructing an N-port strictly non-blocking optical router based on 2×2 Mach-Zehnder optical switch for photonic networks-on-chip is proposed. By analyzing the routing table of the N-port optical router, the relationship between the optical links of port m→port n and port m→port n-1 is indicated, as well as the relationships between the block matrices of the N-port optical router. The strictly non-blocking property of the N-port optical router is proved by the contradiction method. The scale of the N-port optical router can be increased with the improvement of the performance of the Mach-Zehnder optical switch.

  4. Signal transmission in a human body medium-based body sensor network using a Mach-Zehnder electro-optical sensor.

    Science.gov (United States)

    Song, Yong; Hao, Qun; Zhang, Kai; Wang, Jingwen; Jin, Xuefeng; Sun, He

    2012-11-30

    The signal transmission technology based on the human body medium offers significant advantages in Body Sensor Networks (BSNs) used for healthcare and the other related fields. In previous works we have proposed a novel signal transmission method based on the human body medium using a Mach-Zehnder electro-optical (EO) sensor. In this paper, we present a signal transmission system based on the proposed method, which consists of a transmitter, a Mach-Zehnder EO sensor and a corresponding receiving circuit. Meanwhile, in order to verify the frequency response properties and determine the suitable parameters of the developed system, in-vivo measurements have been implemented under conditions of different carrier frequencies, baseband frequencies and signal transmission paths. Results indicate that the proposed system will help to achieve reliable and high speed signal transmission of BSN based on the human body medium.

  5. Signal Transmission in a Human Body Medium-Based Body Sensor Network Using a Mach-Zehnder Electro-Optical Sensor

    Directory of Open Access Journals (Sweden)

    Yong Song

    2012-11-01

    Full Text Available The signal transmission technology based on the human body medium offers significant advantages in Body Sensor Networks (BSNs used for healthcare and the other related fields. In previous works we have proposed a novel signal transmission method based on the human body medium using a Mach-Zehnder electro-optical (EO sensor. In this paper, we present a signal transmission system based on the proposed method, which consists of a transmitter, a Mach-Zehnder EO sensor and a corresponding receiving circuit. Meanwhile, in order to verify the frequency response properties and determine the suitable parameters of the developed system, in-vivo measurements have been implemented under conditions of different carrier frequencies, baseband frequencies and signal transmission paths. Results indicate that the proposed system will help to achieve reliable and high speed signal transmission of BSN based on the human body medium.

  6. 2-μm switchable dual-wavelength fiber laser with cascaded filter structure based on dual-channel Mach-Zehnder interferometer and spatial mode beating effect

    Science.gov (United States)

    Wang, Shun; Lu, Ping; Zhao, Shui; Liu, Deming; Yang, Wei; Zhang, Jiangshan

    2014-06-01

    We demonstrated a 2-μm switchable dual-wavelength fiber laser with cascaded filter structure based on dual-channel Mach-Zehnder interferometer and spatial mode beating effect. Few-mode fiber-embedded Sagnac ring configuration and a Mach-Zehnder interferometer are cascaded to form a multiwavelength filter for our previous 2-μm fiber laser. By adopting suitable fiber length and adjusting the polarization controller, we obtained a 2-μm dual-wavelength fiber laser with switchable wavelength interval. Experimental results revealed that the proposed laser shows higher quality and better stability compared with our previous work and it has potential applications in the fields of atmospheric propagation and microwave photonics.

  7. In Situ Observation of NaCI Crystal Growth by the Vapor Diffusion Method with a Mach-Zehnder Interferometer

    Institute of Scientific and Technical Information of China (English)

    ZHAO Jing; MIAO Hong; DUAN Li; KANG Qi; HE Ling-Hui

    2011-01-01

    Vapor diffusion experiments with different thicknesses of oil barriers are observed by a real-time optical diagnostic system consisting of a Mach Zehnder interferometer, a microscope and an image processor. Spatiotemporal analysis is first employed to extract the absolute concentration evolution and supersaturation during the entire crystallization process. The nucleation and crystal growth processes are then analyzed. It is found that the crystallization process can be easily classified into four stages in our experiments, according to the analysis of interferograms and the absolute concentration curve. This can help us understand the details of crystal growth. The rule of quality change of crystals with increasing thickness of oil barriers is also analyzed, and could be interpreted by the absolute concentration variation and crystallization phase diagram.%Vapor diffusion experiments with different thicknesses of oil barriers are observed by a real-time optical diagnostic system consisting of a Mach Zehnder interferometer,a microscope and an image processor.Spatiotemporal analysis is first employed to extract the absolute concentration evolution and supersaturation during the entire crystallization process.The nucleation and crystal growth processes are then analyzed.It is found that the crystallization process can be easily classified into four stages in our experiments,according to the analysis of interferograms and the absolute concentration curve.This can help us understand the details of crystal growth.The rule of quality change of crystals with increasing thickness of oil barriers is also analyzed,and could be interpreted by the absolute concentration variation and crystallization phase diagram.The growth of large crystals with a high degree of perfection is essential in the chemical industry and the protein field.Vapor diffusion[1] is the most widely used technique in protein crystallization,the principle of which is that the solution gradually reaches

  8. Multi-wavelength Operation of an Er3+-doped Fiber Laser at Room Temperature with a Novel Optical Fiber Mach-Zehnder Interferometer

    Institute of Scientific and Technical Information of China (English)

    AN Hong-Lin; LIN Xiang-Zhi; LIU Hong-Du

    2000-01-01

    A novel multi-wavelength erbium-doped fiber laser with a double-pass Mach-Zehnder fiber interferometer acting both as a comb filter and as a reflection mirror is demonstrated. The spatial hole burning effect introduced by the standing wave cavity configuration enables the simultaneous operation of multiple wavelengths in the homogeneously broadened erbium-doped fiber at room temperature. In the experiment, simultaneous oscillation of four wavelengths at room temperature has been obtained.

  9. Calibration-free and bias-drift-free microwave characterization of dual-drive Mach-Zehnder modulators using heterodyne mixing

    Science.gov (United States)

    Wang, Heng; Zhang, Shangjian; Zou, Xinhai; Zhang, Yali; Lu, Rongguo; Zhang, Zhiyao; Liu, Yong

    2016-03-01

    An electrical method is proposed for the microwave characterization of dual-drive Mach-Zehnder modulators based on heterodyne mixing. The proposed method utilizes the heterodyne products between the two-tone modulated optical sidebands and frequency-shifted optical carrier, and achieves calibration-free and bias-drift-free microwave measurement of dual-drive Mach-Zehnder modulators with high resolution electrical-domain techniques. Our method avoids the extra calibration for the photodetector and reduces half the bandwidth requirement for the photodetector and the electrical spectrum analyzer through carefully choosing a half frequency relationship of the two-tone modulation. Moreover, our measurement avoids the bias drifting problem due to the insensitivity to the bias phase of the modulator under test. The frequency-dependent modulation depths and half-wave voltages are measured for a commercial dual-drive Mach-Zehnder modulator with our method, which agree well with the results obtained by the conventional optical spectrum analysis method.

  10. Comparison of infinite and wedge fringe settings in Mach Zehnder interferometer for temperature field measurement

    Energy Technology Data Exchange (ETDEWEB)

    Haridas, Divya [Department of Physics, National Institute of Technology Calicut, Kerala, 673601 (India); P, Vibin Antony; Sajith, V.; Sobhan, C. B. [School of Nano Science and Technology, National Institute of Technology Calicut, Kerala, 673601 (India)

    2014-10-15

    Interferometric method, which utilizes the interference of coherent light beams, is used to determine the temperature distribution in the vicinity of a vertical heater plate. The optical components are arranged so as to obtain wedge fringe and infinite fringe patterns and isotherms obtained in each case were compared. In wedge fringe setting, image processing techniques has been used for obtaining isotherms by digital subtraction of initial parallel fringe pattern from deformed fringe pattern. The experimental results obtained are compared with theoretical correlations. The merits and demerits of the fringe analysis techniques are discussed on the basis of the experimental results.

  11. A fiber micro-vibration sensor based on single-mode fiber ring laser

    Institute of Scientific and Technical Information of China (English)

    Shenglai Zhen; Renzhu Liu; Benli Yu; Jing Zhang; Baogang Han

    2009-01-01

    A new micro-vibration sensor based on single-mode fiber ring laser is put forward. The Mach-Zehnder interferometric (MZI) detection technique is presented for interrogating laser frequency shift due to the measurand (piezoelectric transducer (PZT) is used to simulate the micro-vibration) induced laser cavity strain from both single- and multi-mode lasers. In the experiment, compared with multi-mode laser sensors, the single-mode laser sensor is proved to be a sensor with high resolution. When the PZT is driven by the analog signal (0.03 rad near 2 kHz), the signal-to-noise ratio (SNR) of output signal from the single-mode laser sensor is close to 55 dB and the sensitivity of the sensor is about 5 x 10-5 rad/Hz1/2.

  12. Improved silica-PLC Mach-Zehnder interferometer type optical switches with error dependence compensation of directional coupler

    Science.gov (United States)

    Wang, Jun; Yi, Jia; Guo, Lijun; Liu, Peng; Hall, Trevor J.; Sun, DeGui

    2017-03-01

    For the most popular structure of planer lightwave circuit (PLC) 2×2 thermo-optic switches, Mach-Zehnder interferometer (MZI), a full range of splitting ratio errors of directional coupler (DC) are investigated. All the parameters determining the splitting ratio are the dimensions and the refractive indices of the waveguide core and cladding layers. In this work, the coherent relationships between the waveguide size and the refractive indices are analyzed and then the error compensation between the width and the refractive index of waveguide core, and the controllable effect of over clad layer refractive index error upon the MZI-type optical switch are all discovered with numerical calculation and BPM simulations. Then, an MZI-type 2×2 thermo-optic switch having a higher error tolerance is established with the efficient optimizations of all the 3 dB-DC parameters. As a result, for the symmetric MZI switch, an insertion loss of 1.5 dB and optical extinction ratio of over 20 dB are realized for the average tolerance of±5.0%. An asymmetric arm optical phase and unequal arm lengths is also employed to improve the uniformities of insertion loss. The agreements between the designs and the experiments are recognized, leading to a wide adoption of practical silica-PLC optical switch products.

  13. Switchable and multi-wavelength linear fiber laser based on Fabry-Perot and Mach-Zehnder interferometers

    Science.gov (United States)

    Gutierrez-Gutierrez, J.; Rojas-Laguna, R.; Estudillo-Ayala, J. M.; Sierra-Hernández, J. M.; Jauregui-Vazquez, D.; Vargas-Treviño, M.; Tepech-Carrillo, L.; Grajales-Coutiño, R.

    2016-09-01

    In this manuscript, switchable and multi-wavelength erbium-doped fiber laser arrangement, based on Fabry-Perot (FPI) and Mach-Zehnder (MZI) interferometers is presented. Here, the FPI is composed by two air-microcavities set into the tip of conventional single mode fiber, this one is used as a partially reflecting mirror and lasing modes generator. And the MZI fabricated by splicing a segment of photonic crystal fiber (PCF) between a single-mode fiber section, was set into an optical fiber loop mirror that acts as full-reflecting and wavelength selective filter. Both interferometers, promotes a cavity oscillation into the fiber laser configuration, besides by curvature applied over the MZI, the fiber laser generates: single, double, triple and quadruple laser emissions with a signal to noise ratio (SNR) of 30 dB. These laser emissions can be switching between them from 1525 nm to 1534 nm by adjusting the curvature radius over the MZI. This laser fiber offers a wavelength and power stability at room temperature, compactness and low implementation cost. Moreover the linear laser proposed can be used in several fields such as spectroscopy, telecommunications and fiber optic sensing systems.

  14. Manufacture tolerance analysis and control for a polymer on-silicon Mach-Zehnder-interferometer-based electro-optic switch

    Institute of Scientific and Technical Information of China (English)

    ZHENG Chuan-tao; MA Chun-sheng; YAN Xin; CUI Zhan-chen; ZHANG Da-ming

    2011-01-01

    To enhance the electro-optic (EO) modulation efficiency and realize the impedance-matching, a polymer-on-silicon multi mode interference (MMI) Mach-Zehnder interferometer (MZI) -based electro-optic (EO) switch is designed and optimized.Under the central operation wavelength of 1550 nm, the driving voltages of the designed switch are O and ±1.375 V,respectively, with a short active region length of 5 mm, and the characteristic impedance of the electrode is about 49.6 Ω.The manufacture tolerance is analyzed for instructing the device fabrication. The results show that to realize ideal switching function, high fabrication accuracy on the buffer thickness, core thickness, electrode width and MMI wavegnide width is extremely required, and a small voltage drift of-0.03-0.05 V is also expected for reducing the crosstalk to less than -30 dB.The allowed 3 dB bandwidth is 60 nm, and within this spectrum range, the insertion loss and crosstalk are less than 6.71 dB and -30 dB, respectively.

  15. An in-line Mach-Zehnder Interferometer Using Thin-core Fiber for Ammonia Gas Sensing With High Sensitivity

    Science.gov (United States)

    Huang, Xinyue; Li, Xueming; Yang, Jianchun; Tao, Chuanyi; Guo, Xiaogang; Bao, Hebin; Yin, Yanjun; Chen, Huifei; Zhu, Yuhua

    2017-01-01

    Ammonia is an important indicator among environmental monitoring parameters. In this work, thin-core fiber Mach-Zehnder interferometer deposited with poly (acrylic acid) (PAA), poly (allyamine hydrochloride) (PAH) and single-walled carbon nanotubes (SWCNTs-COOH) sensing film for the detection of ammonia gas has been presented. The thin-core fiber modal interferometer was made by fusion splicing a small section of thin-core fiber (TCF) between two standard single mode fibers (SMF). A beam propagation method (BPM) is employed for the design of proposed interferometer and numerical simulation. Based on the simulation results, interferometer with a length of 2 cm of thin-core fiber is fabricated and experimentally studied. (PAH/PAA)2 + [PAH/(PAA + SWCNTs-COOH)]8 film is deposited on the outer surface of thin-core fiber via layer-by-layer (LbL) self-assembly technique. The gas sensor coated with (PAH/PAA)2 + [PAH/(PAA + SWCNTs-COOH)]8 film towards NH3 gas exposure at concentrations range from 1 to 960 ppm are analyzed and the sensing capability is demonstrated by optical spectrum analyzer (OSA). Experimental results show that the characteristic wavelength shift has an approximately linear relationship in the range 1–20 ppm, which is in accordance with the numerical simulation. Thus, this paper reveals the potential application of this sensor in monitoring low concentration NH3 gas. PMID:28378783

  16. An in-line Mach-Zehnder Interferometer Using Thin-core Fiber for Ammonia Gas Sensing With High Sensitivity

    Science.gov (United States)

    Huang, Xinyue; Li, Xueming; Yang, Jianchun; Tao, Chuanyi; Guo, Xiaogang; Bao, Hebin; Yin, Yanjun; Chen, Huifei; Zhu, Yuhua

    2017-04-01

    Ammonia is an important indicator among environmental monitoring parameters. In this work, thin-core fiber Mach-Zehnder interferometer deposited with poly (acrylic acid) (PAA), poly (allyamine hydrochloride) (PAH) and single-walled carbon nanotubes (SWCNTs-COOH) sensing film for the detection of ammonia gas has been presented. The thin-core fiber modal interferometer was made by fusion splicing a small section of thin-core fiber (TCF) between two standard single mode fibers (SMF). A beam propagation method (BPM) is employed for the design of proposed interferometer and numerical simulation. Based on the simulation results, interferometer with a length of 2 cm of thin-core fiber is fabricated and experimentally studied. (PAH/PAA)2 + [PAH/(PAA + SWCNTs-COOH)]8 film is deposited on the outer surface of thin-core fiber via layer-by-layer (LbL) self-assembly technique. The gas sensor coated with (PAH/PAA)2 + [PAH/(PAA + SWCNTs-COOH)]8 film towards NH3 gas exposure at concentrations range from 1 to 960 ppm are analyzed and the sensing capability is demonstrated by optical spectrum analyzer (OSA). Experimental results show that the characteristic wavelength shift has an approximately linear relationship in the range 1-20 ppm, which is in accordance with the numerical simulation. Thus, this paper reveals the potential application of this sensor in monitoring low concentration NH3 gas.

  17. Broad-band Mach-Zehnder interferometers as high performance refractive index sensors: theory and monolithic implementation.

    Science.gov (United States)

    Misiakos, K; Raptis, I; Salapatas, A; Makarona, E; Botsialas, A; Hoekman, M; Stoffer, R; Jobst, G

    2014-04-21

    Broad-band Mach-Zehnder interferometry is analytically described and experimentally demonstrated as an analytical tool capable of high accuracy refractive index measurements over a wide spectral range. Suitable photonic engineering of the interferometer sensing and reference waveguides result in sinusoidal TE and TM spectra with substantially different eigen-frequencies. This allows for the instantaneous deconvolution of multiplexed polarizations and enables large spectral shifts and noise reduction through filtering in the Fourier Transform domain. Due to enhanced sensitivity, optical systems can be designed that employ portable spectrum analyzers with nm range resolution without compromising the sensor analytical capability. Practical detection limits in the 10(-6)-10(-7) RIU range are achievable, including temperature effects. Finally, a proof of concept device is realized on a silicon microphotonic chip that monolithically integrates broad-band light sources and single mode silicon nitride waveguides. Refractive index detection limits rivaling that of ring resonators with externally coupled laser sources are demonstrated. Sensitivities of 20 μm/RIU and spectral shifts in the tens of a pm are obtained.

  18. Analysis of frequency noise properties of 729nm extended cavity diode laser with unbalanced Mach-Zehnder interferometer

    Science.gov (United States)

    Pham, Tuan M.; Čížek, Martin; Hucl, Václav; Lazar, Josef; Hrabina, Jan; Řeřucha, Šimon; Lešundák, Adam; Obšil, Petr; Filip, Radim; Slodička, Lukáš; Číp, Ondřej

    2016-12-01

    We report on the frequency noise investigation of a linewidth-suppressed Extended Cavity Diode Laser (ECDL), working at 729 nm. Since the ECDL is intended as an excitation laser for the forbidden transition in a trapped and laser cooled 40Ca+ ion, an Hz-level linewidth is required. We present the experimental design that comprises a two-stage linewidth narrowing and a facility for frequency and noise analysis. The linewidth is first narrowed with a phase lock loop of the ECDL onto a selected component of an optical frequency comb where the frequency noise was suppressed with a fast electronic servo-loop controller that drives the laser injection current with a high bandwidth. The second stage comprises locking the laser onto a selected mode of a high-finesse passive optical cavity. The frequency analysis used an unbalanced Mach-Zehnder interferometer with a fiber spool inserted in the reference arm in order to give a general insight into the signal properties by mixing two separated beams, one of them delayed by the spool, and processing it with a spectral analyzer. Such a frequency noise analysis reveals what are the most significant noises contributions to the laser linewidth, which is a crucial information in field of ion trapping and cooling. The presented experimental results show the effect of the linewidth narrowing with the first stage, where the linewidth of ECDL was narrowed down to a kHz level.

  19. Wide Spectral Characteristics of Si Photonic Crystal Mach-Zehnder Modulator Fabricated by Complementary Metal-Oxide-Semiconductor Process

    Directory of Open Access Journals (Sweden)

    Yosuke Hinakura

    2016-04-01

    Full Text Available Optical modulators for optical interconnects require a small size, small voltage, high speed and wide working spectrum. For this purpose, we developed Si slow-light Mach-Zehnder modulators via a 180 nm complementary metal-oxide-semiconductor process. We employed 200 μm lattice-shifted photonic crystal waveguides with interleaved p-n junctions as phase shifters. The group index spectrum of slow light was almost flat at ng ≈ 20 but exhibited ±10% fluctuation over a wavelength bandwidth of 20 nm. The cutoff frequency measured in this bandwidth ranged from 15 to 20 GHz; thus, clear open eyes were observed in the 25 Gbps modulation. However, the fluctuation in ng was reflected in the extinction ratio and bit-error rate. For a stable error-free operation, a 1 dB margin is necessary in the extinction ratio. In addition, we constructed a device with varied values of ng and confirmed that the extinction ratio at this speed was enhanced by larger ng up to 60. However, this larger ng reduced the cutoff frequency because of increased phase mismatch between slow light and radio frequency signals. Therefore, ng available for 25 Gbps modulation is limited to up to 40 for the current device design.

  20. Ultrafast Laser Fabrication of Novel Fiber Mach-Zehnder Interferometer Sensors and Its Cost-Effective Alternative Manufacturing Methods

    Institute of Scientific and Technical Information of China (English)

    Wang Sumei; Jiang Lan; Li Benye; Zhao Longjiang; Yang Jinpeng; Wang Mengmeng; Xiao Hai; Lu Yongfeng; Hai-Lung Tasi

    2011-01-01

    The recent progresses of fiber sensor fabrication in our group are reviewed. Novel inline fiber Mach-Zehnder interferometer (MZI) sensors with various structures are proposed and manufactured by femtosecond laser fabrication and fusion splicing for high-quality sensing of refractivity-sensitive parameters such as temperature, concentration, humidity, pressure, stress and strain., a) for an MZI sensor with a trench on a single-mode fiber, the refractive index (RI) sensitivity of acetone vapor is about 10 nm/RIU (refractive index unit) and the temperature sensitivity is 51.5 pm/℃ from 200 to 875℃ ; b) For an MZI consisting of two micro-air-cavities, the sensitivity is501.5 nm/RIU and the detection limit is 1. 994 × 10 RIU at the refractive index of 1.4; c) to reduce the fabrication cost, a new fusion-splicing based method is proposed to fabricate MZI sensors; the sensitivity is 664.57 nm/RIU witha detection limit of 1.5 x 10 RIU and its cost is tens of times cheaper than those of commercialized long period fiber Gratings; Also, 5×10 acetone vapors are successfully detected by the MZI sensors coated with zeolite thin films.

  1. Development of an ELT XAO testbed using a Mach-Zehnder wavefront sensor: calibration of the deformable mirror

    CERN Document Server

    Delacroix, Christian; Loupias, Magali; Thiébaut, Eric; Adjali, Louisa; Leger, Jonathan; Tallon, Michel

    2015-01-01

    (abridged) Extreme adaptive optics (XAO) encounters severe difficulties to cope with the high speed (>1kHz), high accuracy and high order requirements for future extremely large telescopes. An innovative high order adaptive optics system using a self-referenced Mach-Zehnder wavefront sensor (MZWFS) allows counteracting these limitations. This sensor estimates very accurately the wavefront phase at small spatial scale by measuring intensity differences between two outputs, with a $\\lambda /4$ path length difference between its two legs, but is limited in dynamic range due to phase ambiguity. During the past few years, such an XAO system has been studied by our team in the framework of 8-meter class telescopes. In this work, we report on our latest results with the XAO testbed recently installed in our lab, and dedicated to high contrast imaging with 30m-class telescopes (such as the E-ELT or the TMT). After reminding the principle of a MZWFS and describing the optical layout of our experiment, we will show the...

  2. Time-dependent simulation and analytical modelling of electronic Mach-Zehnder interferometry with edge-states wave packets

    Science.gov (United States)

    Beggi, Andrea; Bordone, Paolo; Buscemi, Fabrizio; Bertoni, Andrea

    2015-12-01

    We compute the exact single-particle time-resolved dynamics of electronic Mach-Zehnder interferometers based on Landau edge-states transport, and assess the effect of the spatial localization of carriers on the interference pattern. The exact carrier dynamics is obtained by solving numerically the time-dependent Schrödinger equation with a suitable 2D potential profile reproducing the interferometer design. An external magnetic field, driving the system to the quantum Hall regime with filling factor one, is included. The injected carriers are represented by a superposition of edge states, and their interference pattern—controlled via magnetic field and/or area variation—reproduces the one of (Ji et al 2003 Nature 422 415). By tuning the system towards different regimes, we find two additional features in the transmission spectra, both related to carrier localization, namely a damping of the Aharonov-Bohm oscillations with increasing difference in the arms length, and an increased mean transmission that we trace to the energy-dependent transmittance of quantum point contacts. Finally, we present an analytical model, also accounting for the finite spatial dispersion of the carriers, able to reproduce the above effects.

  3. A chitosan-coated humidity sensor based on Mach-Zehnder interferometer with waist-enlarged fusion bitapers

    Science.gov (United States)

    Ni, Kai; Chan, Chi Chiu; Chen, Lihan; Dong, Xinyong; Huang, Ran; Ma, Qifei

    2017-01-01

    A novel humidity sensor, which adopts a Mach-Zehnder interferometer (MZI) in normal single mode fiber (SMF) modified by the deposition of chitosan (a moisture-sensitive natural polymer) on the cladding, is proposed and experimentally demonstrated. It is fabricated by the fusion splicing of a segment between the two SMF with waist-enlarged fusion bitapers. This all-fiber MZI based on SMF incorporates intermodal interference between the core mode and the cladding mode. Due to the fact that it is sensitive to external refractive index and that the RI of the chitosan multi-layer film coat depends on the environmental humidity, the SMF-MZI with a chitosan coating layer of nanometer thickness is employed in humidity measuring. The sensitivity of ∼119.6 pm/RH (relative humidity unit) is achieved within the range from 10% to 90% on the experimental level. Moreover, the chitosan coat has good biocompatibility for in vivo biomedical applications like immunosensing and DNA hybridization detection in the near future.

  4. Mach-Zehnder Interferometer Biochemical Sensor Based on Silicon-on-Insulator Rib Waveguide with Large Cross Section.

    Science.gov (United States)

    Yuan, Dengpeng; Dong, Ying; Liu, Yujin; Li, Tianjian

    2015-08-28

    A high-sensitivity Mach-Zehnder interferometer (MZI) biochemical sensing platform based on Silicon-in-insulator (SOI) rib waveguide with large cross section is proposed in this paper. Based on the analyses of the evanescent field intensity, the mode polarization and cross section dimensions of the SOI rib waveguide are optimized through finite difference method (FDM) simulation. To realize high-resolution MZI read-out configuration based on the SOI rib waveguide, medium-filled trenches are employed and their performances are simulated through two-dimensional finite-difference-time domain (2D-FDTD) method. With the fundamental EH-polarized mode of the SOI rib waveguide with a total rib height of 10 μm, an outside rib height of 5 μm and a rib width of 2.5 μm at the operating wavelength of 1550 nm, when the length of the sensitive window in the MZI configuration is 10 mm, a homogeneous sensitivity of 7296.6%/refractive index unit (RIU) is obtained. Supposing the resolutions of the photoelectric detectors connected to the output ports are 0.2%, the MZI sensor can achieve a detection limit of 2.74 × 10(-6) RIU. Due to high coupling efficiency of SOI rib waveguide with large cross section with standard single-mode glass optical fiber, the proposed MZI sensing platform can be conveniently integrated with optical fiber communication systems and (opto-) electronic systems, and therefore has the potential to realize remote sensing, in situ real-time detecting, and possible applications in the internet of things.

  5. Violation of a Bell-like inequality by a combination of Rayleigh scattering with a Mach-Zehnder setup

    Science.gov (United States)

    Rother, Tom

    2016-07-01

    In this paper I propose a classical optics experiment that results in a maximum violation of a Bell-like inequality. The first part is concerned with the Bell-like inequality (the so-called CHSH-inequality) itself. Its importance and its maximum violation in Quantum Mechanics (QM) are discussed in detail by employing an abstract probability state concept in a 4-dim. but classical event space. A T-matrix that represents the integral part of a corresponding Green's function as well as a statistical operator that contains a negative quasi-probability can be related to the corresponding quantum mechanical experiment. It is demonstrated that the derivation and usage of the T-matrix and the Green's function is equivalent to what is known from classical scattering theory. It is shown moreover that the negative quasi-probability of the statistical operator may be interpreted as a sink of probabilities related to two single events of the considered 4-dim. event space. A necessary condition for the violation of the CHSH-inequality is derived and discussed afterwards. In the second part of this paper I discuss a modification of the 4-dim. event space considered in the first part. It is shown that a combination of conventional Rayleigh scattering with a Mach-Zehnder setup would be able to put this modification into practice. Thus it becomes possible to achieve a maximum violation of the CHSH-inequality, if formulated in terms of intensities, on a pure classical way. The combination of classical light scattering with correlation experiments such as proposed in this paper may open new ways to study and to use the violation of Bell-like inequalities in modern optics.

  6. Frequency measurement of THz waves by electro-optic sampling using Mach-Zehnder-modulator-based flat comb generator

    Science.gov (United States)

    Morohashi, Isao; Kirigaya, Mayu; Kaneko, Yuta; Katayama, Ikufumi; Sakamoto, Takahide; Sekine, Norihiko; Kasamatsu, Akifumi; Hosako, Iwao

    2016-02-01

    In the recent progress in terahertz (THz) devices, various kinds of source devices, such as resonant tunneling diodes, quantum cascade lasers and so forth, have been developed. Frequency measurement of THz radiations, which can operate in high speed and at room-temperature, is important for development of high-performance THz source devices. Recently, frequency measurement using optical combs are demonstrated by several groups. In these techniques, modelocked lasers (MLLs) are used for optical comb source, so that phase-locking techniques are required in order to stabilize the repetition frequency of the MLLs. On the other hand, a modulator-based optical comb generator has high accuracy and stability in the comb spacing, which is comparable to that of microwave signal driving the modulator. Thus it is suitable for frequency measurement of THz waves. In this paper, we demonstrated frequency measurement of THz waves using a Mach-Zehnder-modulator-based flat comb generator (MZ-FCG). The frequency measurement was carried out by an electro-optic (EO) sampling method, where an optical two-tone signal extracted from the optical comb generated by the MZ-FCG was used for the probe light. A 100 GHz signal generated by a W-band frequency multiplier and the probe beam collinearly traveled through an EO crystal, and beat signals between them were measured by a combination of a balanced photodetector and a spectrum analyzer. As a result, frequency measurement of the 100 GHz wave was successfully demonstrated, in which the linewidth of the beat signal was less than 1 Hz.

  7. Performance of a Mach-Zehnder based analogue data recording system for use with the Gas Cherenkov Detector on the NIF

    Science.gov (United States)

    Carpenter, A. C.; Herrmann, H. W.; Beeman, B. V.; Lopez, F. E.; Hernandez, J. E.

    2016-09-01

    This paper covers the performance of a high speed analogue data transmission system. This system uses multiple Mach- Zehnder optical modulators to transmit and record fusion burn history data for the Gas Cherenkov Detector (GCD) on the National Ignition Facility. The GCD is designed to measure the burn duration of high energy gamma rays generated by Deuterium-Tritium (DT) interactions in the NIF. The burn duration of DT fusion can be as short as 10ps and the optical photons generated in the gas Cherenkov cell are measured using a vacuum photodiode with a FWHM of 55ps. A recording system with a 3dB bandwidth of ≥10GHz and a signal to noise ratio of ≥5 for photodiode output voltage of 50mV is presented. The data transmission system uses two or three Mach-Zehnder modulators and an RF amplifier to transmit data optically. This signal is received and recorded by optical to electrical converts and a high speed digital oscilloscope placed outside of the NIF Target Bay. Electrical performance metrics covered include signal to noise ratio (SNR), signal to peak to peak noise ratio, single shot dynamic range, shot to shot dynamic range, system bandwidth, scattering parameters, are shown. Design considerations such as self-test capabilities, the NIF radiation environment, upgrade compatibility, Mach-Zehnder (MZ) biasing, maintainability, and operating considerations for the use of MZs are covered. This data recording system will be used for the future upgrade of the GCD to be used with a Pulse Dilation PMT, currently under development.

  8. Cascaded Mach-Zehnder wavelength filters in silicon photonics for low loss and flat pass-band WDM (de-)multiplexing.

    Science.gov (United States)

    Horst, Folkert; Green, William M J; Assefa, Solomon; Shank, Steven M; Vlasov, Yurii A; Offrein, Bert Jan

    2013-05-20

    We present 1-to-8 wavelength (de-)multiplexer devices based on a binary tree of cascaded Mach-Zehnder-like lattice filters, and manufactured using a 90 nm CMOS-integrated silicon photonics technology. We demonstrate that these devices combine a flat pass-band over more than 50% of the channel spacing with low insertion loss of less than 1.6 dB, and have a small device size of approximately 500 × 400 µm. This makes this type of filters well suited for application as WDM (de-)multiplexer in silicon photonics transceivers for optical data communication in large scale computer systems.

  9. Comparison of all-optical co- and counter-propagating high-speed signal processing in SOA-based Mach-Zehnder interferometers

    DEFF Research Database (Denmark)

    Bischoff, Svend; Buxens, Alvaro; Fischer, S.;

    2001-01-01

    The all-optical signal processing performance of a Mach-Zehnder interferometer (MZI) is investigated. Calculated switching windows are used to investigate and understand the physical mechanisms limiting the high speed performance. Especially, the co- and counter-propagating operation of the MZI...... is discussed and important differences in the performance for the two schemes are addressed. The non-regenerative all-optical clear and drop functionality is investigated for a 2, 4 and 8 x 40 Gbit/s signal, showing good performance in the co-propagating case. Regenerative simultaneous clear and drop...... functionality in a single MZI is demonstrated experimentally and compared to the large signal model predictions....

  10. In-line Mach-Zehnder interferometer composed of microtaper and long-period grating in all-solid photonic bandgap fiber

    Energy Technology Data Exchange (ETDEWEB)

    Wu Zhifang [Key Laboratory of Optical Information and Technology, Ministry of Education and Institute of Modern Optics, Nankai University, Tianjin 300071 (China); OPTIMUS, School of Electrical and Electronics Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637553 (Singapore); Liu Yange; Wang Zhi; Han Tingting; Li Shuo [Key Laboratory of Optical Information and Technology, Ministry of Education and Institute of Modern Optics, Nankai University, Tianjin 300071 (China); Jiang Meng; Ping Shum, Perry [OPTIMUS, School of Electrical and Electronics Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 637553 (Singapore); CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553 (Singapore); Quyen Dinh, Xuan [CINTRA CNRS/NTU/THALES, UMI 3288, Research Techno Plaza, 50 Nanyang Drive, Border X Block, Level 6, Singapore 637553 (Singapore); Thales Solutions Asia Pte Ltd, R and T Department, 28 Changi North Rise, Singapore 498755 (Singapore)

    2012-10-01

    We report a compact in-line Mach-Zehnder interferometer combining a microtaper with a long-period grating (LPG) in a section of all-solid photonic bandgap fiber. Theoretical and experimental investigations reveal that the interferometer works from the interference between the fundamental core mode and the LP{sub 01} cladding supermodes. The mechanism underlying the mode coupling caused by the microtaper can be attributed to a bandgap-shifting as the fiber diameter is abruptly scaled down. In addition, the interferometer designed to strengthen the coupling ratio of the long-period grating has a promising practical application in the simultaneous measurement of curvature and temperature.

  11. Design of Excess 3 to BCD code converter using electro-optic effect of Mach-Zehnder Interferometers for efficient data transmission

    Science.gov (United States)

    Kumar, Santosh; Chanderkanta; Amphawan, Angela

    2016-04-01

    Excess 3 code is one of the most important codes used for efficient data storage and transmission. It is a non-weighted code and also known as self complimenting code. In this paper, a four bit optical Excess 3 to BCD code converter is proposed using electro-optic effect inside lithium-niobate based Mach-Zehnder interferometers (MZIs). The MZI structures have powerful capability to switching an optical input signal to a desired output port. The paper constitutes a mathematical description of the proposed device and thereafter simulation using MATLAB. The study is verified using beam propagation method (BPM).

  12. Zero-Chirp Return-to-Zero Pulses Generation with Two Single-Driver z-Cut Mach-Zehnder Modulators

    Institute of Scientific and Technical Information of China (English)

    QIN Xi; CAO Ji-Hong; ZHANG Feng; WANG Mu-Guang; ZHANG Jian-Yong; JIAN Shui-Sheng

    2007-01-01

    A novel method is proposed to suppress the frequency chirp of single-driver z-cut Mach-Zehnder modulators.Theoretical analysis shows that by multiplying the output pulses of a half clock frequency driving single-driver z-cut modulator with the one delayed odd multiple bit duration,the frequency chirp can be removed entirely,and return-to-zero(RZ)pulses with duty cycles of about 25% and 56% are obtained.An experimental scheme is proposed to validate the proposed method.The experimental results show that perfect 40 GHz zero-chirp RZ pulses can be obtained by using this scheme.

  13. Switchable Multi-Wavelength Erbium-Doped Fiber Lasers Based on a Mach-Zehnder Interferometer Using a Twin-Core Fiber

    Institute of Scientific and Technical Information of China (English)

    FENG Su-Chun; XU Ou; LU Shao-Hua; JIAN Shui-Sheng

    2009-01-01

    A switchable multi-wavelength erbium-doped fiber ring laser based on a compact in-fiber Mach-Zehnder interferometer comb filter at room temperature is presented.The comb filter is formed by splicing a section of twin-core fiber between two single mode fibers.By adjusting the states of the polarization controller appropriately,the laser can be made to operate in stable single-,dual- and three-wavelength lazing states.The operation principle is based on spectral hole burning induced by the saturated effect and polarization hole burning.

  14. 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.

  15. 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

  16. 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.

  17. Thermo-optically driven silicon microring-resonator-loaded Mach-Zehnder modulator for low-power consumption and multiple-wavelength modulation

    Science.gov (United States)

    Gautam, Rajdeep; Kaneshige, Hiroki; Yamada, Hitoshi; Katouf, Redouane; Arakawa, Taro; Kokubun, Yasuo

    2014-02-01

    Low-power-consumption thermo-optically controlled silicon-microring-resonator loaded Mach-Zehnder modulators (MRR-loaded MZMs) are demonstrated. We experimentally characterized a single microring and cascaded-multiple-microring resonators coupled to one arm of a Mach-Zehnder interferometer (MZI). The driving power consumption of the proposed MZM is significantly reduced owing to the enhanced phase shift in the MRR. The device was fabricated on a silicon-on-insulator (SOI) waveguide structure, and each microring is equipped with TiN microheater for thermo-optic tuning. The coupling efficiency between the microring and a busline waveguide was regulated by varying the gap between two waveguides at a directional coupler. The power consumption of single microring and cascaded MRR-loaded MZMs was approximately 0.4 and 1 mW, respectively. The phase-shift enhancement factor of up to 19 with a maximum extinction ratio of 18 dB was obtained experimentally. Multiple-wavelength operation was also demonstrated in the cascaded MRR-loaded MZM.

  18. A novel scheme to generate 40-GHz CSRZ pulse trains using a 10-GHz dual-parallel Mach-Zehnder modulator

    Institute of Scientific and Technical Information of China (English)

    Yanfei Xing; Caiyun Lou

    2011-01-01

    A new technique to generate 40-GHz carrier-suppressed return-to-zero (CSRZ) optical pulse trains using only a 10-GHz dual-parallel Mach-Zehnder modulator (MZM) is presented and experimentally demonstrated. The spectrum of the generated CSRZ pulses is calculated by simulation and compared with conventional MZM-based RZ and CSRZ pulse trains. The experimental results demonstrate that CSRZ pulse trains are obtained, and that the carrier and the unwanted 20-GHz low-frequency component are suppressed by 25 dB. The technique can also be extended to 160-GHz CSRZ pulse generation when 40-GHz devices are employed.%@@ A new technique to generate 40-GHz carrier-suppressed return-to-zero (CSRZ) optical pulse trains using only a 10-GHz dual-parallel Mach-Zehnder modulator (MZM) is presented and experimentally demonstrated. The spectrum of the generated CSRZ pulses is calculated by simulation and compared with conventional MZM-based RZ and CSRZ pulse trains. The experimental results demonstrate that CSRZ pulse trains are obtained, and that the carrier and the unwanted 20-GHz low-frequency component are suppressed by 25 dB. The technique can also be extended to 160-GHz CSRZ pulse generation when 40-GHz devices are employed.

  19. Distributed Fiber-Optic Sensors for Vibration Detection.

    Science.gov (United States)

    Liu, Xin; Jin, Baoquan; Bai, Qing; Wang, Yu; Wang, Dong; Wang, Yuncai

    2016-07-26

    Distributed fiber-optic vibration sensors receive extensive investigation and play a significant role in the sensor panorama. Optical parameters such as light intensity, phase, polarization state, or light frequency will change when external vibration is applied on the sensing fiber. In this paper, various technologies of distributed fiber-optic vibration sensing are reviewed, from interferometric sensing technology, such as Sagnac, Mach-Zehnder, and Michelson, to backscattering-based sensing technology, such as phase-sensitive optical time domain reflectometer, polarization-optical time domain reflectometer, optical frequency domain reflectometer, as well as some combinations of interferometric and backscattering-based techniques. Their operation principles are presented and recent research efforts are also included. Finally, the applications of distributed fiber-optic vibration sensors are summarized, which mainly include structural health monitoring and perimeter security, etc. Overall, distributed fiber-optic vibration sensors possess the advantages of large-scale monitoring, good concealment, excellent flexibility, and immunity to electromagnetic interference, and thus show considerable potential for a variety of practical applications.

  20. Efficient regenerative wavelength conversion at 10Gbit/s over C- and L-band (80nm span) using a Mach-Zehnder interferometer with monolithically integrated semiconductor optical amplifiers

    DEFF Research Database (Denmark)

    Dülk, M.; Fischer, St.; Gamper, E.;

    2000-01-01

    A demonstration is presented of 10Gbit/s 2R regenerative wavelength up- and down-conversion within the C-band as well as up-conversion to the L-band using a monolithically integrated Mach-Zehnder interferometer module with semiconductor optical amplifiers (MZI-SOAs). The converted output signals ...

  1. All-optical Mach-Zehnder interferometer switching based on the phase-shift multiplication effect of an analog on the electromagnetically induced transparency effect

    Science.gov (United States)

    Wang, Boyun; Xiong, Liangbin; Zeng, Qingdong; Chen, Zhihong; Lv, Hao; Ding, Yaoming; Du, Jun; Yu, Huaqing

    2016-06-01

    We theoretically and numerically investigate all-optical Mach-Zehnder interferometer switching based on the phase-shift multiplication effect of an all-optical analog on the electromagnetically induced transparency effect. The free-carrier plasma dispersion effect modulation method is applied to improve the tuning rate with a response time of picoseconds. All observed schemes are analyzed rigorously through finite-difference time-domain simulations and coupled-mode formalism. Compared with no phase-shift multiplication effect, the average pump power of all-optical switching required to yield the π-phase shift difference decreases by 55.1%, and the size of the modulation region is reduced by 50.1% when the average pump power reaches 60.8 mW. This work provides a new direction for low-power consumption and miniaturization of microstructure integration light-controlled switching devices in optical communication and quantum information processing.

  2. A Core-Offset Mach Zehnder Interferometer Based on A Non-Zero Dispersion-Shifted Fiber and Its Torsion Sensing Application

    Science.gov (United States)

    Huerta-Mascotte, Eduardo; Sierra-Hernandez, Juan M.; Mata-Chavez, Ruth I.; Jauregui-Vazquez, Daniel; Castillo-Guzman, Arturo; Estudillo-Ayala, Julian M.; Guzman-Chavez, Ana D.; Rojas-Laguna, Roberto

    2016-01-01

    In this paper, an all-fiber Mach-Zehnder interferometer (MZI) based on a non-zero dispersion-shifted fiber (NZ-DSF) is presented. The MZI was implemented by core-offset fusion splicing one section of a NZ-DSF fiber between two pieces of single mode fibers (SMFs). Here, the NZ-DSF core and cladding were used as the arms of the MZI, while the core-offset sections acted as optical fiber couplers. Thus, a MZI interference spectrum with a fringe contrast (FC) of about 20 dB was observed. Moreover, its response spectrum was experimentally characterized to the torsion parameter and a sensitivity of 0.070 nm/° was achieved. Finally, these MZIs can be implemented in a compact size and low cost. PMID:27294930

  3. Coplanar-waveguide-based silicon Mach-Zehnder modulator using a meandering optical waveguide and alternating-side PN junction loading.

    Science.gov (United States)

    Dong, Po; Sinsky, Jeffrey H; Gui, Chengcheng

    2016-09-15

    We demonstrate a silicon Mach-Zehnder modulator with a coplanar waveguide transmission-line electrode structure using a meandering optical waveguide and alternating-side PN junction loading of the electrodes, which helps suppress the signal distortion caused by the parasitic slot-line mode and improves the electro-optic (EO) bandwidth. The silicon MZM exhibits a π-phase-shift voltage (Vπ) of 4.5 V with an EO 3 dB bandwidth of ∼20  GHz for a 5 mm long phase shifter. This achieved Vπ is among the lowest for silicon-only modulators with a bandwidth of more than 20 GHz.

  4. ALL OPTICAL IMPLEMENTATION OF HIGH SPEED AND LOW POWER REVERSIBLE FULL ADDER USING SEMICONDUCTOR OPTICAL AMPLIFIER BASED MACH-ZEHNDER INTERFEROMETER

    Directory of Open Access Journals (Sweden)

    R. M. Bommi

    2014-01-01

    Full Text Available In the recent years reversible logic design has promising applications in low power computing, optical computing, quantum computing. VLSI design mainly concentrates on low power logic circuit design. In the present scenario researchers have made implementations of reversible logic gates in optical domain for its low energy consumption and high speed. This study is all about designing a reversible Full adder using combination of all optical Toffoli and all optical TNOR and to compare it with the Full adder designed using all optical Toffoli gate in terms of optical cost. All optical TNOR gate can work as a replacement of existing NAND based All optical Toffoli Gate (TG. The gates are designed using Mach-Zehnder Interferometer (MZI based optical switch. The proposed system is developed with the basic of reversibility to design all optical full Adder implemented with CMOS transistors. The design is efficient in terms of both architecture and in power consumption.

  5. Generation of Carrier and Odd Sidebands Suppressed Optical MM-Wave with Signal Only on One Sideband Using an External Integrated Mach-Zehnder Modulator

    Institute of Scientific and Technical Information of China (English)

    XU Wei; XIN Xiang-Jun; ZHAO Tong-Gang; LING Jing; YU Chong-Xiu

    2009-01-01

    A novel scheme to generate millimeter(mm)-wave is proposed where the quadrupling of local radio frequency is formed by using an external integrated Mach-Zehnder modulator through intensity modulation or phase modulation.Generated optical mm-wave signal suffers from neither power periodical fading nor time shift of the sidebands as it is transmitted along the fiber.Receiver sensitivity of our 10Gbit/s radio-over-fiber system based on the proposed scheme is-28.3dBm under intensity modulation while-24dBm under phase modulation after 65 km transmission,and bit error rate is at 10~(-4) level after 100km transmission.Optical carrier in uplink is provided by the central station to simplify the base station,which also reduces the cost of the base station.

  6. Novel RF Interrogation of a Fiber Bragg Grating Sensor Using Bidirectional Modulation of a Mach-Zehnder Electro-Optical Modulator

    Science.gov (United States)

    Choi, Sang-Jin; Mao, Wankai; Pan, Jae-Kyung

    2013-01-01

    We propose and experimentally demonstrate the novel radio-frequency (RF) interrogation of a fiber Bragg grating (FBG) sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM). Based on the microwave photonic technique and active detection, the transfer function of the proposed system was obtained, and the time delay was calculated from the change in the free spectral range (FSR) at different wavelengths over the optimal measuring range. The results show that the time delay and the wavelength variation have a good linear relationship, with a gradient of 9.31 ps/nm. An actual measurement taken with a sensing FBG for temperature variation shows the relationship with a gradient of 0.93 ps/10 °C. The developed system could be used for FBG temperature or strain sensing and other multiplexed sensor applications. PMID:23820744

  7. A Core-Offset Mach Zehnder Interferometer Based on A Non-Zero Dispersion-Shifted Fiber and Its Torsion Sensing Application

    Directory of Open Access Journals (Sweden)

    Eduardo Huerta-Mascotte

    2016-06-01

    Full Text Available In this paper, an all-fiber Mach-Zehnder interferometer (MZI based on a non-zero dispersion-shifted fiber (NZ-DSF is presented. The MZI was implemented by core-offset fusion splicing one section of a NZ-DSF fiber between two pieces of single mode fibers (SMFs. Here, the NZ-DSF core and cladding were used as the arms of the MZI, while the core-offset sections acted as optical fiber couplers. Thus, a MZI interference spectrum with a fringe contrast (FC of about 20 dB was observed. Moreover, its response spectrum was experimentally characterized to the torsion parameter and a sensitivity of 0.070 nm/° was achieved. Finally, these MZIs can be implemented in a compact size and low cost.

  8. A Core-Offset Mach Zehnder Interferometer Based on A Non-Zero Dispersion-Shifted Fiber and Its Torsion Sensing Application.

    Science.gov (United States)

    Huerta-Mascotte, Eduardo; Sierra-Hernandez, Juan M; Mata-Chavez, Ruth I; Jauregui-Vazquez, Daniel; Castillo-Guzman, Arturo; Estudillo-Ayala, Julian M; Guzman-Chavez, Ana D; Rojas-Laguna, Roberto

    2016-06-10

    In this paper, an all-fiber Mach-Zehnder interferometer (MZI) based on a non-zero dispersion-shifted fiber (NZ-DSF) is presented. The MZI was implemented by core-offset fusion splicing one section of a NZ-DSF fiber between two pieces of single mode fibers (SMFs). Here, the NZ-DSF core and cladding were used as the arms of the MZI, while the core-offset sections acted as optical fiber couplers. Thus, a MZI interference spectrum with a fringe contrast (FC) of about 20 dB was observed. Moreover, its response spectrum was experimentally characterized to the torsion parameter and a sensitivity of 0.070 nm/° was achieved. Finally, these MZIs can be implemented in a compact size and low cost.

  9. Novel RF Interrogation of a Fiber Bragg Grating Sensor Using Bidirectional Modulation of a Mach-Zehnder Electro-Optical Modulator

    Directory of Open Access Journals (Sweden)

    Jae-Kyung Pan

    2013-07-01

    Full Text Available We propose and experimentally demonstrate the novel radio-frequency (RF interrogation of a fiber Bragg grating (FBG sensor using bidirectional modulation of a Mach-Zehnder electro-optical modulator (MZ-EOM. Based on the microwave photonic technique and active detection, the transfer function of the proposed system was obtained, and the time delay was calculated from the change in the free spectral range (FSR at different wavelengths over the optimal measuring range. The results show that the time delay and the wavelength variation have a good linear relationship, with a gradient of 9.31 ps/nm. An actual measurement taken with a sensing FBG for temperature variation shows the relationship with a gradient of 0.93 ps/10 °C. The developed system could be used for FBG temperature or strain sensing and other multiplexed sensor applications.

  10. A carboxy-methyl cellulose coated humidity sensor based on Mach-Zehnder interferometer with waist-enlarged bi-tapers

    Science.gov (United States)

    Ma, Qifei; Ni, Kai; Huang, Ran

    2017-01-01

    A fiber-optic Mach-Zehnder interferometer (MZI) humidity sensor is proposed, comprising a pair of waist-enlarged bi-tapers and carboxy-methyl cellulose (CMC) coating. The MZI utilizes intermodal interference between the core mode and cladding modes for the measurement of the effective refractive index (RI) of the CMC film that varies with surrounding humidity, through change in the sensor's interference pattern. The proposed sensor is linearly responsive to relative humidity (RH) within the humidity range from 70% RH to 85% RH, with maximum sensitivity of -0.8578 dB/% RH. The advantages of this sensor are its compact size and a facile fabrication process. More importantly, humidity sensitivity can be improved by changing the thickness of the CMC film, which makes this structure a highly promising for real-time, practical RH monitoring application.

  11. Temperature measurement of axisymmetric partially premixed methane/air flame in a co-annular burner using Mach-Zehnder interferometry

    Science.gov (United States)

    Irandoost, M. S.; Ashjaee, M.; Askari, M. H.; Ahmadi, S.

    2015-11-01

    In this paper partially premixed laminar methane/air co-flow flame is studied experimentally. Methane-air flame is established on an axisymmetric co-annular burner. The fuel-air jet flows from the central tube while the secondary air flows from the region between the inner and the outer tube. The aim is to investigate the flame characteristics for methane/air axisymmetric partially premixed flame using Mach-Zehnder interferometry. Different equivalence ratios (φ=1.4-2.2) and Reynolds numbers (Re=100-1200) are considered in the study. Flame generic visible appearance and the corresponding fringe map structures are also investigated. It is seen that the fringe maps are poorly influenced by equivalence ratio variations at constant Reynolds number but are significantly affected by Reynolds number variations in constant equivalence ratio. Temperatures obtained from optical techniques are compared with those obtained from thermocouples and good agreement is observed. It is concluded that the effect of Reynolds number increment on maximum flame temperature is negligible while equivalence ratio reduction increases maximum flame temperature substantially.

  12. Exploration of Whole Atmosphere Lidar: Mach-zehnder Receiver to Extend Fe Doppler Lidar Wind Measurements from the Thermosphere to the Ground

    Science.gov (United States)

    Smith, John A.; Chu, Xinzhao

    2016-06-01

    A receiver employing a field-widened Mach-Zehnder interferometer (MZI) is investigated for extending the wind measurement range of a narrowband Fe Doppler (372 nm) lidar from its existing measurement range in the mesosphere and lower thermosphere (MLT) down to the ground. This design uses the multiple transmitted frequencies available from the base Fe Doppler lidar in combination with an MZI receiver to make a measurement of the Doppler shift from Rayleigh-Mie scattering that is independent of aerosol backscatter ratio, temperature and pressure of the lidar volume and also independent of geometric overlap, the chopper function and any other factor affecting the signal in both MZI channels equally. A ratio is constructed from the three frequencies and two channels of the interferometer that exhibits a measurement performance of 1.75 times the Cramer-Rao lower bound, which is comparable to the dual MZI (DMZ) while preserving the insensitivity to backscatter spectrum of the quad MZI (QMZ). Using actual data obtained recently from the Fe Doppler lidar, we show the expected measurement performance of this whole atmosphere lidar instrument concept.

  13. Fabrication and evaluation of flexible Mach-Zehnder waveguide structure embedded in a poly(dimethylsiloxane) thin film using a proton microbeam

    Science.gov (United States)

    Parajuli, Raj Kumar; Saruya, Ryota; Akutzu, Naoki; Miura, Satoshi; Kada, Wataru; Kawabata, Shunsuke; Matsubara, Yoshinori; Satoh, Takahiro; Koka, Masashi; Yamada, Naoto; Kamiya, Tomihiro; Miura, Kenta; Hanaizumi, Osamu

    2016-06-01

    A flexible Mach-Zehnder (MZ) optical waveguide was fabricated in a poly(dimethylsiloxane) (PDMS) film by proton beam writing (PBW). A focused 750 keV proton microbeam was used to fabricate a 40 × 20 mm2 MZ optical waveguide structure with a width of 8 µm embedded in a PDMS film for the single-mode light propagation of infrared (IR) laser light. The structure was measured by ion-beam-induced luminescence (IBIL) analysis and the beam fluence was optimized according to the IBIL intensity obtained from the waveguide structure. The entire structure of the MZ waveguide functioned well, confirmed by observing the near-field pattern (NFP) with a tunable IR laser (1.55 µm) for different PDMS film conditions. The optical throughput measurements for different sample configurations were obtained under continuous mechanical stress and a relatively low optical loss was observed at an inclination angle of 16°. Our results suggest that the MZ waveguide can be used for optical interlink connections under continuous mechanical stress.

  14. Low driving voltage Mach-Zehnder interference modulator constructed from an electro-optic polymer on ultra-thin silicon with a broadband operation.

    Science.gov (United States)

    Sato, Hiromu; Miura, Hiroki; Qiu, Feng; Spring, Andrew M; Kashino, Tsubasa; Kikuchi, Takamasa; Ozawa, Masaaki; Nawata, Hideyuki; Odoi, Keisuke; Yokoyama, Shiyoshi

    2017-01-23

    An electro-optic (EO) polymer waveguide using an ultra-thin silicon hybrid has been designed and fabricated. The silicon core has the thickness of 50 nm and a width of 5 μm. The waveguide was completed after covering the cladding with the high temperature stable EO polymer. We have demonstrated a low half-wavelength voltage of 0.9 V at the wavelength of 1.55 μm by using a Mach-Zehnder interference modulator with TM mode operation. The measured modulation corresponded to an effective in-device EO coefficient of 165 pm/V. By utilizing the traveling-wave electrode on the modulator the high-frequency response was tested up to 40 GHz. The 3 dB modulation bandwidth was measured to be 23 GHz. In addition, the high frequency sideband spectral measurement revealed that a linear response of the modulation index against the RF power was confirmed up to 40 GHz signal.

  15. Design of an optical 4-bit binary to BCD converter using electro-optic effect of lithium niobate based Mach-Zehnder interferometers

    Science.gov (United States)

    Kumar, Santosh

    2017-07-01

    Binary to Binary coded decimal (BCD) converter is a basic building block for BCD processing. The last few decades have witnessed exponential rise in applications of binary coded data processing in the field of optical computing thus there is an eventual increase in demand of acceptable hardware platform for the same. Keeping this as an approach a novel design exploiting the preeminent feature of Mach-Zehnder Interferometer (MZI) is presented in this paper. Here, an optical 4-bit binary to binary coded decimal (BCD) converter utilizing the electro-optic effect of lithium niobate based MZI has been demonstrated. It exhibits the property of switching the optical signal from one port to the other, when a certain appropriate voltage is applied to its electrodes. The projected scheme is implemented using the combinations of cascaded electro-optic (EO) switches. Theoretical description along with mathematical formulation of the device is provided and the operation is analyzed through finite difference-Beam propagation method (FD-BPM). The fabrication techniques to develop the device are also discussed.

  16. Design and experimental verification of a novel Mie Doppler wind lidar based on all-fiber Mach-Zehnder frequency discriminator

    Science.gov (United States)

    Wang, Li; Gao, Fei; Wang, Jun; Yan, Qing; Chang, Bo; Hua, Dengxin

    2017-04-01

    Spaceborne Doppler wind lidar is currently one of the hot spots on the lidar technology. The all-fiber Mach-Zehnder interferometer (FMZI) as a frequency discriminator of Doppler wind lidar is proposed for profiling the atmospheric wind velocity. The frequency discriminator system parameters are optimized, and the retrieval method of wind velocity based on FMZI is deduced. The arm length difference of FMZI for the aerosol backscattering signal is optimized to be 74.8 cm at the laser wavelength of 532 nm. The maximum system sensitivity for wind profiling can reach up to 2.62%/(m/s), and the dynamic range of wind velocity is ±18.2 m/s. The system simulation shows that the detection range is up to 6.7 km for 1 m/s wind velocity error at a wind velocity of 15 m/s with laser energy of 250 mJ and telescope diameter of 406 mm. A rotating disc experimental system is designed to simulate the atmospheric wind field for verifying the feasibility of the system, and the results show that there is good agreement between the retrieved wind velocity and simulated wind velocity. The simulation and experimental test results show that FMZI is feasible as a frequency discriminator and can be suitable for direct Mie Doppler lidar, especially for satellite-based platform lidar due to its desirable characteristics, including its small volume, light weight, good stability and compact structure.

  17. Electro-optical time gating based on Mach-Zehnder modulator for multiple access interference elimination in optical code-division multiple access networks

    Science.gov (United States)

    Chen, Yinfang; Wang, Rong; Fang, Tao; Pu, Tao; Xiang, Peng; Zheng, Jilin; Zhu, Huatao

    2014-05-01

    An electro-optical time gating technique, which is based on an electrical return-to-zero (RZ) pulse driven Mach-Zehnder modulator (MZM) for eliminating multiple access interference (MAI) in optical code-division multiple access (OCDMA) networks is proposed. This technique is successfully simulated in an eight-user two-dimensional wavelength-hopping time-spreading system, as well as in a three-user temporal phase encoding system. Results show that in both systems the MAI noise is efficiently removed and the average received power penalty improved. Both achieve error-free transmissions at a bit rate of 2.5 Gb/s. In addition, we also individually discuss effects of parameters in two systems, such as the extinction ratio of the MZM, the duty cycle of the driven RZ pulse, and the time misalignment between the driven pulse and the decoded autocorrelation peak, on the output bit error rate performance. Our work shows that employing a common MZM as a thresholder provides another probability and an interesting cost-effective choice for a smart size, low energy, and less complex thresholding technique for integrated detection in OCDMA networks.

  18. Co-integrated 1.3µm hybrid III-V/silicon tunable laser and silicon Mach-Zehnder modulator operating at 25Gb/s.

    Science.gov (United States)

    Ferrotti, Thomas; Blampey, Benjamin; Jany, Christophe; Duprez, Hélène; Chantre, Alain; Boeuf, Frédéric; Seassal, Christian; Ben Bakir, Badhise

    2016-12-26

    In this paper, the 200mm silicon-on-insulator (SOI) platform is used to demonstrate the monolithic co-integration of hybrid III-V/silicon distributed Bragg reflector (DBR) tunable lasers and silicon Mach-Zehnder modulators (MZMs), to achieve fully integrated hybrid transmitters for silicon photonics. The design of each active component, as well as the fabrication process steps of the whole architecture are described in detail. A data transmission rate up to 25Gb/s has been reached for transmitters using MZMs with active lengths of 2mm and 4mm. Extinction ratios of respectively 2.9dB and 4.7dB are obtained by applying drive voltages of 2.5V peak-to-peak on the MZMs. 25Gb/s data transmission is demonstrated at 1303.5nm and 1315.8nm, with the possibility to tune the operating wavelength by up to 8.5nm in each case, by using metallic heaters above the laser Bragg reflectors.

  19. Compact-sized high-modulation-efficiency silicon Mach-Zehnder modulator based on a vertically dipped depletion junction phase shifter for chip-level integration.

    Science.gov (United States)

    Kim, Gyungock; Park, Jeong Woo; Kim, In Gyoo; Kim, Sanghoon; Jang, Ki-Seok; Kim, Sun Ae; Oh, Jin Hyuk; Joo, Jiho; Kim, Sanggi

    2014-04-15

    We present small-sized depletion-type silicon Mach-Zehnder (MZ) modulator with a vertically dipped PN depletion junction (VDJ) phase shifter based on a CMOS compatible process. The fabricated device with a 100 μm long VDJ phase shifter shows a VπLπ of ∼0.6  V·cm with a 3 dB bandwidth of ∼50  GHz at -2  V bias. The measured extinction ratios are 6 and 5.3 dB for 40 and 50  Gb/s operation under 2.5  Vpp differential drive, respectively. On-chip insertion loss is 3 dB for the maximum optical transmission. This includes the phase-shifter loss of 1.88  dB/100  μm, resulting mostly from the extra optical propagation loss through the polysilicon-plug structure for electrical contact, which can be readily minimized by utilizing finer-scaled lithography nodes. The experimental result indicates that a compact depletion-type MZ modulator based on the VDJ scheme can be a potential candidate for future chip-level integration.

  20. Frequency entanglement characterization of short-pulse pumped SPDC biphoton source with a Mach-Zehnder interferometer

    Science.gov (United States)

    Zhai, Yiwei; Dong, Ruifang; Li, Baihong; Quan, Runai; Wang, Mengmeng; Hou, Feiyan; Liu, Tao; Zhang, Shougang

    2017-06-01

    Frequency entangled biphoton sources have played an important role in quantum information. There are two key characteristics which determine the extent of their applications: the spectral indistinguishability and the degree of frequency entanglement. Previously, the spectral indistinguishability of the biphoton state is measured by the Hong-Ou-Mandel (HOM) interference visibility, whereas the degree of frequency entanglement is normally characterized with independent spectral measurements. However, these two quantum features have not been successfully measured with a single experimental setup. In this paper, we deduce the temporal distribution of a short-pulse pumped type-II spontaneous parametric down converted (SPDC) biphoton source and its relevant temporal entanglement parameter R t for operationally quantifying the degree of frequency entanglement. Furthermore, we theoretically and experimentally demonstrate, due to the inherent group delay, the difference between the signal and idler photons at the exit of the type-II nonlinear crystal, resulting in a HOM-shape dip at both sides of the center fringed envelope of the MZ interferometric coincidence diagram. By measuring the HOM-shape dip depth, the separation between the two sideband dips as well as the MZ fringed envelope width, both the spectral indistinguishability and the temporal entanglement parameter can thus be simultaneously quantified. This implementation provides us a unified and convenient method to characterize the frequency entanglement of the short-pulse pumped biphotons.

  1. Assessment of Fiber Chromatic Dispersion Based on Elimination of Second-Order Harmonics in Optical OFDM Single Sideband Modulation Using Mach Zehnder Modulator

    Science.gov (United States)

    Patel, Dhananjay; Singh, Vinay Kumar; Dalal, U. D.

    2016-07-01

    This work addresses the analytical and numerical investigations of the transmission performance of an optical Single Sideband (SSB) modulation technique generated by a Mach Zehnder Modulator (MZM) with a 90° and 120° hybrid coupler. It takes into account the problem of chromatic dispersion in single mode fibers in Passive Optical Networks (PON), which severely degrades the performance of the system. Considering the transmission length of the fiber, the SSB modulation generated by maintaining a phase shift of π/2 between the two electrodes of the MZM provides better receiver sensitivity. However, the power of higher-order harmonics generated due to the nonlinearity of the MZM is directly proportional to the modulation index, making the SSB look like a quasi-double sideband (DSB) and causing power fading due to chromatic dispersion. To eliminate one of the second-order harmonics, the SSB signal based on an MZM with a 120° hybrid coupler is simulated. An analytical model of conventional SSB using 90° and 120° hybrid couplers is established. The latter suppresses unwanted (upper/lower) first-order and second-order (lower/upper) sidebands. For the analysis, a varying quadrature amplitude modulation (QAM) Orthogonal Frequency Division Multiplexing (OFDM) signal with a data rate of 5 Gb/s is upconverted using both of the SSB techniques and is transmitted over a distance of 75 km in Single Mode Fiber (SMF). The simulation results show that the SSB with 120° hybrid coupler proves to be more immune to chromatic dispersion as compared to the conventional SSB technique. This is in tandem with the theoretical analysis presented in the article.

  2. Novel wideband microwave polarization network using a fully-reconfigurable photonic waveguide interleaver with a two-ring resonator-assisted asymmetric Mach-Zehnder structure.

    Science.gov (United States)

    Zhuang, Leimeng; Beeker, Willem; Leinse, Arne; Heideman, René; van Dijk, Paulus; Roeloffzen, Chris

    2013-02-11

    We propose and demonstrate a novel wideband microwave photonic polarization network for dual linear-polarized antennas. The polarization network is based on a waveguide-implemented fully-reconfigurable optical interleaver using a two-ring resonator-assisted asymmetric Mach-Zehnder structure. For microwave photonic signal processing, this structure is able to serve as a wideband 2 × 2 RF coupler with reconfigurable complex coefficients, and therefore can be used as a polarization network for wideband antennas. Such a device can equip the antennas with not only the polarization rotation capability for linear-polarization signals but also the capability to operate with and tune between two opposite circular polarizations. Operating together with a particular modulation scheme, the device is also able to serve for simultaneous feeding of dual-polarization signals. These photonic-implemented RF functionalities can be applied to wideband antenna systems to perform agile polarization manipulations and tracking operations. An example of such a interleaver has been realized in TriPleX waveguide technology, which was designed with a free spectral range of 20 GHz and a mask footprint of smaller than 1 × 1 cm. Using the realized device, the reconfigurable complex coefficients of the polarization network were demonstrated with a continuous bandwidth from 2 to 8 GHz and an in-band phase ripple of smaller than 5 degree. The waveguide structure of the device allows it to be further integrated with other functional building blocks of a photonic integrated circuit to realize on-chip, complex microwave photonic processors. Of particular interest, it can be included in an optical beamformer for phased array antennas, so that simultaneous wideband beam and polarization trackings can be achieved photonically. To our knowledge, this is the first-time on-chip demonstration of an integrated microwave photonic polarization network for dual linear-polarized antennas.

  3. Multi-step surface functionalization of polyimide based evanescent wave photonic biosensors and application for DNA hybridization by Mach-Zehnder interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Melnik, Eva [Health and Environment Department, Nano Systems, AIT Austrian Institute of Technology GmbH, Donau-City-Strasse 1, 1220 Vienna (Austria); Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, 1090 Vienna (Austria); Bruck, Roman [Health and Environment Department, Nano Systems, AIT Austrian Institute of Technology GmbH, Donau-City-Strasse 1, 1220 Vienna (Austria); Hainberger, Rainer, E-mail: rainer.hainberger@ait.ac.at [Health and Environment Department, Nano Systems, AIT Austrian Institute of Technology GmbH, Donau-City-Strasse 1, 1220 Vienna (Austria); Laemmerhofer, Michael, E-mail: michael.laemmerhofer@univie.ac.at [Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, 1090 Vienna (Austria)

    2011-08-12

    Highlights: {yields} We realize a biosensing platform for polyimide evanescent photonic wave sensors. {yields} We show that the surface functionalization via silanisation and biotinylation followed by streptavidin immobilization do not destroy or damage the thin polyimide film. {yields} A highly dense streptavidin layer enables the immobilisation of biotinylated ligands such as biotinylated ssDNA for the selective measurement of DNA hybridization. - Abstract: The process of surface functionalization involving silanization, biotinylation and streptavidin bonding as platform for biospecific ligand immobilization was optimized for thin film polyimide spin-coated silicon wafers, of which the polyimide film serves as a wave guiding layer in evanescent wave photonic biosensors. This type of optical sensors make great demands on the materials involved as well as on the layer properties, such as the optical quality, the layer thickness and the surface roughness. In this work we realized the binding of a 3-mercaptopropyl trimethoxysilane on an oxygen plasma activated polyimide surface followed by subsequent derivatization of the reactive thiol groups with maleimide-PEG{sub 2}-biotin and immobilization of streptavidin. The progress of the functionalization was monitored by using different fluorescence labels for optimization of the chemical derivatization steps. Further, X-ray photoelectron spectroscopy and atomic force microscopy were utilized for the characterization of the modified surface. These established analytical methods allowed to derive information like chemical composition of the surface, surface coverage with immobilized streptavidin, as well as parameters of the surface roughness. The proposed functionalization protocol furnished a surface density of 144 fmol mm{sup -2} streptavidin with good reproducibility (13.9% RSD, n = 10) and without inflicted damage to the surface. This surface modification was applied to polyimide based Mach-Zehnder interferometer

  4. Investigation of a field-widened Mach-Zehnder receiver to extend Fe Doppler lidar wind measurements from the thermosphere to the ground.

    Science.gov (United States)

    Smith, John A; Chu, Xinzhao

    2016-02-20

    A receiver employing a field-widened Mach-Zehnder interferometer (MZI) is investigated for extending the wind measurement range of a narrow-band Fe Doppler lidar operating at 372 nm from its existing measurement range in the mesosphere and lower thermosphere (MLT) down to near the ground. This design uses the multiple transmitted frequencies available from the base Fe Doppler lidar in combination with a novel MZI receiver to make a measurement of the Doppler shift that rejects the influence of atmospheric parameters such as the aerosol backscatter ratio, temperature, and pressure of the lidar volume and receiver parameters such as the geometric overlap, the chopper function, and any other factor affecting the proportion of the signal in both channels of the MZI equally. A ratio is constructed from the three frequencies and two channels of the interferometer that exhibits a measurement performance of 1.75 times the Cramer-Rao lower bound, which is comparable to the dual MZI (DMZ) while preserving the insensitivity to backscatter spectrum of the quad MZI (QMZ). In addition, we show how the use of multiple transmitted frequencies can yield a wind measurement wherein the accuracy is insensitive to the optical imperfection and misalignment of the MZI or any other factor that affects the contrast, though the precision is still impacted by the fringe contrast. Simply adding a second surface mirror of a particular thickness to the basic tilted MZI can allow the field of the MZI to be widened sufficiently for most resonance Doppler lidar receivers in operation today. Provided that the detection sensitivity in each channel is known, the original resonance fluorescence and Rayleigh scattering signals can be recovered by simply scaling and adding the contributions from both channels. Consequently, the wind and temperature from the MLT region and the temperature from the Rayleigh region can be derived alongside the Rayleigh Doppler wind measurement without compromising the

  5. Robust real-time self-mixing interferometric laser vibration sensor with embedded MEMS accelerometer

    Science.gov (United States)

    Zabit, Usman; Bernal, Olivier D.; Bosch, Thierry

    2012-06-01

    In this paper, we present a real-time implementation of a Self-Mixing (SM) interferometric laser diode (LD) based vibration sensor coupled with an embedded MEMS (microelectromechanical system) accelerometer. Such a sensor allows measuring correct target movements even when the LD based SM sensor is subject to extraneous movements. This results in a vibration sensing system that can be used for embedded applications as there is no more need of keeping the sensor stationary. Such an approach opens the way for the use of such laser sensors in conditions where the use of anti-vibration support is not available or possible. The proposed data fusion between a MEMS accelerometer and a LD based SM sensor results in a robust, compact and low-cost sensing system.

  6. 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.

  7. O tema da dualidade onda-partícula na educação profissional em radiologia médica a partir da simulação do interferômetro de Mach-Zehnder

    OpenAIRE

    Netto, Jader da Silva; Ostermann,Fernanda; Prado,Sandra Denise

    2011-01-01

    Neste artigo apresenta-se a aplicação de uma proposta de introdução de tópicos de física moderna a estudantes de um curso técnico na área da saúde e a avaliação de um software tipo bancada virtual que simula o interferômetro de Mach-Zehnder. A teoria sociointeracionista de Vygotsky e a ênfase curricular Ciência- Tecnologia-Sociedade foram tomados como referenciais. No âmbito do Mestrado Profissional em Ensino de Física da Universidade Federal do Rio Grande do Sul (UFRGS), fez-se a aplicação d...

  8. O tema da dualidade onda-partícula na educação profissional em radiologia médica a partir da simulação do interferômetro de Mach-Zehnder

    OpenAIRE

    Silva Neto,Jader da; Ostermann,Fernanda; Prado,Sandra Denise

    2011-01-01

    Neste artigo apresenta-se a aplicação de uma proposta de introdução de tópicos de física moderna a estudantes de um curso técnico na área da saúde e a avaliação de um software tipo bancada virtual que simula o interferômetro de Mach-Zehnder. A teoria sociointeracionista de Vygotsky e a ênfase curricular Ciência-Tecnologia-Sociedade foram tomados como referenciais. No âmbito do Mestrado Profissional em Ensino de Física da Universidade Federal do Rio Grande do Sul (UFRGS), fez-se a aplicação de...

  9. O tema da dualidade onda-partícula na educação profissional em radiologia médica a partir da simulação do interferômetro de Mach-Zehnder

    OpenAIRE

    Silva Neto,Jader da; Ostermann, Fernanda; Prado, Sandra Denise

    2011-01-01

    Neste artigo apresenta-se a aplicação de uma proposta de introdução de tópicos de física moderna a estudantes de um curso técnico na área da saúde e a avaliação de um software tipo bancada virtual que simula o interferômetro de Mach-Zehnder. A teoria sociointeracionista de Vygotsky e a ênfase curricular Ciência-Tecnologia-Sociedade foram tomados como referenciais. No âmbito do Mestrado Profissional em Ensino de Física da Universidade Federal do Rio Grande do Sul (UFRGS), fez-se a aplicação de...

  10. Transmission of Duobinary Signal in Optical 40 GHz Millimeter-Wave Radio-Over-Fiber Systems Utilizing Dual-Arm LiNbO3 Mach-Zehnder Modulator for Downstream

    Science.gov (United States)

    Dong-Nhat, Nguyen; Malekmohammadi, Amin

    2016-06-01

    In this paper, for the first time transmission of 2.5 Gb/s duobinary signal is investigated for the downlink direction in 40 GHz optical millimeter-wave generation or up-conversion, utilizing a dual-arm LiNb{O}_3 Mach-Zehnder modulator based on different modulation schemes, namely double- and single-sideband (DSB and SSB) and optical carrier suppression (OCS). The up-converted optical millimeter-wave employing OCS modulation scheme indicates the highest back-to-back received optical power and the smallest power penalty after long propagation in the single-mode fiber, in comparison to DSB and SSB. Directly modulated laser in association with OCS modulation scheme has been used to generate duobinary optical millimeter-wave signal in order to minimize the cost and complexity of the system.

  11. A tunable and switchable single-longitudinal-mode dual-wavelength fiber laser incorporating a reconfigurable dual-pass Mach-Zehnder interferometer and its application in microwave generation

    Science.gov (United States)

    Wang, Fei; Xu, En-Ming; Dong, Jian-Ji; Zhang, Xin-Liang

    2011-05-01

    A tunable and switchable single-longitudinal-mode (SLM) dual-wavelength fiber laser incorporating a reconfigurable dual-pass Mach-Zehnder interferometer (MZI) filter was proposed and demonstrated, which can be applied in microwave generation. By incorporating a high extinction ratio (ER) dual-pass MZI into an erbium-doped fiber ring cavity, SLM dual-wavelength lasing can be achieved even using a MZI with relatively little free spectrum range (FSR), and by beating the two wavelengths at a photodetector, a 9.76 GHz microwave signal with a 3-dB bandwidth of less than 10 kHz is obtained. Moreover, by direct linking the two outputs of the MZI, the high ER dual-pass MZI is easily reconfigured as a half FSR dual-pass MZI. Using this structure, switchable SLM dual-wavelength lasing can be conveniently realized.

  12. Optimal calculations for the transmission field of Mach-Zehnder channel waveguide switches%Mach-Zehnder条形光波导开关传输光场的优化计算

    Institute of Scientific and Technical Information of China (English)

    王超燕; 任一涛; 孟荣; 杨贵荣

    2011-01-01

    结合有效折射率法和有限差分光束传播法,实现对三维光波导结构计算的降维处理,运用二维有效折射率--有限差分光束传播方法(EI-FD-BPM)计算Mach-Zehnder光波导开关的传输光场;通过比较不同的光波导结构,优化得到具有较高输出能量的条形光波导光开关及其最佳的结构设计参数(横截面尺寸,器件结构及其尺寸等).表明用二维EI-FD-BPM方法代替三维有限差分光束传播(FD-BPM)方法进行光波导器件设计计算是简便可行的,能有效地减少计算量,节约计算时间,2个方法彼此间的结果差异(对小尺寸光波导结构)在1.5%以内,该方法可在具有较高的计算精度条件下为光波导器件的制备设计提供理论依据.%Calculations for three - dimensional optical waveguides are successfully simplified into two - dimensional ones by combining the effective index method (EIM) with the finite difference beam propagation method ( FD - BPM) , and the optical transmission field of Mach - Zehnder switches is calculated and analyzed by two - dimensional effective index - finite difference beam propagation method (EI - FD - BPM). The structure parameters (e. g. the cross section of channel waveguide, the switch structure and its size) of Mach - Zehnder waveguide switches are optimized and a waveguide switch with higher transmission efficiency is achieved. It is demonstrated that the use of a two - dimensional EI - FD - BPM is feasible and easier instead of a three - dimensional FD - BPM, which the result difference from the two methods for the small waveguide structure is within 1.5% ,and the calculations are reduced greatly, thus save time effectively. The approach provides theoretical guide for the designing and fabricating optical waveguide device at a high accuracy.

  13. 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.

  14. 多路集成有机聚合物光子学射频移相器%Multiple Output Photonic RF Phase Shifter using a novel polymer nested Mach- Zehnder modulators configuration

    Institute of Scientific and Technical Information of China (English)

    吴志浩

    2011-01-01

    This paper demonstrates a new integrated photonic RF phase shifters in the optically controlled phased array radar system and analyses the characteristics and the operation of the device . This device involves a nested Mach - Zehnder modulator and realizes the phase control of each unit by itself; low loss; high stability of the optical output intensity. Measurements of these devices show that multioutputs are independent and have highly linear RF phases over 360° with negligible RF power fluctuation ( below 3 dB ) at the modulation frequency.%本文简要介绍一种新型的集成光子学射频移相器,并对移相器的工作原理及特点进行分析。该新型移相器能够实现对每一阵元的相移量进行独立的调控、相移线性度大、插入损耗小、相移精度和幅度稳定度高等优点。结果表明,输出的射频信号的功率波动小于3dB,得到360°连续线性相移。

  15. A Complete Mathematical Model to Study the Characteristics of an Arbitrary Geometry LiNbO3 Structure for a High-Speed Mach-Zehnder Modulator for RADAR Applications

    Science.gov (United States)

    Raghuwanshi, Sanjeev Kumar; Singh, Mandeep; Sharma, Reena

    2017-06-01

    In graded index fiber, some degree of ellipticity is found. So it is important to study the effect which is little bit different from circularity. With the help of a new method illustrated in this paper, the core fields in case of non-circular profile can be written in a more simple way. The convenient feature of this method is that mode patterns can be found by simple analysis of algebraic equations. Ray path propagations in graded non-circular fibers were already studied by researchers. However, we provide the analysis of mode field using Wentzel-Kramers-Brillouin (WKB) method. In our analysis, the core fields of step index fibers are considered assuming the elliptical core-cladding interface followed by the limiting cases with focus approaches to infinity and focus approaches to zero. Finally, modes for parabolic profile with circular refractive index are discussed with the concept of bounded and leaky modes. The convenient feature of this method is that mode patterns can be analytically studied. In this paper, the main focus is also on the experimental characteristic of optical communication link and of their components. We give an introduction to optical fiber systems and various phenomena related to it. The phenomena of attenuation and dispersion are discussed elaborately and details are provided through experimental observation and verification. All the details about various topics mentioned above are concluded and verified through experiments. This type of an arbitrary optical waveguide structure has a vast application in microwave engineering where the high-speed Mach-Zehnder modulator is going to deployed.

  16. One Atomic Beam as a Detector of Classical Harmonic Vibrations with Micro Amplitudes and Low Frequencies

    CERN Document Server

    Wong, Werner

    2013-01-01

    We propose a simplest detector of harmonic vibrations with micro amplitudes and low frequencies, i.e. the detector consisting of one atomic beam. Here the atomic beam is induced by a plane harmonic wave and has a classical collective harmonic vibrations, which vibrant directions are perpendicular to the wave vectors of atomic beam. Compared with the detector consisting of atomic Mach-Zehnder interferometer, the new detector has two advantages: (1) it is suitable for the detection of the harmonic vibrations induced either by a longitudinal plane harmonic wave or by a transverse plane harmonic wave; (2) the quantum noise fluctuation of the atomic beam is exactly zero.

  17. 基于绝缘体上硅的一种改进的Mach-Zehnder声光调制器∗%An improved Mach-Zehnder acousto-optic mo dulator on a silicon-on-insulator platform

    Institute of Scientific and Technical Information of China (English)

    秦晨; 余辉; 叶乔波; 卫欢; 江晓清

    2016-01-01

    The interdigital transducer (IDT) of the traditional Mach-Zehnder (MZ) acousto-optic modulator on a silicon-on-insulator (SOI) platform is located outside its two arms. The crest and trough of the surface acoustic wave (SAW) are used to modulate the two arms of the MZ interferometer so as to achieve a high modulation efficiency. Therefore, the distance between the two arms must be odd multiples of half acoustic wavelength. However, since the substrate is usually not uniform, the wavelength of the SAW changes as it transmits through the surface of the device. As a result, the exact distance between the two arms is difficult to choose. On the other hand, the SAW losses a portion of energy after passing through the first arm of the MZ interferometer, so the modulation of the second arm becomes much weaker. To solve these problems, we propose a new structure where its IDT is situated in the middle of the two arms of the MZ interferometer. With this scheme, the two arms of the MZ interferometer are located exactly at the crest and the trough of the SAW, while they are modulated with equal strength. In this paper, we first use the finite element method to simulate the acoustic frequency and the surface displacement of the excited SAW. Then we deduce the refractive index variations of all layers according to their acousto-optic effects. After that, we analyze the influences of different factors on the acousto-optic modulation efficiency, including the type and size of waveguide, the thickness of zinc oxide (ZnO) layer, and the area it covers, the number of electrodes, etc. These parameters are accordingly optimized to enhance the modulation efficiency. Modeling result based on COMSOL Multiphysics indicates that when the width of the strip waveguide is 6 µm, the ZnO layer covers only the area under the IDT and has a thickness of 2.2 µm, and the number of the electrodes is 50, the effective refractive index variation of the waveguide reaches 4.08 × 10−4 provided that

  18. 一种改进的2×2 SOI Mach-Zehnder热光开关%An Improvement on 2×2 Silicon-on-Insulator Mach-Zehnder Thermo-Optical

    Institute of Scientific and Technical Information of China (English)

    杨笛; 余金中; 陈少武

    2008-01-01

    本文设计并制作了基于强限制多模干涉耦合器的2×2 SOI马赫-曾德热光开关.这种光开关采用了深刻蚀结构的多模干涉耦合器和输入/输出波导,较大地提高了干涉耦合器的性能并减少了连接耦合损耗.同时,在调制臂区域采用浅刻蚀结构,保持其单模调制状态.深刻蚀多模干涉耦合器具有优越的特性,在实验中测得不均衡度只有0.03 dB,插入损耗-0.6 dB.基于这种耦合器的新型热光开关,其插入损耗为-6.8 dB,其中包括光纤-波导耦合损耗-4.3 dB,开关时间为6.8 μs.%An improved 2×2 silicon-on-insulator Mach-Zehnder thermo-optical switch is designed and fabricated, which is based on strongly guided multimode interference couplers and single-mode phase-shifting arms. The multimode interference couplers and input/output waveguides are deeply etched to improve coupler performances and coupler-waveguide coupling efficiencies. However, shallow etching is used in the phase-shifting arms to guarantee single-mode property. The strongly guided coupler presents an attractive uniformity about 0.03 dB and a low propagation loss of -0.6 dB. The 2×2 switch shows an insertion loss as low as -6.8 dB, where the fiber-waveguide coupling loss of -4.3 dB is included, and the response-time is measured as short as 6.8 μs, which are much better than our previous results.

  19. 一种基于空芯光纤的微型Mach-Zehnder干涉仪%A Miniature Mach-Zehnder Interferometer Based on Hollow-core optical Fiber

    Institute of Scientific and Technical Information of China (English)

    闫小军; 刘艳; 李卫东

    2016-01-01

    Miniature interferometer has a high value in many micro-sensor areas. All-fiber Mach-Zehnder (MZ) interferometer based on hollow-core optical fiber has become a hot research point in recent years. The principle of light transmission and the mechanism of interference about the all-fiber MZ interferometer are researched. In refer⁃ence to the study of the previous air-core optical fiber interferometer, a novel MZ interferometer based on hol⁃low-core optical fiber is proposed. The transmission spectrum of the MZ interferometer in the experimental environ⁃ment is verified. Experimental results show that the free spectral range of the interferometer is about 140 nm when the wavelength is 1 550 nm and the sensor arm length of the interferometer is 50μm. The new MZ interferometer is simulated by using BPM method and simulation results accord with theoretical expectations. At the same time, the stimulated high-order mode is discussed and the transmission characteristics of radiation modes are obtained.%微型干涉仪在许多微传感领域有很高的应用价值。基于空芯光纤的全光纤Mach-Zehnder干涉仪成为了近些年研究的热点。研究了全光纤MZ干涉仪的传光原理及干涉机制。在参考前人对空芯光纤干涉仪研究的基础上,提出了一种基于空芯光纤的新型MZ干涉仪。搭建实验环境对该结构的MZ干涉仪的传输谱进行了验证。实验得出,当波长为1550 nm,传感臂长度为50μm时,自由波谱范围大约为140 nm。利用BPM法对该新型MZ干涉仪进行了仿真,仿真结果符合理论预期。同时对激发出的高阶模式进行了仿真探讨,并且得到辐射模的传输特性。

  20. Interferometric angular characterization of ion-exchanged glass binary phase plates

    Science.gov (United States)

    Moreno, Vicente; Prieto-Blanco, Xesús; Montero, Carlos; Crespo, José; Barral, David; Mouriz, Dolores; Nistal, María C.; Mateo, Eduardo F.; Liñares, Jesús

    2015-04-01

    An interferometric characterization of the phase angular shifting produced by rotation of an ion-exchanged glass binary phase plates is presented. The inverse WKB method is used as a starting point to fabricate the phase plates, because such a method can only characterize the phase shift for normal incidence of the light on the plate. A complete phase angular shifting characterization is made by a Mach-Zehnder interferometer where a four-step phase shifting method is used for acquisition of data and a modified Carre algorithm is applied to data processing. The theoretical phase shifting is calculated by using the phase accumulated by a plane wavefront propagating in an axial graded-index media modelling an ion-exchanged glass phase plate. Experimental results present a good agreement with theoretical predictions.

  1. Atom interferometry with lithium atoms: theoretical analysis and design of an interferometer, applications; Interferometrie atomique avec l'atome de lithium: analyse theorique et construction d'un interferometre, applications

    Energy Technology Data Exchange (ETDEWEB)

    Champenois, C

    1999-12-01

    This thesis is devoted to studies which prepared the construction of an atom Mach-Zehnder interferometer. In such an interferometer, the propagating waves are spatially separated, and the internal state of the atom is not modified. The beam-splitters are diffraction gratings, consisting of standing optical waves near-resonant with an atomic transition. We use the Bloch functions to define the atom wave inside the standing wave grating and thus explain the diffraction process in different cases. We developed a nearly all-analytical model for the propagation of an atom wave inside a Mach-Zehnder interferometer. The contrast of the signal is studied for many cases: phase or amplitude gratings, effects of extra paths, effects of the main mismatches, monochromatic or lightly polychromatic sources. Finally, we discuss three interferometric measurements we think very interesting. The first, the index of refraction of gas for atomic waves, is studied in detail, with numerical simulations. The other measures we propose deal with the electrical properties of lithium. We discuss the ultimate limit for the measure of the static electric polarizability of lithium by atomic interferometry. Then, we discuss how one could measure the possible charge of the lithium atom. We conclude that an optically cooled and collimated atom beam would improve precision. (author)

  2. Bend-insensitive fiber based vibration sensor

    Science.gov (United States)

    Xu, Yanping; Lu, Ping; Baset, Farhana; Bhardwaj, Vedula Ravi; Bao, Xiaoyi

    2014-05-01

    We report two novel fiber-optic vibration sensors based on standard telecom bend-insensitive fiber (BIF). A tapered BIF forming a fiber Mach-Zehnder interferometer could measure continuous and damped vibration from 1 Hz up to 500 kHz. An enclosed microcantilever is fabricated inside the BIF by chemical etching and fusion spliced with a readout singlemode fiber that exhibits a frequency range from 5 Hz to 10 kHz with high signal-to-noise ratio (SNR) up to 68 dB. The unique double cladding structure of the BIF ensures both sensors with advantages of compactness, high resistance to the external disturbance and stronger mechanical strength.

  3. Sensitive acoustic vibration sensor using single-mode fiber tapers.

    Science.gov (United States)

    Li, Yi; Wang, Xiaozhen; Bao, Xiaoyi

    2011-05-01

    Optical fiber sensors are a good alternative to piezoelectric devices in electromagnetic sensitive environments. In this study, we reported a fiber acoustic sensor based on single-mode fiber (SMF) tapers. The fiber taper is used as the sensing arm in a Mach-Zehnder interferometer. Benefiting from their micrometer dimensions, fiber tapers have shown higher sensitivities to the acoustic vibrations than SMFs. Under the same conditions, the thinnest fiber taper in this report, with a diameter of 1.7 µm, shows a 20 dB improvement in the signal to noise ratio as compared to that of an SMF. This acoustic vibration sensor can detect the acoustic waves over the frequencies of 30 Hz-40 kHz, which is limited by the acoustic wave generator in experiments. We also discussed the phase changes of fiber tapers with different diameters under acoustic vibrations.

  4. Comments on X. Yin, A. Wen, Y. Chen, and T. Wang, `Studies in an optical millimeter-wave generation scheme via two parallel dual-parallel Mach-Zehnder modulators', Journal of Modern Optics, 58(8), 2011, pp. 665-673

    Science.gov (United States)

    Hasan, Mehedi; Maldonado-Basilio, Ramón; Hall, Trevor J.

    2015-04-01

    Yin et al. have described an innovative filter-less optical millimeter-wave generation scheme for octotupling of a 10 GHz RF oscillator, or sedecimtupling of a 5 GHz RF oscillator using two parallel dual-parallel Mach-Zehnder modulators (DP-MZMs). The great merit of their design is the suppression of all harmonics except those of order ? (octotupling) or all harmonics except those of order ? (sedecimtupling), where ? is an integer. A demerit of their scheme is the requirement to set a precise RF signal modulation index in order to suppress the zeroth order optical carrier. The purpose of this comment is to show that, in the case of the octotupling function, all harmonics may be suppressed except those of order ?, where ? is an odd integer, by the simple addition of an optical ? phase shift between the two DP-MZMs and an adjustment of the RF drive phases. Since the carrier is suppressed in the modified architecture, the octotupling circuit is thereby released of the strict requirement to set the drive level to a precise value without any significant increase in circuit complexity.

  5. 基于光纤M-Z干涉的高灵敏度液体折射率传感器的实验研究%Experimentally Study on High-sensitivity Fiber-optic Refractometers Based on Mach-Zehnder Interference

    Institute of Scientific and Technical Information of China (English)

    周赢武

    2012-01-01

    A high sensitivity fiber-optic refractive index sensor based on Mach-Zehnder interferometer is proposed and fabricated. The relationship between the resonance wavelength shifts to the refractive index is studied with NaCl and glycerin solution. The experimental results show that the resonance wavelength shifts to longer wavelength with the increase of the refractive index of the surrounding media, and the wavelength shift is nearly linear to the refractive index with a sensitivity is of 4 086 nm/refractive-index as the refractive index ranges from 1. 333 to 1. 356. The sensor is easy to fabricate, compact, and will be usefull in chemical and biotechnological industry.%提出并制备了一种基于Mach-Zehnder干涉效应的高灵敏度光纤液体折射率传感器.分别利用NaCl溶液和甘油溶液,研究了传感器的透射光谱和外界介质折射率的关系.实验结果表明,随着周围介质折射率的增大,传感器干涉谱的极小值点对应的波长向长波方向漂移,在1.333~1.356的折射率变化范围内,极小值点对应的波长的漂移量和折射率的变化具有较好的线性关系,对应的灵敏度约为4086 nm/refractive-index.该传感器制作简单、结构紧凑,在生物和化学测量中具有较好的应用前景.

  6. 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.

  7. 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.

  8. 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.

  9. Atom interferometric measurement of ``Big G'' on the International Space Station

    Science.gov (United States)

    Ashwood, Elizabeth; Kurkcuoglu, Doga Murat; Clark, Charles W.; Edwards, Mark

    2016-05-01

    Recent measurements of Newton's universal gravitational constant (``Big G'') using atom interferometric methods have increased the uncertainty in the value of this important fundamental constant. We have developed tools for rapid simulation and evaluation of atom interferometer (AI) schemes that can be implemented in the Cold Atom Laboratory to be deployed to the International Space Station (ISS) in 2017. We have approximated the solution of the rotating-frame Gross-Pitaevskii equation in both one and three dimensions by using the Lagrangian Variational Method (LVM). The LVM trial wave function is a sum of Nc Gaussian clouds and we have derived equations of motion for the centers, widths, and phase parameters of these clouds. These equations of motion can be rapidly solved for many different AI designs enabling the estimation interferometer sensitivity and the effects of errors. We present two potential schemes as for measuring ``Big G'' on the ISS. These include a Mach-Zehnder-like scheme as well as a design similar to a Foucault Pendulum. Supported by NSF Grant PHY-1413768.

  10. Design, Fabrication and Characterization of LiNbO3-Based Integrated Optical Waveguide Mach-Zehnder Interferometer%铌酸锂基集成光波导马赫-曾德尔干涉仪的设计、制备及其特性的初步测试

    Institute of Scientific and Technical Information of China (English)

    陈方; 刘瑞鹏; 祁志美

    2011-01-01

    设计了具有推挽调制电极和消逝场敏感窗口的铌酸锂(LiNbO3)基集成光波导马赫-曾德尔干涉仪(MZI).利用标准微光机电系统(MOEMS)加工工艺结合高温钛内扩散法制备出三维单模LiNbO3光波导MZI阵列芯片,并对芯片进行了端面抛光,实现了光纤一波导端面输入和输出耦合,并初步调查了干涉仪芯片的相位调制特性,结果表明,在633 nm波长下其半波调制电压为5.61 V,干涉条纹对比度为0.62.当干涉仪芯片被用于生化探测时-这种电光调制功能可用于调节干涉仪芯片的初始相位差和识别其相位差的变化方向.%LiNbO3-based integrated optical waveguide Mach-Zehnder interferometer (MZI) with push-pull electrodes and evanescent field sensing window is developed. By using standard micro-opto-electro-mechanical-system (MOEMS) technique and titanium-indiffusion method, LiNbO3 monomode channel waveguide MZI array with modulating electrodes is fabricated. The near-field profile of the guided mode is detected after launching light into the LiNbO3 waveguide by fiber end-fire coupling. The phase-modulating property of the LiNbO3 MZI is investigated. The experimental results show that the phase modulation of the MZI is fully reversible and its half-wave voltage Vπ is 5.61 V, and fringe contrast is 0.62. The phase-modulating capability allows the initial phase of the MZI device to be a quadrature point to make the device work in the linear-response region for biochemical sensor.

  11. 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.

  12. Parallel phase modulation scheme for interferometric gravitational-wave detectors.

    Science.gov (United States)

    Hartman, M T; Quetschke, V; Tanner, D B; Reitze, D H; Mueller, G

    2014-11-17

    Advanced LIGO (aLIGO) requires multiple frequency sidebands to disentangle all of the main interferometer's length signals. This paper presents the results of a risk reduction experiment to produce two sets of frequency sidebands in parallel, avoiding mixed 'sidebands on sidebands'. Two phase modulation frequencies are applied to separate Electro-Optic Modulators (EOMs), with one EOM in each of the two arms of a Mach-Zehnder interferometer. In this system the Mach-Zehnder's arm lengths are stabilized to reduce relative intensity noise in the recombined carrier beam by feeding a corrective control signal back to the Rubidium Titanyl Phosphate (RTP) EOM crystals to drive the optical path length difference to zero. This setup's use of the RTP crystals as length actuators provides enough bandwidth in the feedback to meet arm length stability requirements for aLIGO.

  13. Laboratory feasibility study of a composite embedded fiber optic sensor for measurement of structural vibrations

    Science.gov (United States)

    Dube, C. M.; Wang, Tom D.; Melton, Robert G.; Jenson, David W.; Koharchik, Mike

    1988-02-01

    The feasibility is assessed of using fiber optic strain sensors embedded in a composite material to measure the magnitude and frequency of structural vibrations for control of flexible elements. This study demonstrates the ability to embed fiber optic strain sensors in a composite material, determines the performance of these sensors, identifies active control system architectures that are matched to the fiber optic system measurands to damp vibrations of large space structures, and estimates the stability achievable by these methods. A detailed laboratory study was performed using a wide band closed-loop-fiber Mach-Zehnder interferometer to conduct transverse vibration measurements on sub-scale composite elements with embedded fiber sensors. The interferometer detects vibrations by measuring the strain transferred by the composite to the embedded optical fiber. The strain sensor demonstrated the ability to track the vibrations of a cantilever beam over a frequency bandwidth ranging from approximately 5 Hz to almost 1000 Hz. The sensor was unable to detect dc strains because of thermal drift and laser power fluctuations. These factors produced a drift in the dc signal level, which was indistinguishable from static strain measurements. Beyond 1000 Hz, the composite element was unable to follow the drive mechanism. The noise equivalent strain was epsilon is approximately 10 to the minus 10th power.

  14. Photo-vibrational spectroscopy of solid and liquid chemicals using laser Doppler vibrometer.

    Science.gov (United States)

    Hu, Qi; Lim, Jacob Song Kiat; Liu, Huan; Fu, Yu

    2016-08-22

    Photoacoustic/photothermal spectroscopy is an established technique for trace detection of chemicals and explosives. However, prior sample preparation is required and the analysis is conducted in a sealed space with a high-sensitivity microphone or a piezo sensor coupled with a lock-in amplifier, limiting the technique to applications in a laboratory environment. Due to the aforementioned requirements, traditionally this technique may not be suitable for defense and security applications where the detection of explosives or hazardous chemicals is required in an open environment at a safe standoff distance. In this study, chemicals in various forms (membrane, powder and liquid) were excited by an intensity-modulated quantum cascade laser (QCL), while a laser Doppler vibrometer (LDV) based on the Mach-Zehnder interferometer was applied to detect the vibration signal resulting from the photocoustic/photothermal effect. The photo-vibrational spectrum obtained by scanning the QCL's wavelength in MIR range, coincides well with the corresponding spectrum obtained using typical FTIR equipment. The experiment demonstrated that the LDV is a capable sensor for applications in photoacoustic/photothermal spectroscopy, with potential to enable the detection of chemicals in open environment at safe standoff distance.

  15. A hybrid single-end-access MZI and Φ-OTDR vibration sensing system with high frequency response

    Science.gov (United States)

    Zhang, Yixin; Xia, Lan; Cao, Chunqi; Sun, Zhenhong; Li, Yanting; Zhang, Xuping

    2017-01-01

    A hybrid single-end-access Mach-Zehnder interferometer (MZI) and phase sensitive OTDR (Φ-OTDR) vibration sensing system is proposed and demonstrated experimentally. In our system, the narrow optical pulses and the continuous wave are injected into the fiber through the front end of the fiber at the same time. And at the rear end of the fiber, a frequency-shift-mirror (FSM) is designed to back propagate the continuous wave modulated by the external vibration. Thus the Rayleigh backscattering signals (RBS) and the back propagated continuous wave interfere with the reference light at the same end of the sensing fiber and a single-end-access configuration is achieved. The RBS can be successfully separated from the interference signal (IS) through digital signal process due to their different intermediate frequency based on frequency division multiplexing technique. There is no influence between these two schemes. The experimental results show 10 m spatial resolution and up to 1.2 MHz frequency response along a 6.35 km long fiber. This newly designed single-end-access setup can achieve vibration events locating and high frequency events response, which can be widely used in health monitoring for civil infrastructures and transportation.

  16. Interferometric measurement of the helical mode of a single photon

    Energy Technology Data Exchange (ETDEWEB)

    Galvez, E J; Coyle, L E; Johnson, E; Reschovsky, B J, E-mail: egalvez@colgate.edu [Department of Physics and Astronomy, Colgate University, 13 Oak Drive, Hamilton, NY 13346 (United States)

    2011-05-15

    We present measurements of the helical mode of single photons and do so by sending heralded photons through a Mach-Zehnder interferometer that prepares the light in a helical mode with topological charge one, and interferes it with itself in the fundamental non-helical mode. Masks placed after the interferometer were used to diagnose the amplitude and phase of the mode of the light. Auxiliary measurements verified that the light was in a non-classical state. The results are in good agreement with theory. The experiments demonstrate in a direct way that single photons carry the entire spatial helical-mode information.

  17. 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...

  18. New detection method for atrazine pesticides with the optical waveguide Mach-Zehnder immunosensor

    NARCIS (Netherlands)

    Schipper, E.F.; Bergevoet, A.J.H.; Kooyman, R.P.H.; Greve, J.

    1997-01-01

    Concentrations of analytes can be determined within a few minutes using on-line analysis of the immunobinding kinetics in a solid phase immunoassay. This approach has been applied to the detection of atrazine. Atrazine is detected, at concentrations around the European Community limit (0.1 ¿g/l) by

  19. Nearly optimal measurement schemes in a noisy Mach-Zehnder interferometer with coherent and squeezed vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Gard, Bryan T.; You, Chenglong; Singh, Robinjeet; Lee, Hwang; Corbitt, Thomas R.; Dowling, Jonathan P. [Louisiana State University, Baton Rouge, LA (United States); Mishra, Devendra K. [Louisiana State University, Baton Rouge, LA (United States); V.S. Mehta College of Science, Physics Department, Bharwari, UP (India)

    2017-12-15

    The use of an interferometer to perform an ultra-precise parameter estimation under noisy conditions is a challenging task. Here we discuss nearly optimal measurement schemes for a well known, sensitive input state, squeezed vacuum and coherent light. We find that a single mode intensity measurement, while the simplest and able to beat the shot-noise limit, is outperformed by other measurement schemes in the low-power regime. However, at high powers, intensity measurement is only outperformed by a small factor. Specifically, we confirm, that an optimal measurement choice under lossless conditions is the parity measurement. In addition, we also discuss the performance of several other common measurement schemes when considering photon loss, detector efficiency, phase drift, and thermal photon noise. We conclude that, with noise considerations, homodyne remains near optimal in both the low and high power regimes. Surprisingly, some of the remaining investigated measurement schemes, including the previous optimal parity measurement, do not remain even near optimal when noise is introduced. (orig.)

  20. Improving the acousto-optical interaction in a Mach-Zehnder interferometer

    DEFF Research Database (Denmark)

    Dühring, Maria Bayard; Sigmund, Ole

    2009-01-01

    A method for modeling the interaction of the mechanical field from a surface acoustic wave and the optical field in the waveguides of a Mach–Zehnder interferometer is presented. The surface acoustic wave is generated by an interdigital transducer using a linear elastic plane model of a piezoelect......A method for modeling the interaction of the mechanical field from a surface acoustic wave and the optical field in the waveguides of a Mach–Zehnder interferometer is presented. The surface acoustic wave is generated by an interdigital transducer using a linear elastic plane model...... of a piezoelectric, inhomogeneous material, and reflections from the boundaries are avoided by applying perfectly matched layers. The optical modes in the waveguides are modeled by time-harmonic wave equations for the magnetic field. The two models are coupled using stress-optical relations and the change...... bigger if the waveguides are kept single moded. It is furthermore shown that the difference increases more than ten times when the waveguides are buried below the surface, where the mechanical stresses have their maximum, and in the case where two interdigital transducers are used the difference...

  1. A novel and small curvature sensor based on butterfly-shape Mach-Zehnder interferometer

    Science.gov (United States)

    Chen, Mao-qing; Zhao, Yong; Lv, Ri-qing; Xia, Feng

    2017-04-01

    A novel hollow-core fiber (HCF) curvature sensor based on a tapered HCF sandwiched between two single mode fibers (Butterfly-Shape Structure) is proposed and experimentally demonstrated. The collapsed region around the first fusion interface excites the high-order modes, and the butterfly shape couples the high-order modes back into the core and interferes with the fundamental mode in the second fusion interface. Simulation of the butterfly-shape structure is carried out using the beam propagation method to determine an optimized size of sensing element. The experimental results show that the variation of the interference spectrum light intensity is almost linearly proportional to the change of curvature, and the curvature sensitivity and resolution of the proposed sensor can be up to -10.9041dB / m-1 and 0.000917m-1 respectively in the range from 0.387 to 1.285 m-1. The proposed curvature sensor is compact size, high sensitive, and inexpensive.

  2. Comment on "Particle path through a nested Mach-Zehnder interferometer"

    Science.gov (United States)

    Vaidman, L.

    2017-06-01

    Griffiths [Phys. Rev. A 94, 032115 (2016), 10.1103/PhysRevA.94.032115] analyzed, in the framework of a consistent histories interpretation, the controversy regarding the approach to the past of a quantum particle introduced by Vaidman [Phys. Rev. A 87, 052104 (2013), 10.1103/PhysRevA.87.052104]. I argue that Griffith's criticism of my approach using an analysis of experiments with weak probes is unfounded.

  3. Characterization of an Optically Integrated Mach-Zehnder Interferometer for the Detection of Biological Agents

    Science.gov (United States)

    1997-04-01

    nanotechnology for chemical and biochemical analysis. The integration of planar waveguides with these technologies can provide new methods of detection...Project Group 33 on automated biosensors. The work described herein is relevant to NATO Panel 7 in that it presents a novel method of chemical-optical...the analytes possess flu- P502399.PDF [Page: 12 of 62] UNCLASSIFIED 2 orescence labels) or by refractometry . Surface plasmon resonance (Refs. 1 and 2

  4. New detection method for atrazine pesticides with the optical waveguide Mach-Zehnder immunosensor

    NARCIS (Netherlands)

    Schipper, E.F.; Schipper, E.F.; Bergevoet, A.J.H.; Kooyman, R.P.H.; Greve, Jan

    1997-01-01

    Concentrations of analytes can be determined within a few minutes using on-line analysis of the immunobinding kinetics in a solid phase immunoassay. This approach has been applied to the detection of atrazine. Atrazine is detected, at concentrations around the European Community limit (0.1 ¿g/l) by

  5. Interferometric sensing platform with dielectric nanostructured thin films.

    Science.gov (United States)

    Celo, D; Post, E; Summers, M; Smy, T; Brett, M J; Albert, J

    2009-04-13

    A new interferometer-based optical sensing platform with nanostructured thin films of ZrO2 or TiO2 as sensing environment has been developed. With the application of an IC compatible Si(3)N(4) waveguide technology, Mach-Zehnder interferometer devices have been fabricated. The application of the glancing angle deposition technique allowed fabrication of nanostructured thin films as the optical sensing environment. Sensing ability of fabricated devices has been demonstrated through the refractive index measurement of a known gas. The transmission spectra and time response measurements have demonstrated a maximum phase shift of Delta phi=pi/10 and a |Delta P(out)|=0.65 dBm. Devices with TiO2 film on the sensing region performed much better than devices with ZrO2, with sensitivity twice as high.

  6. 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...

  7. 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...

  8. 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

  9. 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...

  10. 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.

  11. 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.

  12. 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...

  13. 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

  14. 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.

  15. Imaging and interferometric analysis of protein crystal growth

    Science.gov (United States)

    Raghunandan, Ranjini; Gupta, Anamika Sethia; Muralidhar, K.

    2008-04-01

    Protein crystals are grown under controlled temperature, concentration and vapor pressure conditions, usually by vapor diffusion, liquid-liquid diffusion and dialysis techniques. The present study examines the effects of protein concentration, drop size and reservoir height on the crystal growth of Hen Egg White Lysozyme (HEWL). Crystals are grown by the hanging drop vapor diffusion method using Modular VDX TM Plates. Due to the vapor pressure difference created between the protein drop and the reservoir, evaporation takes place till equilibrium is attained. Crystal formation takes place after a certain level of supersaturation is attained when the protein precipitates out in crystalline form. The observations revealed that the growth is faster for higher lysozyme concentration, smaller drop sizes and larger reservoir heights. The morphology of the crystals is viewed during the growth process using stereomicroscope. The number of crystals formed is the maximum for higher concentrations, drop sizes and reservoir heights. When the number of crystals formed is less, the size of the crystals is comparatively larger. The effect of evaporation of water vapor from the protein drop into the reservoir is studied using Mach-Zehnder interferometry. The recorded interferograms and shadowgraph images indicate the diffusion of condensed water into the reservoir. The radius of the drop is determined using the shadowgraph images of the growth process. The radius decreases with evaporation and the rate of decrease of radius is highest for higher protein concentrations, smaller drop sizes and larger reservoir heights.

  16. Chronology of Fabry-Perot Interferometer Fiber-Optic Sensors and Their Applications: A Review

    Directory of Open Access Journals (Sweden)

    Md. Rajibul Islam

    2014-04-01

    Full Text Available Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed.

  17. Chronology of Fabry-Perot interferometer fiber-optic sensors and their applications: a review.

    Science.gov (United States)

    Islam, Md Rajibul; Ali, Muhammad Mahmood; Lai, Man-Hong; Lim, Kok-Sing; Ahmad, Harith

    2014-04-24

    Optical fibers have been involved in the area of sensing applications for more than four decades. Moreover, interferometric optical fiber sensors have attracted broad interest for their prospective applications in sensing temperature, refractive index, strain measurement, pressure, acoustic wave, vibration, magnetic field, and voltage. During this time, numerous types of interferometers have been developed such as Fabry-Perot, Michelson, Mach-Zehnder, Sagnac Fiber, and Common-path interferometers. Fabry-Perot interferometer (FPI) fiber-optic sensors have been extensively investigated for their exceedingly effective, simple fabrication as well as low cost aspects. In this study, a wide variety of FPI sensors are reviewed in terms of fabrication methods, principle of operation and their sensing applications. The chronology of the development of FPI sensors and their implementation in various applications are discussed.

  18. 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.

  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. 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.

  1. 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

    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......), 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...... link with two optical modes propagating in a FMF, which illustrates its potential as a diagnostic tool for MDM systems....

  2. Design of transmission line driven slot waveguide Mach-Zehnder interferometers and application to analog optical links.

    Science.gov (United States)

    Witzens, Jeremy; Baehr-Jones, Thomas; Hochberg, Michael

    2010-08-02

    Slot waveguides allow joint confinement of the driving electrical radio frequency field and of the optical waveguide mode in a narrow slot, allowing for highly efficient polymer based interferometers. We show that the optical confinement can be simply explained by a perturbation theoretical approach taking into account the continuity of the electric displacement field. We design phase matched transmission lines and show that their impedance and RF losses can be modeled by an equivalent circuit and linked to slot waveguide properties by a simple set of equations, thus allowing optimization of the device without iterative simulations. We optimize the interferometers for analog optical links and predict record performance metrics (V(pi) = 200 mV @ 10 GHz in push-pull configuration) assuming a modest second order nonlinear coefficient (r(33) = 50 pm/V) and slot width (100 nm). Using high performance optical polymers (r(33) = 150 pm/V), noise figures of state of the art analog optical links can be matched while reducing optical power levels by approximately 30 times. With required optical laser power levels predicted at 50 mW, this could be a game changing improvement by bringing high performance optical analog link power requirements in the reach of laser diodes. A modified transmitter architecture allows shot noise limited performance, while reducing power levels in the slot waveguides and enhancing reliability.

  3. Refractometric sensor based on all-fiber coaxial Michelson and Mach-Zehnder interferometers for ethanol detection in fuel

    Science.gov (United States)

    Mosquera, L.; Osório, Jonas H.; Hayashi, Juliano G.; Cordeiro, Cristiano M. B.

    2011-01-01

    A refractometric sensor based on mechanically induced interferometers formed with long period gratings is reported. It is also shown two different setups based on a Michelson and Mach-Zender interferometer and its application to measure ethanol concentration in gasoline.

  4. Optical temperature sensor with enhanced sensitivity by employing hybrid waveguides in a silicon Mach-Zehnder interferometer

    DEFF Research Database (Denmark)

    Guan, Xiaowei; Wang, Xiaoyan; Frandsen, Lars Hagedorn

    2016-01-01

    of the fabricated sensor with silicon/polymer hybrid waveguides is measured to be 172 pm/°C, which is two times larger than a conventional all-silicon optical temperature sensor (∼80 pm/°C). Moreover, a design with silicon/titanium dioxide hybrid waveguides is by calculation expected to have a sensitivity as high...

  5. Photonic integrated Mach-Zehnder interferometer with an on-chip reference arm for optical coherence tomography.

    Science.gov (United States)

    Yurtsever, Günay; Považay, Boris; Alex, Aneesh; Zabihian, Behrooz; Drexler, Wolfgang; Baets, Roel

    2014-04-01

    Optical coherence tomography (OCT) is a noninvasive, three-dimensional imaging modality with several medical and industrial applications. Integrated photonics has the potential to enable mass production of OCT devices to significantly reduce size and cost, which can increase its use in established fields as well as enable new applications. Using silicon nitride (Si3N4) and silicon dioxide (SiO2) waveguides, we fabricated an integrated interferometer for spectrometer-based OCT. The integrated photonic circuit consists of four splitters and a 190 mm long reference arm with a foot-print of only 10 × 33 mm(2). It is used as the core of a spectral domain OCT system consisting of a superluminescent diode centered at 1320 nm with 100 nm bandwidth, a spectrometer with 1024 channels, and an x-y scanner. The sensitivity of the system was measured at 0.25 mm depth to be 65 dB with 0.1 mW on the sample. Using the system, we imaged human skin in vivo. With further optimization in design and fabrication technology, Si3N4/SiO2 waveguides have a potential to serve as a platform for passive photonic integrated circuits for OCT.

  6. Detailed experimental investigation of an all-active dual-order mode Mach-Zehnder wavelength converter

    DEFF Research Database (Denmark)

    Wolfson, David; Fjelde, Tina; Kloch, Allan;

    2000-01-01

    A new all-active DOMO converter has been assessed experimentally at 10 Gbit/s showing almost wavelength-independent performance for signal and CW wavelengths converting the entire EDFA window. Good performance has also been demonstrated at 20 Gbit/s.......A new all-active DOMO converter has been assessed experimentally at 10 Gbit/s showing almost wavelength-independent performance for signal and CW wavelengths converting the entire EDFA window. Good performance has also been demonstrated at 20 Gbit/s....

  7. Reconfigurable and ultra-sensitive in-line Mach-Zehnder interferometer based on the fusion of microfiber and microfluid

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Shecheng [Key Laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071 (China); Institute of Micro and Nano Optics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China); Zhang, Weigang, E-mail: zhangwg@nankai.edu.cn, E-mail: haozhang@nankai.edu.cn; Zhang, Hao, E-mail: zhangwg@nankai.edu.cn, E-mail: haozhang@nankai.edu.cn [Key Laboratory of Optical Information Science and Technology, Ministry of Education, Institute of Modern Optics, Nankai University, Tianjin 300071 (China); Zhang, Chonglei [Institute of Micro and Nano Optics, Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering, Shenzhen University, Shenzhen 518060 (China)

    2015-02-23

    A reconfigurable Mach-Zenhnder interferometer (MZI) based on a microfluidic cavity (MFC) constructed by embedding a microfiber between two segments of single-mode fibers with pre-designed lateral offset has been proposed and experimentally demonstrated. The MFC serves as an interference arm with an eccentric annular cross section and allows convenient sample (gas or liquids) replacement procedure. The microfiber works as the other interference arm that provides the proposed device with ease of reconstruction and also enhances the force sensitivity. The re-configurability and the ultra-wide tuning sensitivity range are demonstrated by immersing the MZI constructed with a 484 μm-long-MFC and a microfiber 44 μm in diameter in different droplets. Ultrahigh sensitivities of 34.65 nm/°C (∼88 380 nm/RIU) and −493.7 nm/N (∼−590 pm/με) are experimentally achieved using a droplet with a refractive index of ∼1.44.

  8. Violation of a Bell-like inequality by a combination of Rayleigh scattering with a Mach-Zehnder setup

    OpenAIRE

    Rother, Tom

    2016-01-01

    In this paper I propose a classical optics experiment that results in a maximum violation of a Bell-like inequality. The first part is concerned with the Bell-like inequality (the so-called CHSH-inequality) itself. Its importance and its maximum violation in Quantum Mechanics (QM) are discussed in detail by employing an abstract probability state concept in a 4-dim. but classical event space. A T-matrix that represents the integral part of a corresponding Green's function as well as a sta...

  9. Electro-optic Mach-Zehnder Interferometer based Optical Digital Magnitude Comparator and 1's Complement Calculator

    Science.gov (United States)

    Kumar, Ajay; Raghuwanshi, Sanjeev Kumar

    2016-06-01

    The optical switching activity is one of the most essential phenomena in the optical domain. The electro-optic effect-based switching phenomena are applicable to generate some effective combinational and sequential logic circuits. The processing of digital computational technique in the optical domain includes some considerable advantages of optical communication technology, e.g. immunity to electro-magnetic interferences, compact size, signal security, parallel computing and larger bandwidth. The paper describes some efficient technique to implement single bit magnitude comparator and 1's complement calculator using the concepts of electro-optic effect. The proposed techniques are simulated on the MATLAB software. However, the suitability of the techniques is verified using the highly reliable Opti-BPM software. It is interesting to analyze the circuits in order to specify some optimized device parameter in order to optimize some performance affecting parameters, e.g. crosstalk, extinction ratio, signal losses through the curved and straight waveguide sections.

  10. All-optical DAC using counter-propagating optical and electrical pulses in a Mach-Zehnder modulator.

    Science.gov (United States)

    Lowery, Arthur James

    2014-10-20

    A novel method of converting binary-level electrical pulses into multi-level optical pulses using only a conventional traveling-wave optical modulator is presented. The method provides low inter-pulse interference due to the counter-propagating pulses, low amplitude noise, and a timing jitter determined chiefly by the quality of the optical pulse source. The method only requires one electrical drive per modulator and provides low-jitter variable-amplitude optical pulses that are suitable for shaping into a wide variety of modulation formats using a programmable optical filter.

  11. 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.

  12. Fabrication of 2×2 Thermo-Optic Switches with Organic-Inorganic Hybrid Materials Prepared by Sol-Gel Technique

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    2×2 Mach-Zehnder interferometric thermo-optic switch was fabricated with organic/inorganic hybrid materials by sol-gel technique and direct UV patterning. The switching time of device was measured to be 4.2 ms and switching power 9.3 mW.

  13. 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...

  14. 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...

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Laser interferometric measurements of a laser-preionization-triggered spark column

    Science.gov (United States)

    Kimura, W. D.; Kushner, M. J.; Crawford, E. A.; Byron, S. R.

    1986-06-01

    A KrF laser (248 nm) is used to volume preionization trigger a 40-100 kV, greater than 10-kA, 100-ns spark gap switch. This method of triggering creates reproducible and axisymmetric spark columns having low temperature and spatial jitter. A short pulse (less than 5 ns) tunable dye laser and a Mach-Zehnder interferometer are used to obtain spatial and temporal measurements of the spark column. The spatial resolution of the interferograms is better than 5 microns. The fringe shifts of the interferograms are used to calculate the electron and heavy particle density distributions within the spark column as a function of time during the spark. Results are presented for sparks in 5 percent SF6/20 percent N2/75 percent He and 1 percent Xe/99 percent H2 gas mixtures. dc and pulsed self-breakdown voltages are also measured in order to provide a reference for the laser-triggered results. Data on laser-triggering reliability and spark breakdown delay time are also presented.

  1. Apparent contact angles induced by evaporation into air: interferometric measurements and lubrication-type modeling

    Science.gov (United States)

    Colinet, Pierre; Tsoumpas, Yannis; Dehaeck, Sam; Rednikov, Alexey

    2014-11-01

    For volatile liquids, finite contact angles on solid substrates can occur even in the case of perfect wetting, immobile contact lines and ideally smooth surfaces. This is a fluid-dynamic effect due to evaporation typically intensifying towards a small vicinity of the contact line. In the present talk, we first overview recent theoretical results on the subject, where we focus primarily on the case of diffusion-limited evaporation into air. The model is based upon the so-called de Gennes' paradigm, incorporating simultaneously the spreading coefficient and the disjoining pressure in the form of an inverse cubic law. Then we carry out comparison with experimental results for the contact angles of evaporating sessile drops of several perfectly-wetting HFE liquids of different volatility recently obtained by Mach-Zehnder interferometry. The scaling-type theoretical prediction for the apparent contact angle is found to be in good agreement with experimental measurements. Another model based upon the Kelvin effect (curvature dependence of the saturation conditions) is also briefly discussed, an important conceptual feature of which being that contact-line singularities (both evaporation- and motion-induced) can be fully regularized, in contrast with the first model. Support from ESA, BELSPO and FRS-FNRS is gratefully acknowledged.

  2. 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...

  3. 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.

  4. 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 ...

  5. 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.

  6. Vibration-displacement measurements with a highly stabilised optical fiber Michelson interferometer system

    Science.gov (United States)

    Xie, Fang; Ren, Junyu; Chen, Zhimin; Feng, Qibo

    2010-02-01

    A highly stabilised vibration-displacement measurement system, which employs fiber Bragg gratings (FBGs) to interleave two fiber Michelson interferometers that share the common-interferometric-optical path, is presented. The phase change in the interferometric signals of the two fiber Michelson interferometers have been tracked, respectively, with two electronic feedback loops. One of the fiber interferometers is used to stabilise the system by the use of an electronic feedback loop to compensate the environmental disturbances. The second fiber interferometer is used to perform the measurement task and employs another electronic feedback loop to track the phase change in the interferometric signal. The measurement system is able to measure vibration-displacement and provide the sense of direction of the displacement. The frequency range of the measured vibration-displacement is from 0.1 to 200 Hz and the measurement resolution is 10 nm.

  7. 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.

  8. 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.

  9. 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.

  10. 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...

  11. 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...

  12. 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.

  13. Applications of monolithic fiber interferometers and actively controlled fibers

    OpenAIRE

    Rugeland, Patrik

    2013-01-01

    The objective of this thesis was to develop applications of monolithic fiber devices and actively controlled fibers. A special twin-core fiber known as a ‘Gemini’ fiber was used to construct equal arm-length fiber interferometers, impervious to temperature and mechanical perturbations. A broadband add/drop multiplexer was constructed by inscribing fiber Bragg gratings in the arms of a Gemini Mach-Zehnder interferometer. A broadband interferometric nanosecond switch was constructed from a micr...

  14. 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.

  15. Twin suppression in digital holography by means of speckle reduction

    OpenAIRE

    2009-01-01

    A method for numerically removing the twin image in on-axis digital holography, based on multiple digital holograms, is discussed. The digital holograms under examination are captured experimentally using an in-line modified Mach-Zehnder interferometric setup and subsequently reconstructed numerically. The technique is suitable for both transmission and reflection geometry. Each individual hologram is recorded with a statistically independent diffuse illumination field. This is achieved by sh...

  16. 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.

  17. 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

  18. Waves & vibrations

    OpenAIRE

    Nicolas, Maxime

    2016-01-01

    Engineering school; This course is designed for students of Polytech Marseille, engineering school. It covers first the physics of vibration of the harmonic oscillator with damping and forcing, coupled oscillators. After a presentation of the wave equation, the vibration of strings, beams and membranes are studied.

  19. Mach-Zehnder Interferometer Thermo-Optical Modulator with Fast Response%快速响应SOI马赫曾德热光调制器

    Institute of Scientific and Technical Information of China (English)

    魏红振; 余金中; 夏金松; 严清峰; 刘忠立; 房昌水

    2002-01-01

    给出了Y分支MZI热光调制器的模型,实验研制了基于SOI(silicon-on-insulator)的MZI热光调制器,调制器的消光比为-16.5dB,开关的上升时间为10μs,下降时间为20μs,相应的功耗为0.39W.

  20. Characterization and Performance Comparison of Low-Voltage, High-Speed, Push-Pull and Traveling-Wave Silicon Mach-Zehnder Modulators

    Science.gov (United States)

    2014-03-27

    combination of the PNA internally changing to a mixer with more noise, and the low level of input optical power to the LCA ...loop and not closed-loop motors , so a recursive search algorithm was developed to ensure that the power optimization algorithm accurately and...location where the highest power reading was found. Because of the fact that the motor is open-loop, the position to which the algorithm returns is not

  1. All-Optical Regenerative OTDM Add/Drop Multiplexing at 40 Gbit/s using Monolithic InP Mach-Zehnder Interferometer

    DEFF Research Database (Denmark)

    Buxens, Alvaro A.; Clausen, Anders; Poulsen, Henrik Nørskov;

    2000-01-01

    We report a novel method for simultaneous add-drop multiplexing in OTDM systems which includes regenerative capabilities and perfect clearing of the drop channel time slot. The principle has been demonstrated at 40 Gb/s showing an excellent performance....

  2. Tunable and switchable multi-wavelength erbium-doped fiber ring laser based on a modified dual-pass Mach-Zehnder interferometer

    CERN Document Server

    Luo, Ai-Ping; Xu, Wen-Cheng

    2010-01-01

    A tunable and switchable multi-wavelength erbium-doped fiber ring laser based on a new type tunable comb filter is proposed and demonstrated. By adjusting the polarization controllers, dual-function operation of the channel spacing tunability and the wavelength switching (interleaving) can be readily achieved. Up to 29 stable lasing lines with 0.4 nm spacing and 14 lasing wavelengths with 0.8 nm spacing in 3 dB bandwidth were obtained at room temperature. In addition, the lasing output, including the number of the lasing lines, the lasing evenness and the lasing locations, can also be flexibly adjusted through the wavelength-dependent polarization rotation mechanism.

  3. A Novel Dynamic Wavelength Cross-connect Based on Mach-Zehnder Interferometer Optical ad/drop Multiplexer and Optical Space Switch

    DEFF Research Database (Denmark)

    Xueyan, Zheng; Liu, Fenghai

    1999-01-01

    We have proposed a novel dynamic WXC based on MZI-OADM. The advantages of this dynamic WXC are very low differential insertion loss, using less exchanging units than reported structures, and the ability to be integrated. In experiment, the three channels from the path with maximum OADMs in a 2×2 ...

  4. 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

  5. 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.

  6. 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.

  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. 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).

  9. 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...

  10. 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.

  11. 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.

  12. 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.

  13. 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 ...

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Good Vibrations

    OpenAIRE

    Panesar, Lucy

    2007-01-01

    Good Vibrations was a market research exercise conducted by Felicity (my alter-ego) and assistants to help develop marketing and packaging for an electro-therapeutic device (vibrator) used to treat hysteria and other female stress related disorders. It was a live art work commissioned by The Live Art Development Agency for East End Collaborations on 6th May 2007 and the South London Gallery for Bonkersfest on 2nd June 2007.

  1. Vibration sensors

    Science.gov (United States)

    Gupta, Amita; Singh, Ranvir; Ahmad, Amir; Kumar, Mahesh

    2003-10-01

    Today, vibration sensors with low and medium sensitivities are in great demand. Their applications include robotics, navigation, machine vibration monitoring, isolation of precision equipment & activation of safety systems e.g. airbags in automobiles. Vibration sensors have been developed at SSPL, using silicon micromachining to sense vibrations in a system in the 30 - 200 Hz frequency band. The sensing element in the silicon vibration sensor is a seismic mass suspended by thin silicon hinges mounted on a metallized glass plate forming a parallel plate capacitor. The movement of the seismic mass along the vertical axis is monitored to sense vibrations. This is obtained by measuring the change in capacitance. The movable plate of the parallel plate capacitor is formed by a block connected to a surrounding frame by four cantilever beams located on sides or corners of the seismic mass. This element is fabricated by silicon micromachining. Several sensors in the chip sizes 1.6 cm x 1.6 cm, 1 cm x 1 cm and 0.7 cm x 0.7 cm have been fabricated. Work done on these sensors, techniques used in processing and silicon to glass bonding are presented in the paper. Performance evaluation of these sensors is also discussed.

  2. Interferometric and schlieren characterization of the plasmas and shock wave dynamics during laser-triggered discharge in atmospheric air

    Science.gov (United States)

    Wei, Wenfu; Li, Xingwen; Wu, Jian; Yang, Zefeng; Jia, Shenli; Qiu, Aici

    2014-08-01

    This paper describes our efforts to reveal the underlying physics of laser-triggered discharges in atmospheric air using a Mach-Zehnder interferometer and schlieren photography. Unlike the hemispherical shock waves that are produced by laser ablation, bell-like morphologies are observed during laser-triggered discharges. Phase shifts are recovered from the interferograms at a time of 1000 ns by the 2D fast Fourier transform method, and then the values of the refractive index are deduced using the Abel inversion. An abundance of free electrons is expected near the cathode surface. The schlieren photographs visualize the formation of stagnation layers at ˜600 ns in the interaction zones of the laser- and discharge-produced plasmas. Multiple reflected waves are observed at later times with the development of shock wave propagations. Estimations using the Taylor-Sedov self-similar solution indicated that approximately 45.8% and 51.9% of the laser and electrical energies are transferred into the gas flow motions, respectively. Finally, numerical simulations were performed, which successfully reproduced the main features of the experimental observations, and provided valuable insights into the plasma and shock wave dynamics during the laser-triggered discharge.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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...

  15. 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.

  16. 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.

  17. Acoustic vibration sensor based on nonadiabatic tapered fibers.

    Science.gov (United States)

    Xu, Ben; Li, Yi; Sun, Miao; Zhang, Zhen-Wei; Dong, Xin-Yong; Zhang, Zai-Xuan; Jin, Shang-Zhong

    2012-11-15

    A simple and low-cost vibration sensor based on single-mode nonadiabatic fiber tapers is proposed and demonstrated. The environmental vibrations can be detected by demodulating the transmission loss of the nonadiabatic fiber taper. Theoretical simulations show that the transmission loss is related to the microbending of the fiber taper induced by vibrations. Unlike interferometric sensors, this vibration sensor does not need any feedback loop to control the quadrature point to obtain a stable performance. In addition, it has no requirement for the coherence of the light source and is insensitive to temperature changes. Experimental results show that this sensing system has a wide frequency response range from a few hertz to tens of kilohertz with the maximal signal to noise ratio up to 73 dB.

  18. Urban vibrations

    DEFF Research Database (Denmark)

    Morrison, Ann; Knudsen, L.; Andersen, Hans Jørgen

    2012-01-01

    In   this   paper   we   describe   a   field   study   conducted   with   a   wearable   vibration   belt   where   we   test   to   determine   the   vibration   intensity   sensitivity   ranges   on   a   large   diverse   group   of   participants   with   evenly   distributed  ages  and......   lab   studies   in   that   we   found   a   decreased   detection   rate   in   busy   environments.   Here   we   test   with   a   much   larger   sample   and   age   range,   and   contribute   with   the   first   vibration  sensitivity  testing  outside  the  lab  in  an  urban   public...

  19. Optical inspection of liquid crystal variable retarder inhomogeneities.

    Science.gov (United States)

    Vargas, Javier; Uribe-Patarroyo, Néstor; Antonio Quiroga, Juan; Alvarez-Herrero, Alberto; Belenguer, Tomás

    2010-02-01

    Liquid crystal variable retarders (LCVRs) are starting to be widely used in optical systems because of their capacity to provide a controlled variable optical retardance between two orthogonal components of incident polarized light or to introduce a known phase shifting (PS) between coherent waves, both by means of an applied voltage. Typically, the retardance or PS introduced by an LCVR is not homogeneous across the aperture. On the one hand, the LCVR glass substrates present a global bend that causes an overall variation of the retardance or PS. On the other hand, in the manufacturing process of an LCVR, there sometimes appears a set of micro-air bubbles that causes local retardance or PS inhomogeneities. In this work, we present an interferometric technique based on a Mach-Zehnder interferometer that is insensitive to vibrations and capable of inspecting and characterizing the LCVR's retardance or PS inhomogeneities. The feasibility of the proposed method is demonstrated in the experimental results, where the LCVR retardance is measured with an error of about 0.2 rad. The thickness of possible micro-air bubbles is obtained with a resolution of about 50 nm.

  20. Vibrational spectroscopy

    Science.gov (United States)

    Umesh P. Agarwal; Rajai Atalla

    2010-01-01

    Vibrational spectroscopy is an important tool in modern chemistry. In the past two decades, thanks to significant improvements in instrumentation and the development of new interpretive tools, it has become increasingly important for studies of lignin. This chapter presents the three important instrumental methods-Raman spectroscopy, infrared (IR) spectroscopy, and...

  1. Vibrating minds

    CERN Document Server

    2009-01-01

    Ed Witten is one of the leading scientists in the field of string theory, the theory that describes elementary particles as vibrating strings. This week he leaves CERN after having spent a few months here on sabbatical. His wish is that the LHC will unveil supersymmetry.

  2. 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.

  3. Simultaneous Static Strain, Temperature and Vibration Measurement Using an Integrated FBG/EFPI Sensor

    Institute of Scientific and Technical Information of China (English)

    曾祥楷; 饶云江

    2001-01-01

    A novel technique for simultaneous measurement of static strain, temperature and vibration in health monitoring of structures is demonstrated using an integrated in-fibre Bragg grating (FBG)/extrinsic Fabry-Pérot interferometer (EFPI) sensor. The EFPI sensor provides static strain and vibration information simultaneously by using the channel-spectrum method and the low-coherence interferometric technique, respectively. The FBG sensor is used for temperature measurement. The experimental results show that a static-strain accuracy of l20με, a temperature accuracy of +l℃ and a vibration resolution of 1 nm have been achieved with a good repeatability.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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

  9. 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

  10. 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.

  11. 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.

  12. 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

  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. 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.

  15. 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.

  16. 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...

  17. 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...

  18. 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.

  19. An Atomic Gravitational Wave Interferometric Sensor (AGIS)

    Energy Technology Data Exchange (ETDEWEB)

    Dimopoulos, Savas; /Stanford U., Phys. Dept.; Graham, Peter W.; /SLAC; Hogan, Jason M.; Kasevich, Mark A.; /Stanford U., Phys. Dept.; Rajendran, Surjeet; /SLAC /Stanford U., Phys. Dept.

    2008-08-01

    We propose two distinct atom interferometer gravitational wave detectors, one terrestrial and another satellite-based, utilizing the core technology of the Stanford 10m atom interferometer presently under construction. Each configuration compares two widely separated atom interferometers run using common lasers. The signal scales with the distance between the interferometers, which can be large since only the light travels over this distance, not the atoms. The terrestrial experiment with baseline {approx} 1 km can operate with strain sensitivity {approx} 10{sup -19}/{radical}Hz in the 1 Hz-10 Hz band, inaccessible to LIGO, and can detect gravitational waves from solar mass binaries out to megaparsec distances. The satellite experiment with baseline {approx} 1000 km can probe the same frequency spectrum as LISA with comparable strain sensitivity {approx} 10{sup -20}/{radical}Hz. The use of ballistic atoms (instead of mirrors) as inertial test masses improves systematics coming from vibrations, acceleration noise, and significantly reduces spacecraft control requirements. We analyze the backgrounds in this configuration and discuss methods for controlling them to the required levels.

  20. 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.

  1. Theory of vibration protection

    CERN Document Server

    Karnovsky, Igor A

    2016-01-01

    This text is an advancement of the theory of vibration protection of mechanical systems with lumped and distributed parameters. The book offers various concepts and methods of solving vibration protection problems, discusses the advantages and disadvantages of different methods, and the fields of their effective applications. Fundamental approaches of vibration protection, which are considered in this book, are the passive, parametric and optimal active vibration protection. The passive vibration protection is based on vibration isolation, vibration damping and dynamic absorbers. Parametric vibration protection theory is based on the Shchipanov-Luzin invariance principle. Optimal active vibration protection theory is based on the Pontryagin principle and the Krein moment method. The book also contains special topics such as suppression of vibrations at the source of their occurrence and the harmful influence of vibrations on humans. Numerous examples, which illustrate the theoretical ideas of each chapter, ar...

  2. 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...

  3. 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).

  4. 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.

  5. 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...

  6. 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...

  7. 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 ...

  8. 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...

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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).

  5. 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.

  6. 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...

  7. Cryogenically cooled ultra low vibration silicon mirrors for gravitational wave observatories

    Science.gov (United States)

    Shapiro, Brett; Adhikari, Rana X.; Aguiar, Odylio; Bonilla, Edgard; Fan, Danyang; Gan, Litawn; Gomez, Ian; Khandelwal, Sanditi; Lantz, Brian; MacDonald, Tim; Madden-Fong, Dakota

    2017-01-01

    Interferometric gravitational wave observatories recently launched a new field of gravitational wave astronomy with the first detections of gravitational waves in 2015. The number and quality of these detections is limited in part by thermally induced vibrations in the mirrors, which show up as noise in these interferometers. One way to reduce this thermally induced noise is to use low temperature mirrors made of high purity single-crystalline silicon. However, these low temperatures must be achieved without increasing the mechanical vibration of the mirror surface or the vibration of any surface within close proximity to the mirrors. The vibration of either surface can impose a noise inducing phase shift on the light within the interferometer or physically push the mirror through oscillating radiation pressure. This paper proposes a system for the Laser Interferometric Gravitational-wave Observatory (LIGO) to achieve the dual goals of low temperature and low vibration to reduce the thermally induced noise in silicon mirrors. Experimental results are obtained at Stanford University to prove that these dual goals can be realized simultaneously.

  8. Vibration-displacement measurements based on the phase tracking of an optical fiber Michelson interferometer

    Science.gov (United States)

    Xie, Fang; Chen, Zhimin; Ren, Junyu; Feng, Qibo

    2009-04-01

    A vibration-displacement measurement system based on tracking the phase variation of an optical fiber Michelson interferometer with electronic feedback loops is presented. The measurement system includes two sets of electronic feedback loops. One electronic feedback loop is used to compensate for the low frequency drifts in the phase of the interferometric signal that results from environmental disturbances, while the other one is used to track the phase variation induced by the measured vibration displacement, and thus realize the measurement of the vibration displacement and provide a sense of direction of the displacement simultaneously. The measurement system is designed to be capable of measuring vibration displacement with frequencies ranging from 1.5 to 200 Hz, with measurement resolution reaching 13 nm.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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...

  18. 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.

  19. 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%.

  20. Portable vibration exciter

    Science.gov (United States)

    Beecher, L. C.; Williams, F. T.

    1970-01-01

    Gas-driven vibration exciter produces a sinusoidal excitation function controllable in frequency and in amplitude. It allows direct vibration testing of components under normal loads, removing the possibility of component damage due to high static pressure.

  1. Control System Damps Vibrations

    Science.gov (United States)

    Kopf, E. H., Jr.; Brown, T. K.; Marsh, E. L.

    1983-01-01

    New control system damps vibrations in rotating equipment with help of phase-locked-loop techniques. Vibrational modes are controlled by applying suitable currents to drive motor. Control signals are derived from sensors mounted on equipment.

  2. Vibration measurements based on demodulating the phase of a fiber 3dB-coupler Michelson interferometer

    Science.gov (United States)

    Li, Min; Xie, Fang; Ren, Junyu

    2009-11-01

    A fiber interferometric vibration measurement system which is based on demodulating the phase of a fiber Michelson interferometer which is made with a fiber 3dB-coupler is presented. In the work, the system employed the characteristics of fiber Brag gratings (FBGs) to interleave two fiber Michelson interferometers which share almost the same part of the main optical path. One of the fiber interferometers is used to stabilize the system, employing an electronic feedback loop to drive a piezoelectric actuator to tune the optical path of the reference beam in order to keep the interferometer in quadrature state. By this way, the low frequency drifts in the phase of the interferometric signals which are resulted from environmental disturbances are compensated for. The other one is used to perform the measurement task. By employing the characteristics of 3dB-coupler, the interferometric signals from the two outputs of the 3dB-couper are 180º out of phase. The two interferometric signals are input into an electronic processor and convert into currents, which are linear to the power of the optical interferometric light. The signals are collected by NI USB-5132 acquisition card and processed by a program in a personal computer. The measurement system is configured with fiber and fiber components which are integrated together. As the cutoff frequency of the feedback loop is 1.5Hz, the measurement system is capable of measuring vibration with frequencies bigger than 1.5Hz and the amplitude of the measured vibration is not limited.

  3. Modeling for IFOG Vibration Error Based on the Strain Distribution of Quadrupolar Fiber Coil.

    Science.gov (United States)

    Gao, Zhongxing; Zhang, Yonggang; Zhang, Yunhao

    2016-07-21

    Improving the performance of interferometric fiber optic gyroscope (IFOG) in harsh environment, especially in vibrational environment, is necessary for its practical applications. This paper presents a mathematical model for IFOG to theoretically compute the short-term rate errors caused by mechanical vibration. The computational procedures are mainly based on the strain distribution of quadrupolar fiber coil measured by stress analyzer. The definition of asymmetry of strain distribution (ASD) is given in the paper to evaluate the winding quality of the coil. The established model reveals that the high ASD and the variable fiber elastic modulus in large strain situation are two dominant reasons that give rise to nonreciprocity phase shift in IFOG under vibration. Furthermore, theoretical analysis and computational results indicate that vibration errors of both open-loop and closed-loop IFOG increase with the raise of vibrational amplitude, vibrational frequency and ASD. Finally, an estimation of vibration-induced IFOG errors in aircraft is done according to the proposed model. Our work is meaningful in designing IFOG coils to achieve a better anti-vibration performance.

  4. Modeling for IFOG Vibration Error Based on the Strain Distribution of Quadrupolar Fiber Coil

    Directory of Open Access Journals (Sweden)

    Zhongxing Gao

    2016-07-01

    Full Text Available Improving the performance of interferometric fiber optic gyroscope (IFOG in harsh environment, especially in vibrational environment, is necessary for its practical applications. This paper presents a mathematical model for IFOG to theoretically compute the short-term rate errors caused by mechanical vibration. The computational procedures are mainly based on the strain distribution of quadrupolar fiber coil measured by stress analyzer. The definition of asymmetry of strain distribution (ASD is given in the paper to evaluate the winding quality of the coil. The established model reveals that the high ASD and the variable fiber elastic modulus in large strain situation are two dominant reasons that give rise to nonreciprocity phase shift in IFOG under vibration. Furthermore, theoretical analysis and computational results indicate that vibration errors of both open-loop and closed-loop IFOG increase with the raise of vibrational amplitude, vibrational frequency and ASD. Finally, an estimation of vibration-induced IFOG errors in aircraft is done according to the proposed model. Our work is meaningful in designing IFOG coils to achieve a better anti-vibration performance.

  5. Two all-optical logic gates in a single photonic interferometer

    Science.gov (United States)

    Araújo, Antônio; Oliveira, Antônio; Martins, Francisco; Coelho, Amarílio; Fraga, Wilton; Nascimento, José

    2015-11-01

    In this paper is presented the all-optical AND and OR gates with high contrast ratio in a single interferometric configuration, i.e., when two logic signals are modulated in the input of the interferometer, so we have the OR gate in the first output and the AND gate in the second output. These logic gates were obtained by numerical investigation of the Mach-Zehnder interferometer constituted of dual-core nonlinear photonic crystal fiber operating with ultrashort fundamental solitons of 100 fs. To represent the logic information, pulse amplitude modulation by amplitude shift-keying was used.

  6. Temperature Measurement of Small Objects by Mach—Zehnder Interferometer

    Institute of Scientific and Technical Information of China (English)

    Y.T.Wong; B.Liu; 等

    1993-01-01

    A Mach-Zehnder Interferometer incorporated with image processing has been set up to study the temperature field of small objects.Small objects with width to height rations ranging from 0.33 to 1.0 subjected to natural convection are used to simulate the condition at which the end effects are significant.Interferogram representing the temperature gradient is captured.digitized,and image processed with the aid of an image processing unit.A simple correction model is proposed to treat the stored interferometric data.The interference data are found to compare well with those provided by the thermocouples.

  7. Deep ultraviolet laser micromachining of novel fibre optic devices

    Science.gov (United States)

    Li, J.; Dou, J.; Herman, P. R.; Fricke-Begemann, T.; Ihlemann, J.; Marowsky, G.

    2007-04-01

    A deep ultraviolet F2 laser, with output at 157-nm wavelength, has been adopted for micro-shaping the end facets of single and multi-mode silica optical fibres. The high energy 7.9-eV photons drive strong interactions in the wide-bandgap silica fibres to enable the fabrication of surface-relief microstructures with high spatial resolution and smooth surface morphology. Diffraction gratings, focusing lenses, and Mach-Zehnder interferometric structures have been micromachined onto the cleaved-fibre facets and optically characterized. F2-laser micromachining is shown to be a rapid and facile means for direct-writing of novel infibre photonic components.

  8. Quantitative Morphological and Biochemical Studies on Human Downy Hairs using 3-D Quantitative Phase Imaging

    CERN Document Server

    Lee, SangYun; Lee, Yuhyun; Park, Sungjin; Shin, Heejae; Yang, Jongwon; Ko, Kwanhong; Park, HyunJoo; Park, YongKeun

    2015-01-01

    This study presents the morphological and biochemical findings on human downy arm hairs using 3-D quantitative phase imaging techniques. 3-D refractive index tomograms and high-resolution 2-D synthetic aperture images of individual downy arm hairs were measured using a Mach-Zehnder laser interferometric microscopy equipped with a two-axis galvanometer mirror. From the measured quantitative images, the biochemical and morphological parameters of downy hairs were non-invasively quantified including the mean refractive index, volume, cylinder, and effective radius of individual hairs. In addition, the effects of hydrogen peroxide on individual downy hairs were investigated.

  9. Subcarrier multiplexing tolerant dispersion transmission system employing optical broadband sources.

    Science.gov (United States)

    Grassi, Fulvio; Mora, José; Ortega, Beatriz; Capmany, José

    2009-03-16

    This paper presents a novel SCM optical transmission system for next-generation WDM-PONs combining broadband optical sources and a Mach-Zehnder interferometric structure. The approach leeds to transport RF signals up to 50 GHz being compatible with RoF systems since a second configuration has been proposed in order to overcome dispersion carrier suppression effect using DSB modulation. The theoretical analysis validates the potentiality of the system also considering the effects of the dispersion slope over the transmission window.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong

    2013-01-01

    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  2. The behaviour of lubricated EHD contacts subjected to vibrations

    Science.gov (United States)

    Zhang, X.; Glovnea, R. P.

    2017-02-01

    Machine components containing contacts working in elastohydrodynamic (EHD) conditions are often subjected to vibrations. These may be originated from the mechanism or machine the contact is part of, the surrounding environment and within the contact itself. The influence of vibrations upon the behaviour of elastohydrodynamic films has been studied experimentally in a number of papers, but a comprehensive study of the effect of the parameters of the oscillatory motion upon the film thickness has not been carried out yet. In this study the authors evaluate the effect of the frequency of the oscillatory motion upon the EHD film thickness. Optical interferometry is used to measure lubricant film thickness in a ball-on-flat disc arrangement. A high – speed camera records the interferometric images for later analysis and conversion into film thickness maps. The disc runs at a constant angular velocity while the ball is driven by the traction forces developed in the EHD film. In steady state conditions, this would ensure pure rolling conditions, however in the present investigation the ball is subjected to harmonic vibrations in a direction perpendicular to the plane of the film. The contact under study is lubricated by basic oils and the temperature is kept at a constant value of 60°C. The aim of this paper is to understand how vibrations influence the lubricant film formation.

  3. Thermal Vibrational Convection

    Science.gov (United States)

    Gershuni, G. Z.; Lyubimov, D. V.

    1998-08-01

    Recent increasing awareness of the ways in which vibrational effects can affect low-gravity experiments have renewed interest in the study of thermal vibrational convection across a wide range of fields. For example, in applications where vibrational effects are used to provide active control of heat and mass transfer, such as in heat exchangers, stirrers, mineral separators and crystal growth, a sound understanding of the fundamental theory is required. In Thermal Vibrational Convection, the authors present the theory of vibrational effects caused by a static gravity field, and of fluid flows which appear under vibration in fluid-filled cavities. The first part of the book discusses fluid-filled cavities where the fluid motion only appears in the presence of temperature non-uniformities, while the second considers those situations where the vibrational effects are caused by a non-uniform field. Throughout, the authors concentrate on consideration of high frequency vibrations, where averaging methods can be successfully applied in the study of the phenomena. Written by two of the pioneers in this field, Thermal Vibrational Convection will be of great interest to scientists and engineers working in the many areas that are concerned with vibration, and its effect on heat and mass transfer. These include hydrodynamics, hydro-mechanics, low gravity physics and mechanics, and geophysics. The rigorous approach adopted in presenting the theory of this fascinating and highly topical area will facilitate a greater understanding of the phenomena involved, and will lead to the development of more and better-designed experiments.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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...

  9. 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.

  10. 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...

  11. 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.

  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. 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.

  19. 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.

  20. 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?

  1. 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.

  2. SAR Interferometric Analysis Of Ground Deformation At Santorini Volcano (Greece)

    Science.gov (United States)

    Papageorgiou, Elena; Foumelis, Michael; Parcharidis, Issaak

    2012-01-01

    The core of the present study builds on ground deformation monitoring by SAR Interferometry at Santorini Volcanic Complex (Greece). Dataset used for this case study, include the entire archive of ERS SAR and ENVISAT ASAR data for both ascending and descending orbits covering almost two decades of observations (1992-2010). Deformation signals of millimeter-level accuracy were retrieved from both SAR and ASAR datasets, by way of the Interferometric Stacking technique. The linear rate of differential phases and the corresponding errors were estimated by averaging the unwrapped differential interferograms. Subsequently, vertical deformation rates were calculated by the combination of LOS measurements in ascending and descending acquisition geometries. The observed ground deformation shows mainly subsidence in the central part of Santorini Caldera, at Nea Kammeni Island, equal to -5.1 ±0.7 mm/yr, and -6.3 ±1.2 mm/yr for the periods 1992-2000 and 2003-2010 respectively, while both signs of movements (uplift and subsidence) of lower scale magnitude were recognized elsewhere on the volcano. In fact, higher deformation rates for the period after 2003 (ranging between -4.6 mm/yr and 5.6 mm/yr), compared to the lower values of the period 1992-2000 (from -1.7 mm/yr to 2.7 mm/yr), indicate increase in the undergoing deformation of the volcanic complex. Finally, this work presents an attempt to obtain integrated interferometric results of ground deformation from both ERS and ENVISAT sensors in order to allow future investigations on the deformation sources of the volcanic complex, which could be further exploited in the volcanic hazard and risk assessment.

  3. Vibrating fuel grapple. [LMFBR

    Science.gov (United States)

    Chertock, A.J.; Fox, J.N.; Weissinger, R.B.

    A reactor refueling method is described which utilizes a vibrating fuel grapple for removing spent fuel assemblies from a reactor core. It incorporates a pneumatic vibrator in the grapple head which allows additional withdrawal capability without exceeding the allowable axial force limit. The only moving part in the vibrator is a steel ball, pneumatically driven by a gas, such as argon, around a track, with centrifugal force created by the ball being transmitted through the grapple to the assembly handling socket.

  4. 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.

  5. Vibrational properties of uracil

    Institute of Scientific and Technical Information of China (English)

    WANG Zhiping; ZHANG Fengshou; ZENG Xianghua; ZHOU Hongyu; GU Bin; CHENG Wei

    2006-01-01

    A semiempirical molecular dynamics model is developed to study the vibrational frequencies of uracil at very low kinetic temperature by using the Fourier transform of velocity autocorrelation function of trajectories of molecular dynamics simulations. The finite difference harmonic method is used to assign the vibrational frequency of each mode. The calculated frequencies are found to be in good agreement with experimental measurements. Moreover, we make up for the lost vibrational modes in experiments self-consistently. A total of 30 vibrational modes and their corresponding frequencies are reported.

  6. PREFACE: Vibrations at surfaces Vibrations at surfaces

    Science.gov (United States)

    Rahman, Talat S.

    2011-12-01

    This special issue is dedicated to the phenomenon of vibrations at surfaces—a topic that was indispensible a couple of decades ago, since it was one of the few phenomena capable of revealing the nature of binding at solid surfaces. For clean surfaces, the frequencies of modes with characteristic displacement patterns revealed how surface geometry, as well as the nature of binding between atoms in the surface layers, could be different from that in the bulk solid. Dispersion of the surface phonons provided further measures of interatomic interactions. For chemisorbed molecules on surfaces, frequencies and dispersion of the vibrational modes were also critical for determining adsorption sites. In other words, vibrations at surfaces served as a reliable means of extracting information about surface structure, chemisorption and overlayer formation. Experimental techniques, such as electron energy loss spectroscopy and helium-atom-surface scattering, coupled with infra-red spectroscopy, were continually refined and their resolutions enhanced to capture subtleties in the dynamics of atoms and molecules at surfaces. Theoretical methods, whether based on empirical and semi-empirical interatomic potential or on ab initio electronic structure calculations, helped decipher experimental observations and provide deeper insights into the nature of the bond between atoms and molecules in regions of reduced symmetry, as encountered on solid surfaces. Vibrations at surfaces were thus an integral part of the set of phenomena that characterized surface science. Dedicated workshops and conferences were held to explore the variety of interesting and puzzling features revealed in experimental and theoretical investigations of surface vibrational modes and their dispersion. One such conference, Vibrations at Surfaces, first organized by Harald Ibach in Juelich in 1980, continues to this day. The 13th International Conference on Vibrations at Surfaces was held at the University of

  7. Ultra-Low Noise Quad Photoreceiver for Space Based Laser Interferometric Gravity Wave Detection Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Gravity wave detection using space-based long-baseline laser interferometric sensors imposes stringent noise requirements on the system components, including the...

  8. 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...

  9. High-accuracy interferometric measurements of flatness and parallelism of a step gauge

    CSIR Research Space (South Africa)

    Kruger, OA

    2001-01-01

    Full Text Available for the calibration of step gauges to a high accuracy. A system was also developed for interferometric measurements of the flatness and parallelism of gauge block faces for use in uncertainty calculations....

  10. An estimation method for InSAR interferometric phase combined with image auto-coregistration

    Institute of Scientific and Technical Information of China (English)

    LI Hai; LI Zhenfang; LIAO Guisheng; BAO Zheng

    2006-01-01

    In this paper we propose a method to estimate the InSAR interferometric phase of the steep terrain based on the terrain model of local plane by using the joint subspace projection technique proposed in our previous paper. The method takes advantage of the coherence information of neighboring pixel pairs to auto-coregister the SAR images and employs the projection of the joint signal subspace onto the corresponding joint noise subspace to estimate the terrain interferometric phase. The method can auto-coregister the SAR images and reduce the interferometric phase noise simultaneously. Theoretical analysis and computer simulation results show that the method can provide accurate estimate of the interferometric phase (interferogram) of very steep terrain even if the coregistration error reaches one pixel. The effectiveness of the method is verified via simulated data and real data.

  11. Vibrational Schroedinger Cats

    Science.gov (United States)

    Kis, Z.; Janszky, J.; Vinogradov, An. V.; Kobayashi, T.

    1996-01-01

    The optical Schroedinger cat states are simple realizations of quantum states having nonclassical features. It is shown that vibrational analogues of such states can be realized in an experiment of double pulse excitation of vibrionic transitions. To track the evolution of the vibrational wave packet we derive a non-unitary time evolution operator so that calculations are made in a quasi Heisenberg picture.

  12. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 4th edition of this textbook on linear stochastic vibration...

  13. [Vibration on agricultural tractors].

    Science.gov (United States)

    Peretti, Alessandro; Delvecchio, Simone; Bonomini, Francesco; di Bisceglie, Anita Pasqua; Colosio, Claudio

    2013-01-01

    In the article, details related to the diffusion of agricultural tractors in Italy are given and considerations about the effects of vibration on operators, the sources of vibration and suggestions to reduce them are presented. The acceleration values observed in Italy amongst 244 tractors and levels of worker exposure are shown by means of histograms. The relevant data variability is discussed.

  14. Picking up good vibrations

    NARCIS (Netherlands)

    Eijk, A.

    2010-01-01

    The methods that need to be employed to develop the better vibration guidelines to assess the integrity of a reciprocating compressor system are discussed. An R&D project of the European Forum of Reciprocating Compressors (EFRC) has been initiated to develop guidelines for vibrations in reciprocatin

  15. Vibration Theory, Vol. 3

    DEFF Research Database (Denmark)

    Nielsen, Søren R. K.

    The present textbook has been written based on previous lecture notes for a course on stochastic vibration theory that is being given on the 9th semester at Aalborg University for M. Sc. students in structural engineering. The present 2nd edition of this textbook on linear stochastic vibration th...

  16. Mechanical vibration and shock analysis, sinusoidal vibration

    CERN Document Server

    Lalanne, Christian

    2014-01-01

    Everything engineers need to know about mechanical vibration and shock...in one authoritative reference work! This fully updated and revised 3rd edition addresses the entire field of mechanical vibration and shock as one of the most important types of load and stress applied to structures, machines and components in the real world. Examples include everything from the regular and predictable loads applied to turbines, motors or helicopters by the spinning of their constituent parts to the ability of buildings to withstand damage from wind loads or explosions, and the need for cars to m

  17. Response to the comment on "Paradox of photons disconnected trajectories being located by means of `weak measurements' in the nested Mach-Zehnder interferometer" (JETP Letters 105, 152 (2017))

    Science.gov (United States)

    Nikolaev, G. N.

    2017-04-01

    In [JETP Lett. 105(3), 152 (2017)], a clear and comprehensive analysis of the paradoxical results of experiment [Phys. Rev. Lett. 111, 240402 (2013)] was carried out on the basis of the classical wave theory of light, which presupposes the continuity of possible of light paths. It was shown that the paradoxical results of the experiment are due not to the discontinuity of the trajectories of light, as claimed in [Phys. Rev. Lett. 111, 240402 (2013)], but to the used way of detecting the path of photons. The experiment modification proposed in [JETP Lett. 105(3), 152 (2017)] allows us to eliminate the seeming discontinuity of the light trajectories. In Comment [arXiv:1705.02137 (2017)] to the article such modification is declared unreasonable. This Response to the Comment shows that this statement is not based on clear and logical arguments. Instead, it is only asserted that the proposed modification "violates the faithfulness indication of the trace" of photons. Therefore, the Comment's criticism can not be considered as well-founded. Consequently, the conclusion of [JETP Lett. 105(3), 152 (2017)] that a new concept of disconnected trajectories proposed by the authors of work [Phys. Rev. Lett. 111, 240402 (2013)] is unnecessary, remains valid.

  18. Simultaneous generation of 40, 80 and 120 GHz optical millimeter-wave from one Mach-Zehnder modulator and demonstration of millimeter-wave transmission and down-conversion

    Science.gov (United States)

    Zhou, Wen; Qin, Chaoyi

    2017-09-01

    We demonstrate multi-frequency QPSK millimeter-wave (mm-wave) vector signal generation enabled by MZM-based optical carrier suppression (OCS) modulation and in-phase/quadrature (I/Q) modulation. We numerically simulate the generation of 40-, 80- and 120-GHz vector signal. Here, the three different signals carry the same QPSK modulation information. We also experimentally realize 11Gbaud/s QPSK vector signal transmission over 20 km fiber, and the generation of the vector signals at 40-GHz, 80-GHz and 120-GHz. The experimental results show that the bit-error-rate (BER) for all the three different signals can reach the forward-error-correction (FEC) threshold of 3.8×10-3. The advantage of the proposed system is that provide high-speed, high-bandwidth and high-capacity seamless access of TDM and wireless network. These features indicate the important application prospect in wireless access networks for WiMax, Wi-Fi and 5G/LTE.

  19. Shaped pulse electric-field construction and interferometric characterization: The SPECIFIC method

    CERN Document Server

    Coughlan, Matthew A; Weber, Stefan M; Bowlan, Pamela; Trebino, Rick; Levis, Robert J

    2009-01-01

    A method is reported for creating, generating, and measuring parametrically shaped pulses for time-bandwidth product >>5, which consists of a parametric pulse-shaping algorithm, a spatial light modulation system and a single shot interferometric characterization scheme (SEA TADPOLE) . The utilization of these tools marks the inception of a new method called SPECIFIC, shaped-pulse electric-field construction and interferometric characterization, capable of producing complex shaped laser pulses for coherent control experiments.

  20. Vibration control in accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Montag, C.

    2011-01-01

    In the vast majority of accelerator applications, ground vibration amplitudes are well below tolerable magnet jitter amplitudes. In these cases, it is necessary and sufficient to design a rigid magnet support structure that does not amplify ground vibration. Since accelerator beam lines are typically installed at an elevation of 1-2m above ground level, special care has to be taken in order to avoid designing a support structure that acts like an inverted pendulum with a low resonance frequency, resulting in untolerable lateral vibration amplitudes of the accelerator components when excited by either ambient ground motion or vibration sources within the accelerator itself, such as cooling water pumps or helium flow in superconducting magnets. In cases where ground motion amplitudes already exceed the required jiter tolerances, for instance in future linear colliders, passive vibration damping or active stabilization may be considered.

  1. Vibrations of rotating machinery

    CERN Document Server

    Matsushita, Osami; Kanki, Hiroshi; Kobayashi, Masao; Keogh, Patrick

    2017-01-01

    This book opens with an explanation of the vibrations of a single degree-of-freedom (dof) system for all beginners. Subsequently, vibration analysis of multi-dof systems is explained by modal analysis. Mode synthesis modeling is then introduced for system reduction, which aids understanding in a simplified manner of how complicated rotors behave. Rotor balancing techniques are offered for rigid and flexible rotors through several examples. Consideration of gyroscopic influences on the rotordynamics is then provided and vibration evaluation of a rotor-bearing system is emphasized in terms of forward and backward whirl rotor motions through eigenvalue (natural frequency and damping ratio) analysis. In addition to these rotordynamics concerning rotating shaft vibration measured in a stationary reference frame, blade vibrations are analyzed with Coriolis forces expressed in a rotating reference frame. Other phenomena that may be assessed in stationary and rotating reference frames include stability characteristic...

  2. Vibrational Spectroscopy of Biomembranes

    Science.gov (United States)

    Schultz, Zachary D.; Levin, Ira W.

    2011-07-01

    Vibrational spectroscopy, commonly associated with IR absorption and Raman scattering, has provided a powerful approach for investigating interactions between biomolecules that make up cellular membranes. Because the IR and Raman signals arise from the intrinsic properties of these molecules, vibrational spectroscopy probes the delicate interactions that regulate biomembranes with minimal perturbation. Numerous innovative measurements, including nonlinear optical processes and confined bilayer assemblies, have provided new insights into membrane behavior. In this review, we highlight the use of vibrational spectroscopy to study lipid-lipid interactions. We also examine recent work in which vibrational measurements have been used to investigate the incorporation of peptides and proteins into lipid bilayers, and we discuss the interactions of small molecules and drugs with membrane structures. Emerging techniques and measurements on intact cellular membranes provide a prospective on the future of vibrational spectroscopic studies of biomembranes.

  3. STATISTICAL CHARACTERISTICS INVESTIGATION OF PREDICTION ERRORS FOR INTERFEROMETRIC SIGNAL IN THE ALGORITHM OF NONLINEAR KALMAN FILTERING

    Directory of Open Access Journals (Sweden)

    E. L. Dmitrieva

    2016-05-01

    Full Text Available Basic peculiarities of nonlinear Kalman filtering algorithm applied to processing of interferometric signals are considered. Analytical estimates determining statistical characteristics of signal values prediction errors were obtained and analysis of errors histograms taking into account variations of different parameters of interferometric signal was carried out. Modeling of the signal prediction procedure with known fixed parameters and variable parameters of signal in the algorithm of nonlinear Kalman filtering was performed. Numerical estimates of prediction errors for interferometric signal values were obtained by formation and analysis of the errors histograms under the influence of additive noise and random variations of amplitude and frequency of interferometric signal. Nonlinear Kalman filter is shown to provide processing of signals with randomly variable parameters, however, it does not take into account directly the linearization error of harmonic function representing interferometric signal that is a filtering error source. The main drawback of the linear prediction consists in non-Gaussian statistics of prediction errors including cases of random deviations of signal amplitude and/or frequency. When implementing stochastic filtering of interferometric signals, it is reasonable to use prediction procedures based on local statistics of a signal and its parameters taken into account.

  4. Fundamental study of microelectronic chip response under laser ultrasonic-interferometric inspection using C-scan method

    Science.gov (United States)

    Yang, Lei; Gong, Jie; Ume, I. Charles

    2014-02-01

    In modern surface mount packaging technologies, such as flip chips, chip scale packages, and ball grid arrays(BGA), chips are attached to the substrates/printed wiring board (PWB) using solder bump interconnections. The quality of solder bumps between the chips and the substrate/board is difficult to inspect. Laser ultrasonic-interferometric technique was proved to be a promising approach for solder bump inspection because of its noncontact and nondestructive characteristics. Different indicators extracted from received signals have been used to predict the potential defects, such as correlation coefficient, error ratio, frequency shifting, etc. However, the fundamental understanding of the chip behavior under laser ultrasonic inspection is still missing. Specifically, it is not sure whether the laser interferometer detected out-of-plane displacements were due to wave propagation or structural vibration when the chip was excited by pulsed laser. Plus, it is found that the received signals are chip dependent. Both challenges impede the interpretation of acquired signals. In this paper, a C-scan method was proposed to study the underlying phenomenon during laser ultrasonic inspection. The full chip was inspected. The response of the chip under laser excitation was visualized in a movie resulted from acquired signals. Specifically, a BGA chip was investigated to demonstrate the effectiveness of this method. By characterizing signals using discrete wavelet transform(DWT), both ultrasonic wave propagation and vibration were observed. Separation of them was successfully achieved using ideal band-pass filter and visualized in resultant movies, too. The observed ultrasonic waves were characterized and their respective speeds were measured by applying 2-D FFT. The C-scan method, combined with different digital signal processing techniques, was proved to be an very effective methodology to learn the behavior of chips under laser excitation. This general procedure can be

  5. Robust Radio Interferometric Calibration Using the t-Distribution

    CERN Document Server

    Kazemi, 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 due to interference or due to errors in the sky model would have adverse effects on processing based on a Gaussian noise model. Most of the shortcomings of calibration such as the loss in flux or coherence, and the appearance of spurious sources, could be attributed to the deviations of the underlying noise model. In this paper, we propose to improve the robustness of calibration by using a noise model based on Student's t distribution. Student's t noise is a special case of Gaussian noise when the variance is unknown. Unlike Gaussian noise model based calibration, traditional least squares minimization would not directly extend to a case when we have a Student's t noise model. Therefore, we use a variant of the Ex...

  6. Sculpting the disk around T Cha: an interferometric view

    CERN Document Server

    Olofsson, Johan; Bouquin, Jean-Baptiste Le; Berger, Jean-Philippe; Lacour, Sylvestre; Ménard, François; Henning, Thomas; Crida, Aurélien; Burtscher, Leonard; Meeus, Gwendolyn; Ratzka, Thorsten; Pinte, Christophe; Augereau, Jean-Charles; Malbet, Fabien; Lazareff, Bernard; Traub, Wesley A

    2013-01-01

    (Abridged) Circumstellar disks are believed to be the birthplace of planets and are expected to dissipate on a timescale of a few Myr. The processes responsible for the removal of the dust and gas will strongly modify the radial distribution of the dust and consequently the SED. In particular, a young planet will open a gap, resulting in an inner disk dominating the near-IR emission and an outer disk emitting mostly in the far-IR. We analyze a full set of data (including VLTI/Pionier, VLTI/Midi, and VLT/NaCo/Sam) to constrain the structure of the transition disk around TCha. We used the Mcfost radiative transfer code to simultaneously model the SED and the interferometric observations. We find that the dust responsible for the emission in excess in the near-IR must have a narrow temperature distribution with a maximum close to the silicate sublimation temperature. This translates into a narrow inner dusty disk (0.07-0.11 AU). We find that the outer disk starts at about 12 AU and is partially resolved by the P...

  7. Passive interferometric symmetries of multimode Gaussian pure states

    Science.gov (United States)

    Gabay, Natasha; Menicucci, Nicolas C.

    2016-05-01

    As large-scale multimode Gaussian states begin to become accessible in the laboratory, their representation and analysis become a useful topic of research in their own right. The graphical calculus for Gaussian pure states provides powerful tools for their representation, while this work presents a useful tool for their analysis: passive interferometric (i.e., number-conserving) symmetries. Here we show that these symmetries of multimode Gaussian states simplify calculations in measurement-based quantum computing and provide constructive tools for engineering large-scale harmonic systems with specific physical properties, and we provide a general mathematical framework for deriving them. Such symmetries are generated by linear combinations of operators expressed in the Schwinger representation of U (2 ) , called nullifiers because the Gaussian state in question is a zero eigenstate of them. This general framework is shown to have applications in the noise analysis of continuous-various cluster states and is expected to have additional applications in future work with large-scale multimode Gaussian states.

  8. 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.

  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. 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.

  11. Interferometric measurement of the angular velocity of moving humans

    Science.gov (United States)

    Nanzer, Jeffrey A.

    2012-06-01

    This paper presents an analysis of the measurement of the angular velocity of walking humans using a millimeter-wave correlation interferometer. Measurement of the angular velocity of moving objects is a desirable function in remote sensing applications. Doppler radar sensors are able to measure the signature of moving humans based on micro-Doppler analysis; however, a person moving with little to no radial velocity produces negligible Doppler returns. Measurement of the angular movement of humans can be done with traditional radar techniques, however the process involves either continuous tracking with narrow beamwidth or angle-of-arrival estimation algorithms. A new method of measuring the angular velocity of moving objects using interferometry has recently been developed which measures the angular velocity of an object without tracking or complex processing. The frequency of the interferometer signal response is proportional to the angular velocity of the object as it passes through the interferometer beam pattern. In this paper, the theory of the interferometric measurement of angular velocity is covered and simulations of the response of a walking human are presented. Simulations are produced using a model of a walking human to show the significant features associated with the interferometer response, which may be used in classification algorithms.

  12. Code-modulated interferometric imaging system using phased arrays

    Science.gov (United States)

    Chauhan, Vikas; Greene, Kevin; Floyd, Brian

    2016-05-01

    Millimeter-wave (mm-wave) imaging provides compelling capabilities for security screening, navigation, and bio- medical applications. Traditional scanned or focal-plane mm-wave imagers are bulky and costly. In contrast, phased-array hardware developed for mass-market wireless communications and automotive radar promise to be extremely low cost. In this work, we present techniques which can allow low-cost phased-array receivers to be reconfigured or re-purposed as interferometric imagers, removing the need for custom hardware and thereby reducing cost. Since traditional phased arrays power combine incoming signals prior to digitization, orthogonal code-modulation is applied to each incoming signal using phase shifters within each front-end and two-bit codes. These code-modulated signals can then be combined and processed coherently through a shared hardware path. Once digitized, visibility functions can be recovered through squaring and code-demultiplexing operations. Pro- vided that codes are selected such that the product of two orthogonal codes is a third unique and orthogonal code, it is possible to demultiplex complex visibility functions directly. As such, the proposed system modulates incoming signals but demodulates desired correlations. In this work, we present the operation of the system, a validation of its operation using behavioral models of a traditional phased array, and a benchmarking of the code-modulated interferometer against traditional interferometer and focal-plane arrays.

  13. Broadband circular interferometric millimetre-wave ISAR for threat detection

    Directory of Open Access Journals (Sweden)

    S. Bertl

    2007-06-01

    Full Text Available To detect threats on a person's body surface the application of millimetre-waves is possible. In order to get a view of the person from all sides either the person has to be rotated standing on a turntable (Inverse Synthetic Aperture Radar, ISAR or a sensor is moved on a circular path around the person (Synthetic Aperture Radar, SAR. The goal of the reconstruction is to obtain information about the shape of the threats and their positions in all three dimensions. At first the reconstruction is done along range and azimuth, which span the principal surface given by the sensor configuration. This paper reports on two methods to obtain the third spatial dimension. Due to the circular shape and its 3D focussing ability of the aperture this information can be obtained by the evaluation of the image focus. Secondly, if two coherent receiving channels are used, a possibility to achieve 3D spatial resolution is the processing of the interferometric phase. A comparison between these two will be presented.

  14. Model Order Selection in Multi-baseline Interferometric Radar Systems

    Directory of Open Access Journals (Sweden)

    Fulvio Gini

    2005-12-01

    Full Text Available Synthetic aperture radar interferometry (InSAR is a powerful technique to derive three-dimensional terrain images. Interest is growing in exploiting the advanced multi-baseline mode of InSAR to solve layover effects from complex orography, which generate reception of unexpected multicomponent signals that degrade imagery of both terrain radar reflectivity and height. This work addresses a few problems related to the implementation into interferometric processing of nonlinear algorithms for estimating the number of signal components, including a system trade-off analysis. Performance of various eigenvalues-based information-theoretic criteria (ITC algorithms is numerically investigated under some realistic conditions. In particular, speckle effects from surface and volume scattering are taken into account as multiplicative noise in the signal model. Robustness to leakage of signal power into the noise eigenvalues and operation with a small number of looks are investigated. The issue of baseline optimization for detection is also addressed. The use of diagonally loaded ITC methods is then proposed as a tool for robust operation in the presence of speckle decorrelation. Finally, case studies of a nonuniform array are studied and recommendations for a proper combination of ITC methods and system configuration are given.

  15. The linearized inversion of the generalized interferometric multiple imaging

    KAUST Repository

    Aldawood, Ali

    2016-09-06

    The generalized interferometric multiple imaging (GIMI) procedure can be used to image duplex waves and other higher order internal multiples. Imaging duplex waves could help illuminate subsurface zones that are not easily illuminated by primaries such as vertical and nearly vertical fault planes, and salt flanks. To image first-order internal multiple, the GIMI framework consists of three datuming steps, followed by applying the zero-lag cross-correlation imaging condition. However, the standard GIMI procedure yields migrated images that suffer from low spatial resolution, migration artifacts, and cross-talk noise. To alleviate these problems, we propose a least-squares GIMI framework in which we formulate the first two steps as a linearized inversion problem when imaging first-order internal multiples. Tests on synthetic datasets demonstrate the ability to localize subsurface scatterers in their true positions, and delineate a vertical fault plane using the proposed method. We, also, demonstrate the robustness of the proposed framework when imaging the scatterers or the vertical fault plane with erroneous migration velocities.

  16. Optimal detection of burst events in gravitational wave interferometric observatories

    CERN Document Server

    Viceré, A

    2002-01-01

    We consider the problem of detecting a burst signal of unknown shape. We introduce a statistic which generalizes the excess power statistic proposed by Flanagan and Hughes and extended by Anderson et al. The statistic we propose is shown to be optimal for arbitrary noise spectral characteristic, under the two hypotheses that the noise is Gaussian, and that the prior for the signal is uniform. The statistic derivation is based on the assumption that a signal affects only affects N samples in the data stream, but that no other information is a priori available, and that the value of the signal at each sample can be arbitrary. We show that the proposed statistic can be implemented combining standard time-series analysis tools which can be efficiently implemented, and the resulting computational cost is still compatible with an on-line analysis of interferometric data. We generalize this version of an excess power statistic to the multiple detector case, also including the effect of correlated noise. We give full...

  17. 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.

  18. 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.

  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. Interferometric radio transient reconstruction in compressed sensing framework

    CERN Document Server

    Jiang, M; Starck, J -L; Corbel, S; Tasse, C

    2015-01-01

    Imaging by aperture synthesis from interferometric data is a well-known, but is a strong ill-posed inverse problem. Strong and faint radio sources can be imaged unambiguously using time and frequency integration to gather more Fourier samples of the sky. However, these imagers assumes a steady sky and the complexity of the problem increases when transients radio sources are also present in the data. Hopefully, in the context of transient imaging, the spatial and temporal information are separable which enable extension of an imager fit for a steady sky. We introduce independent spatial and temporal wavelet dictionaries to sparsely represent the transient in both spatial domain and temporal domain. These dictionaries intervenes in a new reconstruction method developed in the Compressed Sensing (CS) framework and using a primal-dual splitting algorithm. According to the preliminary tests in different noise regimes, this new "Time-agile" (or 2D-1D) method seems to be efficient in detecting and reconstructing the...

  1. Super-Virtual Refraction Interferometric Redatuming: Enhancing the Refracted Energy

    KAUST Repository

    Aldawood, Ali

    2012-02-26

    onshore seismic data processing. Refraction tomography is becoming a common way to estimate an accurate near surface velocity model. One of the problems with refraction tomography is the low signal to noise ration in far offset data. To improve, we propose using super-virtual refraction interferometry to enhance the weak energy at far offsets. We use Interferometric Green\\'s functions to redatum sources by cross-correlating two traces recorded at receiver stations, A and B, from a source at location W. The result is a redatumed trace with a virtual source at A and a receiver at B, which can also be obtained by correlating two traces recorded at A and B from different shots. Stacking them would enhance the signal-to-noise ratio of this "virtual" trace. We next augment redatuming with convolution and stacking. The trace recorded at B from a virtual source at A is convolved with the original trace recorded at A from a source at W. The result is a "super-virtual" trace at B in the far-offset from a source at W. Stacking N traces gives a vN-improvement. We applied our method to noisy synthetic and field data recorded over a complex near-surface and we could pick more traces at far offsets. It was possible to accommodate more picks resulting in a better subsurface coverage

  2. Radio interferometric gain calibration as a complex optimization problem

    Science.gov (United States)

    Smirnov, O. M.; Tasse, C.

    2015-05-01

    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 as special cases of this, and place them in the context of the general formalism. Finally, we present an implementation and some applied results of COHJONES, another specialized direction-dependent calibration algorithm derived from the formalism.

  3. Ultrasensitive interferometric on-chip microscopy of transparent objects

    Science.gov (United States)

    Terborg, Roland A.; Pello, Josselin; Mannelli, Ilaria; Torres, Juan P.; Pruneri, Valerio

    2016-01-01

    Light microscopes can detect objects through several physical processes, such as scattering, absorption, and reflection. In transparent objects, these mechanisms are often too weak, and interference effects are more suitable to observe the tiny refractive index variations that produce phase shifts. We propose an on-chip microscope design that exploits birefringence in an unconventional geometry. It makes use of two sheared and quasi-overlapped illuminating beams experiencing relative phase shifts when going through the object, and a complementary metal-oxide-semiconductor image sensor array to record the resulting interference pattern. Unlike conventional microscopes, the beams are unfocused, leading to a very large field of view (20 mm2) and detection volume (more than 0.5 cm3), at the expense of lateral resolution. The high axial sensitivity (<1 nm) achieved using a novel phase-shifting interferometric operation makes the proposed device ideal for examining transparent substrates and reading microarrays of biomarkers. This is demonstrated by detecting nanometer-thick surface modulations on glass and single and double protein layers. PMID:27386571

  4. 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.

  5. 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.

  6. Large-Area Semiconducting Graphene Nanomesh Tailored by Interferometric Lithography.

    Science.gov (United States)

    Kazemi, Alireza; He, Xiang; Alaie, Seyedhamidreza; Ghasemi, Javad; Dawson, Noel Mayur; Cavallo, Francesca; Habteyes, Terefe G; Brueck, Steven R J; Krishna, Sanjay

    2015-07-01

    Graphene nanostructures are attracting a great deal of interest because of newly emerging properties originating from quantum confinement effects. We report on using interferometric lithography to fabricate uniform, chip-scale, semiconducting graphene nanomesh (GNM) with sub-10 nm neck widths (smallest edge-to-edge distance between two nanoholes). This approach is based on fast, low-cost, and high-yield lithographic technologies and demonstrates the feasibility of cost-effective development of large-scale semiconducting graphene sheets and devices. The GNM is estimated to have a room temperature energy bandgap of ~30 meV. Raman studies showed that the G band of the GNM experiences a blue shift and broadening compared to pristine graphene, a change which was attributed to quantum confinement and localization effects. A single-layer GNM field effect transistor exhibited promising drive current of ~3.9 μA/μm and ON/OFF current ratios of ~35 at room temperature. The ON/OFF current ratio of the GNM-device displayed distinct temperature dependence with about 24-fold enhancement at 77 K.

  7. Spatially multiplexed interferometric microscopy with partially coherent illumination

    Science.gov (United States)

    Picazo-Bueno, José Ángel; Zalevsky, Zeev; García, Javier; Ferreira, Carlos; Micó, Vicente

    2016-10-01

    We have recently reported on a simple, low cost, and highly stable way to convert a standard microscope into a holographic one [Opt. Express 22, 14929 (2014)]. The method, named spatially multiplexed interferometric microscopy (SMIM), proposes an off-axis holographic architecture implemented onto a regular (nonholographic) microscope with minimum modifications: the use of coherent illumination and a properly placed and selected one-dimensional diffraction grating. In this contribution, we report on the implementation of partially (temporally reduced) coherent illumination in SMIM as a way to improve quantitative phase imaging. The use of low coherence sources forces the application of phase shifting algorithm instead of off-axis holographic recording to recover the sample's phase information but improves phase reconstruction due to coherence noise reduction. In addition, a less restrictive field of view limitation (1/2) is implemented in comparison with our previously reported scheme (1/3). The proposed modification is experimentally validated in a regular Olympus BX-60 upright microscope considering a wide range of samples (resolution test, microbeads, swine sperm cells, red blood cells, and prostate cancer cells).

  8. Interferometric method to measure the Goos-Hänchen shift.

    Science.gov (United States)

    Prajapati, Chandravati; Ranganathan, Dilip; Joseph, Joby

    2013-04-01

    We propose and demonstrate an interferometric method to measure the Goos-Hänchen (GH) shift, which is based on observing the interference between p- and s-polarized beams. In our method both p- and s-polarized beams are observed simultaneously and across the entire beam profile. To demonstrate our method, we measured the GH shift of aluminum (Al) and glass at different values of the incidence angle ranging from 20° to 70°, with a helium-neon laser as source. We compared the experimental result with theoretical calculations and found a good agreement between them. Our method also enables us to measure the GH shift at any point across the entire beam profile, for arbitrary beam profiles. This is not possible with the methods currently in use. We presented the observed values for the Gaussian mode used, which enables us to find the relative shifts between the p and s components at various points on the incident profile after reflection.

  9. INTERFEROMETRIC STUDIES OF HOT STARS AT SYDNEY UNIVERSITY

    Directory of Open Access Journals (Sweden)

    J. G. Robertson

    2010-01-01

    Full Text Available 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 de haz de multi-longitud de onda PAVO. SUSI funciona en visible más que en longitudes de onda del IR y tiene líneas de base de hasta 160 m, así que estábien adaptado al estudio de estrellas calientes. Se han realizado algunos estudios y se planean más estudios cuando se haya concluido la puesta en operación del sistema PAVO. La conversión del sistema para permitir la operación remota, permitirá que sean emprendidos mayores proyectos científicos.

  10. Deconvolution of interferometric data using interior point iterative algorithms

    Science.gov (United States)

    Theys, C.; Lantéri, H.; Aime, C.

    2016-09-01

    We address the problem of deconvolution of astronomical images that could be obtained with future large interferometers in space. The presentation is made in two complementary parts. The first part gives an introduction to the image deconvolution with linear and nonlinear algorithms. The emphasis is made on nonlinear iterative algorithms that verify the constraints of non-negativity and constant flux. The Richardson-Lucy algorithm appears there as a special case for photon counting conditions. More generally, the algorithm published recently by Lanteri et al. (2015) is based on scale invariant divergences without assumption on the statistic model of the data. The two proposed algorithms are interior-point algorithms, the latter being more efficient in terms of speed of calculation. These algorithms are applied to the deconvolution of simulated images corresponding to an interferometric system of 16 diluted telescopes in space. Two non-redundant configurations, one disposed around a circle and the other on an hexagonal lattice, are compared for their effectiveness on a simple astronomical object. The comparison is made in the direct and Fourier spaces. Raw "dirty" images have many artifacts due to replicas of the original object. Linear methods cannot remove these replicas while iterative methods clearly show their efficacy in these examples.

  11. 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.

  12. Coherent vibrational dynamics

    CERN Document Server

    Lanzani, Guglielmo; De Silvestri, Sandro

    2007-01-01

    Vibrational spectroscopy is a powerful investigation tool for a wide class of materials covering diverse areas in physics, chemistry and biology. The continuous development in the laser field regarding ultrashort pulse generation has led to the possibility of producing light pulses that can follow vibrational motion coupled to the electronic transitions in molecules and solids in real time. Aimed at researchers and graduate students using vibrational spectroscopy, this book provides both introductory chapters as well as more advanced contents reporting on recent progress. It also provides a good starting point for scientists seeking a sound introduction to ultrafast optics and spectroscopic techniques.

  13. Digital signal processing for velocity measurements in dynamical material's behaviour studies

    Science.gov (United States)

    Devlaminck, Julien; Luc, Jérôme; Chanal, Pierre-Yves

    2014-03-01

    In this work, we describe different configurations of optical fiber interferometers (types Michelson and Mach-Zehnder) used to measure velocities during dynamical material's behaviour studies. We detail the algorithms of processing developed and optimized to improve the performance of these interferometers especially in terms of time and frequency resolutions. Three methods of analysis of interferometric signals were studied. For Michelson interferometers, the time-frequency analysis of signals by Short-Time Fourier Transform (STFT) is compared to a time-frequency analysis by Continuous Wavelet Transform (CWT). The results have shown that the CWT was more suitable than the STFT for signals with low signal-to-noise, and low velocity and high acceleration areas. For Mach-Zehnder interferometers, the measurement is carried out by analyzing the phase shift between three interferometric signals (Triature processing). These three methods of digital signal processing were evaluated, their measurement uncertainties estimated, and their restrictions or operational limitations specified from experimental results performed on a pulsed power machine.

  14. Vibrating wire alignment technique

    CERN Document Server

    Xiao-Long, Wang; lei, Wu; Chun-Hua, Li

    2013-01-01

    Vibrating wire alignment technique is a kind of method which through measuring the spatial distribution of magnetic field to do the alignment and it can achieve very high alignment accuracy. Vibrating wire alignment technique can be applied for magnet fiducialization and accelerator straight section components alignment, it is a necessary supplement for conventional alignment method. This article will systematically expound the international research achievements of vibrating wire alignment technique, including vibrating wire model analysis, system frequency calculation, wire sag calculation and the relation between wire amplitude and magnetic induction intensity. On the basis of model analysis this article will introduce the alignment method which based on magnetic field measurement and the alignment method which based on amplitude and phase measurement. Finally, some basic questions will be discussed and the solutions will be given.

  15. Vibration enhanced quantum transport

    CERN Document Server

    Semião, F L; Milburn, G J

    2009-01-01

    In this paper, we study the role of a collective vibrational motion in the phenomenon of electronic energy transfer (EET) between chromophores with different electronic transition frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduce correlations in the energy gap fluctuations which cause coherent EET. We present a simple model describing the coupling between the chromophores and a common vibrational mode, and find that vibration can indeed lead to an enhancement in the transport of excitations across the quantum network. Furthermore, in our model phase information is partially retained in the transfer process from a donor to an acceptor, as experimentally demonstrated in the conjugated polymer system. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.

  16. NIF Ambient Vibration Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C.R.; Hoehler, M.S., S.C. Sommer

    1999-11-29

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  17. NIF Ambient Vibration Measurements

    Energy Technology Data Exchange (ETDEWEB)

    Noble, C.R.; Hoehler, M.S., S.C. Sommer

    1999-11-29

    LLNL has an ongoing research and development project that includes developing data acquisition systems with remote wireless communication for monitoring the vibrations of large civil engineering structures. In order to establish the capability of performing remote sensing over an extended period of time, the researchers needed to apply this technology to a real structure. The construction of the National Ignition Facility provided an opportunity to test the data acquisition system on a large structure to monitor whether the facility is remaining within the strict ambient vibration guidelines. This document will briefly discuss the NIF ambient vibration requirements and summarize the vibration measurements performed during the Spring and Summer of 1999. In addition, a brief description of the sensors and the data acquisition systems will be provided in Appendix B.

  18. 2008 Vibrational Spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Philip J. Reid

    2009-09-21

    The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

  19. Interferometric laser imaging for in-flight cloud droplet sizing

    Science.gov (United States)

    Dunker, Christina; Roloff, Christoph; Grassmann, Arne

    2016-12-01

    A non-intrusive particle sizing method with a high spatial distribution is used to estimate cloud droplet spectra during flight test campaigns. The interferometric laser imaging for droplet sizing (ILIDS) method derives particle diameters of transparent spheres by evaluating the out-of-focus image patterns. This sizing approach requires a polarized monochromatic light source, a camera including an objective lens with a slit aperture, a synchronization unit and a processing tool for data evaluation. These components are adapted to a flight test environment to enable the microphysical investigation of different cloud genera. The present work addresses the design and specifications of ILIDS system, flight test preparation and selected results obtained in the lower and middle troposphere. The research platform was a Dornier Do228-101 commuter aircraft at the DLR Flight Operation Center in Braunschweig. It was equipped with the required instrumentation including a high-energy laser as the light source. A comprehensive data set of around 71 800 ILIDS images was acquired over the course of five flights. The data evaluation of the characteristic ILIDS fringe patterns relies, among other things, on a relationship between the fringe spacing and the diameter of the particle. The simplest way to extract this information from a pattern is by fringe counting, which is not viable for such an extensive number of data. A brief contrasting comparison of evaluation methods based on frequency analysis by means of fast Fourier transform and on correlation methods such as minimum quadratic difference is used to encompass the limits and accuracy of the ILIDS method for such applications.

  20. Observing the Sun with micro-interferometric devices: a didactic experiment

    Science.gov (United States)

    Defrère, D.; Absil, O.; Hanot, C.; Riaud, P.; Magette, A.; Marion, L.; Wertz, O.; Finet, F.; Steenackers, M.; Habraken, S.; Surdej, A.; Surdej, J.

    2014-04-01

    Measuring the angular diameter of celestial bodies has long been the main purpose of stellar interferometry and was its historical motivation. Nowadays, stellar interferometry is widely used for various other scientific purposes that require very high angular resolution measurements. In terms of angular spatial scales probed, observing distant stars located 10 to 100~pc away with a large hectometric interferometer is equivalent to observing our Sun with a micrometric baseline. Based on this idea, we have manufactured a set of micro-interferometric devices and tested them on the sky. The micro-interferometers consist of a chrome layer deposited on a glass plate that has been drilled by laser lithography to produce micron-sized holes with configurations corresponding to proposed interferometer projects such as CARLINA, ELSA, KEOPS, and OVLA. In this paper, we describe these interferometric devices and present interferometric observations of the Sun made in the framework of Astrophysics lectures being taught at the Liège University. By means of a simple photographic camera placed behind a micro-interferometric device, we observed the Sun and derived its angular size. This experiment provides a very didactic way to easily obtain fringe patterns similar to those that will be obtained with future large imaging arrays. A program written in C also allows to reproduce the various point spread functions and fringe patterns observed with the micro-interferometric devices for different types of sources, including the Sun.