WorldWideScience

Sample records for polarizing michelson interferometer

  1. Michelson Interferometer

    Science.gov (United States)

    Rogers, Ryan

    2007-01-01

    The Michelson Interferometer is a device used in many applications, but here it was used to measure small differences in distance, in the milli-inch range, specifically for defects in the Orbiter windows. In this paper, the method of using the Michelson Interferometer for measuring small distances is explained as well as the mathematics of the system. The coherence length of several light sources was calculated in order to see just how small a defect could be measured. Since white light is a very broadband source, its coherence length is very short and thus can be used to measure small defects in glass. After finding the front and back reflections from a very thin glass slide with ease and calculating the thickness of it very accurately, it was concluded that this system could find and measure small defects on the Orbiter windows. This report also discusses a failed attempt for another use of this technology as well as describes an area of promise for further analysis. The latter of these areas has applications for finding possible defects in Orbiter windows without moving parts.

  2. The tempo-spatially modulated polarization atmosphere Michelson interferometer.

    Science.gov (United States)

    Zhang, ChunMin; Zhu, HuaChun; Zhao, Baochang

    2011-05-09

    A space-based tempo-spatially modulated polarization atmosphere Michelson interferometer (TSMPAMI) is described. It uses the relative movement between the TSMPAMI and the measured target to change optical path difference. The acquisition method of interferogram is presented. The atmospheric temperatures and horizontal winds can be derived from the optical observations. The measurement errors of the winds and temperatures are discussed through simulations. In the presence of small-scale structures of the atmospheric fields, the errors are found to be significantly influenced by the mismatch of the scenes observed by the adjacent CCD sub-areas aligned along the orbiter's track during successive measurements due to the orbital velocity and the exposure time. For most realistic conditions of the orbit and atmosphere, however, the instrument is proven suitable for measuring the atmospheric parameters. © 2011 Optical Society of America

  3. Michelson and His Interferometer

    Science.gov (United States)

    Shankland, Robert S.

    1974-01-01

    Presents a brief historical account of Michelson's invention of his interferometer with some subsequent ingenious applications of its capabilities for precise measurement discussed in details, including the experiment on detrmination of the diameters for heavenly bodies. (CC)

  4. Polarization Beam Splitter Based on a Self-Collimation Michelson Interferometer in a Silicon Photonic Crystal

    International Nuclear Information System (INIS)

    Chen Xi-Yao; Lin Gui-Min; Li Jun-Jun; Xu Xiao-Fu; Jiang Jun-Zhen; Qiang Ze-Xuan; Qiu Yi-Shen; Li Hui

    2012-01-01

    A polarization beam splitter based on a self-collimation Michelson interferometer (SMI) in a hole-type silicon photonic crystal is proposed and numerically demonstrated. Utilizing the polarization dependence of the transmission spectra of the SMI and polarization peak matching method, the SMI can work as a polarization beam splitter (PBS) by selecting an appropriate path length difference in the structure. Based on its novel polarization beam splitting mechanics, the polarization extinction ratios (PERs) for TM and TE modes are as high as 18.4 dB and 24.3 dB, respectively. Since its dimensions are only several operating wavelengths, the PBS may have practical applications in photonic integrated circuits. (fundamental areas of phenomenology(including applications))

  5. Mariner 9 Michelson interferometer.

    Science.gov (United States)

    Hanel, R.; Schlachman, B.; Rodgers, D.; Breihan, E.; Bywaters, R.; Chapman, F.; Rhodes, M.; Vanous, D.

    1972-01-01

    The Michelson interferometer on Mariner 9 measures the thermal emission spectrum of Mars between 200 and 2000 per cm (between 5 and 50 microns) with a spectral resolution of 2.4 per cm in the apodized mode. A noise equivalent radiance of 0.5 x 10 to the minus 7th W/sq cm/ster/cm is deduced from data recorded in orbit around Mars. The Mariner interferometer deviates in design from the Nimbus 3 and 4 interferometers in several areas, notably, by a cesium iodide beam splitter and certain aspects of the digital information processing. Special attention has been given to the problem of external vibration. The instrument performance is demonstrated by calibration data and samples of Mars spectra.

  6. AMI: Augmented Michelson Interferometer

    Science.gov (United States)

    Furió, David; Hachet, Martin; Guillet, Jean-Paul; Bousquet, Bruno; Fleck, Stéphanie; Reuter, Patrick; Canioni, Lionel

    2015-10-01

    Experiments in optics are essential for learning and understanding physical phenomena. The problem with these experiments is that they are generally time consuming for both their construction and their maintenance, potentially dangerous through the use of laser sources, and often expensive due to high technology optical components. We propose to simulate such experiments by way of hybrid systems that exploit both spatial augmented reality and tangible interaction. In particular, we focus on one of the most popular optical experiments: the Michelson interferometer. In our approach, we target a highly interactive system where students are able to interact in real time with the Augmented Michelson Interferometer (AMI) to observe, test hypotheses and then to enhance their comprehension. Compared to a fully digital simulation, we are investigating an approach that benefits from both physical and virtual elements, and where the students experiment by manipulating 3D-printed physical replicas of optical components (e.g. lenses and mirrors). Our objective is twofold. First, we want to ensure that the students will learn with our simulator the same concepts and skills that they learn with traditional methods. Second, we hypothesis that such a system opens new opportunities to teach optics in a way that was not possible before, by manipulating concepts beyond the limits of observable physical phenomena. To reach this goal, we have built a complementary team composed of experts in the field of optics, human-computer interaction, computer graphics, sensors and actuators, and education science.

  7. Guided magnonic Michelson interferometer.

    Science.gov (United States)

    Ahmed, Muhammad H; Jeske, Jan; Greentree, Andrew D

    2017-01-30

    Magnonics is an emerging field with potential applications in classical and quantum information processing. Freely propagating magnons in two-dimensional media are subject to dispersion, which limits their effective range and utility as information carriers. We show the design of a confining magnonic waveguide created by two surface current carrying wires placed above a spin-sheet, which can be used as a primitive for reconfigurable magnonic circuitry. We theoretically demonstrate the ability of such guides to counter the transverse dispersion of the magnon in a spin-sheet, thus extending the range of the magnon. A design of a magnonic directional coupler and controllable Michelson interferometer is shown, demonstrating its utility for information processing tasks.

  8. Polarization-dependent in-line quasi-Michelson interferometer based on PM-PCF reflection.

    Science.gov (United States)

    Du, Yanying; Qiao, Xueguang; Rong, Qiangzhou; Zhang, Jing; Feng, Dingyi; Wang, Ruohui; Sun, Hao; Hu, Manli; Feng, Zhongyao

    2013-05-20

    An in-line fiber quasi-Michelson interferometer (IFQMI) working on reflection is proposed and experimentally demonstrated. The sensing head is fabricated by splicing a section of polarization-maintaining photonic crystal fiber (PM-PCF) with a lead-in single mode fiber (SMF). Some cladding modes are excited into the PM-PCF via the mismatch-core splicing interface between PM-PCF and SMF. Besides, two orthogonal polarized-modes are formed due to the inherent multiholes cladding structure of the PM-PCF. A well-defined interference pattern is obtained as the result of cladding-orthogonal modes interference. The IFQMI with 20 cm long PM-PCF is proposed for strain and torsion measurements. A strain sensitivity of -1.3 pm/με and a torsion sensitivity of -19.17 pm/deg are obtained, respectively. The proposed device with 10 cm long PM-PCF exhibits a considered temperature sensitivity of 9.9 pm/°C. The IFQMI has a compact structure and small size, making it a good candidate for multiparameter measurements.

  9. Michelson interferometer for measuring temperature

    OpenAIRE

    Xie, Dong; Xu, Chunling; wang, Anmin

    2016-01-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displa...

  10. Michelson Interferometer (MINT)

    Science.gov (United States)

    Lacis, Andrew; Carlson, Barbara

    1993-01-01

    MINT is a Michelson interferometer designed to measure the thermal emission from the earth at high spectral resolution (2/cm) over a broad spectral range (250-1700/cm, 6-40 mu m) with contiguous 3-pixel wide (12 mrad, 8 km field of view) along-track sampling. MINT is particularly well suited for monitoring cloud properties (cloud cover, effective temperature, optical thickness, ice/water phase, and effective particle size) both day and night, as well as tropospheric water vapor, ozone, and temperature. The key instrument characteristics that make MINT ideally suited for decadal monitoring purposes are: high wavelength to wavelength precision across the full IR spectrum with high spectral resolution; space-proven long-term durability and calibration stability; and small size, low cost, low risk instrument incorporating the latest detector and electronics technology. MINT also incorporates simplicity in design and operation by utilizing passively cooled DTGS detectors and nadir viewing geometry (with target motion compensation). MINT measurement objectives, instrument characteristics, and key advantages are summarized in this paper.

  11. Polar cap mesosphere wind observations: comparisons of simultaneous measurements with a Fabry-Perot interferometer and a field-widened Michelson interferometer.

    Science.gov (United States)

    Fisher, G M; Killeen, T L; Wu, Q; Reeves, J M; Hays, P B; Gault, W A; Brown, S; Shepherd, G G

    2000-08-20

    Polar cap mesospheric winds observed with a Fabry-Perot interferometer with a circle-to-line interferometer optical (FPI/CLIO) system have been compared with measurements from a field-widened Michelson interferometer optimized for E-region winds (ERWIN). Both instruments observed the Meinel OH emission emanating from the mesopause region (approximately 86 km) at Resolute Bay, Canada (74.9 degrees N, 94.9 degrees W). This is the first time, to our knowledge, that winds measured simultaneously from a ground-based Fabry-Perot interferometer and a ground-based Michelson interferometer have been compared at the same location. The FPI/CLIO and ERWIN instruments both have a capability for high temporal resolution (less than 10 min for a full scan in the four cardinal directions and the zenith). Statistical comparisons of hourly mean winds for both instruments by scatterplots show excellent agreement, indicating that the two optical techniques provide equivalent observations of mesopause winds. Small deviations in the measured wind can be ascribed to the different zenith angles used by the two instruments. The combined measurements illustrate the dominance of the 12-h wave in the mesopause winds at Resolute Bay, with additional evidence for strong gravity wave activity with much shorter periods (tens of minutes). Future operations of the two instruments will focus on observation of complementary emissions, providing a unique passive optical capability for the determination of neutral winds in the geomagnetic polar cap at various altitudes near the mesopause.

  12. Michelson interferometer for measuring temperature

    Science.gov (United States)

    Xie, Dong; Xu, Chunling; Wang, An Min

    2017-09-01

    We investigate that temperature can be measured by a modified Michelson interferometer, where at least one reflected mirror is replaced by a thermalized sample. Both of two mirrors replaced by the corresponding two thermalized samples can help to approximatively improve the resolution of temperature up to twice than only one mirror replaced by a thermalized sample. For further improving the precision, a nonlinear medium can be employed. The Michelson interferometer is embedded in a gas displaying Kerr nonlinearity. We obtain the analytical equations and numerically calculate the precision with parameters within the reach of current technology, proving that the precision of temperature can be greatly enhanced by using a nonlinear medium. Our results show that one can create an accurate thermometer by measuring the photons in the Michelson interferometer, with no need to directly measure the population of thermalized sample.

  13. Influence of the tilting reflection mirror on the temperature and wind velocity retrieved by a polarizing atmospheric Michelson interferometer.

    Science.gov (United States)

    Zhang, Chunmin; Li, Ying

    2012-09-20

    The principles of a polarizing atmospheric Michelson interferometer are outlined. The tilt of its reflection mirror results in deflection of the reflected beam and affects the intensities of the observed inteferogram. This effect is systematically analyzed. Both rectangular and circular apertures are considered. The theoretical expression of the modulation depth and phase of the interferogram are derived. These parameters vary with the inclination angle of the mirror and the distance between the deflection center and the optical axis and significantly influence the retrieved temperature and wind speed. If the wind and temperature errors are required to be less than 3 m/s and 5 K, the deflection angle must be less than 0.5°. The errors are also dependent on the shape of aperture. If the reflection mirror is deflected in one direction, the temperature error is smaller for a circular aperture (1.3 K) than for a rectangular one (2.6 K), but the wind velocity errors are almost the same (less than 3 m/s). If the deflection center and incident light beam are coincident, the temperature errors are 3 × 10(-4) K and 0.45 K for circular and rectangular apertures, respectively. The wind velocity errors are 1.2 × 10(-3) m/s and 0.06 m/s. Both are small. The result would be helpful for theoretical research and development of the static polarization wind imaging interferometer.

  14. In-fiber integrated Michelson interferometer.

    Science.gov (United States)

    Yuan, Libo; Yang, Jun; Liu, Zhihai; Sun, Jiaxing

    2006-09-15

    A novel fiber-optic in-fiber integrated Michelson interferometer has been proposed and demonstrated. It consists of a segment of two-core fiber with a mirrored fiber end. The sensing characteristics based on the two-core fiber bending, corresponding to the shift of the phase of the two-core in-fiber integrated Michelson interferometer, are investigated.

  15. Unequal-Arms Michelson Interferometers

    Science.gov (United States)

    Tinto, Massimo; Armstrong, J. W.

    2000-01-01

    Michelson interferometers allow phase measurements many orders of magnitude below the phase stability of the laser light injected into their two almost equal-length arms. If, however, the two arms are unequal, the laser fluctuations can not be removed by simply recombining the two beams. This is because the laser jitters experience different time delays in the two arms, and therefore can not cancel at the photo detector. We present here a method for achieving exact laser noise cancellation, even in an unequal-arm interferometer. The method presented in this paper requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam. By linearly combining the two data sets with themselves, after they have been properly time shifted, we show that it is possible to construct a new data set that is free of laser fluctuations. An application of this technique to future planned space-based laser interferometer detector3 of gravitational radiation is discussed.

  16. Multiple spacecraft Michelson stellar interferometer

    Science.gov (United States)

    Stachnik, R. V.; Arnold, D.; Melroy, P.; Mccormack, E. F.; Gezari, D. Y.

    1984-01-01

    Results of an orbital analysis and performance assessment of SAMSI (Spacecraft Array for Michelson Spatial Interferometry) are presented. The device considered includes two one-meter telescopes in orbits which are identical except for slightly different inclinations; the telescopes achieve separations as large as 10 km and relay starlight to a central station which has a one-meter optical delay line in one interferometer arm. It is shown that a 1000-km altitude, zero mean inclination orbit affords natural scanning of the 10-km baseline with departures from optical pathlength equality which are well within the corrective capacity of the optical delay line. Electric propulsion is completely adequate to provide the required spacecraft motions, principally those needed for repointing. Resolution of 0.00001 arcsec and magnitude limits of 15 to 20 are achievable.

  17. Broadband measurements of electron cyclotron emission in TFTR [Tokamak Fusion Test Reactor] using a quasi-optical light collection system and a polarizing Michelson interferometer

    International Nuclear Information System (INIS)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; Diesso, M.; McCarthy, M.P.; Montague, J.; Rocco, R.

    1988-04-01

    For the past three years, a Fourier transform spectrometer diagnostic system, employing a fast-scanning polarizing Michelson interferometer, has been operating on the TFTR tokamak at Princeton Plasma Physics Laboratory. It is used to measure the electron cyclotron emission spectrum over the range 2.5 to 18 cm/sup /minus/1/ (75-540 GHz) with a resolution of 0.123 cm/sup /minus/1/(3.7 GHz), at a rate of 72 spectra per second. The quasi-optical system for collecting the light and transporting it through the interferometer to the detector has been designed using the concepts of both Gaussian and geometrical optics in order to produce a system that is efficient over the entire spectral range. The commerical Michelson interferometer was custom-made for this project and is at the state of the art for this type of specialized instrument. Various pre-installation and post-installation tests of the optical system and the interferometer were performed and are reported here. An error propagation analysis of the absolute calibration process is given. Examples of electron cyclotron emission spectra measured in two polarization directions are given, and electron temperature profiles derived from each of them are compared. 34 refs., 17 figs

  18. Broadband measurements of electron cyclotron emission in TFTR (Tokamak Fusion Test Reactor) using a quasi-optical light collection system and a polarizing Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Stauffer, F.J.; Boyd, D.A.; Cutler, R.C.; Diesso, M.; McCarthy, M.P.; Montague, J.; Rocco, R.

    1988-04-01

    For the past three years, a Fourier transform spectrometer diagnostic system, employing a fast-scanning polarizing Michelson interferometer, has been operating on the TFTR tokamak at Princeton Plasma Physics Laboratory. It is used to measure the electron cyclotron emission spectrum over the range 2.5 to 18 cm/sup /minus/1/ (75-540 GHz) with a resolution of 0.123 cm/sup /minus/1/(3.7 GHz), at a rate of 72 spectra per second. The quasi-optical system for collecting the light and transporting it through the interferometer to the detector has been designed using the concepts of both Gaussian and geometrical optics in order to produce a system that is efficient over the entire spectral range. The commerical Michelson interferometer was custom-made for this project and is at the state of the art for this type of specialized instrument. Various pre-installation and post-installation tests of the optical system and the interferometer were performed and are reported here. An error propagation analysis of the absolute calibration process is given. Examples of electron cyclotron emission spectra measured in two polarization directions are given, and electron temperature profiles derived from each of them are compared. 34 refs., 17 figs.

  19. A Michelson interferometer for ultracold neutrons

    International Nuclear Information System (INIS)

    Steyerl, A.; Malik, S.S.; Steinhauser, K.A.; Berger, L.

    1979-01-01

    We propose a neutron Michelson Interferometer installed within a focussing 'gravity diffractometer' for ultracold neutrons. In this arrangement the expected interference pattern depends only on the well-defined vertical component of neutron wavevector. Possible applications of such an interferometer are discussed. (orig.)

  20. Algorithms for Unequal-Arm Michelson Interferometers

    Science.gov (United States)

    Giampieri, Giacomo; Hellings, Ronald W.; Tinto, Massimo; Bender, Peter L.; Faller, James E.

    1994-01-01

    A method of data acquisition and data analysis is described in which the performance of Michelson-type interferometers with unequal arms can be made nearly the same as interferometers with equal arms. The method requires a separate readout of the relative phase in each arm, made by interfering the returning beam in each arm with a fraction of the outgoing beam.

  1. Michelson interferometer based spatial phase shift shearography.

    Science.gov (United States)

    Xie, Xin; Yang, Lianxiang; Xu, Nan; Chen, Xu

    2013-06-10

    This paper presents a simple spatial phase shift shearography based on the Michelson interferometer. The Michelson interferometer based shearographic system has been widely utilized in industry as a practical nondestructive test tool. In the system, the Michelson interferometer is used as a shearing device to generate a shearing distance by tilting a small angle in one of the two mirrors. In fact, tilting the mirror in the Michelson interferometer also generates spatial frequency shift. Based on this feature, we introduce a simple Michelson interferometer based spatial phase shift shearography. The Fourier transform (FT) method is applied to separate the spectrum on the spatial frequency domain. The phase change due to the loading can be evaluated using a properly selected windowed inverse-FT. This system can generate a phase map of shearography by using only a single image. The effects of shearing angle, spatial resolution of couple charge device camera, and filter methods are discussed in detail. The theory and the experimental results are presented.

  2. Wide Angle Michelson Doppler Imaging Interferometer (WAMDII)

    Science.gov (United States)

    Roberts, B.

    1986-01-01

    The wide angle Michelson Doppler imaging interferometer (WAMDII) is a specialized type of optical Michelson interferometer working at sufficiently long path difference to measure Doppler shifts and to infer Doppler line widths of naturally occurring upper atmospheric Gaussian line emissions. The instrument is intended to measure vertical profiles of atmospheric winds and temperatures within the altitude range of 85 km to 300 km. The WAMDII consists of a Michelson interferometer followed by a camera lens and an 85 x 106 charge coupled device photodiode array. Narrow band filters in a filter wheel are used to isolate individual line emissions and the lens forms an image of the emitting region on the charge coupled device array.

  3. Nonlinear Michelson interferometer for improved quantum metrology

    OpenAIRE

    Luis, Alfredo; Rivas, Ángel

    2015-01-01

    We examine quantum detection via a Michelson interferometer embedded in a gas with Kerr nonlinearity. This nonlinear interferometer is illuminated by pulses of classical light. This strategy combines the robustness against practical imperfections of classical light with the improvement provided by nonlinear processes. Regarding ultimate quantum limits, we stress that, as a difference with linear schemes, the nonlinearity introduces pulse duration as a new variable into play along with the ene...

  4. Thermoluminescence spectra measured with a Michelson interferometer

    International Nuclear Information System (INIS)

    Haschberger, P.

    1991-01-01

    A Michelson interferometer was redesigned to prove its capabilities in the measurement of short-lived, low-intensity thermoluminescence spectra. Interferograms are collected during heating up the thermoluminescent probe in a heater plate. A personal computer controls the data acquisition and processes the Fourier transform. As the results show, even a comparatively simple and limited setup leads to relevant and reproducible spectra. (author)

  5. The effect of rotations on Michelson interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Maraner, Paolo, E-mail: pmaraner@unibz.it

    2014-11-15

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations.

  6. The effect of rotations on Michelson interferometers

    International Nuclear Information System (INIS)

    Maraner, Paolo

    2014-01-01

    In the contest of the special theory of relativity, it is shown that uniform rotations induce a phase shift in Michelson interferometers. The effect is second order in the ratio of the interferometer’s speed to the speed of light, further suppressed by the ratio of the interferometer’s arms length to the radius of rotation and depends on the interferometer’s position in the co-rotating frame. The magnitude of the phase shift is just beyond the sensitivity of turntable rotated optical resonators used in present tests of Lorentz invariance. It grows significantly large in Earth’s rotated kilometer-scale Fabry–Perot enhanced interferometric gravitational-wave detectors where it appears as a constant bias. The effect can provide the means of sensing center and radius of rotations. - Highlights: • Rotations induce a phase shift in Michelson interferometers. • Earth’s rotation induces a constant bias in Michelson interferometers. • Michelson interferometers can be used to sense center and radius of rotations

  7. Phase conjugate Michelson interferometer for optical logic

    Science.gov (United States)

    Khoury, Jed

    2017-05-01

    The interference theory is developed for of the phase conjugate Michelson interferometer in which its ordinary mirrors are replaced by a single externally pumped phase conjugate mirror. According to the theory, it was found that for an interferometer with two equal arms, the path length difference depends solely on the initial alignment of the two input beams, and the vertical alignment readout. Small vertical misalignments in the readout beam by mrad causes a huge change in the phase difference in the phase between the two interferometer arms beam. The phase difference is proportional to the interferometer arm lengths. The overlap between the phase conjugate beams is not affected by the interferometer beam alignment. The interferometer is proposed for nondestructive testing and the design all optical logic and associated fuzzy logic for ultrafast optical pattern recognition.

  8. Digital holographic Michelson interferometer for nanometrology

    Science.gov (United States)

    Sevrygin, Alexander A.; Korotkov, V. I.; Pulkin, S. A.; Tursunov, I. M.; Venediktov, D. V.; Venediktov, V. Yu.; Volkov, O. V.

    2014-11-01

    The paper considers the dynamic holographic interferometry schemes with amplification (multiplication) of holographic fringes and with correction for distortions, imposed by the interferometer scheme elements. The use of digital microscope and of the matrix light modulator with direct addressing provides the completely digital closed-loop performance of the overall system for real-time evaluation of nano-scale objects size. Considered schemes were verified in the laboratory experiment, using the Michelson micro-interferometer, equipped by the USB-microscope and digital holography stage, equipped by the Holoeye spatial light modulator.

  9. Multiple reflection Michelson interferometer with picometer resolution.

    Science.gov (United States)

    Pisani, Marco

    2008-12-22

    A Michelson interferometer based on an optical set-up allowing multiple reflection between two plane mirrors performs the multiplication of the optical path by a factor N, proportionally increasing the resolution of the measurement. A multiplication factor of almost two orders of magnitude has been demonstrated with a simple set-up. The technique can be applied to any interferometric measurement where the classical interferometer limits due to fringe nonlinearities and quantum noise are an issue. Applications in precision engineering, vibration analysis, nanometrology, and spectroscopy are foreseen.

  10. Naturally stable Sagnac-Michelson nonlinear interferometer.

    Science.gov (United States)

    Lukens, Joseph M; Peters, Nicholas A; Pooser, Raphael C

    2016-12-01

    Interferometers measure a wide variety of dynamic processes by converting a phase change into an intensity change. Nonlinear interferometers, making use of nonlinear media in lieu of beamsplitters, promise substantial improvement in the quest to reach the ultimate sensitivity limits. Here we demonstrate a new nonlinear interferometer utilizing a single parametric amplifier for mode mixing-conceptually, a nonlinear version of the conventional Michelson interferometer with its arms collapsed together. We observe up to 99.9% interference visibility and find evidence for noise reduction based on phase-sensitive gain. Our configuration utilizes fewer components than previous demonstrations and requires no active stabilization, offering new capabilities for practical nonlinear interferometric-based sensors.

  11. Michelson interferometer based interleaver design using classic IIR filter decomposition.

    Science.gov (United States)

    Cheng, Chi-Hao; Tang, Shasha

    2013-12-16

    An elegant method to design a Michelson interferometer based interleaver using a classic infinite impulse response (IIR) filter such as Butterworth, Chebyshev, and elliptic filters as a starting point are presented. The proposed design method allows engineers to design a Michelson interferometer based interleaver from specifications seamlessly. Simulation results are presented to demonstrate the validity of the proposed design method.

  12. An X-ray BBB Michelson interferometer.

    Science.gov (United States)

    Sutter, John P; Ishikawa, Tetsuya; Kuetgens, Ulrich; Materlik, Gerhard; Nishino, Yoshinori; Rostomyan, Armen; Tamasaku, Kenji; Yabashi, Makina

    2004-09-01

    A new X-ray Michelson interferometer based on the BBB interferometer of Bonse and Hart and designed for X-rays of wavelength approximately 1 A was described in a previous paper. Here, a further test carried out at the SPring-8 1 km beamline BL29XUL is reported. One of the BBB's mirrors was displaced by a piezo to introduce the required path-length difference. The resulting variation of intensity with piezo voltage as measured by an avalanche photodiode could be ascribed to the phase variation resulting from the path-length change, with a small additional contribution from the change of the position of the lattice planes of the front mirror relative to the rest of the crystal. This 'Michelson fringe' interpretation is supported by the observed steady movement across the output beam of the interference fringes produced by a refractive wedge when the piezo voltage was ramped. The front-mirror displacement required for one complete fringe at the given wavelength is only 0.675 A; therefore, a quiet environment is vital for operating this device, as previous experiments have shown.

  13. Special topics in infrared interferometry. [Michelson interferometer development

    Science.gov (United States)

    Hanel, R. A.

    1985-01-01

    Topics in IR interferometry related to the development of a Michelson interferometer are treated. The selection and reading of the signal from the detector to the analog to digital converter is explained. The requirements for the Michelson interferometer advance speed are deduced. The effects of intensity modulation on the interferogram are discussed. Wavelength and intensity calibration of the interferometer are explained. Noise sources (Nyquist or Johnson noise, phonon noise), definitions of measuring methods of noise, and noise measurements are presented.

  14. Distributed acoustic sensing with Michelson interferometer demodulation

    Science.gov (United States)

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

    2017-09-01

    The distributed acoustic sensing (DAS) has been extensively studied and widely used. A distributed acoustic sensing system based on the unbalanced Michelson interferometer with phase generated carrier (PGC) demodulation was designed and tested. The system could directly obtain the phase, amplitude, frequency response, and location information of sound wave at the same time and measurement at all points along the sensing fiber simultaneously. Experiments showed that the system successfully measured the acoustic signals with a phase-pressure sensitivity about-148 dB (re rad/μPa) and frequency response ripple less than 1.5 dB. The further field experiment showed that the system could measure signals at all points along the sensing fiber simultaneously.

  15. Plasma flow velocity measurements using a modulated Michelson interferometer

    International Nuclear Information System (INIS)

    Howard, J.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (orig.)

  16. EIT Based Gas Detector Design by Using Michelson Interferometer

    International Nuclear Information System (INIS)

    Abbasian, K.; Rostami, A.; Abdollahi, M. H.

    2011-01-01

    Electromagnetically induced transparency (EIT) is one of the interesting phenomena of light-matter interaction which modifies matter properties for propagation of light. In other words, we can change the absorption and refractive index (RI) in neighborhood of the resonant frequency using EIT. In this paper, we have doped 3-level quantum dots in one of the Michelson Interferometer's mirror and used EIT to change its RI. So, a controllable phase difference between lights in two arms of interferometer is created. Long response time is the main drawback of Michelson interferometer based sensor, which is resolved by this technique.

  17. Analysis of a four-mirror-cavity enhanced Michelson interferometer.

    Science.gov (United States)

    Thüring, André; Lück, Harald; Danzmann, Karsten

    2005-12-01

    We investigate the shot-noise-limited sensitivity of a four-mirror-cavity enhanced Michelson interferometer. The intention of this interferometer topology is the reduction of thermal lensing and the impact of the interferometers contrast although transmissive optics are used with high circulating powers. The analytical expressions describing the light fields and the frequency response are derived. Although the parameter space has 11 dimensions, a detailed analysis of the resonance feature gives boundary conditions allowing systematic parameter studies.

  18. X-ray-ultraviolet beam splitters for the Michelson interferometer

    International Nuclear Information System (INIS)

    Delmotte, Franck; Ravet, Marie-Francoise; Bridou, Francoise; Varniere, Francoise; Zeitoun, Philippe; Hubert, Sebastien; Vanbostal, Laurent; Soullie, Gerard

    2002-01-01

    With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of the membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 deg. provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed

  19. X-ray-ultraviolet beam splitters for the Michelson interferometer.

    Science.gov (United States)

    Delmotte, Franck; Ravet, Marie-Françoise; Bridou, Françoise; Varnière, Françoise; Zeitoun, Philippe; Hubert, Sébastien; Vanbostal, Laurent; Soullie, Gérard

    2002-10-01

    With the aim of realizing a Michelson interferometer working at 13.9 nm, we have developed a symmetrical beam splitter with multilayers deposited on the front and back sides of a silicon nitride membrane. On the basis of the experimental optical properties of the membrane, simulations have been performed to define the multilayer structure that provides the highest reflectivity-transmission product. Optimized Mo-Si multilayers have been successfully deposited on both sides of t he membrane by use of the ion-beam sputtering technique, with a thickness-period reproducibility of 0.1 nm. Measurements by means of synchrotron radiation at 13.9 nm and at an angle of 45 degrees provide a reflectivity of 14.2% and a transmission of 15.2% for a 60% s-polarized light, close to the simulated values. Such a beam splitter has been used for x-ray laser Michelson interferometry at 13.9 nm. The first interferogram is discussed.

  20. A reconfigurable optofluidic Michelson interferometer using tunable droplet grating.

    Science.gov (United States)

    Chin, L K; Liu, A Q; Soh, Y C; Lim, C S; Lin, C L

    2010-04-21

    This paper presents a novel optofluidic Michelson interferometer based on droplet microfluidics used to create a droplet grating. The droplet grating is formed by a stream of plugs in the microchannel with constant refractive index variation. It has a real-time tunability in the grating period through varying the flow rates of the liquids and index variation via different combinations of liquids. The optofluidic Michelson interferometer is highly sensitive and is suitable for the measurement of biomedical and biochemical buffer solutions. The experimental results show that it has a sensitivity of 66.7 nm per refractive index unit (RIU) and a detection range of 0.086 RIU.

  1. Performance evaluation of a thermal Doppler Michelson interferometer system.

    Science.gov (United States)

    Mani, Reza; Dobbie, Steven; Scott, Alan; Shepherd, Gordon; Gault, William; Brown, Stephen

    2005-11-20

    The thermal Doppler Michelson interferometer is the primary element of a proposed limb-viewing satellite instrument called SWIFT (Stratospheric Wind Interferometer for Transport studies). SWIFT is intended to measure stratospheric wind velocities in the altitude range of 15-45 km. SWIFT also uses narrowband tandem etalon filters made of germanium to select a line out of the thermal spectrum. The instrument uses the same technique of phase-stepping interferometry employed by the Wind Imaging Interferometer onboard the Upper Atmosphere Research Satellite. A thermal emission line of ozone near 9 microm is used to detect the Doppler shift due to winds. A test bed was set up for this instrument that included the Michelson interferometer and the etalon filters. For the test bed work, we investigate the behavior of individual components and their combination and report the results.

  2. Double-grating interferometer with a one-to-one correspondence with a Michelson interferometer.

    Science.gov (United States)

    Xu, Yande; Sasaki, Osami; Suzuki, Takamasa

    2003-10-01

    We describe a double-grating interferometer that has a one-to-one correspondence with a Michelson interferometer. The half spatial periods of the gratings are equivalent to the wavelengths of the interferometer. The widths of the interference fringes can be changed easily. The intensity distribution of the interference pattern is independent of the wavelength of the light source used. The surface profile of an object can be measured because two interference beams can coincide precisely on the image plane of the object. The measuring range is much larger than that of a Michelson interferometer.

  3. Liquid-helium-cooled Michelson interferometer

    Science.gov (United States)

    Augason, G. C.; Young, N.

    1972-01-01

    Interferometer serves as a rocket-flight spectrometer for examination of the far infrared emission spectra of astronomical objects. The double beam interferometer is readily adapted to make spectral scans and for use as a detector of discrete line emissions.

  4. Two-photon quantum interference in a Michelson interferometer

    International Nuclear Information System (INIS)

    Odate, Satoru; Wang Haibo; Kobayashi, Takayoshi

    2005-01-01

    We have observed two-photon quantum interference in a Michelson interferometer. For the first time, we experimentally demonstrated two-photon quantum interference patterns, which show the transition from nonsubwavelength interference fringes to the general subwavelength interference. At the same time, a photon bunching effect was also shown by a postselection. The |1, 1> state with a single photon in a mode corresponding to each arm of the interferometer was exclusively postselected by using path difference between two arms

  5. Quantitative Phase Determination by Using a Michelson Interferometer

    Science.gov (United States)

    Pomarico, Juan A.; Molina, Pablo F.; D'Angelo, Cristian

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as…

  6. Measurement of Refractive Index Using a Michelson Interferometer.

    Science.gov (United States)

    Fendley, J. J.

    1982-01-01

    Describes a novel and simple method of measuring the refractive index of transparent plates using a Michelson interferometer. Since it is necessary to use a computer program when determining the refractive index, undergraduates could be given the opportunity of writing their own programs. (Author/JN)

  7. Plasma flow velocity measurements using a modulated Michelson interferometer

    NARCIS (Netherlands)

    Howard, J.; Meijer, F. G.

    1997-01-01

    This paper discusses the possibility of flow velocity reconstruction using passive spectroscopic techniques. We report some preliminary measurements of the toroidal flow velocity of hydrogen atoms in the RTP tokamak using a phase modulated Michelson interferometer. (C) 1997 Elsevier Science S.A.

  8. Computerized evaluation optical measuring thin films by the help of Michelson`s interferometer

    Czech Academy of Sciences Publication Activity Database

    Bartoněk, L.; Keprt, Jiří

    2002-01-01

    Roč. 9, č. 2 (2002), s. 27-34 ISSN 1335-0803 R&D Projects: GA MŠk LN00A015 Institutional research plan: CEZ:AV0Z1010921 Keywords : Michelson `s interferometer * computerized evaluation Subject RIV: BH - Optics, Masers, Lasers

  9. Optical path difference measurements with a two-step parallel phase shifting interferometer based on a modified Michelson configuration

    Science.gov (United States)

    Toto-Arellano, Noel Ivan; Serrano-Garcia, David I.; Rodriguez-Zurita, Gustavo

    2017-09-01

    We report an optical implementation of a parallel phase-shifting quasi-common path interferometer using two modified Michelson interferometers to generate two interferograms. By using a displaceable polarizer's array, placed on the image plane, we can obtain four phase-shifted interferograms in two captures. The system operates as a quasi-common path interferometer generating four beams, which are to interfere with alignment procedures on the mirrors of the Michelson configurations. The optical phase data are retrieved using the well-known four-step algorithms. To present the capabilities of the system, experimental results obtained from transparent structures are presented.

  10. Optical displacement measurement with GaAs/AlGaAs-based monolithically integrated Michelson interferometers

    OpenAIRE

    Hofstetter, Daniel; Zappe, H. P.; Dändliker, René

    2008-01-01

    Two monolithically integrated optical displacement sensors fabricated in the GaAs/AlGaAs material system are reported. These single-chip microsystems are configured as Michelson interferometers and comprise a distributed Bragg reflector (DBR) laser, photodetectors, phase shifters, and waveguide couplers. While the use of a single Michelson interferometer allows measurement of displacement magnitude only, a double Michelson interferometer with two interferometer signals in phase quadrature als...

  11. Improved double-pass michelson interferometer

    Science.gov (United States)

    Schindler, R. A.

    1978-01-01

    Interferometer design separates beams by offsetting centerlines of cat's-eye retroreflectors vertically rather than horizontally. Since beam splitter is insensitive to minimum-thickness condition in this geometry, relatively-low-cost, optically flat plate can be used.

  12. Development of stable monolithic wide-field Michelson interferometers.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian; Chen, Zhiping

    2011-07-20

    Bulk wide-field Michelson interferometers are very useful for high precision applications in remote sensing and astronomy. A stable monolithic Michelson interferometer is a key element in high precision radial velocity (RV) measurements for extrasolar planets searching and studies. Thermal stress analysis shows that matching coefficients of thermal expansion (CTEs) is a critical requirement for ensuring interferometer stability. This requirement leads to a novel design using BK7 and LAK7 materials, such that the monolithic interferometer is free from thermal distortion. The processes of design, fabrication, and testing of interferometers are described in detail. In performance evaluations, the field angle is typically 23.8° and thermal sensitivity is typically -2.6×10(-6)/°C near 550 nm, which corresponds to ∼800 m/s/°C in the RV scale. Low-cost interferometer products have been commissioned in multiple RV instruments, and they are producing high stability performance over long term operations. © 2011 Optical Society of America

  13. Phase correction for a Michelson interferometer with misaligned mirrors

    Science.gov (United States)

    Goorvitch, D.

    1975-01-01

    The phase correction for a Michelson interferometer with misaligned mirrors in converging light is shown to give rise to a quadratic phase shift. In general, the calculation of a spectrum from the measured interferogram needs phase correction. Phase corrections have been well worked out for the cases of a linear phase shift and a phase that is slowly varying. The standard procedures for correcting calculated spectra need to be modified, however, to remove any phase errors resulting from misaligned mirrors.

  14. Infrared spectra of lunar soils. [using a Michelson interferometer

    Science.gov (United States)

    Aronson, J. R.; Emslie, A. G.; Smith, E. M.

    1979-01-01

    Measured data obtained by Michelson interferometer spectrometer were stored in a computer file and smoothed by being passed forward and backward through a digital four-pole low pass filter. Infrared spectra of the 10 lunar samples are presented in the format of brightness temperature versus frequency. The mol % of feldspar, pyroxene, olivine, ilmenite and ferromagnetic silicate in each sample is presented in tables. The reflectance spectra of ilmenite and enstatite are shown in graphs.

  15. Fiber inline Michelson interferometer fabricated by a femtosecond laser.

    Science.gov (United States)

    Yuan, Lei; Wei, Tao; Han, Qun; Wang, Hanzheng; Huang, Jie; Jiang, Lan; Xiao, Hai

    2012-11-01

    A fiber inline Michelson interferometer was fabricated by micromachining a step structure at the tip of a single-mode optical fiber using a femtosecond laser. The step structure splits the fiber core into two reflection paths and produces an interference signal. A fringe visibility of 18 dB was achieved. Temperature sensing up to 1000°C was demonstrated using the fabricated assembly-free device.

  16. Near-infrared spectral imaging Michelson interferometer for astronomical applications

    Science.gov (United States)

    Wells, C. W.; Potter, A. E.; Morgan, T. H.

    1980-01-01

    The design and operation of an imaging Michelson interferometer-spectrometer used for near-infrared (0.8 micron to 2.5 microns) spectral imaging are reported. The system employs a rapid scan interferometer modified for stable low resolution (250/cm) performance and a 42 element PbS linear detector array. A microcomputer system is described which provides data acquisition, coadding, and Fourier transformation for near real-time presentation of the spectra of all 42 scene elements. The electronic and mechanical designs are discussed and telescope performance data presented.

  17. A Michelson interferometer for X-rays and thermal neutrons

    International Nuclear Information System (INIS)

    Appel, A.

    1992-01-01

    The introduced interferometer consists of an LLL interferometer and a phase-displacing Bragg groove component. A part of the radiation path between the Lane mirrors in the Bragg grooves is replaced by a radiation path, whose wave number vector has a slightly different direction compared to the Lane case by the refraction correction. If the angles of incidence in the two grooves are different, then a difference in path is produced between the beams producing interference. This is the first X-ray interferometer which works like an optical Michelson interferometer. As there are no basic limits to resolution by absorption or dispersion, for example, it opens up the possibility of carrying out Fourier spectroscopy in the A wavelength range. (orig.) [de

  18. Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Monolithic Interferometer Design and Test

    Science.gov (United States)

    Harlander, John M.; Englert, Christoph R.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Zastera, Vaz; Bach, Bernhard W.; Mende, Stephen B.

    2017-10-01

    The design and laboratory tests of the interferometers for the Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument which measures thermospheric wind and temperature for the NASA-sponsored Ionospheric Connection (ICON) Explorer mission are described. The monolithic interferometers use the Doppler Asymmetric Spatial Heterodyne (DASH) Spectroscopy technique for wind measurements and a multi-element photometer approach to measure thermospheric temperatures. The DASH technique and overall optical design of the MIGHTI instrument are described in an overview followed by details on the design, element fabrication, assembly, laboratory tests and thermal control of the interferometers that are the heart of MIGHTI.

  19. Michelson-type Radio Interferometer for University Education

    Science.gov (United States)

    Koda, Jin; Barrett, J. W.; Hasegawa, T.; Hayashi, M.; Shafto, G.; Slechta, J.

    2013-01-01

    Despite the increasing importance of interferometry in astronomy, the lack of educational interferometers is an obstacle to training the futue generation of astronomers. Students need hands-on experiments to fully understand the basic concepts of interferometry. Professional interferometers are often too complicated for education, and it is difficult to guarantee access for classes in a university course. We have built a simple and affordable radio interferometer for education and used it for an undergraduate and graduate laboratory project. This interferometer's design is based on the Michelson & Peace's stellar optical interferometer, but operates at a radio wavelength using a commercial broadcast satellite dish and receiver. Two side mirrors are surfaced with kitchen aluminum foil and slide on a ladder, providing baseline coverage. This interferometer can resolve and measure the diameter of the Sun, a nice daytime experiment which can be carried out even under a marginal weather (i.e., partial cloud coverage). Commercial broadcast satellites provide convenient point sources. By comparing the Sun and satellites, students can learn how an interferometer works and resolves structures in the sky.

  20. Superposition of helical beams by using a Michelson interferometer.

    Science.gov (United States)

    Gao, Chunqing; Qi, Xiaoqing; Liu, Yidong; Weber, Horst

    2010-01-04

    Orbital angular momentum (OAM) of a helical beam is of great interests in the high density optical communication due to its infinite number of eigen-states. In this paper, an experimental setup is realized to the information encoding and decoding on the OAM eigen-states. A hologram designed by the iterative method is used to generate the helical beams, and a Michelson interferometer with two Porro prisms is used for the superposition of two helical beams. The experimental results of the collinear superposition of helical beams and their OAM eigen-states detection are presented.

  1. Modulation depth of Michelson interferometer with Gaussian beam.

    Science.gov (United States)

    Välikylä, Tuomas; Kauppinen, Jyrki

    2011-12-20

    Mirror misalignment or the tilt angle of the Michelson interferometer can be estimated from the modulation depth measured with collimated monochromatic light. The intensity of the light beam is usually assumed to be uniform, but, for example, with gas lasers it generally has a Gaussian distribution, which makes the modulation depth less sensitive to the tilt angle. With this assumption, the tilt angle may be underestimated by about 50%. We have derived a mathematical model for modulation depth with a circular aperture and Gaussian beam. The model reduces the error of the tilt angle estimate to below 1%. The results of the model have been verified experimentally.

  2. The Michelson interferometer-how to detect invisible interference patterns

    International Nuclear Information System (INIS)

    Verovnik, Ivo; Likar, Andrej

    2004-01-01

    In a Michelson interferometer, the contrast of the interference pattern fades away due to incoherence of light when the mirrors are not in equidistant positions. We propose an experiment where the distance between the interference fringes can be determined, even when the difference in length of the interferometer arms is far beyond the coherence length of the light, i.e. when the interference pattern disappears completely for the naked eye. We used a semiconductor laser with two photodiodes as sensors, which enabled us to follow the fluctuations of the light intensity on the screen. The distance between invisible interference fringes was determined from periodic changes of the summed fluctuating signal, obtained by changing the distance between the two sensors

  3. Quantitative phase determination by using a Michelson interferometer

    International Nuclear Information System (INIS)

    Pomarico, Juan A; Molina, Pablo F; Angelo, Cristian D'

    2007-01-01

    The Michelson interferometer is one of the best established tools for quantitative interferometric measurements. It has been, and is still successfully used, not only for scientific purposes, but it is also introduced in undergraduate courses for qualitative demonstrations as well as for quantitative determination of several properties such as refractive index, wavelength, optical thickness, etc. Generally speaking, most of the measurements are carried out by determining phase distortions through the changes in the location and/or shape of the interference fringes. However, the extreme sensitivity of this tool, for which minimum deviations of the conditions of its branches can cause very large modifications in the fringe pattern, makes phase changes difficult to follow and measure. The purpose of this communication is to show that, under certain conditions, the sensitivity of the Michelson interferometer can be 'turned down' allowing the quantitative measurement of phase changes with relative ease. As an example we present how the angle (or, optionally, the refractive index) of a transparent standard optical wedge can be determined. Experimental results are shown and compared with the data provided by the manufacturer showing very good agreement

  4. Integrated fiber Michelson interferometer based on poled hollow twin-core fiber.

    Science.gov (United States)

    Liu, Zhihai; Bo, Fusen; Wang, Lei; Tian, Fengjun; Yuan, Libo

    2011-07-01

    We propose an integrated fiber Michelson interferometer based on a poled hollow twin-core fiber. The Michelson interferometer can be used as an electro-optic modulator by thermal poling one core of the twin-core fiber and introducing second-order nonlinearity in the fiber. The proposed fiber Michelson interferometer is experimentally demonstrated under driving voltages at the frequency range of 149 to 1000 Hz. The half-wave voltage of the poled fiber is 135 V, and the effective second-order nonlinear coefficient χ² is 1.23 pm/V.

  5. Development of high resolution Michelson interferometer for stable phase-locked ultrashort pulse pair generation.

    Science.gov (United States)

    Okada, Takumi; Komori, Kazuhiro; Goshima, Keishiro; Yamauchi, Shohgo; Morohashi, Isao; Sugaya, Takeyoshi; Ogura, Mutsuo; Tsurumachi, Noriaki

    2008-10-01

    We developed a high resolution Michelson interferometer with a two-frequency He-Ne laser positioning system in order to stabilize the relative phase of a pulse pair. The control resolution corresponded to a 12 as time resolution or a phase of 1.5 degrees at 900 nm. This high resolution Michelson interferometer can generate a phase-locked pulse pair either with a specific relative phase such as 0 or pi radians or with an arbitrary phase. Coherent control of an InAs self-assembled quantum dot was demonstrated using the high resolution Michelson interferometer with a microspectroscopy system.

  6. Detection of Laser Generated Ultrasonic Wave Using Michelson Interferometer

    International Nuclear Information System (INIS)

    Kim, Kyung Cho; Yamawaki, Hisashi; Jhang, Kyung Young

    2000-01-01

    In this paper, ultrasonic wave in the thermoelastic regime was generated in a steel disk by illuminating a pulse laser (Q-switched Nd:YAG) on the surface of the sample and was detected on the other side by Michelson interferometer which was stabilized by feed back control. The experimentally detected displacement waveform of the ultrasonic wave showed good agreement with the theoretically expected one. Also it was shown that sound speeds of longitudinal and shear wave were similar to ones measured by pulse-echo method using a contact transducer. As an application of the noncontact ultrasonic measurement by using laser based ultrasonics, the sound speed in the sample was monitored while the sample was heated in a furnace, and the result showed that it decreased according to the increase of sample temperature

  7. Detection of laser generated ultrasonic wave using Michelson interferometer

    International Nuclear Information System (INIS)

    Kim, Kyung Cho; Nakano, Hidetoshi; Jhang, Kyung Young

    1999-01-01

    A stabilized Michelson Interferometer is proposed in order to detect the laser-generated ultrasonic waves in fee from the external noise such as low frequency mechanical vibration. In order to confirm the performance, theoretically expected waveforms were compared with experimentally detected ones in thermo-elastic region, where we generated ultrasonic wave in steel disk by using a Q-switched Nd:YAG laser. Also sound velocities of longitudinal and shear components were measured and they showed good agreement with the typical values in steel. Finally, the change of sound velocity according to the temperature change was measured to show that the proposed technique could be applied to the characterization of high temperature materials.

  8. WAMDII: The Wide Angle Michelson Doppler Imaging Interferometer

    Science.gov (United States)

    1992-01-01

    As part of an effort to learn more about the upper atmosphere and how it is linked to the weather experienced each day, NASA and NRCC are jointly sponsoring the Wide Angle Michelson Doppler Imaging Interferometer (WAMDII) Mission. WAMDII will measure atmospheric temperature and wind speed in the upper atmosphere. In addition to providing data on the upper atmosphere, the wind speed and temperature readings WAMDII takes will also be highly useful in developing and updating computer simulated models of the upper atmosphere. These models are used in the design and testing of equipment and software for Shuttles, satellites, and reentry vehicles. In making its wind speed and temperature measurements, WAMDII examines the Earth's airglow, a faint photochemical luminescence caused by the influx of solar ultraviolet energy into the upper atmosphere. During periods of high solar flare activity, the amount of this UV energy entering the upper atmosphere increases, and this increase may effect airglow emissions.

  9. Investigation of michelson interferometer for volatile organic compound sensor

    International Nuclear Information System (INIS)

    Marzuarman; Rivai, Muhammad; Sardjono, Tri Arief; Purwanto, Djoko

    2017-01-01

    The sensor device is required to monitor harmful gases in the environments and industries. Many volatile organic compounds adsorbed on the sensor material will result in changes of the optical properties including the refractive index and the film thickness. This study designed and realized a vapor detection device using the principle of Michelson Interferometer. The laser light beamed with a wavelength of 620 nm was divided by using a beam splitter. Interference occurredwhen the two separated lights were recombined. The phase difference between the two beams determined whether the interference would destruct or construct each other to produce the curved fringes. The vapor samples used in these experiments were ethanol and benzene. The results showed that the ethanol concentration of 1611-32210 ppm produced a fringe shift of 197 pixels, while the concentration of benzene of 964-19290 ppm produced a fringe shift of 273 pixels. (paper)

  10. Transverse coherence measurement using a folded Michelson interferometer.

    Science.gov (United States)

    Dean, Jesse; Bercx, Martin; Nantel, Marc; Marjoribanks, Robin

    2007-06-01

    The transverse coherence of a 1 ps pulsed laser beam was measured using a technique involving a modified Michelson interferometer and separate reference images. Using this technique, the transverse coherence of a selected plane in the laser beam was determined, in this case at the exit of a channel in a metal foil self-drilled by the laser. Images of each arm were used as references. Through this technique, it is possible to use the interference patterns produced with uneven intensity distributions and for pulsed lasers on a single-shot basis. The results of these measurements were then shown to be in agreement with those obtained using a Young's double-slit setup.

  11. Wide angle Michelson Doppler imaging interferometer. [measuring atmospheric emissions

    Science.gov (United States)

    Shepherd, G. G.

    1980-01-01

    The optical system, stepping control, phase and modulation depth, array detector, and directions sensor are described for a specialized type of Michelson interferometer which works at sufficiently high resolution to measure the line widths and Doppler shifts of naturally occurring atmospheric emissions. With its imaging capability, the instrument can potentially supply this data independently for each element of the 100 x 100 detector array. The experiment seeks: (1) to obtain vertical profiles of atmospheric winds and temperatures as functions of latitude by observing near the limb; (2) to acquire exploratory wind and temperature data on smaller scale structures in airglow irregularities and in auroral forms; and (3) to collaborate with other Spacelab experiments, such as barium cloud releases, in providing wind and temperature data.

  12. Dissipative optomechanics in a Michelson-Sagnac interferometer.

    Science.gov (United States)

    Xuereb, André; Schnabel, Roman; Hammerer, Klemens

    2011-11-18

    Dissipative optomechanics studies the coupling of the motion of an optical element to the decay rate of a cavity. We propose and theoretically explore a realization of this system in the optical domain, using a combined Michelson-Sagnac interferometer, which enables a strong and tunable dissipative coupling. Quantum interference in such a setup results in the suppression of the lower motional sideband, leading to strongly enhanced cooling in the non-sideband-resolved regime. With state-of-the-art parameters, ground-state cooling and low-power quantum-limited position transduction are both possible. The possibility of a strong, tunable dissipative coupling opens up a new route towards observation of such fundamental optomechanical effects as nonlinear dynamics. Beyond optomechanics, the suggested method can be readily transferred to other setups involving nonlinear media, atomic ensembles, or single atoms.

  13. Broadband sensitivity enhancement of detuned dual-recycled Michelson interferometers with EPR entanglement

    Science.gov (United States)

    Brown, Daniel D.; Miao, Haixing; Collins, Chris; Mow-Lowry, Conor; Töyrä, Daniel; Freise, Andreas

    2017-09-01

    We demonstrate the applicability of the EPR entanglement squeezing scheme for enhancing the shot-noise-limited sensitivity of detuned dual-recycled Michelson interferometers. In particular, this scheme is applied to the GEO600 interferometer. The effect of losses throughout the interferometer, arm length asymmetries, and imperfect separation of the signal and idler beams is considered.

  14. Analysis of the Localization of Michelson Interferometer Fringes Using Fourier Optics and Temporal Coherence

    Science.gov (United States)

    Narayanamurthy, C. S.

    2009-01-01

    Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in "Principles of Optics" by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer…

  15. Analysis of the localization of Michelson interferometer fringes using Fourier optics and temporal coherence

    International Nuclear Information System (INIS)

    Narayanamurthy, C S

    2009-01-01

    Fringes formed in a Michelson interferometer never localize in any plane, in the detector plane and in the localization plane. Instead, the fringes are assumed to localize at infinity. Except for some explanation in Principles of Optics by Born and Wolf (1964 (New York: Macmillan)), the fringe localization phenomena of Michelson's interferometer have never been analysed seriously in any book. Because Michelson's interferometer is one of the important and fundamental optical experiments taught at both undergraduate and graduate levels, it would be appropriate to explain the localization of these fringes. In this paper, we analyse the localization of Michelson interferometer fringes using Fourier optics and temporal coherence, and show that they never localize at any plane even at infinity

  16. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers

    International Nuclear Information System (INIS)

    Hilbert, Vinzenz; Fuchs, Silvio; Paulus, Gerhard G.; Zastrau, Ulf; Blinne, Alexander; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Förster, Eckhart

    2013-01-01

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed

  17. Direct UV written Michelson interferometer for RZ signal generation using phase-to-intensity modulation conversion

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Geng, Yan; Zsigri, Beata

    2005-01-01

    An integrated Michelson delay interferometer structure making use of waveguide gratings as reflective elements is proposed and fabricated by direct ultraviolet writing. Successful return-to-zero alternate-mark-inversion signal generation using phase-to-intensity modulation conversion...

  18. An extreme ultraviolet Michelson interferometer for experiments at free-electron lasers.

    Science.gov (United States)

    Hilbert, Vinzenz; Blinne, Alexander; Fuchs, Silvio; Feigl, Torsten; Kämpfer, Tino; Rödel, Christian; Uschmann, Ingo; Wünsche, Martin; Paulus, Gerhard G; Förster, Eckhart; Zastrau, Ulf

    2013-09-01

    We present a Michelson interferometer for 13.5 nm soft x-ray radiation. It is characterized in a proof-of-principle experiment using synchrotron radiation, where the temporal coherence is measured to be 13 fs. The curvature of the thin-film beam splitter membrane is derived from the observed fringe pattern. The applicability of this Michelson interferometer at intense free-electron lasers is investigated, particularly with respect to radiation damage. This study highlights the potential role of such Michelson interferometers in solid density plasma investigations using, for instance, extreme soft x-ray free-electron lasers. A setup using the Michelson interferometer for pseudo-Nomarski-interferometry is proposed.

  19. Preliminary result of bunch length measurement using a modified Michelson interferometer

    International Nuclear Information System (INIS)

    Lin Xuling; Luo Feng; Bei Hua; Dai Zhimin; Chinese Academy of Sciences, Beijing; Zhang Jianbing; Lu Shanliang; Yu Tiemin

    2009-01-01

    Based on the femtosecond accelerator device which was built at the Shanghai Institute of Applied Physics (SINAP), recently a modified far infrared Michelson interferometer has been developed to measure the length of electron bunches via the optical autocorrelation method. Compared with our former normal Michelson interferometer, we use a hollow retroreflector instead of a flat mirror as the reflective mirror. The experimental setup and results of the bunch length measurement will be described in this paper. (authors)

  20. Dual-recycled cavity-enhanced Michelson interferometer for gravitational-wave detection.

    Science.gov (United States)

    Müller, Guido; Delker, Tom; Tanner, David B; Reitze, David

    2003-03-01

    The baseline design for an Advanced Laser Interferometer Gravitational-Wave Observatory (Advanced LIGO) is a dual-recycled Michelson interferometer with cavities in each of the Michelson interferometer arms. We describe one possible length-sensing and control scheme for such a dual-recycled, cavity-enhanced Michelson interferometer. We discuss the principles of this scheme and derive the first-order sensing signals. We also present a successful experimental verification of our length-sensing system using a prototype tabletop interferometer. Our results demonstrate the robustness of the scheme against deviations from the idealized design. We also identify potential weaknesses and discuss possible improvements. These results as well as other benchtop experiments that we present form the basis for a sensing and control scheme for Advanced LIGO.

  1. Infrared spectroscopy with a balloon borne Michelson interferometer. Pt. 2

    International Nuclear Information System (INIS)

    Moorwood, A.F.M.; Salinari, P.; Furniss, I.; Jennings, R.E.; King, K.J.

    1980-01-01

    Observations of the [O III] ionic fine structure lines at 52 μm and 88 μm, made at a resolution of 0.05 cm -1 with a balloon borne telescope and Michelson interferometer, are presented for the H II regions W 51, G33.6-0.2. M 17 S, M 17 N, NGC 6357, and NGC 6334. This is the first time that both [O III] lines have been measured simultaneously. Values for the electron density deduced from the line ratios are found to agree with the radio data, while the O ++ abundances indicate a lower excitation than expected in many cases. The [O I] line at 63 μm was also detected in NGC 6357. In addition, we report the first detection of the [N III] line at 57 μm which was observed from both sources in M 17 and gives the abundance ratio N/O = 0.13. This line was also marginally detected on W 51. (orig.)

  2. Digital holographic amplification of interferograms in the Michelson interferometer using the phase-only LCOS modulator

    Science.gov (United States)

    Balbekin, Nikolay; Petrov, Nikolay; Pul'kin, Sergey; Shoev, Vladislav; Sevryugin, Alexander; Tursunov, Ibrohim; Venediktov, Dmitrii; Venediktov, Vladimir

    2017-10-01

    The method of amplification of hologram was applied to the so-called Rozhdestvenskiy hooks, that were obtained in the Rozhdestvenskiy interferometer (Michelson interferometer, combined with a grating spectrograph). In such a device the absorption lines reveal themselves as specific "hooks", whose curvature provides the information about the atomic oscillator force. The holographic amplification "smoothes" the hooks and thus makes their analysis much simpler.

  3. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature

    NARCIS (Netherlands)

    Schmuck, S.; Fessey, J.; Gerbaud, T.; Alper, B.; Beurskens, M. N. A.; de la Luna, E.; Sirinelli, A.; Zerbini, M.

    2012-01-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron

  4. Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements

    NARCIS (Netherlands)

    Nijholt, J.L.M.

    1998-01-01

    This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much

  5. Detection method of nonlinearity errors by statistical signal analysis in heterodyne Michelson interferometer.

    Science.gov (United States)

    Hu, Juju; Hu, Haijiang; Ji, Yinghua

    2010-03-15

    Periodic nonlinearity that ranges from tens of nanometers to a few nanometers in heterodyne interferometer limits its use in high accuracy measurement. A novel method is studied to detect the nonlinearity errors based on the electrical subdivision and the analysis method of statistical signal in heterodyne Michelson interferometer. Under the movement of micropositioning platform with the uniform velocity, the method can detect the nonlinearity errors by using the regression analysis and Jackknife estimation. Based on the analysis of the simulations, the method can estimate the influence of nonlinearity errors and other noises for the dimensions measurement in heterodyne Michelson interferometer.

  6. Improved operation of the Michelson interferometer electron cyclotron emission diagnostic on DIII-D

    International Nuclear Information System (INIS)

    Austin, M.E.; Ellis, R.F.; Doane, J.L.; James, R.A.

    1997-01-01

    The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and a reduction of calibration error from 15% to 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter-wavelength frequency and very stable transmission characteristics over time. Further reduction in error was realized through special signal processing of the calibration and plasma interferograms. copyright 1997 American Institute of Physics

  7. Improved operation of the Michelson interferometer ECE diagnostic on DIII-D

    International Nuclear Information System (INIS)

    Austin, M.E.; Ellis, R.F.; Doane, J.L.; James, R.A.

    1996-05-01

    The measurement of accurate temperature profiles is critical for transport analysis and equilibrium reconstruction in the DIII-D tokamak. Recent refinements in the Michelson interferometer diagnostic have produced more precise electron temperature measurements from electron cyclotron emission and made them available for a wider range of discharge conditions. Replacement of a lens-relay with a low-loss corrugated waveguide transmission system resulted in an increase in throughput of 6 dB and reduction of calibration error to around 5%. The waveguide exhibits a small polarization scrambling fraction of 0.05 at the quarter wavelength frequency and very stable transmission characteristics over time. Further reduction in error has been realized through special signal processing of the calibration and plasma interferograms

  8. Studies of Gravity Waves Using Michelson Interferometer Measurements of OH (3-1 Bands

    Directory of Open Access Journals (Sweden)

    Young-In Won

    2001-06-01

    Full Text Available As part of a long-term program for polar upper atmospheric studies, temperatures and intensities of the OH (3-1 bands were derived from spectrometric observations of airglow emissions over King Sejong station (62.22o S, 301.25o E. These measurements were made with a Michelson interferometer to cover wavelength regions between 1000 nm and 2000 nm. A spectral analysis was performed to individual nights of data to acquire information on the waves in the upper mesosphere/lower thermosphere. It is assumed that the measured fluctuations in the intensity and temperature of the OH (3-1 airglow were caused by gravity waves propagating through the emission layer. Correlation of intensity and temperature variation revealed oscillations with periods ranging from 2 to 9 hours. We also calculated Krassovsky's parameter and compared with published values.

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

    International Nuclear Information System (INIS)

    Mosquera, L; Osorio, 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-Zehnder interferometer and its application to measure ethanol concentration in gasoline.

  10. A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber

    International Nuclear Information System (INIS)

    Frazão, O; Silva, S F; Viegas, J; Baptista, J M; Santos, J L; Roy, P

    2010-01-01

    A hybrid Fabry–Perot/Michelson interferometer sensor using a dual asymmetric core microstructured fiber is demonstrated. The hybrid interferometer presents three waves. Two parallel Fabry–Perot cavities with low finesse are formed between the splice region and the end of a dual-core microstructured fiber. A Michelson configuration is obtained by the two small cores of the microstructured fiber. The spectral response of the hybrid interferometer presents two pattern fringes with different frequencies due to the respective optical path interferometers. The hybrid interferometer was characterized in strain and temperature presenting different sensitivity coefficients for each topology. Due to these characteristics, this novel sensing head is able to measure strain and temperature, simultaneously

  11. Optical refractometer based on an asymmetrical twin-core fiber Michelson interferometer.

    Science.gov (United States)

    Zhou, Ai; Zhang, Yanhui; Li, Guangping; Yang, Jun; Wang, Yuzhuo; Tian, Fengjun; Yuan, Libo

    2011-08-15

    We report and demonstrate an optical refractometer based on a compact fiber Michelson interferometer. The Michelson interferometer is composed of an asymmetrical twin-core fiber containing a central core and a side core. By chemically etching a segment of the twin-core fiber until the side core is exposed, the effective index of the side core in the etched region is sensitive to the environmental refractive index, which leads to a shift of the transmission spectrum of the Michelson interferometer. The experimental results show that such a device has a refractive index resolution of more than 800 nm/refractive index unit in the range of 1.34-1.37. © 2011 Optical Society of America

  12. Proposal of Michelson-Morley experiment via single photon interferometer: Interpretation of Michelson-Morley experimental results using de Broglie-Bohm picture

    OpenAIRE

    Sato, Masanori

    2004-01-01

    The Michelson-Morley experiment is considered via a single photon interferometer and we propose the interpretation of the Michelson-Morley experimental results using de Broglie-Bohm picture. We point out that the Michelson-Morley experiment revealed the interference of photons, however, it did not reveal the photons simultaneous arrival at the beam splitter. According to the de Broglie-Bohm picture, the quantum potential nonlocally determines the interference of photons. The interference of t...

  13. Determination of refractive indices of biconvex lenses by use of a Michelson interferometer.

    Science.gov (United States)

    Chhaniwal, Vani K; Anand, Arun; Narayanamurthy, C S

    2006-06-10

    Measurements of lens parameters such as focal length, radius of curvature, and refractive index are important. We describe a measurement method that utilizes a Michelson interferometer to determine parameters of thin, convex lenses. The real fringe system formed by a Michelson interferometer is used to determine the focal lengths and the radii of curvature of the lenses. The refractive index of the lens material is determined from the thin-lens formula. We were able to determine the refractive indices to an accuracy as great as 99.97%. A detailed theoretical and experimental analysis is given.

  14. Secondary wavelength stabilization of unbalanced Michelson interferometers for the generation of low-jitter pulse trains.

    Science.gov (United States)

    Shalloo, R J; Corner, L

    2016-09-01

    We present a double unbalanced Michelson interferometer producing up to four output pulses from a single input pulse. The interferometer is stabilized with the Hänsch-Couillaud method using an auxiliary low power continuous wave laser injected into the interferometer, allowing the stabilization of the temporal jitter of the output pulses to 0.02 fs. Such stabilized pulse trains would be suitable for driving multi-pulse laser wakefield accelerators, and the technique could be extended to include amplification in the arms of the interferometer.

  15. Dispersed single-phase-step Michelson interferometer for Doppler imaging using sunlight.

    Science.gov (United States)

    Wan, Xiaoke; Ge, Jian

    2012-09-15

    A Michelson interferometer is dispersed with a fiber array-fed spectrograph, providing 59 Doppler sensing channels using sunlight in the 510-570 nm wavelength region. The interferometer operates at a single-phase-step mode, which is particularly advantageous in multiplexing and data processing compared to the phase-stepping mode of other interferometer spectrometer instruments. Spectral templates are prepared using a standard solar spectrum and simulated interferometer modulations, such that the correlation function with a measured 1D spectrum determines the Doppler shift. Doppler imaging of a rotating cylinder is demonstrated. The average Doppler sensitivity is ~12 m/s, with some channels reaching ~5 m/s.

  16. Design of a birefringent Michelson interferometer-based interleaver with ultra-low dispersion and low cost.

    Science.gov (United States)

    Hu, Haocheng; Zheng, Baozhong; Liu, Qingming; Li, Yang; Wu, Li; Gu, Shijie

    2011-11-21

    We design and demonstrate a birefringent Michelson interferometer based interleaver with ultra-low dispersion and low cost. The interleaver consists of polarizing beam splitters (PBS's) and quarter-wave plates and half-wave plates. The PBS's based Michelson interferometers provide the optical path difference for interference between the two orthogonal polarization components and the half-wave plates provide the birefringent needed to minimize ripple of output. The designed interleaver with two-stage interferometer in a 50 GHz channel spacing application exhibits a 0.5 dB passband and a 25 dB stopband both 27 GHz; a channel isolation higher than 35 dB and chromatic dispersion less than ±5 ps/nm within 0.5 dB passband; 1.3 dB insertion loss and 0.3 dB PDL; 0.04 GHz/°C thermal stability. Since all of the optical components can be optically bonded together, the device is robust and easy to be aligned, which reduces labor cost. © 2011 Optical Society of America

  17. A Michelson interferometer/polarimeter on the Tokamak Fusion Test Reactor (TFTR)

    International Nuclear Information System (INIS)

    Park, H.K.; Mansfield, D.K.; Johnson, L.C.; Ma, C.H.

    1987-01-01

    A multichannel interferometer/polarimeter for the Tokamak Fusion Test Reactor (TFTR) has been developed in order to study the time dependent plasma current density (J/sub p/) and electron density (n/sub e/) profile simultaneously. The goal of the TFTR is demonstration of breakeven via dueuterium and tritium (DT) plasma. In order to be operated and maintained during DT operation phase, the system is designed based on the Michelson geometry which possesses intrinsic standing wave problems. So far, there has been no observable signals due to these standing waves. However, a standing wave resulted from the beam path design to achieve a optimum use of the laser power was found. This standing wave has not prevented initial 10 channel interferometer operation. However, a single channel polarimeter test indicated this standing wave was fatal for Faraday notation measurements. Techniques employing 1/2 wave plates and polarizers have been applied to eliminate this standing wave problem. The completion of 10 channel Faraday rotation measurements may be feasible in the near future

  18. Experiments on the Porch Swing Bearing of Michelson Interferometer for Low Resolution FTIR

    OpenAIRE

    Tuomas Välikylä; Jyrki Kauppinen

    2013-01-01

    Porch swing bearing for the linear motion of the mirror in Michelson interferometer for mid-infrared low resolution Fourier transform spectrometer was studied experimentally using the modulation depth of the collimated laser beam. The mirror tilting was measured to be lower than 5 μrad over 3 mm mirror travel using two different bearings assemblies. Additionally, the manufacturing tolerances of the bearing type were proved to be loose enough not to limit the interferometer application. These ...

  19. Reduction of quantum noise in the Michelson interferometer by use of squeezed vacuum states

    International Nuclear Information System (INIS)

    Assaf, Ohad; Ben-Aryeh, Yacob

    2002-01-01

    We develop further the unified model for treating photon-counting and radiation-pressure fluctuations in the Michelson interferometer with input of squeezed vacuum state. The dependence of the quantum fluctuations on the phase of the input light is calculated. The analysis is restricted to a single-mode interferometer, but generalized in a way that includes both harmonic-oscillator and floating mirrors. We compare our results with those of other authors

  20. Electrically switchable holographic liquid crystal/polymer Fresnel lens using a Michelson interferometer.

    Science.gov (United States)

    Jashnsaz, Hossein; Mohajerani, Ezeddin; Nemati, Hossein; Razavi, Seyed Hossein; Alidokht, Isa Ahmad

    2011-06-10

    A holographic technique for fabricating an electrically switchable liquid crystal/polymer composite Fresnel lens is reported. A Michelson interferometer is used to produce the required Fresnel pattern, by placing a convex lens into one path of the interferometer. Simplicity of the method and the possibility of fabricating different focal length lenses in a single arrangement are advantages of the method. The performance of the fabricated lens was demonstrated and its electro-optical properties were investigated for its primary focal length.

  1. System analysis of a tilted field-widened Michelson interferometer for high spectral resolution lidar.

    Science.gov (United States)

    Liu, Dong; Hostetler, Chris; Miller, Ian; Cook, Anthony; Hair, Johnathan

    2012-01-16

    High spectral resolution lidars (HSRLs) have shown great value in aircraft aerosol remote sensing application and are planned for future satellite missions. A compact, robust, quasi-monolithic tilted field-widened Michelson interferometer is being developed as the spectral discrimination filter for an second-generation HSRL(HSRL-2) at NASA Langley Research Center. The Michelson interferometer consists of a cubic beam splitter, a solid arm and an air arm. Piezo stacks connect the air arm mirror to the body of the interferometer and can tune the interferometer within a small range. The whole interferometer is tilted so that the standard Michelson output and the reflected complementary output can both be obtained. In this paper, the transmission ratio is proposed to evaluate the performance of the spectral filter for HSRL. The transmission ratios over different types of system imperfections, such as cumulative wavefront error, locking error, reflectance of the beam splitter and anti-reflection coatings, system tilt, and depolarization angle are analyzed. The requirements of each imperfection for good interferometer performance are obtained.

  2. Using a Michelson Interferometer to Measure Coefficient of Thermal Expansion of Copper

    Science.gov (United States)

    Scholl, Ryan; Liby, Bruce W.

    2009-01-01

    When most materials are heated they expand. This concept is usually demonstrated using some type of mechanical measurement of the linear expansion of a metal rod. We have developed an alternative laboratory method for measuring thermal expansion by using a Michelson interferometer. Using the method presented, interference, interferometry, and the…

  3. Simple Ultra-Low-Cost Undergraduate Holography Using a Modified Michelson Interferometer.

    Science.gov (United States)

    Rudmin, J. W.; And Others

    1980-01-01

    A technique is presented for producing holograms using equipment which is already in the possesion of the majority of college physics departments, which includes a slightly modified Michelson interferometer, a helium-neon laser, and a long focal-length lens. Production of high quality holograms has been achieved by inexperienced undergraduates…

  4. A method for the coherence measurement of the supercontinuum source using Michelson interferometer

    International Nuclear Information System (INIS)

    Semenova, V A; Tsypkin, A V; Putilin, S E; Bespalov, V G

    2014-01-01

    Coherent properties of supercontinuum sources are highly significant for various applications, including low-coherence interferometry and optical frequency metrology. We propose a fast method for the spatial and temporal self-coherence of the SC measurement using Michelson interferometer without a mirror movement. Furthermore, we present self-coherence measurements of the supercontinuum, generated in microstructured fiber at 780 nm.

  5. Quantum Mechanical Noise in a Michelson Interferometer with Nonclassical Inputs: Nonperturbative Treatment

    Science.gov (United States)

    King, Sun-Kun

    1996-01-01

    The variances of the quantum-mechanical noise in a two-input-port Michelson interferometer within the framework of the Loudon-Ni model were solved exactly in two general cases: (1) one coherent state input and one squeezed state input, and (2) two photon number states inputs. Low intensity limit, exponential decaying signal and the noise due to mixing were discussed briefly.

  6. A calibration mechanism based on the principles of the Michelson interferometer micro-thrust test device

    Science.gov (United States)

    Yan, Biao; Wang, Hai; Yang, Chunlai; Wen, Li

    2017-08-01

    A micro-thrust test system based on Michelson interferometer was proposed and tested. The relationship between thrust and output voltage of the calibration component in the system was calculated and verified with numerical modeling. The fitting function of the calibration component was obtained, which will be tested during future thrust test experiments.

  7. The comparison of environmental effects on michelson and fabry-perot interferometers utilized for the displacement measurement.

    Science.gov (United States)

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-01-01

    The optical structure of general commercial interferometers, e.g., the Michelson interferometers, is based on a non-common optical path. Such interferometers suffer from environmental effects because of the different phase changes induced in different optical paths and consequently the measurement precision will be significantly influenced by tiny variations of the environmental conditions. Fabry-Perot interferometers, which feature common optical paths, are insensitive to environmental disturbances. That would be advantageous for precision displacement measurements under ordinary environmental conditions. To verify and analyze this influence, displacement measurements with the two types of interferometers, i.e., a self-fabricated Fabry-Perot interferometer and a commercial Michelson interferometer, have been performed and compared under various environmental disturbance scenarios. Under several test conditions, the self-fabricated Fabry-Perot interferometer was obviously less sensitive to environmental disturbances than a commercial Michelson interferometer. Experimental results have shown that induced errors from environmental disturbances in a Fabry-Perot interferometer are one fifth of those in a Michelson interferometer. This has proved that an interferometer with the common optical path structure will be much more independent of environmental disturbances than those with a non-common optical path structure. It would be beneficial for the solution of interferometers utilized for precision displacement measurements in ordinary measurement environments.

  8. Broadband squeezing of quantum noise in a Michelson interferometer with Twin-Signal-Recycling.

    Science.gov (United States)

    Thüring, André; Gräf, Christian; Vahlbruch, Henning; Mehmet, Moritz; Danzmann, Karsten; Schnabel, Roman

    2009-03-15

    Twin-Signal-Recycling (TSR) builds on the resonance doublet of two optically coupled cavities and efficiently enhances the sensitivity of an interferometer at a dedicated signal frequency. We report on what we believe to be the first experimental realization of a TSR Michelson interferometer and also its broadband enhancement by squeezed light injection. The complete setup was stably locked, and a broadband quantum noise reduction of the interferometers shot noise by a factor of up to 4 dB was demonstrated. The system was characterized by measuring its quantum noise spectra for several tunings of the TSR cavities. We found good agreement between the experimental results and numerical simulations.

  9. Naked eye picometer resolution in a Michelson interferometer using conjugated twisted beams.

    Science.gov (United States)

    Emile, Olivier; Emile, Janine

    2017-01-15

    Michelson interferometry is one of the most widely used techniques for accuracy measurements. Its main characteristic feature is to infer a displacement in one of the arms of the interferometer from a phase measurement. Two different twisted beams, also called vortex beams, with opposite twisted rotations in each arm of the interferometer interfere in a daisy flower-like pattern. The number of petals is twice the topological charge. Their position depends on the relative phase of the beams. Naked eye detection of 44 pm displacements is achieved. The sensitivity of such an interferometer together with possible further improvements, and applications are then discussed.

  10. Enlarging the angle of view in Michelson-interferometer-based shearography by embedding a 4f system.

    Science.gov (United States)

    Wu, Sijin; He, Xiaoyuan; Yang, Lianxiang

    2011-07-20

    Digital shearography based on Michelson interferometers suffers from the disadvantage of a small angle of view due to the structure. We demonstrate a novel digital shearography system with a large angle of view. In the optical arrangement, the imaging lens is in front of the Michelson interferometer rather than behind it as in traditional digital shearography. Thus, the angle of view is no longer limited by the Michelson interferometer. The images transmitting between the separate lens and camera are accomplished by a 4f system in the new style of shearography. The influences of the 4f system on shearography are also discussed. © 2011 Optical Society of America

  11. Michelson interferometer with diffractively-coupled arm resonators in second-order Littrow configuration.

    Science.gov (United States)

    Britzger, Michael; Wimmer, Maximilian H; Khalaidovski, Alexander; Friedrich, Daniel; Kroker, Stefanie; Brückner, Frank; Kley, Ernst-Bernhard; Tünnermann, Andreas; Danzmann, Karsten; Schnabel, Roman

    2012-11-05

    Michelson-type laser-interferometric gravitational-wave (GW) observatories employ very high light powers as well as transmissively-coupled Fabry-Perot arm resonators in order to realize high measurement sensitivities. Due to the absorption in the transmissive optics, high powers lead to thermal lensing and hence to thermal distortions of the laser beam profile, which sets a limit on the maximal light power employable in GW observatories. Here, we propose and realize a Michelson-type laser interferometer with arm resonators whose coupling components are all-reflective second-order Littrow gratings. In principle such gratings allow high finesse values of the resonators but avoid bulk transmission of the laser light and thus the corresponding thermal beam distortion. The gratings used have three diffraction orders, which leads to the creation of a second signal port. We theoretically analyze the signal response of the proposed topology and show that it is equivalent to a conventional Michelson-type interferometer. In our proof-of-principle experiment we generated phase-modulation signals inside the arm resonators and detected them simultaneously at the two signal ports. The sum signal was shown to be equivalent to a single-output-port Michelson interferometer with transmissively-coupled arm cavities, taking into account optical loss. The proposed and demonstrated topology is a possible approach for future all-reflective GW observatory designs.

  12. Triple Michelson interferometer for a third-generation gravitational wave detector

    International Nuclear Information System (INIS)

    Freise, A; Chelkowski, S; Hild, S; Pozzo, W Del; Perreca, A; Vecchio, A

    2009-01-01

    The upcoming European design study 'Einstein gravitational-wave Telescope' represents the first step towards a substantial, international effort for the design of a third-generation interferometric gravitational wave detector. It is generally believed that third-generation instruments might not be installed into existing infrastructures but will provoke a new search for optimal detector sites. Consequently, the detector design could be subject to fewer constraints than the on-going design of the second-generation instruments. In particular, it will be prudent to investigate alternatives to the traditional L-shaped Michelson interferometer. In this paper, we review an old proposal to use three Michelson interferometers in a triangular configuration. We use this example of a triple Michelson interferometer to clarify the terminology and will put this idea into the context of more recent research on interferometer technologies. Furthermore, the benefits of a triangular detector will be used to motivate this design as a good starting point for a more detailed research effort towards a third-generation gravitational-wave detector.

  13. Development of a control scheme of homodyne detection for extracting ponderomotive squeezing from a Michelson interferometer

    International Nuclear Information System (INIS)

    Sakata, Shihori; Kawamura, Seiji; Sato, Shuichi; Somiya, Kentaro; Arai, Koji; Fukushima, Mitsuhiro; Sugamoto, Akio

    2006-01-01

    We developed a control scheme of homodyne detection. To operate the homodyne detector as easy as possible, a simple Michelson interferometer is used. Here a motivation that the control scheme of the homodyne detection is developed is for our future experiment of extracting the ponderomotively squeezed vacuum fluctuations. To obtain the best signalto- noise ratio using the homodyne detection, the homodyne phase should be optimized. The optimization of the homodyne phase is performed by changing a phase of a local oscillator for the homodyne detection from a point at which a signal is maximized. In fact, in this experiment, using the developed control scheme, we locked the Michelson interferometer with the homodyne detector and changed the phase of the local oscillator for the homodyne detection. Then, we measured signals quantity changed by changing the phase of the local oscillator for the homodyne detection. Here we used the output from the homodyne detection as the signal

  14. Microwave Michelson interferometer system report of first use on a railgun, Green Farm, San Diego, CA

    Science.gov (United States)

    Hawke, R. S.; Greenwood, D.; Morrison, J.; Schildmeyer, F.

    1993-10-01

    This report summarizes the successful first attempt to use a Michelson microwave interferometer to measure the position of a projectile throughout its acceleration by a railgun. The test was performed at the DNA Green Farm facility operated by Maxwell Labs Inc. The test was performed using the ARDEC-ACB gun to accelerate a 1.1 kg polycarbonate projectile to about 2.5 km/s. The projectile had an initial injection velocity of about 490 m/s.

  15. Quasi zero-background tunable diode laser absorption spectroscopy employing a balanced Michelson interferometer.

    Science.gov (United States)

    Guan, Zuguang; Lewander, Märta; Svanberg, Sune

    2008-12-22

    Tunable diode laser spectroscopy (TDLS) normally observes small fractional absorptive reductions in the light flux. We show, that instead a signal increase on a zero background can be obtained. A Michelson interferometer, which is initially balanced out in destructive interference, is perturbed by gas absorption in one of its arms. Both theoretical analysis and experimental demonstration show that the proposed zero-background TDLS can improve the achievable signal-to-noise ratio.

  16. A compact, high resolution Michelson interferometer for atmospheric spectroscopy in the near ultraviolet

    Science.gov (United States)

    Sander, Stanley P.; Cageao, Richard P.; Friedl, Randall R.

    1993-01-01

    A new, compact Fourier Transform Michelson interferometer (FTUV) with an apodized resolving power greater than 300,000 at 300 nm, high throughput and wide spectral coverage has been developed. The objectives include atmospheric spectroscopy (direct solar absorption and solar scattering) and laboratory spectroscopy of transient species. In this paper, we will briefly describe the prototype FTUV instrument and the results of preliminary laboratory investigations of OH and ClO spectra in emission and absorption.

  17. Refractive index sensor based on an abrupt taper Michelson interferometer in a single-mode fiber.

    Science.gov (United States)

    Tian, Zhaobing; Yam, Scott S-H; Loock, Hans-Peter

    2008-05-15

    A simple refractive index sensor based on a Michelson interferometer in a single-mode fiber is constructed and demonstrated. The sensor consists of a single symmetrically abrupt taper region in a short piece of single-mode fiber that is terminated by approximately 500 nm thick gold coating. The sensitivity of the new sensor is similar to that of a long-period-grating-type sensor, and its ease of fabrication offers a low-cost alternative to current sensing applications.

  18. Universal Michelson Gires-Tournois interferometer optical interleaver based on digital signal processing.

    Science.gov (United States)

    Zhang, Juan; Yang, Xiaowei

    2010-03-01

    Optical interleavers based on Michelson Gires-Tournois interferometer (MGTI) with arbitrary cascaded reflectors for symmetrical or asymmetrical periodic frequency response with arbitrary duty cycles are defined as universal MGTI optical interleaver (UMGTIOI). It can significantly enhance flexibility and applicability of optical networks. A novel and simple method based on digital signal processing is proposed for the design of UMGTIOI. Different kinds of design examples are given to confirm effectiveness of the method.

  19. Control of the phase characteristics of Stokes waves in a Michelson interferometer with SBS mirrors

    Science.gov (United States)

    Gordeev, A. A.; Efimkov, V. F.; Zubarev, I. G.; Mikhailov, S. I.

    2016-12-01

    It is found that, when using stimulated Brillouin scattering (SBS) mirrors (mounted in a ring Michelson interferometer) with counterfocusing, under pumping by pulses with steep (2 - 3 {\\text{ns}}) leading edges and applying Freon FC-75 as an active medium, the phase difference of the Stokes waves on the semitransparent interferometer mirror obeys the dependence Δ \\varphi = 2Δ k Δ l (Δ k is the difference in the magnitudes of the pump and Stokes component wave vectors and Δ l is the difference in the optical arm lengths).

  20. Improvement on a Michelson interferometer for bunch length measurement of a femtosecond accelerator

    International Nuclear Information System (INIS)

    Lin Xuling; Bei Hua; Zhang Jianbing; Dai Zhimin

    2009-01-01

    Based on the femtosecond accelerator facility at Shanghai Institute of Applied Physics (SINAP), a conventional far-infrared Michelson interferometer was built to measure the bunch length by means of optical autocorrelation. However, according to the preliminary experiment result, the resolution of interferometer is not good enough, because the mirror-driving mechanism makes the moving mirror tend to tilt or wobble as it retards. Considering of the allowable errors, we calculate the maximum allowable titling angle of the moving mirror, and discuss the alignment plan in this paper. (authors)

  1. Atom Michelson interferometer on a chip using a Bose-Einstein condensate.

    Science.gov (United States)

    Wang, Ying-Ju; Anderson, Dana Z; Bright, Victor M; Cornell, Eric A; Diot, Quentin; Kishimoto, Tetsuo; Prentiss, Mara; Saravanan, R A; Segal, Stephen R; Wu, Saijun

    2005-03-11

    An atom Michelson interferometer is implemented on an "atom chip." The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms.

  2. Atom Michelson interferometer on a chip using a Bose-Einstein condensate

    International Nuclear Information System (INIS)

    Wang Yingju; Anderson, Dana Z.; Cornell, Eric A.; Diot, Quentin; Kishimoto, Tetsuo; Segal, Stephen R.; Bright, Victor M.; Saravanan, R.A.; Prentiss, Mara; Wu Saijun

    2005-01-01

    An atom Michelson interferometer is implemented on an 'atom chip'. The chip uses lithographically patterned conductors and external magnetic fields to produce and guide a Bose-Einstein condensate. Splitting, reflecting, and recombining of condensate atoms are achieved by a standing-wave light field having a wave vector aligned along the atom waveguide. A differential phase shift between the two arms of the interferometer is introduced by either a magnetic-field gradient or with an initial condensate velocity. Interference contrast is still observable at 20% with an atom propagation time of 10 ms

  3. Fast and low power Michelson interferometer thermo-optical switch on SOI.

    Science.gov (United States)

    Song, Junfeng; Fang, Q; Tao, S H; Liow, T Y; Yu, M B; Lo, G Q; Kwong, D L

    2008-09-29

    We designed and fabricated silicon-on-insulator based Michelson interferometer (MI) thermo-optical switches with deep etched trenches for heat-isolation. Switch power was reduced approximately 20% for the switch with deep etched trenches, and the MI saved approximately 50% power than that of the Mach-Zehnder interferometer. 10.6 mW switch power, approximately 42 micros switch time for the MI with deep trenches, 13.14 mW switch power and approximately 34 micros switch time for the MI without deep trenches were achieved.

  4. Displacement measurement using an optoelectronic oscillator with an intra-loop Michelson interferometer.

    Science.gov (United States)

    Lee, Jehyun; Park, Sooyoung; Seo, Dae Han; Yim, Sin Hyuk; Yoon, Seokchan; Cho, D

    2016-09-19

    We report on measurement of small displacements with sub-nanometer precision using an optoelectronic oscillator (OEO) with an intra-loop Michelson interferometer. In comparison with conventional homodyne and heterodyne detection methods, where displacement appears as a power change or a phase shift, respectively, in the OEO detection, the displacement produces a shift in the oscillation frequency. In comparison with typical OEO sensors, where the frequency shift is proportional to the OEO oscillation frequency in radio-frequency domain, the frequency shift in our method with an intra-loop interferometer is proportional to an optical frequency. We constructed a hybrid apparatus and compared characteristics of the OEO and heterodyne detection methods.

  5. A differential Michelson interferometer with orthogonal single frequency laser for nanometer displacement measurement

    International Nuclear Information System (INIS)

    Yan, Liping; Chen, Benyong; Wang, Bin

    2017-01-01

    A novel differential Michelson laser interferometer is proposed to eliminate the influence of environmental fluctuations for nanometer displacement measurement. This differential interferometer consists of two homodyne interferometers in which two orthogonal single frequency beams share common reference arm and partial measurement arm. By modulating the displacement of the common reference arm with a piezoelectric transducer, the common-mode displacement drift resulting from the environmental disturbances can be well suppressed and the measured displacement as differential-mode displacement signal is achieved. In addition, a phase difference compensation method is proposed for accurately determining the phase difference between interference signals by correcting the time interval according to the average speed in one cycle of interference signal. The nanometer displacement measurement experiments were performed to demonstrate the effectiveness and feasibility of the proposed interferometer and show that precision displacement measurement with standard deviation less than 1 nm has been achieved. (paper)

  6. Experimental demonstration of a variable reflectivity signal recycled Michelson interferometer for gravitational wave detection

    International Nuclear Information System (INIS)

    De Vine, G.; Shaddock, D.; McClelland, D.

    2002-01-01

    Full text: One technique of improving the sensitivity of interferometric gravitational wave detectors is to implement a signal mirror. This involves placing a mirror at the output of the Michelson interferometer. The gravitational wave signal is then 'recycled' back into the interferometer where it can coherently add with the gravitational wave signal still being produced. The frequency of the improved sensitivity is dependent on the position of the signal mirror, while the peak height and bandwidth are dependent on the reflectivity of the signal mirror. This is because the signal mirror forms a cavity with the Michelson interferometer and this cavity has a resonant frequency dependent on its length and a bandwidth dependent on its finesse, which are a function of signal mirror position and reflectivity, respectively. Due to the varying and/or unknown nature of the gravitational wave frequencies and wave-forms, it is desirable to be able to control both the peak frequency and bandwidth of the detector. The peak frequency can be easily adjusted by altering the signal mirror position. The bandwidth, however, is fixed with the signal mirror reflectivity. In a long base-line gravitational wave detector it is impractical to swap the signal mirror with one of different reflectivity for a number of reasons, for example, the detector's high vacuum would have to be broken, realignment performed and locking re-acquired. This is addressed by the proposal of two different forms of variable reflectivity signal mirror (VRSM): a Fabry-Perot cavity and a Michelson interferometer. These are analysed and the reasons for choosing to investigate the Michelson VRSM are given. The reasons include the potential for easier control and the smooth variation in reflectivity with arm length difference. The experiment is discussed and the results of the first demonstration of variable reflectivity signal recycling are presented in the form of frequency responses obtained by injecting a second

  7. Quantum noise of a Michelson-Sagnac interferometer with a translucent mechanical oscillator

    International Nuclear Information System (INIS)

    Yamamoto, Kazuhiro; Friedrich, Daniel; Westphal, Tobias; Gossler, Stefan; Danzmann, Karsten; Schnabel, Roman; Somiya, Kentaro; Danilishin, Stefan L.

    2010-01-01

    Quantum fluctuations in the radiation pressure of light can excite stochastic motions of mechanical oscillators thereby realizing a linear quantum opto-mechanical coupling. When performing a precise measurement of the position of an oscillator, this coupling results in quantum radiation pressure noise. Up to now this effect has not been observed yet. Generally speaking, the strength of radiation pressure noise increases when the effective mass of the oscillator is decreased or when the power of the reflected light is increased. Recently, extremely light SiN membranes (≅100 ng) with high mechanical Q values at room temperature (≥10 6 ) have attracted attention as low thermal noise mechanical oscillators. However, the power reflectance of these membranes is much lower than unity (<0.4 at a wavelength of 1064 nm) which makes the use of advanced interferometer recycling techniques to amplify the radiation pressure noise in a standard Michelson interferometer inefficient. Here, we propose and theoretically analyze a Michelson-Sagnac interferometer that includes the membrane as a common end mirror for the Michelson interferometer part. In this topology, both power and signal recycling can be used even if the reflectance of the membrane is much lower than unity. In particular, signal recycling is a useful tool because it does not involve a power increase at the membrane. We derive the formulas for the quantum radiation pressure noise and the shot noise of an oscillator position measurement and compare them with theoretical models of the thermal noise of a SiN membrane with a fundamental resonant frequency of 75 kHz and an effective mass of125 ng. We find that quantum radiation pressure noise should be observable with a power of 1 W at the central beam splitter of the interferometer and a membrane temperature of 1 K.

  8. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature.

    Science.gov (United States)

    Schmuck, S; Fessey, J; Gerbaud, T; Alper, B; Beurskens, M N A; de la Luna, E; Sirinelli, A; Zerbini, M

    2012-12-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The current state of the interferometer hardware, the calibration setup, and the analysis technique for calibration and plasma operation are described. A new, full-system, absolute calibration employing continuous data acquisition has been performed recently and the calibration method and results are presented. The noise level in the measurement is very low and as a result the electron cyclotron emission spectrum and thus the spatial profile of the electron temperature are determined to within ±5% and in the most relevant region to within ±2%. The new calibration shows that the absolute response of the system has decreased by about 15% compared to that measured previously and possible reasons for this change are presented. Temperature profiles measured with the Michelson interferometer are compared with profiles measured independently using Thomson scattering diagnostics, which have also been recently refurbished and recalibrated, and agreement within experimental uncertainties is obtained.

  9. Quantum mechanical noise in coherent-state and squeezed-state Michelson interferometers

    International Nuclear Information System (INIS)

    Assaf, Ohad; Ben-Aryeh, Yacob

    2002-01-01

    In the present study we extend and generalize previous results for coherent-state and squeezed-state Michelson interferometer quantum mechanical uncertainties (or fluctuations), which are commonly referred to as 'quantum noise'. The calculation of photon counting (PC) fluctuations in the squeezed-state interferometer is extended to fourth-order correlation functions used as the measured signal. We also generalize a 'unified model' for treating both PC and radiation pressure fluctuations in the coherent-state interferometer, by using mathematical methods which apply to Kerr-type interactions. The results are more general than those reported previously in two ways. First, we obtain exact expressions, which lead to previous results under certain approximations. Second, we deal with cases in which the responses of the two mirrors to radiation pressure are not equal

  10. Optical-feedback semiconductor laser Michelson interferometer for displacement measurements with directional discrimination

    International Nuclear Information System (INIS)

    Rodrigo, Peter John; Lim, May; Saloma, Caesar

    2001-01-01

    An optical-feedback semiconductor laser Michelson interferometer (OSMI) is presented for measuring microscopic linear displacements without ambiguity in the direction of motion. The two waves from the interferometer arms, one from the reference mirror and the other from the reflecting moving target, are fed back into the lasing medium (λ=830 nm), causing variations in the laser output power. We model the OSMI into an equivalent Fabry-Perot resonator and derive the dependence of the output power (and the junction voltage) on the path difference between the two interferometer arms. Numerical and experimental results consistently show that the laser output power varies periodically (period, λ/2) with path difference. The output power variation exhibits an asymmetric behavior with the direction of motion, which is used to measure, at subwavelength resolution, the displacement vector (both amplitude and direction) of the moving sample. Two samples are considered in the experiments: (i) a piezoelectric transducer and (ii) an audio speaker

  11. Frequency locking of a field-widened Michelson interferometer based on optimal multi-harmonics heterodyning.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Zhou, Yudi; Yang, Yongying; Luo, Jing; Zhang, Yupeng; Shen, Yibing; Liu, Chong; Bai, Jian; Wang, Kaiwei; Su, Lin; Yang, Liming

    2016-09-01

    A general resonant frequency locking scheme for a field-widened Michelson interferometer (FWMI), which is intended as a spectral discriminator in a high-spectral-resolution lidar, is proposed based on optimal multi-harmonics heterodyning. By transferring the energy of a reference laser to multi-harmonics of different orders generated by optimal electro-optic phase modulation, the heterodyne signal of these multi-harmonics through the FWMI can reveal the resonant frequency drift of the interferometer very sensitively within a large frequency range. This approach can overcome the locking difficulty induced by the low finesse of the FWMI, thus contributing to excellent locking accuracy and lock acquisition range without any constraint on the interferometer itself. The theoretical and experimental results are presented to verify the performance of this scheme.

  12. Study on the wide-angle Michelson interferometer with large air gap.

    Science.gov (United States)

    Gao, Haiyang; Tang, Yuanhe; Hua, Dengxin; Liu, Hanchen

    2011-10-10

    A wide-angle Michelson interferometer with large air gap is proposed to effectively reduce the size of the glass arms and constraint on material. It provides a novel and practical instrument for ground based wind measurement of the upper atmosphere. The field widening conditions for the large air gap are calculated in theory. For the five spectral lines of 557.7 nm, 630.0 nm, 732.0 nm, 834.6 nm, and 865.7 nm, the optimal results under ideal condition are obtained with air gaps of 1.0 cm, 1.5 cm, and 2.0 cm, respectively. With the fixed optical path difference (OPD) of 7.495 cm, three pairs of glass arms are optimized. The pair with length of 1.5 cm for air gap, 5.765 cm for H-ZF12, and 2.956 cm for H-ZLaF54, has better effect of field widening than the other two pairs and its OPD variation is only within 0.30 wavelengths at incident angle of 3°. For developing a more practical wide-angle Michelson interferometer, the H-K9L glass with size of 4.445 cm is employed as the arm material of solid interferometer. The experiment for field of view of 3° is designed and the data processing and analysis for 60 images show the agreement between experimental results and theoretical simulation. The OPD variations are only within 0.27 wavelengths for image edge. The feasibility and practicality of the wide-angle Michelson interferometer with large air gap is proved by means of theory and experiment. © 2011 Optical Society of America

  13. Measurement of two-dimensional Doppler wind fields using a field widened Michelson interferometer.

    Science.gov (United States)

    Langille, Jeffery A; Ward, William E; Scott, Alan; Arsenault, Dennis L

    2013-03-10

    An implementation of the field widened Michelson concept has been applied to obtain high resolution two-dimensional (2D) images of low velocity (interferometer scanning mirror position is controlled to subangstrom precision with subnanometer repeatability using the multi-application low-voltage piezoelectric instrument control electronics developed by COM DEV Ltd.; it is the first implementation of this system as a phase stepping Michelson. In this paper the calibration and characterization of the Doppler imaging system is described and the planned implementation of this new technique for imaging 2D wind and irradiance fields using the earth's airglow is introduced. Observations of Doppler winds produced by a rotating wheel are reported and shown to be of sufficient precision for buoyancy wave observations in airglow in the mesopause region of the terrestrial atmosphere.

  14. Study of optically thin electron cyclotron emission from TFTR using a Michelson interferometer

    International Nuclear Information System (INIS)

    Stauffer, F.J.; Boyd, D.A.

    1986-01-01

    The TFTR Michelson interferometer, which is used as an electron temperature diagnostic, has a spectral range of 75-540 GHz. This range is adequate for measuring at least the first three cyclotron harmonics, and it spans both optically thick and thin portions of the ECE spectrum. During the most recent opening of the TFTR vacuum vessel, a concave, carbon reflector was installed on the back wall of the vessel, opposite the light collecting optic of the Michelson system. The reflector is designed to prevent the observation of optically thin ECE that originates from a location that is outside the field of view of the light collecting optic. If this is achieved, it should be possible to derive the electron density profile from measurements of either the extraordinary mode third harmonic or the ordinary mode second harmonic. An analysis of ECE spectra that have been measured before and after installation of the reflector is presented

  15. Microwave interrogated large core fused silica fiber Michelson interferometer for strain sensing.

    Science.gov (United States)

    Hua, Liwei; Song, Yang; Huang, Jie; Lan, Xinwei; Li, Yanjun; Xiao, Hai

    2015-08-20

    A Michelson-type large core optical fiber sensor has been developed, which is designed based on the optical carrier-based microwave interferometry technique, and fabricated by using two pieces of 200-μm diameter fused silica core fiber as two arms of the Michelson interferometer. The interference fringe pattern caused by the optical path difference of the two arms is interrogated in the microwave domain, where the fringe visibility of 40 dB has easily been obtained. The strain sensing at both room temperature and high temperatures has been demonstrated by using such a sensor. Experimental results show that this sensor has a linear response to the applied strain, and also has relatively low temperature-strain cross talk. The dopant-free quality of the fused silica fiber provides high possibility for the sensor to have promising strain sensing performance in a high temperature environment.

  16. Field-widened Michelson interferometer for spectral discrimination in high-spectral-resolution lidar: theoretical framework.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Luo, Jing; Yang, Yongying; Zhou, Yudi; Zhang, Yupeng; Duan, Lulin; Su, Lin; Yang, Liming; Shen, Yibing; Wang, Kaiwei; Bai, Jian

    2015-05-04

    A field-widened Michelson interferometer (FWMI) is developed to act as the spectral discriminator in high-spectral-resolution lidar (HSRL). This realization is motivated by the wide-angle Michelson interferometer (WAMI) which has been used broadly in the atmospheric wind and temperature detection. This paper describes an independent theoretical framework about the application of the FWMI in HSRL for the first time. In the framework, the operation principles and application requirements of the FWMI are discussed in comparison with that of the WAMI. Theoretical foundations for designing this type of interferometer are introduced based on these comparisons. Moreover, a general performance estimation model for the FWMI is established, which can provide common guidelines for the performance budget and evaluation of the FWMI in the both design and operation stages. Examples incorporating many practical imperfections or conditions that may degrade the performance of the FWMI are given to illustrate the implementation of the modeling. This theoretical framework presents a complete and powerful tool for solving most of theoretical or engineering problems encountered in the FWMI application, including the designing, parameter calibration, prior performance budget, posterior performance estimation, and so on. It will be a valuable contribution to the lidar community to develop a new generation of HSRLs based on the FWMI spectroscopic filter.

  17. Physical interpretation of the fringe shift measured on Michelson interferometer in optical media

    International Nuclear Information System (INIS)

    Demjanov, V.V.

    2010-01-01

    The shift of the interference fringe in the Michelson interferometer is absent in vacuum but present in measurements performed in dielectric media with the refractive index greater than unity. This experimental observation induced me to interpret physical processes occurred in the Michelson interferometer in a conceptually new way. I rejected the generally accepted additive rule c±v for composition of the velocity v of the inertial body and the speed c of light as inapplicable in principle to non-inertial objects which electromagnetic waves just belong to. I used instead the non-relativistic formula of Fresnel for drag of light by a moving optical medium. This formula, and taking into account the physical effect of Lorentz contraction of the arm of interferometer, enabled me to construct the theoretical model that reproduces in essential features the parabolic dependence of the shift of the interference fringe on the dielectric permittivity of the light-carrying material. The Earth's speed relative to aether found from the experimental curve was estimated as 140-480 km/s. The range of the values refers to the projection of the speed on the horizontal plane of the experimental setup measured at various time of day and night.

  18. Analysis of a sub-shot-noise power recycled Michelson interferometer

    International Nuclear Information System (INIS)

    McKenzie, K; Buchler, B C; Shaddock, D A; Lam, P K; McClelland, D E

    2004-01-01

    The sensitivity of interferometric gravitational wave detectors is ultimately limited by the 'quantum noise' of light. In this paper we compare results from a bench-top experiment and a theoretical model which show how squeezed states of light may be used to modify the quantum noise behaviour of a power recycled Michelson interferometer. We develop a simple theoretical model of the experiment and find close agreement of theoretical and experimental results. We measure quantum noise suppression of 2.3 dB and demonstrate the lock stability of the experiment for long periods

  19. An ultrastable Michelson interferometer for high-resolution spectroscopy in the XUV.

    Science.gov (United States)

    Corsi, C; Liontos, I; Cavalieri, S; Bellini, M; Venturi, G; Eramo, R

    2015-02-23

    We developed an ultra-stable and accurately-controllable Michelson interferometer to be used in a deeply unbalanced arm configuration for split-pulse XUV Ramsey-type spectroscopy with high-order laser harmonics. The implemented active and passive stabilization systems allow one to reach instabilities in the nanometer range over meters of relative optical path differences. Producing precisely delayed pairs of pump pulses will generate XUV harmonic pulses that may significantly improve the achievable spectral resolution and the precision of absolute frequency measurements in the XUV.

  20. Correction of detector nonlinearity for the balloonborne Michelson Interferometer for Passive Atmospheric Sounding.

    Science.gov (United States)

    Kleinert, Anne

    2006-01-20

    The detectors used in the cryogenic limb-emission sounder MIPAS-B2 (Michelson Interferometer for Passive Atmospheric Sounding) show a nonlinear response, which leads to radiometric errors in the calibrated spectra if the nonlinearity is not taken into account. In the case of emission measurements, the dominant error that arises from the nonlinearity is the changing detector responsivity as the incident photon load changes. The effect of the distortion of a single interferogram can be neglected. A method to characterize the variable responsivity and to correct for this effect is proposed. Furthermore, a detailed error estimation is presented.

  1. Correlated two-photon interference in a dual-beam Michelson interferometer

    International Nuclear Information System (INIS)

    Kwiat, P.G.; Vareka, W.A.; Hong, C.K.; Nathel, H.; Chiao, R.Y.

    1990-01-01

    We report on an interference effect arising from a two-photon entangled state produced in a potassium dihydrogen phosphate (KDP) crystal pumped by an ultraviolet argon-ion laser. Two conjugate beams of signal and idler photons were injected in a parallel configuration into a single Michelson interferometer, and detected separately by two photomultipliers, while the difference in its arm lengths was slowly scanned. The coincidence rate exhibited fringes with a visibility of nearly 50%, and a period given by half the ultraviolet (not the signal or idler) wavelength, while the singles rate exhibited no fringes

  2. Active stabilization of a Michelson interferometer at an arbitrary phase with subnanometer resolution.

    Science.gov (United States)

    Grassani, Davide; Galli, Matteo; Bajoni, Daniele

    2014-04-15

    We report on the active stabilization of a Michelson interferometer at an arbitrary phase angle with a precision better than 1° at λ=632.8  nm, which corresponds to a precision in the optical path difference between the two arms of less than 1 nm. The stabilization method is ditherless, and the error signal is computed from the spatial shift of the interference pattern of a reference laser, measured in real-time with a CCD array detector. We discuss the usefulness of this method for nanopositioning, optical interferometry, and quantum optical experiments.

  3. First Measurements of High Frequency Cross-Spectra from a Pair of Large Michelson Interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Aaron S.; Gustafson, Richard; Hogan, Craig; Kamai, Brittany; Kwon, Ohkyung; Lanza, Robert; McCuller, Lee; Meyer, Stephan S.; Richardson, Jonathan; Stoughton, Chris; Tomlin, Raymond; Waldman, Samuel; Weiss, Rainer

    2016-09-01

    Measurements are reported of high frequency cross-spectra of signals from the Fermilab Holometer, a pair of co-located 39 m, high power Michelson interferometers. The instrument obtains differential position sensitivity to cross-correlated signals far exceeding any previous measurement in a broad frequency band extending to the 3.8 MHz inverse light crossing time of the apparatus. A model of universal exotic spatial shear correlations that matches the Planck scale holographic information bound of space-time position states is excluded to 4.6{\\sigma} significance.

  4. Active feedback regulation of a Michelson interferometer to achieve zero-background absorption measurements.

    Science.gov (United States)

    Lundin, Patrik; Guan, Zuguang; Svanberg, Sune

    2011-01-20

    An active phase-controlling scheme based on a proportional-integral-derivative-controlled piezoelectric transducer is presented with the purpose of stabilizing a quasi-zero-background absorption spectrometer. A fiber-based balanced Michelson interferometer is used, and absorption due to a gas sample in one of its arms results in an increased light signal to a detector, which otherwise, thanks to destructive interference, experiences a very low light level. With the presented approach, the sensitivity of already potent absorption measurement techniques, e.g., based on modulation, could be improved even further.

  5. Adaption of the Michelson interferometer for a better understanding of the temporal coherence in lasers

    Science.gov (United States)

    Illarramendi, M. A.; Zubia, J.; Arrue, J.; Ayesta, I.

    2017-08-01

    In this work, we show a design of a laboratory exercise in which a digital camera has been coupled to a Michelson interferometer based on free-propagation arms. By using the camera, our students measure the evolution of the interference patterns as a function of the difference between the optical paths of the arms. In this way, they obtain the corresponding reduction of the contrast of the fringes. The analysis of the results allows one to calculate the coherence length, and also to relate the temporal coherence of the employed laser with its spectral line profile. The exercise has been carried out with two lasers, which present different coherence lengths.

  6. Michelson interferometer with separated inputs and outputs, double pass, and compensation

    Science.gov (United States)

    Mather, J. C.; Jennings, D. E.

    1985-01-01

    A novel configuration is proposed for a Michelson interferometer spectrometer, which will be insensitive to tilts or displacements, and which employs separated inputs and outputs and double passing for higher resolution. The great advantage of such a compensated design is a relaxation of mechanical tolerances, which is especially beneficial for instruments in hostile environments. The Atmospheric Trace Molecule Spectroscopy project, which must work reliably after being subjected to the vibrations of a Space Shuttle launch, would benefit from the use of such an instrument.

  7. Measuring the separation of the sodium D-doublet with a Michelson interferometer

    Science.gov (United States)

    D'Anna, M.; Corridoni, T.

    2018-01-01

    Revisiting a method proposed by Fizeau in 1862, in this paper we measure the separation of the Na-doublet (the wavelength difference {{Δ }}λ between the two emission D-lines of the sodium spectrum) with a didactical Michelson interferometer. We describe the setup, how the measurements have been done and develop a mathematical model in order to explain the principal features of the collected data. Discussing the limits of this model, we suggest further experimental and theoretical extensions of the experience, also focusing on the didactical aspects to show how this experiment could bring advanced modern physics topics into high schools.

  8. Length sensing and control of a Michelson interferometer with power recycling and twin signal recycling cavities.

    Science.gov (United States)

    Gräf, Christian; Thüring, André; Vahlbruch, Henning; Danzmann, Karsten; Schnabel, Roman

    2013-03-11

    The techniques of power recycling and signal recycling have proven as key concepts to increase the sensitivity of large-scale gravitational wave detectors by independent resonant enhancement of light power and signal sidebands within the interferometer. Developing the latter concept further, twin signal recycling was proposed as an alternative to conventional detuned signal recycling. Twin signal recycling features the narrow-band sensitivity gain of conventional detuned signal recycling but furthermore facilitates the injection of squeezed states of light, increases the detector sensitivity over a wide frequency band and requires a less complex detection scheme for optimal signal readout. These benefits come at the expense of an additional recycling mirror, thus increasing the number of degrees of freedom in the interferometer which need to be controlled.In this article we describe the development of a length sensing and control scheme and its successful application to a tabletop-scale power recycled Michelson interferometer with twin signal recycling. We were able to lock the interferometer in all relevant longitudinal degrees of freedom and thus laid the foundation for further investigations of this interferometer configuration to evaluate its viability for the application in gravitational wave detectors.

  9. Heterodyne displacement interferometer, insensitive for input polarization

    NARCIS (Netherlands)

    Meskers, A.J.H.; Spronck, J.W.; Munnig Schmidt, R.H.

    2014-01-01

    Periodic nonlinearity (PNL) in displacement interferometers is a systematic error source that limits measurement accuracy. The PNL of coaxial heterodyne interferometers is highly influenced by the polarization state and orientation of the source frequencies. In this Letter, we investigate this error

  10. Ghost reflections of Gaussian beams in anamorphic optical systems with an application to Michelson interferometer.

    Science.gov (United States)

    Abd El-Maksoud, Rania H

    2016-02-20

    In this paper, a methodology is developed to model and analyze the effect of undesired (ghost) reflections of Gaussian beams that are produced by anamorphic optical systems. The superposition of these beams with the nominal beam modulates the nominal power distribution at the recording plane. This modulation may cause contrast reduction, veiling parts of the nominal image, and/or the formation of spurious interference fringes. The developed methodology is based on synthesizing the beam optical paths into nominal and ghost optical beam paths. Similar to the nominal beam, we present the concept that each ghost beam is characterized by a beam size, wavefront radius of curvature, and Gouy phase in the paraxial regime. The nominal and ghost beams are sequentially traced through the system and formulas for estimating the electric field magnitude and phase of each ghost beam at the recording plane are presented. The effective electric field is the addition of the individual nominal and ghost electric fields. Formulas for estimating Gouy phase, the shape of the interference fringes, and the central interference order are introduced. As an application, the theory of the formation of the interference fringes by Michelson interferometer is presented. This theory takes into consideration the ghost reflections that are formed by the beam splitter. To illustrate the theory and to show its wide applicability, simulation examples that include a Mangin mirror, a Michelson interferometer, and a black box optical system are provided.

  11. Elimination of drift in a fiber-Bragg-grating-based multiplexed Michelson interferometer measurement system.

    Science.gov (United States)

    Ren, Junyu; Xie, Fang; Chen, Zhimin

    2010-02-01

    Random phase drift in single-mode optical fiber interferometers used with measurement systems, which is resulted from various types of environmental disturbances, should be eliminated in order to obtain high measurement precision. We propose an optical fiber interferometric measurement system which has the function of self-eliminating the random phase drift and is stable and robust enough for real-time precision measurement. By employing the characteristics of fiber Bragg gratings, the system interleaves two fiber Michelson interferometers together that share the common-interferometric-optical path. The signal of one of the interferometers is used to stabilize the system while the signal of the other interferometer is used for measurement. An electronic feedback loop for the stabilizing action is designed. The bandwidth of the feedback loop is 5 kHz, sufficiently wide to eliminate random phase drift resulted from various environmental disturbances. The system is endowed with high stability and therefore suitable for real-time precision measurement. By means of an active phase tracking technique to measure displacement, the linear regression coefficient of the displacement measurement results is 0.9998.

  12. Resolving fringe ambiguities of a wide-field Michelson interferometer using visibility measurements of a noncollimated laser beam.

    Science.gov (United States)

    Wan, Xiaoke; Wang, Ji; Ge, Jian

    2009-09-10

    An actively stabilized interferometer with a constant optical path difference is a key element in long-term astronomical observation, and resolving interference fringe ambiguities is important to produce high-precision results for the long term. We report a simple and reliable method of resolving fringe ambiguities of a wide-field Michelson interferometer by measuring the interference visibility of a noncollimated single-frequency laser beam. Theoretical analysis shows that the interference visibility is sensitive to a subfringe phase shift, and a wide range of beam arrangements is suitable for real implementation. In an experimental demonstration, a Michelson interferometer has an optical path difference of 7 mm and a converging monitoring beam has a numerical aperture of 0.045 with an incidental angle of 17 degrees. The resolution of visibility measurements corresponds to approximately 1/16 fringe in the interferometer phase shift. The fringe ambiguity-free region is extended over a range of approximately 100 fringes.

  13. Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

    NARCIS (Netherlands)

    Mandrosov, V. I.

    The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is

  14. The use of balanced homodyne and squeezed states for detecting weak optical signals in a Michelson interferometer

    International Nuclear Information System (INIS)

    Ben-Aryeh, Y.

    2011-01-01

    The possibility of using squeezed states and balanced homodyne detection of optical signals in a Michelson interferometer is discussed. The present analysis describes photon statistics measurements effects related to quadrature balanced homodyne detection showing the advantage of using this scheme for detecting weak optical signals.

  15. A bit-rate flexible and power efficient all-optical demultiplexer realised by monolithically integrated Michelson interferometer

    DEFF Research Database (Denmark)

    Vaa, Michael; Mikkelsen, Benny; Jepsen, Kim Stokholm

    1996-01-01

    A novel bit-rate flexible and very power efficient all-optical demultiplexer using differential optical control of a monolithically integrated Michelson interferometer with MQW SOAs is demonstrated at 40 to 10 Gbit/s. Gain switched DFB lasers provide ultra stable data and control signals....

  16. First mesospheric wind images using the Michelson interferometer for airglow dynamics imaging.

    Science.gov (United States)

    Langille, J A; Ward, W E; Nakamura, T

    2016-12-10

    The Michelson interferometer for airglow dynamics imaging (MIADI) is a ground-based instrument that combines an imaging capability with the Doppler Michelson interferometry in order to remotely detect motions in the mesopause region using spectrally isolated airglow emissions: the O(S1) emission at 557.73 nm and the OH (6, 2) P1 (2) at 839.918 nm. A measurement and analysis approach has been developed that allows simultaneous images of the line-of-sight Doppler wind field and irradiance field to be obtained. A working field instrument was installed and tested at a field site outside Fredericton, NB (45.96 N, 66.65 W) during the summer of 2014. Successful measurements over a 6 h period were obtained on 31 July 2014. This paper describes the MIADI measurement and analysis approach and presents the work that has been done to extract images of the line-of-sight Doppler wind field and irradiances from these observations. The imaging capability is validated by identifying the presence of large-scale and small-scale geophysical perturbations in the images.

  17. Performance of a Rapid-Scan Vacuum Michelson Interferometer at the NSLS

    International Nuclear Information System (INIS)

    Brierly, P.; Dumas, P.; Smith, M.; Williams, G.P.

    2001-01-01

    A commercial Nicolet Magna series rapid-scan Michelson Fourier Transform Infrared (FTIR) was installed in a vacuum housing and integrated into the U4IR beamline at the National Synchrotron Light Source at Brookhaven National Laboratory. The frequency reference laser was mounted outside vacuum, but the moving mirror mechanism and the dynamic alignment system for the fixed mirror were in vacuum. The performance of the instrument was measured in the usual way by measuring the repeatability of data collected under specific conditions of aperture, resolution and mirror scanning velocity. We briefly discuss the beamline design, to put the interferometer in context, then present signal to noise data which we discuss in terms of both instrument performance and also storage ring stability. Under optimal conditions, the instrument has a reproducibility of 0.01% in 1 minute of measuring time at a resolution of 2 cmss, -1 , over a range from 100-3000 cm -1

  18. Hyperfine spectrum measurement of an optically pumped far-infrared laser with a Michelson interferometer

    International Nuclear Information System (INIS)

    Zuo, Z G; Ling, F R; Wang, P; Liu, J S; Yao, J Q; Weng, C X

    2013-01-01

    In this letter, we present a Michelson interferometer for the hyperfine spectrum measurement of an optically pumped far-infrared laser with a highest frequency resolution of 3–5 GHz. CH 3 OH gas with a purity of 99.9%, is pumped by the CO 2 9P36 and 9R10 laser lines to generate terahertz lasers with frequencies of 2.52 and 3.11 THz, respectively. Moreover, except for the center frequency, which is in good agreement with theoretical work, some additional frequencies on both sides of the center frequency are obtained at a frequency interval of 0.15 THz. Meanwhile, the mechanism behind the observed experimental results is also investigated. (letter)

  19. Optical stream-cipher-like system for image encryption based on Michelson interferometer.

    Science.gov (United States)

    Yang, Bing; Liu, Zhengjun; Wang, Bo; Zhang, Yan; Liu, Shutian

    2011-01-31

    A novel optical image encryption scheme based on interference is proposed. The original image is digitally encoded into one phase-only mask by employing an improved Gerchberg-Saxton phase retrieval algorithm together with another predefined random phase mask which serves as the encryption key. The decryption process can be implemented optically based on Michelson interferometer by using the same key. The scheme can be regarded as a stream-cipher-like encryption system, the encryption and decryption keys are the same, however the operations are different. The position coordinates and light wavelength can also be used as additional keys during the decryption. Numerical simulations have demonstrated the validity and robustness of the proposed method.

  20. Investigation of shear distance in Michelson interferometer-based shearography for mechanical characterization

    International Nuclear Information System (INIS)

    Lee, Jung-Ryul; Yoon, Dong-Jin; Kim, Jung-Seok; Vautrin, Alain

    2008-01-01

    Shearography is a growing industrial field in both quantitative mechanical characterization and relatively qualitative non-destructive testing. In shearography, shear distance is the most important parameter to control measurement performances. In this paper, the role of the shear distance is systematically investigated, focusing on the application of full-field mechanical characterization. A modified Michelson interferometer is considered as the shearing device, which is most commonly adopted for mechanical characterization applications because it enables easy and precise shearing and phase shifting. This paper also includes theoretical and experimental investigations of the relationship between shear distance and performance issues such as the immeasurable zone in the target with discontinuity, signal-to-noise ratio, sensitivity and shear distortion. In addition, this study is verified with actual shearographic results and a phase-shifting grid method capable of full-field displacement evaluation in the submicrometer regime

  1. ECE diagnostic for the TARA tandem mirror machine using a fast-scanning Michelson interferometer

    International Nuclear Information System (INIS)

    Guharay, S.K.; Boyd, D.A.; Ellis, R.F.

    1986-01-01

    This ECE (electron cyclotron emission) diagnostic utilizes a fast-scanning Michelson interferometer to determine two parameters, the temperature and the loss cone angle, of the distribution function of the hot electrons (Tapprox. >100 keV) generated in the axisymmetric plug plasma of the TARA tandem mirror device. The radiation transport system employs a lens relay and a low-pass grating filter in order to transmit the synchrotron radiation over a spectral range of 2.9--18.6 cm -1 . This enables us to study the emitted radiation spectrum up to the 40th harmonic of the electron--cyclotron frequency in the plug plasma (B = 5 kG). Details of the design principles and the development of the diagnostic at TARA will be presented

  2. Heterogeneous all-solid multicore fiber based multipath Michelson interferometer for high temperature sensing.

    Science.gov (United States)

    Duan, Li; Zhang, Peng; Tang, Ming; Wang, Ruoxu; Zhao, Zhiyong; Fu, Songnian; Gan, Lin; Zhu, Benpeng; Tong, Weijun; Liu, Deming; Shum, Perry Ping

    2016-09-05

    A compact high temperature sensor utilizing a multipath Michelson interferometer (MI) structure based on weak coupling multicore fiber (MCF) is proposed and experimentally demonstrated. The device is fabricated by program-controlled tapering the spliced region between single mode fiber (SMF) and a segment of MCF. After that, a spherical reflective structure is formed by arc-fusion splicing the end face of MCF. Theoretical analysis has been implemented for this specific multipath MI structure; beam propagation method based simulation and corresponding experiments were performed to investigate the effect of taper and spherical end face on system's performance. Benefiting from the multipath interferences and heterogeneous structure between the center core and surrounding cores of the all-solid MCF, an enhanced temperature sensitivity of 165 pm/°C up to 900°C and a high-quality interference spectrum with 25 dB fringe visibility were achieved.

  3. Measurements of refractive indices and thermo-optical coefficients using a white-light Michelson interferometer.

    Science.gov (United States)

    Rocha, A C P; Silva, J R; Lima, S M; Nunes, L A O; Andrade, L H C

    2016-08-20

    A dispersive white-light Michelson interferometer was used to determine the wavelength dependence of the refractive index (n) in the visible range from 425 to 775 nm and the thermo-optical coefficient (dn/dT) of fused silica (FS) and borosilicate glass (BK7). For FS, the values obtained for n and dn/dT at 546 nm were 1.46079 and 11.3×10-6  K-1, respectively, while the values for BK7 glass were 1.51825 and 2.2×10-6  K-1, respectively, which is in good agreement with the literature. The accuracy of the methodology used for n was almost 10-6, enabling precise spectroscopic characterization of materials across a wide spectral range.

  4. Effect of input spectrum on the spectral switch characteristics in a white-light Michelson interferometer.

    Science.gov (United States)

    Brundavanam, Maruthi M; Viswanathan, Nirmal K; Rao, D Narayana

    2009-12-01

    We report here a detailed experimental study to demonstrate the effect of source spectral characteristics such as spectral bandwidth (Deltalambda), peak wavelength (lambda(0)), and shape of the spectrum on the spectral shifts and spectral switches measured due to temporal correlation in a white-light Michelson interferometer operated in the spectral domain. Behavior of the spectral switch characteristics such as the switch position, switch amplitude, and switch symmetry are discussed in detail as a function of optical path difference between the interfering beams. The experimental results are compared with numerical calculations carried out using interference law in the spectral domain with modified source spectral characteristics. On the basis of our results we feel that our study is of critical importance in the selection of source spectral characteristics to further improve the longitudinal resolution or the measurement sensitivity in spectral-domain optical coherence tomography and microscopy.

  5. Measurements of femtosecond pulse temporal profile by means of a Michelson interferometer with a Schottky junction.

    Science.gov (United States)

    Ling, Yan; Lu, Fang

    2006-12-20

    We introduce a new method for femtosecond pulse shape measurement. The interference of two pulses is employed rather than the second-harmonic generation (SHG). Usually, the measurements of the femtosecond pulse is realized by an interferometer in combination with a nonlinear optical material, while the measurement that we describe is realized by means of a Michelson interferometer with a Schottky junction. Only a metal-semiconductor junction (Schottky junction) is needed, and neither the nonlinear optical material nor a photodetector is included. The two-photon absorption arises when the light is strong enough, while there is only a one-photon absorption when the light is weak. And the calculations are in good agreement with the experimental results. In principle, the new technique could be used for the measuring of pulses with any duration and with very low power. Unlike the SHG scheme, in the new method the quality of optics, mechanics, and other elements of the scheme are not essential, and the measurement is easily realized, but the results are quite precise and very sensitive to the light.

  6. The Michelson Stellar Interferometer Error Budget for Triple Triple-Satellite Configuration

    Science.gov (United States)

    Marathay, Arvind S.; Shiefman, Joe

    1996-01-01

    This report presents the results of a study of the instrumentation tolerances for a conventional style Michelson stellar interferometer (MSI). The method used to determine the tolerances was to determine the change, due to the instrument errors, in the measured fringe visibility and phase relative to the ideal values. The ideal values are those values of fringe visibility and phase that would be measured by a perfect MSI and are attributable solely to the object being detected. Once the functional relationship for changes in visibility and phase as a function of various instrument errors is understood it is then possible to set limits on the instrument errors in order to ensure that the measured visibility and phase are different from the ideal values by no more than some specified amount. This was done as part of this study. The limits we obtained are based on a visibility error of no more than 1% and a phase error of no more than 0.063 radians (this comes from 1% of 2(pi) radians). The choice of these 1% limits is supported in the literture. The approach employed in the study involved the use of ASAP (Advanced System Analysis Program) software provided by Breault Research Organization, Inc., in conjunction with parallel analytical calculations. The interferometer accepts object radiation into two separate arms each consisting of an outer mirror, an inner mirror, a delay line (made up of two moveable mirrors and two static mirrors), and a 10:1 afocal reduction telescope. The radiation coming out of both arms is incident on a slit plane which is opaque with two openings (slits). One of the two slits is centered directly under one of the two arms of the interferometer and the other slit is centered directly under the other arm. The slit plane is followed immediately by an ideal combining lens which images the radiation in the fringe plane (also referred to subsequently as the detector plane).

  7. Michelson interferometer vibrometer using self-correcting synthetic-heterodyne demodulation.

    Science.gov (United States)

    Connelly, Michael J; Galeti, José Henrique; Kitano, Cláudio

    2015-06-20

    Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity detection in interferometric sensors, as it can provide an output signal that is immune to interferometric drift. With the advent of cost-effective, high-speed real-time signal-processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In synthetic heterodyne, to obtain the actual dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a method is described for determining the former and setting the Bessel function argument to a set value, which ensures maximum sensitivity. Conventional synthetic-heterodyne demodulation requires the use of two in-phase local oscillators; however, the relative phase of these oscillators relative to the interferometric signal is unknown. It is shown that, by using two additional quadrature local oscillators, a demodulated signal can be obtained that is independent of this phase difference. The experimental interferometer is a Michelson configuration using a visible single-mode laser, whose current is sinusoidally modulated at a frequency of 20 kHz. The detected interferometer output is acquired using a 250 kHz analog-to-digital converter and processed in real time. The system is used to measure the displacement sensitivity frequency response and linearity of a piezoelectric mirror shifter over a range of 500 Hz to 10 kHz. The experimental results show good agreement with two data-obtained independent techniques: the signal coincidence and denominated n-commuted Pernick method.

  8. Compact magnetic-field sensor based on optical microfiber Michelson interferometer and Fe3O4 nanofluid.

    Science.gov (United States)

    Deng, Ming; Sun, Xiaokang; Han, Meng; Li, Decai

    2013-02-01

    We report a magnetic-field sensor by merging the advantages of optical fiber Michelson interferometers with that of magnetic fluid. Compact and low-cost optical fiber Michelson interferometers were first fabricated by a high-frequency CO(2) laser, and then they were inserted into glass capillaries with water-based Fe(3)O(4) magnetic fluid as sensing elements. The sensing characteristics have been investigated and the experimental results show that the reflective spectrum of the fiber-magnetic sensor linearly shifted with the change of the magnetic-field strength that is perpendicular to the axial of the devices. The fiber-magnetic sensor with interference arm's diameter of 50 μm is most sensitive to the external magnetic field, and the sensitivity is up to 64.9 pm/mT, which is 20 times higher than that of 125 μm diameter.

  9. Process control system using polarizing interferometer

    Science.gov (United States)

    Schultz, T.J.; Kotidis, P.A.; Woodroffe, J.A.; Rostler, P.S.

    1994-02-15

    A system for nondestructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading. 38 figures.

  10. Process control system using polarizing interferometer

    Science.gov (United States)

    Schultz, Thomas J.; Kotidis, Petros A.; Woodroffe, Jaime A.; Rostler, Peter S.

    1994-01-01

    A system for non-destructively measuring an object and controlling industrial processes in response to the measurement is disclosed in which an impulse laser generates a plurality of sound waves over timed increments in an object. A polarizing interferometer is used to measure surface movement of the object caused by the sound waves and sensed by phase shifts in the signal beam. A photon multiplier senses the phase shift and develops an electrical signal. A signal conditioning arrangement modifies the electrical signals to generate an average signal correlated to the sound waves which in turn is correlated to a physical or metallurgical property of the object, such as temperature, which property may then be used to control the process. External, random vibrations of the workpiece are utilized to develop discernible signals which can be sensed in the interferometer by only one photon multiplier. In addition the interferometer includes an arrangement for optimizing its sensitivity so that movement attributed to various waves can be detected in opaque objects. The interferometer also includes a mechanism for sensing objects with rough surfaces which produce speckle light patterns. Finally the interferometer per se, with the addition of a second photon multiplier is capable of accurately recording beam length distance differences with only one reading.

  11. [A new method of anti-jamming ability improvement for Michelson Interferometer].

    Science.gov (United States)

    Li, Yang-Jun; Lian, Su-Jie; Shi, Jia; Guo, Ya-Fei; Wang, Gao

    2014-05-01

    In order to improve anti-jamming capability of Michelson interferometer system, replace the traditional structure of the moving mirror scanning was replaced, an interference system based on electro-optic modulation of crystal refractive index was designed to achieve optical path scanning. The system modulated voltage signal on the variable refractive crystal, to generate cyclical changes, changed the refractive index to control optical path difference in the original optical path system. Using electronic scanning to replace of mechanical scanning, improved the system's noise immunity was improved. In the electro-optic modulation process, computed the maximum optical path difference of the system was computed, and analyzed of the crystal thickness and crystal diffraction efficiency of the modulation process were analyzed. The simulation experiment shows that, with the modulation voltage range increasing, the available range of the optical path is also increased, and the system spectrum resolving power will also increase accordingly. Meanwhile, in the modulation process set the modulation range was set to make the energy of diffraction energy losses less than 10% of the total energy, so as to ensure a better signal to noise ratio. Experimental results show that, as the modulation voltage changes, interference fringes occurred continuously moved. When the voltage is further increased, the nonlinear error appears. After non-linear error correction for the system, spectrum resolution reached to 7. 2 cm-1, slightly lower than the original system. But its anti-jamming capability is greatly enhanced, as in the absence of experimental platform for seismic conditions, conventional interferometer relative error is more than 20%, while the relative error of the system is less than 5%, in line with the design requirements. It was proved that the anti-jamming capability of the system was enhanced greatly, when the static electro-optical modulation was used.

  12. An improved Michelson interferometer: smoothing out the rough spots for a more effective teaching tool

    Science.gov (United States)

    Eastman, Clarke K.

    2017-08-01

    The Michelson interferometer is a classic tool for demonstrating the wave nature of light, and it is a cornerstone of the optics curriculum. But many students' experiences with this device are higher in frustration than they are in learning. That situation motivated an effort to make aligning the tool less a test of a visual acuity and patience, and more of an introduction to optics phenomena and optical engineering. Key improvements included an added beam-splitter to accommodate multiple observers, a modified telescope to quickly and reliably obtain parallel mirrors, and a series of increasing spectral-width light sources to obtain equal path lengths. This greatly improved students' chances of success, as defined by achieving "white light fringes". When presenting these new features to the students, high importance is placed on understanding why alignment was so difficult with the original design, and why the changes made alignment easier. By exposing the rationale behind the improvements, students can observe the process of problem-solving in an optical engineering scenario. Equally important is the demonstration that solutions can be devised or adapted based on the parts at hand, and that implementations only achieve a highly "polished' state after several design iterations.

  13. Absolute distance measurement with micrometer accuracy using a Michelson interferometer and the iterative synthetic wavelength principle.

    Science.gov (United States)

    Alzahrani, Khaled; Burton, David; Lilley, Francis; Gdeisat, Munther; Bezombes, Frederic; Qudeisat, Mohammad

    2012-02-27

    We present a novel system that can measure absolute distances of up to 300 mm with an uncertainty of the order of one micrometer, within a timeframe of 40 seconds. The proposed system uses a Michelson interferometer, a tunable laser, a wavelength meter and a computer for analysis. The principle of synthetic wave creation is used in a novel way in that the system employs an initial low precision estimate of the distance, obtained using a triangulation, or time-of-flight, laser system, or similar, and then iterates through a sequence of progressively smaller synthetic wavelengths until it reaches micrometer uncertainties in the determination of the distance. A further novel feature of the system is its use of Fourier transform phase analysis techniques to achieve sub-wavelength accuracy. This method has the major advantages of being relatively simple to realize, offering demonstrated high relative precisions better than 5 × 10(-5). Finally, the fact that this device does not require a continuous line-of-sight to the target as is the case with other configurations offers significant advantages.

  14. Field-widened Michelson interferometer for spectral discrimination in high-spectral-resolution lidar: practical development.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Zhang, Yupeng; Yang, Yongying; Zhou, Yudi; Luo, Jing; Bai, Jian; Shen, Yibing; Wang, Kaiwei; Liu, Chong; Su, Lin; Yang, Liming

    2016-04-04

    A field-widened Michelson interferometer (FWMI), which is intended as the spectroscopic discriminator in ground-based high-spectral-resolution lidar (HSRL) for atmospheric aerosol detection, is described in this paper. The structure, specifications and design of the developed prototype FWMI are introduced, and an experimental approach is proposed to optimize the FWMI assembly and evaluate its comprehensive characteristic simultaneously. Experimental results show that, after optimization process, the peak-to-valley (PV) value and root-mean-square (RMS) value of measured OPD variation for the FWMI are 0.04λ and 0.008λ respectively among the half divergent angle range of 1.5 degree. Through an active locking technique, the frequency of the FWMI can be locked to the laser transmitter with accuracy of 27 MHz for more than one hour. The practical spectral discrimination ratio (SDR) for the developed FWMI is evaluated to be larger than 86 if the divergent angle of incident beam is smaller than 0.5 degree. All these results demonstrate the great potential of the developed FWMI as the spectroscopic discriminator for HSRLs, as well as the feasibility of the proposed design and optimization process. This paper is expected to provide a good entrance for the lidar community in future HSRL developments using the FWMI technique.

  15. Michelson Interferometer for Global High-Resolution Thermospheric Imaging (MIGHTI): Instrument Design and Calibration

    Science.gov (United States)

    Englert, Christoph R.; Harlander, John M.; Brown, Charles M.; Marr, Kenneth D.; Miller, Ian J.; Stump, J. Eloise; Hancock, Jed; Peterson, James Q.; Kumler, Jay; Morrow, William H.; Mooney, Thomas A.; Ellis, Scott; Mende, Stephen B.; Harris, Stewart E.; Stevens, Michael H.; Makela, Jonathan J.; Harding, Brian J.; Immel, Thomas J.

    2017-10-01

    The Michelson Interferometer for Global High-resolution Thermospheric Imaging (MIGHTI) instrument was built for launch and operation on the NASA Ionospheric Connection Explorer (ICON) mission. The instrument was designed to measure thermospheric horizontal wind velocity profiles and thermospheric temperature in altitude regions between 90 km and 300 km, during day and night. For the wind measurements it uses two perpendicular fields of view pointed at the Earth's limb, observing the Doppler shift of the atomic oxygen red and green lines at 630.0 nm and 557.7 nm wavelength. The wavelength shift is measured using field-widened, temperature compensated Doppler Asymmetric Spatial Heterodyne (DASH) spectrometers, employing low order échelle gratings operating at two different orders for the different atmospheric lines. The temperature measurement is accomplished by a multichannel photometric measurement of the spectral shape of the molecular oxygen A-band around 762 nm wavelength. For each field of view, the signals of the two oxygen lines and the A-band are detected on different regions of a single, cooled, frame transfer charge coupled device (CCD) detector. On-board calibration sources are used to periodically quantify thermal drifts, simultaneously with observing the atmosphere. The MIGHTI requirements, the resulting instrument design and the calibration are described.

  16. 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.

  17. 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.

  18. Optimization of a Michelson interferometer with a rotating retroreflector in opitcal design, spectral resolution, and optical throughput

    International Nuclear Information System (INIS)

    Haschberger, P.; Tank, V.

    1993-01-01

    A newly designed Michelson interferometer for Fourier spectroscopy utilizes a nutating retroreflector (cube corner mirror) to generate alterations in geometrical and optical paths. The practical optomechanical design of a Fourier-transform spectrometer incorporating a rotating retroreflector for path-length alteration is considered. (The instrument has been given the name MIROR, for Michelson Interferometer with a Rotating Retroreflector.) Two parameters of the instrument are essential: the maximum optical path difference, which yields the spectral resolution of the instrument, and the diameter of the transmitted beam, which determines the throughput and hence the achievable signal-to-noise ratio. The maximum allowable beam diameter is calculated as a function of the geometry and the orientation of the rotating retroreflector and the other optical components. The geometrical configuration and the orientation of all the optical components with respect to one another are also optimized for the maximum transmitted beam diameter when the required path difference is given. A principal investigation of different possible configurations of the optical components is presented. Then a quantitative optimization for an interferometer employing a retroreflector having a 5-in. (12.7-cm) aperture diameter requiring an optical path difference of more than 10 cm (spectral resolution better than 0.1 cm -1 ) is performed. Finally a simplified but enhanced design is described. 10 refs., 15 figs

  19. Laser phase and frequency noise measurement by Michelson interferometer composed of a 3 × 3 optical fiber coupler.

    Science.gov (United States)

    Xu, Dan; Yang, Fei; Chen, Dijun; Wei, Fang; Cai, Haiwen; Fang, Zujie; Qu, Ronghui

    2015-08-24

    A laser phase and frequency noise measurement method by an unbalanced Michelson interferometer composed of a 3 × 3 optical fiber coupler is proposed. The relations and differences of the power spectral density (PSD) of differential phase and frequency fluctuation, PSD of instantaneous phase and frequency fluctuation, phase noise and linewidth are derived strictly and discussed carefully. The method obtains the noise features of a narrow linewidth laser conveniently without any specific assumptions or noise models. The technique is also used to characterize the noise features of a narrow linewidth external-cavity semiconductor laser, which confirms the correction and robustness of the method.

  20. Spatio-temporal coherence of free-electron laser radiation in the extreme ultraviolet determined by a Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Hilbert, V.; Rödel, C.; Zastrau, U., E-mail: ulf.zastrau@uni-jena.de [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Brenner, G.; Düsterer, S.; Dziarzhytski, S.; Harmand, M.; Przystawik, A.; Redlin, H.; Toleikis, S. [Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, 22607 Hamburg (Germany); Döppner, T.; Ma, T. [Lawrence Livermore National Laboratory, 7000 East Avenue, Livermore, California 94550 (United States); Fletcher, L. [Department of Physics, University of California, Berkeley, California 94720 (United States); Förster, E. [Institut für Optik und Quantenelektronik, Friedrich-Schiller-Universität, Max-Wien-Platz 1, 07743 Jena (Germany); Helmholtz-Institut Jena, Fröbelstieg 3, 07743 Jena (Germany); Glenzer, S. H.; Lee, H. J. [SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025 (United States); Hartley, N. J. [Department of Physics, Clarendon Laboratory, University of Oxford, Parks Road, Oxford OX1 3PU (United Kingdom); Kazak, L.; Komar, D.; Skruszewicz, S. [Institut für Physik, Universität Rostock, 18051 Rostock (Germany); and others

    2014-09-08

    A key feature of extreme ultraviolet (XUV) radiation from free-electron lasers (FELs) is its spatial and temporal coherence. We measured the spatio-temporal coherence properties of monochromatized FEL pulses at 13.5 nm using a Michelson interferometer. A temporal coherence time of (59±8) fs has been determined, which is in good agreement with the spectral bandwidth given by the monochromator. Moreover, the spatial coherence in vertical direction amounts to about 15% of the beam diameter and about 12% in horizontal direction. The feasibility of measuring spatio-temporal coherence properties of XUV FEL radiation using interferometric techniques advances machine operation and experimental studies significantly.

  1. Detecting mode hopping in single-longitudinal-mode fiber ring lasers based on an unbalanced fiber Michelson interferometer.

    Science.gov (United States)

    Ma, Mingxiang; Hu, Zhengliang; Xu, Pan; Wang, Wei; Hu, Yongming

    2012-10-20

    A method of detecting mode hopping for single-longitudinal-mode (SLM) fiber ring lasers has been proposed and experimentally demonstrated. The method that is based on an unbalanced Michelson interferometer (MI) utilizing phase generated carrier modulation instantly transforms mode-hopping dynamics into steep phase changes of the interferometer. Multiform mode hops in an SLM erbium-doped fiber ring laser with an 18.6 MHz mode spacing have been detected exactly in real-time domain and discussed in detail. Numerical results show that the MI-based method has a high testing sensitivity for identifying mode hopping, which will play a significant role in evaluating the output stability of SLM fiber lasers.

  2. A Michelson interferometer system for testing the stability of a piezo-electric actuator intended for use in space

    International Nuclear Information System (INIS)

    Aplin, K L; Middleton, K F

    2007-01-01

    The Laser Interferometer Space Antenna (LISA) experiment will search for gravitational waves generated by cataclysmic events far back in astronomical history. LISA is an interferometer formed by three spacecraft positioned five million km apart, and to observe gravitational waves, it must monitor test mass positions with picometre level resolution. One of the numerous technological challenges is to identify an actuator with appropriate accuracy, precision and stability for positioning of the optical fibres used to deliver LISA's laser sources. We have developed a Michelson interferometer system to determine the temporal and thermal stability of candidate actuators, with an emphasis on characterisation in the milliHertz frequency range required for gravitational wave detection in space. This paper describes the interferometer data logging and calibration and presents preliminary results in the form of a 'noise spectrum' generated from the small perturbation of a nominally static mirror. The maximum displacement of the mirror was ∼50 nm with sub-Hz noise levels of 0.1-1 nm√Hz. This is within the LISA noise specification, and confirms that the apparatus is stable enough for the characterisation of the actuator

  3. Application of Young-Michelson and Brown-Twiss interferometers for determining geometric parameters of nonplanar rough objects

    International Nuclear Information System (INIS)

    Mandrosov, V I

    2008-01-01

    The possibility of using Young-Michelson and Brown-Twiss interferometers for measuring the angular dimensions and parameters of the surface shape of remote passively scattering and self-luminous nonplanar rough objects by optical radiation propagating from them is substantiated. The analysis is based on the properties of approximate transverse functions of field coherence B t and B t ' and intensity coherence B ti and B ti ' formed by the time averaging of the products of fields and intensities taken at two points of a receiving aperture (the prime denotes self-luminous objects). The averaging time is set to be much longer than the coherence time of radiation propagating from an object. It is shown that for the radiation coherence length much smaller than the depth of the visible region of the object, the functions B t and B t ' are proportional to the Fourier transform of the intensity distribution in the image of a remote object, which is the generalisation of the Van Cittert-Zernicke theorem to the case of a nonplanar object, while functions B ti and B ti ' are proportional to the squares of the modulus of the Fourier transform of this distribution. It is also shown that the recording of functions B t and B t ' with a Young-Michelson interferometer gives only the angular dimensions of the visible region of objects, whereas the recording of functions B ti and B ti ' with a Brown-Twiss interferometer allows one to find these dimensions and the radius of curvature of the object surface. (laser radiation scattering)

  4. Structural-Thermal-Optical-Performance (STOP) Model Development and Analysis of a Field-widened Michelson Interferometer

    Science.gov (United States)

    Scola, Salvatore J.; Osmundsen, James F.; Murchison, Luke S.; Davis, Warren T.; Fody, Joshua M.; Boyer, Charles M.; Cook, Anthony L.; Hostetler, Chris A.; Seaman, Shane T.; Miller, Ian J.; hide

    2014-01-01

    An integrated Structural-Thermal-Optical-Performance (STOP) model was developed for a field-widened Michelson interferometer which is being built and tested for the High Spectral Resolution Lidar (HSRL) project at NASA Langley Research Center (LaRC). The performance of the interferometer is highly sensitive to thermal expansion, changes in refractive index with temperature, temperature gradients, and deformation due to mounting stresses. Hand calculations can only predict system performance for uniform temperature changes, under the assumption that coefficient of thermal expansion (CTE) mismatch effects are negligible. An integrated STOP model was developed to investigate the effects of design modifications on the performance of the interferometer in detail, including CTE mismatch, and other three- dimensional effects. The model will be used to improve the design for a future spaceflight version of the interferometer. The STOP model was developed using the Comet SimApp'TM' Authoring Workspace which performs automated integration between Pro-Engineer®, Thermal Desktop®, MSC Nastran'TM', SigFit'TM', Code V'TM', and MATLAB®. This is the first flight project for which LaRC has utilized Comet, and it allows a larger trade space to be studied in a shorter time than would be possible in a traditional STOP analysis. This paper describes the development of the STOP model, presents a comparison of STOP results for simple cases with hand calculations, and presents results of the correlation effort to bench-top testing of the interferometer. A trade study conducted with the STOP model which demonstrates a few simple design changes that can improve the performance seen in the lab is also presented.

  5. Temporal characterization of short-pulse third-harmonic generation in an atomic gas by a transmission-grating Michelson interferometer.

    Science.gov (United States)

    Papadogiannis, N A; Nersisyan, G; Goulielmakis, E; Rakitzis, T P; Hertz, E; Charalambidis, D; Tsakiris, G D; Witte, K

    2002-09-01

    By use of a transmission-grating-based Michelson interferometer, second-order interferometric as well as intensity autocorrelation traces of the third harmonic of a Ti:sapphire 50-fs laser beam produced in Ar have been measured. The duration of the harmonic is found to be that expected from lowest-order perturbation theory. At this wavelength, the performance of the interferometer with respect to pulse-front distortion and dispersion is found to be satisfactory. This result is a first step toward the use of the interferometer for the temporal characterization of higher harmonics or harmonic superposition forming attosecond pulse trains.

  6. Performance evaluation of a dual fringe-imaging Michelson interferometer for air parameter measurements with a 355 nm Rayleigh-Mie lidar.

    Science.gov (United States)

    Cézard, Nicolas; Dolfi-Bouteyre, Agnès; Huignard, Jean-Pierre; Flamant, Pierre H

    2009-04-20

    A new concept of spectrum analyzer is proposed for short-range lidar measurements in airborne applications. It implements a combination of two fringe-imaging Michelson interferometers to analyze the Rayleigh-Mie spectrum backscattered by molecules and particles at 355 nm. The objective is to perform simultaneous measurements of four variables: the air speed, the air temperature and density, and the particle scattering ratio. The Cramer-Rao bounds are calculated to evaluate the best expectable measurement accuracies. The performance optimization shows that a Michelson interferometer with a path difference of 3 cm is optimal for air speed measurements in clear air. To optimize density, temperature, and scattering ratio measurements, the second interferometer should be set to a path difference of 10 cm at least; 20 cm would be better to be less sensitive to the actual Rayleigh-Brillouin line shape.

  7. SAMSI: An orbiting spatial interferometer for micro-arc second astronomical observations. [Spacecraft Array for Michelson Spatial Interferometry (SAMSI)

    Science.gov (United States)

    Stachnik, R. V.; Gezari, D. Y.

    1985-01-01

    The concept and performance of (SAMSI) Spacecraft Array for Michelson Spatial Interferometry, an orbiting spatial interferometer comprised of three free-flying spacecraft, two collector telescopes and a central mixing station are described. In the one-dimensional interferometry mode orbits exist which provide natural scanning of the baseline. These orbits place extremely small demands on thrusters and fuel consumption. Resolution of 0.00001 arcsecond and magnitude limits of mv = 15 to 20 are achievable in a single orbit. In the imaging mode, SAMSI could synthesize images equivalent to those produced by equal diameter filled apertures in space, making use of the fuel resupply capability of a space station. Simulations indicate that image reconstruction can be performed with milliarcsecond resolution to a visual magnitude 12 in 12 hr of spiral scanning integration time.

  8. Broadband micro-Michelson interferometer with multi-optical-path beating using a sphered-end hollow fiber.

    Science.gov (United States)

    Chen, Nan-Kuang; Lu, Kuan-Yi; Shy, Jow-Tsong; Lin, Chinlon

    2011-06-01

    We demonstrate a high-sensitivity broadband (1250-1650 nm) fiber micro-Michelson interferometer using a single-mode fiber end-spliced with a sphered-end hollow-core fiber. The hollow core is slightly smaller than the solid core of a single-mode fiber, so the fractional power of the core mode is converted into cladding modes. The excited cladding modes propagate at distinct optical paths along the hollow-core fiber and have individual foci outside the spherical lens. The reflected core mode, generated at the solid core-air interface, and the reflected cladding modes, generated at external material, interfere with each other to produce beating in the interference signals. © 2011 Optical Society of America

  9. Michelson interferometer design for Linac Coherent Light Source (LCLS) applications in the 15-1.5 Aa wavelength range

    International Nuclear Information System (INIS)

    Tatchyn, Roman

    2000-01-01

    In recent years the continuing development of linac-driven X-Ray Free Electron Laser (XRFEL) designs has significantly expanded the parameter space associated with 3rd and earlier-generation synchrotron radiation sources. In particular, in contrast to the >100 ps pulse durations typical of storage rings, temporal lengths extending down to the <100 fs regime will become available. For example, for the SLAC Linac Coherent Light Source (LCLS) a pulse duration of ∼200-300 fs with finer temporal features extending down to ∼1 fs is anticipated. The characterization of the phase space distributions of such pulses poses a significant challenge for instrumentation design both with regard to the brevity of the pulse structure as well as the X-ray (15-1.5 Aa) wavelength range of the FEL line. In this paper we assess a Michelson interferometer design aimed at characterizing the coherence length of the SLAC LCLS and discuss considerations related to its operation

  10. High-temperature sensor based on an abrupt-taper Michelson interferometer in single-mode fiber.

    Science.gov (United States)

    Xu, Le; Jiang, Lan; Wang, Sumei; Li, Benye; Lu, Yongfeng

    2013-04-01

    This study proposes a high-temperature sensor based on an abrupt fiber-taper Michelson interferometer (FTMI) in single-mode fiber fabricated by a fiber-taper machine and electric-arc discharge. The proposed FTMI is applied to measure temperature and refractive index (RI). A high temperature sensitivity of 118.6 pm/°C is obtained in the temperature range of 500°C-800°C. The wavelength variation is only -0.335 nm for the maximum attenuation peak, with the external RI changed from 1.333 to 1.3902, which is desirable for high-temperature sensing to eliminate the cross sensitivity to RI.

  11. SU-E-T-410: Fringe Stability and Phase Shift Measurements in a Michelson Interferometer for Optical Calorimetry

    International Nuclear Information System (INIS)

    Flores-Martinez, E; Malin, M; DeWerd, L

    2014-01-01

    Purpose: To identify the variables limiting the resolution of a Michelson interferometer used to measure phase shifts (PS) in water as part of a radiometric calorimeter. Methods: We investigated the output stability of a He-Ne laser and a laser diode. The short and long term stability of the fringe pattern in a Michelson interferometer was tested with different types of lasers, thermal insulation arrangements, damping systems and optical mounts to optimize system performance. PS were induced by electrically heating water in a 1 cm quartz cuvette located in one of the interferometer arms. The PS was calculated from fringe intensity changes and compared to a calculated PS using thermocouple-measured temperature changes in the water. Results: The intensity of the laser diode is more stable, but the gas laser’s profile is more suitable for fringe analysis and has better temporal coherence. The laser requires a warm-up time of 4 hours before its output is stabilized (SNR>95). The fringe’s stability strongly depends on the thermal insulation. When the interferometer is exposed to ambient temperature swings of 0.7 K, it is not possible to stabilize the fringe pattern. Enclosing the system in a 2.5 cm-thick Styrofoam box improves the SNR, but further insulation will be needed to increase the SNR above 50. High frequency noise is significantly reduced by damping the system.Inducing a temperature rise in water, starting at 299 K, the average temperature increase for a 2π PS is 0.29 ± 0.02 K and the proportionality constant is -21.1 ± 0.8 radians/K. This is 5.8% lower than the calculated value using the thermocouple. Conclusion: Interferometric PS measurements of temperature may provide an alternative to thermistors for water calorimetry. The resolution of the current prototype is limited by ambient temperature stability. Calculated and measured thermally-induced PS in water agreed to within 5.8%

  12. A Fabry-Pérot interferometer with wire-grid polarizers as beamsplitters at terahertz frequencies

    Science.gov (United States)

    Harrison, H.; Lancaster, A. J.; Konoplev, I. V.; Doucas, G.; Aryshev, A.; Shevelev, M.; Terunuma, N.; Urakawa, J.; Huggard, P. G.

    2018-03-01

    The design of a compact Fabry-Pérot interferometer (FPi) and results of the experimental studies carried out using the device are presented. Our FPi uses freestanding wire-grid polarizers (WGPs) as beamsplitters and is suitable for use at terahertz (THz) frequencies. The FPi was studied at the LUCX facility, KEK, Japan, and an 8 MeV linear electron accelerator was used to generate coherent Smith-Purcell radiation. The FPi was designed to be easy to align and reposition for experiments at linear accelerator facilities. All of the components used were required to have a flat or well understood frequency response in the THz range. The performance of the FPi with WGPs was compared to that of a Michelson interferometer and the FPi is seen to perform well. The effectiveness of the beamsplitters used in the FPi is also investigated. Measurements made with the FPi using WGPs, the preferred beamsplitters, are compared to measurements made with the FPi using silicon wafers as alternative beamsplitters. The FPi performs well with both types of beamsplitter in the frequency range used (0.3-0.5 THz). The successful measurements taken with the FPi demonstrate a compact and adaptable interferometer that is capable of analyzing THz radiation over a broad frequency range. The scheme is particularly well suited for polarization studies of THz radiation produced in an accelerator environment.

  13. A study of a space-station-associated multiple spacecraft Michelson spatial interferometer

    Science.gov (United States)

    Stachnik, R. V.

    1983-01-01

    One approach to Michelson spatial interferometry at optical wavelengths involves use of an array of spacecraft in which two widely-separated telescopes collect light from a star and direct it to a third, centrally-located, device which combines the beams in order to detect and measure interference fringes. The original version of a spacecraft array for Michelson spatial interferometry (SAMSI) was modified so that the system uses the fuel resupply capability of a space station. The combination of this fuel resupply capability with a method of obtaining image Fourier transform phase information, necessary for full image reconstruction, permits SAMSI to be used to synthesize images equivalent to those produced by huge apertures in space. Synthesis of apertures in the 100 to 500 meter range is discussed. Reconstruction can be performed to a visual magnitude of at least 8 for a 100 A passband in 9 hours. Data are simultaneously collected for image generation from 0.1 micron to 18 microns. In the one-dimensional mode, measurements can be made every 90 minutes (including acquisition and repointing time) for objects as faint as 19th magnitude in the visible.

  14. Design of a monolithic Michelson interferometer for fringe-imaging in a near-field, UV, direct detection Doppler wind lidar

    OpenAIRE

    Herbst, Jonas; Vrancken, Patrick

    2016-01-01

    The low-biased, fast, airborne, short-range, and range-resolved determination of atmospheric wind speeds plays a key role in wake vortex and turbulence mitigation strategies and would improve flight safety, comfort, and economy. In this work, a concept for an airborne, UV, direct-detection Doppler wind lidar receiver is presented. A monolithic, tilted, field-widened, fringe-imaging Michelson interferometer (FWFIMI) combines the Advantages of low angular sensitivity, high thermo-mecha...

  15. Interferometric filters for spectral discrimination in high-spectral-resolution lidar: performance comparisons between Fabry-Perot interferometer and field-widened Michelson interferometer.

    Science.gov (United States)

    Cheng, Zhongtao; Liu, Dong; Yang, Yongying; Yang, Liming; Huang, Hanlu

    2013-11-10

    Thanks to wavelength flexibility, interferometric filters such as Fabry-Perot interferometers (FPIs) and field-widened Michelson interferometers (FWMIs) have shown great convenience for spectrally separating the molecule and aerosol scattering components in the high-spectral-resolution lidar (HSRL) return signal. In this paper, performance comparisons between the FPI and FWMI as a spectroscopic discrimination filter in HSRL are performed. We first present a theoretical method for spectral transmission analysis and quantitative evaluation on the spectral discrimination. Then the process in determining the parameters of the FPI and FWMI for the performance comparisons is described. The influences from the incident field of view (FOV), the cumulative wavefront error induced by practical imperfections, and the frequency locking error on the spectral discrimination performance of the two filters are discussed in detail. Quantitative analyses demonstrate that FPI can produce higher transmittance while the remarkable spectral discrimination is one of the most appealing advantages of FWMI. As a result of the field-widened design, the FWMI still performs well even under the illumination with large FOV while the FPI is only qualified for a small incident angle. The cumulative wavefront error attaches a great effect on the spectral discrimination performance of the interferometric filters. We suggest if a cumulative wavefront error is less than 0.05 waves RMS, it is beneficial to employ the FWMI; otherwise, FPI may be more proper. Although the FWMI shows much more sensitivity to the frequency locking error, it can outperform the FPI given a locking error less than 0.1 GHz is achieved. In summary, the FWMI is very competent in HSRL applications if these practical engineering and control problems can be solved, theoretically. Some other estimations neglected in this paper can also be carried out through the analytical method illustrated herein.

  16. In-fiber quasi-Michelson interferometer with a core-cladding-mode fiber end-face mirror.

    Science.gov (United States)

    Rong, Qiangzhou; Qiao, Xueguang; Du, Yanying; Feng, Dingyi; Wang, Ruohui; Ma, Yue; Sun, Hao; Hu, Manli; Feng, Zhongyao

    2013-03-01

    An in-fiber quasi-Michelson interferometer working on reflection is proposed and experimentally demonstrated. The device consists of a short section of multimode fiber (MMF) followed by a single-mode fiber (SMF) whose end face is terminated by a thick silver film. The MMF excites cladding modes into downstream SMF via the mismatched-core splicing interface. The core-cladding modes are reflected back by the silver film and recoupled to the core of lead-in SMF through the MMF. A well-defined interference pattern is obtained as the result of core-cladding mode interference. A configuration with a 40 mm pigtail SMF at a wavelength of 1528 nm exhibits a water level sensitivity of -49.8 pm/mm and a liquid refractive index sensitivity of -574.6 (pm/mm)/RIU (refractive index unit). In addition, the selected dip provides a considered temperature sensitivity of -61.26 pm/°C and a high displacement sensitivity of -1018.6 pm/mm.

  17. 100 years since Michelson and Morley - the quest for the ultimate interferometer

    International Nuclear Information System (INIS)

    Bachor, H.A.; McClelland, D.E.

    1989-01-01

    This paper summarise some of the achievements of optical interferometry in its 100 years of existence. It is shown how over the decades, developments in optics, lasers, electronics and quantum mechanics have led to dramatic improvements in sensitivity, with the most recent developments aiming at a δL/L of 10 -12 . In addition, digital image processing and laser stabilisation techniques were combined to analyse optical surfaces with a resolution of 1/500 of a fringe. Some of interferometer applications are discussed and these include radio astronomy, laser gyroscopes, the visualisation of flows and the diagnostic of laboratory plasmas. 18 refs., 2 figs

  18. Demonstration of a squeezed-light-enhanced power- and signal-recycled Michelson interferometer.

    Science.gov (United States)

    Vahlbruch, Henning; Chelkowski, Simon; Hage, Boris; Franzen, Alexander; Danzmann, Karsten; Schnabel, Roman

    2005-11-18

    We report on the experimental combination of three advanced interferometer techniques for gravitational wave detection, namely, power recycling, detuned signal recycling, and squeezed field injection. For the first time, we experimentally prove the compatibility of especially the latter two. To achieve a broadband nonclassical sensitivity improvement, we applied a filter cavity for compensation of quadrature rotation. The signal-to-noise ratio was improved by up to 2.8 dB beyond the coherent state's shot noise. The complete setup was stably locked for arbitrary times and characterized by injected single-sideband modulation fields.

  19. Improved synthetic-heterodyne Michelson interferometer vibrometer using phase and gain control feedback.

    Science.gov (United States)

    Galeti, José Henrique; Kitano, Cláudio; Connelly, Michael J

    2015-12-10

    Synthetic-heterodyne demodulation is a useful technique for dynamic displacement and velocity measurement using interferometric sensors as it can provide an output signal which is immune to interferometric drift. With the advent of cost effective, high-speed real-time signal processing systems and software, processing of the complex signals encountered in interferometry has become more feasible. In conventional synthetic-heterodyne demodulation schemes, to obtain the dynamic displacement or vibration of the object under test requires knowledge of the interferometer visibility and also the argument of two Bessel functions. In this paper, a new synthetic-heterodyne demodulation method is described leading to an expression for the dynamic displacement and velocity of the object under test that is significantly less sensitive to the received optical power. In addition, the application of two independent phase and gain feedback loops is used to compensate for the nonideal gain and phase response of the anti-aliasing filter required for the signal acquisition of the received wideband interferometer signal. The efficacy of the improved system is demonstrated by measuring the displacement sensitivity frequency response and linearity of a Piezoelectric Mirror-Shifter (PMS) over a range of 200 Hz-9 kHz. In addition, the system is used to measure the response of the PMS to triangular and impulse type stimuli. The experimental results show excellent agreement with measurements taken using two independent industry standard calibration methods.

  20. O2 nightglow snapshots of the 1.27 μm emission at low latitudes on Mars with a static field-widened Michelson interferometer

    Science.gov (United States)

    Zhang, Rui; Ward, William E.; Zhang, Chunmin

    2017-12-01

    A static field-widened Michelson interferometer is designed to observe the atmospheric dynamics at low latitudes of Mars, targeting the 1.27 μm O2(a1Δg) nightglow, which has not yet been accurately detected due to its low intensity. To the best of our knowledge, this design is the first demonstration of implementing divided-mirror technique by refringent materials in a field-widened Michelson interferometer. Different optical path difference (OPD) in each quadrant is generated by four highly reflective pyramid-shaped prisms made of different refringent materials attached to each solid arm of Michelson interferometer. In this way four samples of interferogram are obtained simultaneously, from which the airglow volume emission rate, as well as the line-of-sight velocity and temperature of the air parcel where the emission forms can be derived in a single integration time. To achieve the best field-widening, compactness and thermal compensation, all possible combination of ten pieces of glasses were searched within the Sumita glass catalogue using a computer program and some interesting results are listed. The OPD used in this calculation concerns rays in the plane perpendicular to the sides of the prism only, other cases need further examination. This instrument's performance in measuring atmospheric dynamics is analysed, using the wind velocity uncertainty as primary criterion. Calculations show that it can measure the wind with an accuracy better than 2 m/s if the band volume emission rate of O2 nightglow is greater than 5 kph cm-3 s-1.

  1. Composite cavity based fiber optic Fabry–Perot strain sensors demodulated by an unbalanced fiber optic Michelson interferometer with an electrical scanning mirror

    International Nuclear Information System (INIS)

    Zhang, Jianzhong; Yang, Jun; Sun, Weimin; Yuan, Libo; Jin, Wencai; Peng, G D

    2008-01-01

    A composite cavity based fiber optic Fabry–Perot strain sensor system, interrogated by a white light source and demodulated by an unbalanced fiber optic Michelson interferometer with an electrical scanning mirror, is proposed and demonstrated. Comparing with the traditional extrinsic fiber optic Fabry–Perot strain sensor, the potential multiplexing capability and the dynamic measurement range are improved simultaneously. At the same time, the measurement stability of the electrical scanning mirror system is improved by the self-referenced signal of the sensor structure

  2. Albert Abraham Michelson

    Indian Academy of Sciences (India)

    Albert Michelson built his interferometer in order to determine the effect of Earth's rotation on the speed of light. The null result supported the crucial assumption in Einstein's special theory of relativity and was the final nail in the coffin of classical mechanics. The interferometer is also being currently used in the detection of ...

  3. Dense plasmas interferometry using an X-UV laser. Development of an X-UV Michelson interferometer at 13.9 nm

    International Nuclear Information System (INIS)

    Hubert, S.

    2001-01-01

    After having recalled some aspects related to the physics of plasmas produced by interaction between laser and matter, and related to inertial confinement fusion or ICF (discussion of laser energy absorption, X conversion, parametric and hydrodynamic instabilities, and so on), this research thesis presents various techniques used for plasma diagnosis in order to justify the use of interferometry for the investigation of the electronic density distribution of these plasmas. The physical principle of this diagnosis technique is described and two types of X-UV interferometer are presented, one of them being chosen as more suitable for the study of ICF-type plasmas. The author then describes and reports the experimental investigation performed with a two-mirror Fresnel interferometer and a 21.2 nm zinc X-UV laser: description of the interferometer operation and characteristics, of the specifically designed image system, discussion of plasma interferogram simulations. Then, he reports the development of a Michelson-type X-UV interferometer at 13.9 nm. The operation principle is recalled, and the preliminary modelling phase is reported. The imaging system is presented and results of the interferogram modelling phase are presented [fr

  4. Reconfiguration of the multiwavelength operation of optical fiber ring lasers by the modifiable intra-cavity induced losses of an in-fiber tip probe modal Michelson interferometer

    Science.gov (United States)

    Salceda-Delgado, G.; Martinez-Rios, A.; Sierra-Hernandez, J. M.; Rodríguez-Carreón, V. C.; Toral-Acosta, D.; Selvas-Aguilar, R.; Álvarez-Tamayo, R. I.; Castillo-Guzman, A. A.; Rojas-Laguna, R.

    2018-03-01

    A straightforward and versatile method for switching from single to different multiwavelength laser emission in ring cavity fiber lasers is proposed and demonstrated experimentally. The method is based on using the changeable interference pattern from an optical fiber modal Michelson interferometer as a wavelength selective filter into the ring cavity laser. The interferometer is constructed using a bi-conical tapered fiber and a single-mode fiber segment, with these being spliced together to form an optical fiber tip probe. When the length of the single-mode fiber piece is modified, the phase difference between the interfering modes of the interferometer causes a change in the interferometer free spectral range. As a consequence, the laser intra-cavity losses lead to gain competition, which allows us to adjust the number of simultaneously generated laser lines. A multiwavelength reconfiguration of the laser from one up to a maximum of eight emission lines was obtained, with a maximum SNR of around 47 dBm.

  5. Design of a monolithic Michelson interferometer for fringe imaging in a near-field, UV, direct-detection Doppler wind lidar.

    Science.gov (United States)

    Herbst, Jonas; Vrancken, Patrick

    2016-09-01

    The low-biased, fast, airborne, short-range, and range-resolved determination of atmospheric wind speeds plays a key role in wake vortex and turbulence mitigation strategies and would improve flight safety, comfort, and economy. In this work, a concept for an airborne, UV, direct-detection Doppler wind lidar receiver is presented. A monolithic, tilted, field-widened, fringe-imaging Michelson interferometer (FWFIMI) combines the advantages of low angular sensitivity, high thermo-mechanical stability, independence of the specific atmospheric conditions, and potential for fast data evaluation. Design and integration of the FWFIMI into a lidar receiver concept are described. Simulations help to evaluate the receiver design and prospect sufficient performance under different atmospheric conditions.

  6. Albert Abraham Michelson

    Indian Academy of Sciences (India)

    Some experiments change the face of a subject, and some experiments do that many times over. Albert Michelson built his interferometer in order to determine the effect of Earth's rotation on the speed of light. The null result supported the crucial assumption in Einstein's special theory of relativity and was the final nail in the ...

  7. A far-infrared Michelson interferometer for tokamak electron density measurements using computer-generated reference fringes

    International Nuclear Information System (INIS)

    Krug, P.A.; Stimson, P.A.; Falconer, I.S.

    1986-01-01

    A simple far-infrared interferometer which uses the 394 μm laser line from optically-pumped formic acid vapour to measure tokamak electron density is described. This interferometer is unusual in requiring only one detector and a single probing beam since reference fringes during the plasma shot are obtained by computer interpolation between the fringes observed immediately before and after the shot. Electron density has been measured with a phase resolution corresponding to + - 1/20 wavelength fringe shift, which is equivalent to a central density resolution of + - 0.1 x 10 19 m -3 for an assumed parabolic density distribution in a plasma of diameter of 0.2 m, and with a time resolution of 0.2 ms. (author)

  8. GMTR: two-dimensional geo-fit multitarget retrieval model for michelson interferometer for passive atmospheric sounding/environmental satellite observations.

    Science.gov (United States)

    Carlotti, Massimo; Brizzi, Gabriele; Papandrea, Enzo; Prevedelli, Marco; Ridolfi, Marco; Dinelli, Bianca Maria; Magnani, Luca

    2006-02-01

    We present a new retrieval model designed to analyze the observations of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), which is on board the ENVironmental SATellite (ENVISAT). The new geo-fit multitarget retrieval model (GMTR) implements the geo-fit two-dimensional inversion for the simultaneous retrieval of several targets including a set of atmospheric constituents that are not considered by the ground processor of the MIPAS experiment. We describe the innovative solutions adopted in the inversion algorithm and the main functionalities of the corresponding computer code. The performance of GMTR is compared with that of the MIPAS ground processor in terms of accuracy of the retrieval products. Furthermore, we show the capability of GMTR to resolve the horizontal structures of the atmosphere. The new retrieval model is implemented in an optimized computer code that is distributed by the European Space Agency as "open source" in a package that includes a full set of auxiliary data for the retrieval of 28 atmospheric targets.

  9. Accurately computing the optical pathlength difference for a michelson interferometer with minimal knowledge of the source spectrum.

    Science.gov (United States)

    Milman, Mark H

    2005-12-01

    Astrometric measurements using stellar interferometry rely on precise measurement of the central white light fringe to accurately obtain the optical pathlength difference of incoming starlight to the two arms of the interferometer. One standard approach to stellar interferometry uses a channeled spectrum to determine phases at a number of different wavelengths that are then converted to the pathlength delay. When throughput is low these channels are broadened to improve the signal-to-noise ratio. Ultimately the ability to use monochromatic models and algorithms in each of the channels to extract phase becomes problematic and knowledge of the spectrum must be incorporated to achieve the accuracies required of the astrometric measurements. To accomplish this an optimization problem is posed to estimate simultaneously the pathlength delay and spectrum of the source. Moreover, the nature of the parameterization of the spectrum that is introduced circumvents the need to solve directly for these parameters so that the optimization problem reduces to a scalar problem in just the pathlength delay variable. A number of examples are given to show the robustness of the approach.

  10. Adaptable Optical Fiber Displacement-Curvature Sensor Based on a Modal Michelson Interferometer with a Tapered Single Mode Fiber.

    Science.gov (United States)

    Salceda-Delgado, G; Martinez-Rios, A; Selvas-Aguilar, R; Álvarez-Tamayo, R I; Castillo-Guzman, A; Ibarra-Escamilla, B; Durán-Ramírez, V M; Enriquez-Gomez, L F

    2017-06-02

    A compact, highly sensitive optical fiber displacement and curvature radius sensor is presented. The device consists of an adiabatic bi-conical fused fiber taper spliced to a single-mode fiber (SMF) segment with a flat face end. The bi-conical taper structure acts as a modal coupling device between core and cladding modes for the SMF segment. When the bi-conical taper is bent by an axial displacement, the symmetrical bi-conical shape of the tapered structure is stressed, causing a change in the refractive index profile which becomes asymmetric. As a result, the taper adiabaticity is lost, and interference between modes appears. As the bending increases, a small change in the fringe visibility and a wavelength shift on the periodical reflection spectrum of the in-fiber interferometer is produced. The displacement sensitivity and the spectral periodicity of the device can be adjusted by the proper selection of the SMF length. Sensitivities from around 1.93 to 3.4 nm/mm were obtained for SMF length between 7.5 and 12.5 cm. Both sensor interrogations, wavelength shift and visibility contrast, can be used to measure displacement and curvature radius magnitudes.

  11. Quadratic Sagnac effect — the influence of the gravitational potential of the Coriolis force on the phase difference between the arms of a rotating Michelson interferometer (an explanation of D C Miller's experimental results, 1921 – 1926)

    International Nuclear Information System (INIS)

    Malykin, G B; Pozdnyakova, V I

    2015-01-01

    It is shown that when an equal-arm Michelson interferometer is involved in rotation (for example, Earth's rotation around its axis or around the Sun) and its arms are oriented differently with respect to the plane of rotation, a phase difference arises between the light rays that pass through different arms. This phase difference is due to the fact that the arms experience variously the Newtonian (nonrelativistic) scalar gravitational potential of the Coriolis forces. It is shown that the phase difference is proportional to the length of the interferometer arm, the square of the angular velocity of the rotation, and the square of the distance from the center of rotation — hence, the proposal to call this phenomenon the quadratic Sagnac effect. In the present paper, we consider, as an illustrative example, the results of the once well-known experiments of D C Miller, who claimed to observe the translational motion of Earth relative to the hypothetical ‘luminiferous ether’. It is shown that this claim can actually be explained by the fact that, because of the orbital revolution of Earth, the time dilations in the orthogonal arms of the Michelson interferometer are influenced differently by the scalar gravitational potential of the Coriolis forces. (methodological notes)

  12. Supplement to the paper 'Quadratic Sagnac effect — the influence of the gravitational potential of the Coriolis force on the phase difference between the arms of a rotating Michelson interferometer (an explanation of D C Miller's experimental results, 1921 – 1926)' (Usp. Fiz. Nauk185 431 (2015) [Phys. Usp.58 398 (2015)])

    International Nuclear Information System (INIS)

    Malykin, G B; Pozdnyakova, V I

    2015-01-01

    The paper 'Quadratic Sagnac effect — the influence of the gravitational potential of the Coriolis force on the phase difference between the arms of a rotating Michelson interferometer (an explanation of D C Miller's experimental results, 1921 – 1926)' (Usp. Fiz. Nauk 185 431 (2015) [Phys. Usp. 58 398 (2015)]) is amended and supplemented with information concerning earlier work on the influence of rotation on Michelson – Morley's nonzero results. (letters to the editors)

  13. The Experiment of Michelson and Morley

    Indian Academy of Sciences (India)

    interferential refractor', later known as the. 'Michelson interferometer'. This time difference would give rise to a phase differ- ence between the two rays of light, and their interference pattern. (alternate dark and bright bands called fringes) would ...

  14. Polarization Dependence Suppression of Optical Fiber Grating Sensor in a π-Shifted Sagnac Loop Interferometer

    Directory of Open Access Journals (Sweden)

    Jaebum Son

    2010-04-01

    Full Text Available In the sensing applications of optical fiber grating, it is necessary to reduce the transmission-type polarization dependence to isolate the sensing parameter. It is experimentally shown that the polarization-dependent spectrum of acousto-optic long-period fiber grating sensors can be suppressed in the transmission port of a π-shifted Sagnac loop interferometer. General expressions for the transmittance and reflectance are derived for transmission-type, reflection-type, and partially reflecting/transmitting-type polarization-dependent optical devices. The compensation of polarization dependence through the counter propagation in the Sagnac loop interferometer is quantitatively measured for a commercial in-line polarizer and an acousto-optic long-period fiber grating sensor.

  15. a Spinning Polarizer and Spinning Analyzer Method for Visualizing the Isochromates in Conoscopic Interferometers

    Science.gov (United States)

    Olorunsola, Oluwatobi; Dada, Oluwaseye; Wang, Pengqian

    2013-09-01

    We have developed a spinning polarizer and spinning analyzer (SPSA) method to visualize the whole isochromatic fringes in conoscopic interferometers for the study of optically anisotropic materials. This simple method completely eliminates the broad and dark isogyre fringes appearing in a conventional conoscopic interferometer where a linear polarizer and a linear analyzer (LPLA) are used. Our method allows the direct visualization of the isochromates on the viewing screen by eyes in real time, without the need of additional optics or detectors other than those used in a conventional conoscopic interferometer, and no additional computation is required. This method works at any polarization state of the input light, and at any wavelength permitted by the polarizers. In the case of polychromatic illumination our method reveals the isochromates of all colors indiscriminatively, in comparison to the method of circular polarizer and circular analyzer (CPCA), which is considerably subject to spectrum modulation due to the dispersion in the retardation of the quarter-wave plates. The proposed method is demonstrated in a lithium niobate (LiNbO3) crystal driven by an external electric field.

  16. Global peroxyacetyl nitrate (PAN retrieval in the upper troposphere from limb emission spectra of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS

    Directory of Open Access Journals (Sweden)

    N. Glatthor

    2007-06-01

    Full Text Available We use limb emission spectra of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS onboard the ENVIronmental SATellite (ENVISAT to derive the first global distribution of peroxyacetyl nitrate (PAN in the upper troposphere. PAN is generated in tropospheric air masses polluted by fuel combustion or biomass burning and acts as a reservoir and carrier of NOx in the cold free troposphere. PAN exhibits continuum-like broadband structures in the mid-infrared region and was retrieved in a contiguous analysis window covering the wavenumber region 775–800 cm−1. The interfering species CCl4, HCFC-22, H2O, ClONO2, CH3CCl3 and C2H2 were fitted along with PAN, whereas pre-fitted profiles were used to model the contribution of other contaminants like ozone. Sensitivity tests consisting in retrieval without consideration of PAN demonstrated the existence of PAN signatures in MIPAS spectra obtained in polluted air masses. The analysed dataset consists of 10 days between 4 October and 1 December 2003. This period covers the end of the biomass burning season in South America and South and East Africa, in which generally large amounts of pollutants are produced and distributed over wide areas of the southern hemispheric free troposphere. Indeed, elevated PAN amounts of 200–700 pptv were measured in a large plume extending from Brasil over the Southern Atlantic, Central and South Africa, the South Indian Ocean as far as Australia at altitudes between 8 and 16 km. Enhanced PAN values were also found in a much more restricted area between northern subtropical Africa and India. The most significant northern midlatitude PAN signal was detected in an area at 8 km altitude extending from China into the Chinese Sea. The average mid and high latitude PAN amounts found at 8 km were around 125 pptv in the northern, but only between 50 and 75 pptv in the

  17. The Explanation of Michelson's Experiment

    International Nuclear Information System (INIS)

    Klinaku, Shukri

    2010-01-01

    In this paper we will prove that the Lorentz factor doesn't exist on the relative motion. In fact this factor is the result of a wrong calculation of Michelson. His mistake was approved by Lorentz and other physicists, including Einstein. Michelson in order to implement his idea with his interferometer in 1881, made the following mistake: he made the calculation according to the only principle of relativity which was known by physics--the Galileo principle, but he didn't faithfully apply this principle. In this paper, the principle of Galileo will be implemented exactly to Michelson's experiment and the result will show us that physics doesn't need the postulates of the year 1905.

  18. CIV Polarization Measurements using a Vacuum Ultraviolet Fabry-Perot Interferometer

    Science.gov (United States)

    West, Edward; Gary, G. Allen; Cirtain, Jonathan; David, John; Kobayashi, Ken; Pietraszewski, Chris

    2009-01-01

    Marshall Space Flight Center's (MSFC) is developing a Vacuum Ultraviolet (VUV) Fabry-P rot Interferometer that will be launched on a sounding rocket for high throughput, high-cadence, extended field of view CIV (155nm) measurements. These measurements will provide (i) Dopplergrams for studies of waves, oscillations, explosive events, and mass motions through the transition region, and, (ii), polarization measurements to study the magnetic field in the transition region. This paper will describe the scientific goals of the instrument, a brief description of the optics and the polarization characteristics of the VUV Fabry P rot.

  19. Self-calibrating interferometer

    International Nuclear Information System (INIS)

    Nussmeier, T.A.

    1982-01-01

    A self-calibrating interferometer is disclosed which forms therein a pair of Michelson interferometers with one beam length of each Michelson interferometer being controlled by a common phase shifter. The transfer function measured from the phase shifter to either of a pair of detectors is sinusoidal with a full cycle for each half wavelength of phase shifter travel. The phase difference between these two sinusoidal detector outputs represents the optical phase difference between a path of known distance and a path of unknown distance

  20. Measuring polarization dependent dispersion of non-polarizing beam splitter cubes with spectrally resolved white light interferometry

    Science.gov (United States)

    Csonti, K.; Hanyecz, V.; Mészáros, G.; Kovács, A. P.

    2017-06-01

    In this work we have measured the group-delay dispersion of an empty Michelson interferometer for s- and p-polarized light beams applying two different non-polarizing beam splitter cubes. The interference pattern appearing at the output of the interferometer was resolved with two different spectrometers. It was found that the group-delay dispersion of the empty interferometer depended on the polarization directions in case of both beam splitter cubes. The results were checked by inserting a glass plate in the sample arm of the interferometer and similar difference was obtained for the two polarization directions. These results show that to reach high precision, linearly polarized white light beam should be used and the residual dispersion of the empty interferometer should be measured at both polarization directions.

  1. On the importance of the Michelson-Morley experiment

    International Nuclear Information System (INIS)

    Strel'tsov, V.N.

    1992-01-01

    The opinion of an important role of the Michelson-Morley experiment in the establishment of the pronciple oof the light velocity constancy is expressed. It is stressed that the used of radar length for the treatment of the Michelson-Morley experiment leads to the elongation formulas for the longitudinal arm of an interferometer. 24 refs

  2. Stable fiber interferometer

    International Nuclear Information System (INIS)

    Izmajlov, G.N.; Nikolaev, F.A.; Ozolin, V.V.; Grigor'yants, V.V.; Chamorovskij, Yu.K.

    1989-01-01

    The problem of construction the long-base Michelson interferometer for gravitational wave detection is discussed. Possible sources of noise and instability are considered. It is shown that evacuation of fiber interferometer, the winding of its arms on the glass ceramic bases, stabilization of radiation source frequency and seismic isolation of the base allow one to reduce its instability to the level, typical of mirror interferometer with the comparable optical base. 10 refs.; 2 figs

  3. Michelson wide-field stellar interferometry

    NARCIS (Netherlands)

    Montilla, I.

    2004-01-01

    The main goal of this thesis is to develop a system to permit wide field operation of Michelson Interferometers. A wide field of view is very important in applications such as the observation of extended or multiple objects, the fringe acquisition and/ or tracking on a nearby unresolved object, and

  4. Multispectral infrared imaging interferometer

    Science.gov (United States)

    Potter, A. E., Jr.

    1971-01-01

    Device permitting simultaneous viewing of infrared images at different wavelengths consists of imaging lens, Michelson interferometer, array of infrared detectors, data processing equipment for Fourier transformation of detector signal, and image display unit. Invention is useful in earth resources applications, nondestructive testing, and medical diagnoses.

  5. Japanese large-scale interferometers

    CERN Document Server

    Kuroda, K; Miyoki, S; Ishizuka, H; Taylor, C T; Yamamoto, K; Miyakawa, O; Fujimoto, M K; Kawamura, S; Takahashi, R; Yamazaki, T; Arai, K; Tatsumi, D; Ueda, A; Fukushima, M; Sato, S; Shintomi, T; Yamamoto, A; Suzuki, T; Saitô, Y; Haruyama, T; Sato, N; Higashi, Y; Uchiyama, T; Tomaru, T; Tsubono, K; Ando, M; Takamori, A; Numata, K; Ueda, K I; Yoneda, H; Nakagawa, K; Musha, M; Mio, N; Moriwaki, S; Somiya, K; Araya, A; Kanda, N; Telada, S; Sasaki, M; Tagoshi, H; Nakamura, T; Tanaka, T; Ohara, K

    2002-01-01

    The objective of the TAMA 300 interferometer was to develop advanced technologies for kilometre scale interferometers and to observe gravitational wave events in nearby galaxies. It was designed as a power-recycled Fabry-Perot-Michelson interferometer and was intended as a step towards a final interferometer in Japan. The present successful status of TAMA is presented. TAMA forms a basis for LCGT (large-scale cryogenic gravitational wave telescope), a 3 km scale cryogenic interferometer to be built in the Kamioka mine in Japan, implementing cryogenic mirror techniques. The plan of LCGT is schematically described along with its associated R and D.

  6. A study of far-infrared Michelson interferometry based on fast plasma scanning

    International Nuclear Information System (INIS)

    Bartlett, D.V.; Hewitt, G.L.; Robinson, L.C.; Tait, G.D.

    1976-02-01

    Fast far-infrared multiplex spectroscopy based on a plasma-scanned Michelson interferometer is studied. Our experiments show that the interferometer has sub-millisecond time response and high spectral resolving power. In addition to a description of the experimental performance of the interferometer, we develop and discuss two different methods of interferogram inversion. (author)

  7. Polarization speed meter for gravitational-wave detection

    Science.gov (United States)

    Wade, Andrew R.; McKenzie, Kirk; Chen, Yanbei; Shaddock, Daniel A.; Chow, Jong H.; McClelland, David E.

    2012-09-01

    We propose a modified configuration of an advanced gravitational-wave detector that is a speed-meter-type interferometer with improved sensitivity with respect to quantum noise. With the addition of polarization-controlling components to the output of an arm cavity Michelson interferometer, an orthogonal polarization state of the interferometer can be used to store signal, returning it later with opposite phase to cancel position information below the storage bandwidth of the opposite mode. This modification provides an alternative to an external kilometer-scale Fabry-Pérot cavity, as presented in earlier work of Purdue and Chen [Phys. Rev. D 66, 122004 (2002)]. The new configuration requires significantly less physical infrastructure to achieve speed meter operation. The quantity of length and alignment degrees of freedom is also reduced. We present theoretical calculations to show that such a speed meter detector is capable of beating the strain sensitivity imposed by the standard quantum limit over a broad range of frequencies for Advanced Laser Interferometer Gravitational-wave Observatory-like parameters. The benefits and possible difficulties of implementing such a scheme are outlined. We also present results for tuning of the speed meter by adjusting the degree of polarization coupling, a novel possibility that does not exist in previously proposed designs, showing that there is a smooth transition from speed meter operation to that of a signal-recycling Michelson behavior.

  8. Faraday-Michelson system for quantum cryptography.

    Science.gov (United States)

    Mo, Xiao-Fan; Zhu, Bing; Han, Zheng-Fu; Gui, You-Zhen; Guo, Guang-Can

    2005-10-01

    Quantum key distribution provides unconditional security for communication. Unfortunately, current experimental schemes are not suitable for long-distance fiber transmission because of phase drift or Rayleigh backscattering. In this Letter we present a unidirectional intrinsically stable scheme that is based on Michelson-Faraday interferometers, in which ordinary mirrors are replaced with 90 degree Faraday mirrors. With the scheme, a demonstration setup was built and excellent stability of interference fringe visibility was achieved over a fiber length of 175 km. Through a 125 km long commercial communication fiber cable between Beijing and Tianjin, the key exchange was performed with a quantum bit-error rate of less than 6%, which is to our knowledge the longest reported quantum key distribution experiment under field conditions.

  9. Optical diameters of stars measured with the Mt. Wilson Mark III interferometer

    International Nuclear Information System (INIS)

    Simon, R.S.; Mozurkewich, D.; Johnston, K.J.; Gaume, R.; Hutter, D.J.; Bowers, P.F.; Colavita, M.M.; Shao, M.

    1990-01-01

    Reliable stellar angular diameters can now be determined using the Mark III Optical Interferometer located on Mt. Wilson, California. The Mark III is a Michelson Interferometer capable of measuring the interferometric fringe visibility for stars using interferometer baselines varying from 3 to 31.5 meters in length. Angular diameters measured with the Mark III Optical Interferometer are presented for 12 stars at wavelengths of 450 and 800 nm. 10 refs

  10. Interferometer techniques for gravitational-wave detection.

    Science.gov (United States)

    Bond, Charlotte; Brown, Daniel; Freise, Andreas; Strain, Kenneth A

    2016-01-01

    Several km-scale gravitational-wave detectors have been constructed worldwide. These instruments combine a number of advanced technologies to push the limits of precision length measurement. The core devices are laser interferometers of a new kind; developed from the classical Michelson topology these interferometers integrate additional optical elements, which significantly change the properties of the optical system. Much of the design and analysis of these laser interferometers can be performed using well-known classical optical techniques; however, the complex optical layouts provide a new challenge. In this review, we give a textbook-style introduction to the optical science required for the understanding of modern gravitational wave detectors, as well as other high-precision laser interferometers. In addition, we provide a number of examples for a freely available interferometer simulation software and encourage the reader to use these examples to gain hands-on experience with the discussed optical methods.

  11. O2 atmospheric band measurements with WINDII: Performance of a narrow band filter/wide angle Michelson combination in space

    International Nuclear Information System (INIS)

    Ward, W.E.; Hersom, C.H.; Tai, C.C.; Gault, W.A.; Shepherd, G.G.; Solheim, B.H.

    1994-01-01

    Among the emissions viewed by the Wind Imaging Interferometer (WINDII) on the Upper Atmosphere Research Satellite (UARS) are selected lines in the (0-0) transition of the O2 atmospheric band. These lines are viewed simultaneously using a narrow band filter/wide-angle Michelson interferometer combination. The narrow band filter is used to separate the lines on the CCD (spectral-spatial scanning) and the Michelson used to modulate the emissions so that winds and rotational temperatures may be measured from the Doppler shifts and relative intensities of the lines. In this report this technique will be outlined and the on-orbit behavior since launch summarized

  12. A wave optics approach to the theory of the Michelson-Morley experiment

    Science.gov (United States)

    Smid, Thomas

    2017-11-01

    A consistent classical wave optics approach to the theory of the Michelson-Morley experiment shows that the original theory as applied by Michelson and Morley and others does not calculate the optical paths of the two beams correctly, primarily because of incorrectly assuming a right angle reflection in the instrument’s reference frame for the transverse beam, but also because of the incorrect assumption of aberration for the wave fronts. The theory presented in this work proves the expected variation of the phase difference when rotating the interferometer to be more than twice as large and also strongly asymmetrical around the zero line.

  13. Potentiality of an orbiting interferometer for space-time experiments

    International Nuclear Information System (INIS)

    Grassi Strini, A.M.; Strini, G.; Tagliaferri, G.

    1979-01-01

    It is suggested that by putting a Michelson interferometer aboard a spacecraft orbiting around the earth, very substantial progress could be made in space-time experiments. It is estimated that in measurements of e.g. some anisotropy of the light velocity, a spacecraft-borne interferometer of quite small size (0.1 m arm-length) would reach a sensitivity greater by a factor of approximately 10 8 than the best achievements to date of ground-based devices. (author)

  14. Atomic-resolution measurements with a new tunable diode laser-based interferometer

    DEFF Research Database (Denmark)

    Silver, R.M.; Zou, H.; Gonda, S.

    2004-01-01

    We develop a new implementation of a Michelson interferometer designed to make measurements with an uncertainty of less than 20 pm. This new method uses a tunable diode laser as the light source, with the diode laser wavelength continuously tuned to fix the number of fringes in the measured optical...... laser Michelson interferometer....... path. The diode laser frequency is measured by beating against a reference laser. High-speed, accurate frequency measurements of the beat frequency signal enables the diode laser wavelength to be measured with nominally 20-pm accuracy for the measurements described. The new interferometer design...

  15. Uniform spacing interrogation of a Fourier domain mode-locked fiber Bragg grating sensor system using a polarization-maintaining fiber Sagnac interferometer

    International Nuclear Information System (INIS)

    Lee, Hwi Don; Jeong, Myung Yung; Chen, Zhongping; Kim, Chang-Seok; Jung, Eun Joo

    2013-01-01

    A novel linearized interrogation method is presented for a Fourier domain mode-locked (FDML) fiber Bragg grating (FBG) sensor system. In a high speed regime over several tens of kHz modulations, a sinusoidal wave is available to scan the center wavelength of an FDML wavelength-swept laser, instead of a conventional triangular wave. However, sinusoidal wave modulation suffers from an exaggerated non-uniform wavelength-spacing response in demodulating the time-encoded parameter to the absolute wavelength. In this work, the calibration signal from a polarization-maintaining fiber Sagnac interferometer shares the FDML wavelength-swept laser for FBG sensors to convert the time-encoded FBG signal to the wavelength-encoded uniform-spacing signal. (paper)

  16. Uniform spacing interrogation of a Fourier domain mode-locked fiber Bragg grating sensor system using a polarization-maintaining fiber Sagnac interferometer

    Science.gov (United States)

    Lee, Hwi Don; Jung, Eun Joo; Jeong, Myung Yung; Chen, Zhongping; Kim, Chang-Seok

    2013-06-01

    A novel linearized interrogation method is presented for a Fourier domain mode-locked (FDML) fiber Bragg grating (FBG) sensor system. In a high speed regime over several tens of kHz modulations, a sinusoidal wave is available to scan the center wavelength of an FDML wavelength-swept laser, instead of a conventional triangular wave. However, sinusoidal wave modulation suffers from an exaggerated non-uniform wavelength-spacing response in demodulating the time-encoded parameter to the absolute wavelength. In this work, the calibration signal from a polarization-maintaining fiber Sagnac interferometer shares the FDML wavelength-swept laser for FBG sensors to convert the time-encoded FBG signal to the wavelength-encoded uniform-spacing signal.

  17. Virgo: a laser interferometer to detect gravitational waves

    NARCIS (Netherlands)

    Accadia, T.; van den Brand, J.F.J.; Bulten, H.J.; Ketel, T.J.; van der Voet, H.; Mul, F.A.; Rabeling, D.S.

    2012-01-01

    This paper presents a complete description of Virgo, the French-Italian gravitational wave detector. The detector, built at Cascina, near Pisa (Italy), is a very large Michelson interferometer, with 3 km-long arms. In this paper, following a presentation of the physics requirements, leading to the

  18. Correlation functions formed by a femtosecond pulse interferometer

    NARCIS (Netherlands)

    Cui, M.; Bhattacharya, N.; Urbach, H.P.; Van den berg, S.A.

    2008-01-01

    We experimentally demonstrate that a stabilized femtosecond frequency comb can be applied as a tool for distance measurement. The scheme is based on optical interference between individual pulses in a Michelson type interferometer. The cross-correlation functions between individual pulses with a

  19. The Virgo 3 km interferometer for gravitational wave detection

    NARCIS (Netherlands)

    Acernese, F.; Amico, Paolo; Alshourbagy, Mohamed; Antonucci, Federica; Aoudia, S.; Astone, P.; Avino, Saverio; Baggio, L.; Ballardin, G.; Barone, F.; Barsotti, L.; Barsuglia, M.; Bauer, Th. S.; Bigotta, Stefano; Bizouard, M. A.; Boccara, Albert-Claude; Bondu, F.; Bosi, Leone; Bradaschia, C.; van den Brand, J. F. J.; Birindelli, Simona; Braccini, Stefano; Brillet, A.; Brisson, V.; Buskulic, D.; Cagnoli, G.; Calloni, E.; Campagna, Enrico; Carbognani, F.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cesarini, E.; Chassande-Mottin, E.; Clapson, A-C; Cleva, F.; Coccia, E.; Corda, C.; Corsi, A.; Cottone, F.; Coulon, J. -P.; Cuoco, E.; D'Antonio, S.; Dari, A.; Dattilo, V.; Davier, M.; Del Prete, M.; Rosa, R.; Di Fiore, L.; Di Lieto, A.; Di Virgilio, A.; Dujardin, B.; Evans, M.; Fafone, V.; Ferrante, I.; Fidecaro, F.; Fiori, I.; Flaminio, R.; Fournier, J. -D.; Frasca, S.; Frasconi, F.; Gammaitoni, L.; Garufi, F.; Genin, E.; Gennai, A.; Giazotto, A.; Giordano, L.; Granata, V.; Greverie, C.; Grosjean, D.; Guidi, G.; Hamdani, S.U.; Hebri, S.; Heitmann, H.; Hello, P.; Huet, D.; Kreckelbergh, S.; La Penna, P.; Laval, M.; Leroy, N.; Letendre, N.; Lopez, B.; Lorenzini, M.; Loriette, V.; Losurdo, G.; Mackowski, J. -M.; Majorana, E.; Man, C. N.; Mantovani, M.; Marchesoni, F.; Marion, F.; Marque, J.; Martelli, F.; Masserot, A.; Menzinger, F.; Milano, L.; Minenkov, Y.; Moins, C.; Moreau, J.; Morgado, N.; Mosca, S.; Mours, B.; Neri, I.; Nocera, F.; Pagliaroli, G.; Pallottino, G. V.; Palomba, C.; Paoletti, F.; Pardi, S.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Piergiovanni, F.; Pinard, L.; Poggiani, R.; Punturo, M.; Puppo, P.; van der Putten, S.; Rapagnani, P.; Regimbau, T.; Reita, V.; Remillieux, A.; Ricci, F.; Ricciardi, I.; Rocchi, A.; Romano, R.; Ruggi, P.; Russo, G.; Solimeno, S.; Spallicci, A.; Tarallo, M.; Terenzi, R.; Tonelli, M.; Toncelli, A.; Tournefier, E.; Travasso, F.; Tremola, C.; Vajente, G.; Verkindt, D.; Vetrano, F.; Vicere, A.; Vinet, J. -Y.; Vocca, H.; Yvert, M.

    Virgo, designed, constructed and developed by the French-Italian VIRGO collaboration located in Cascina (Pisa, Italy) and aiming to detect gravitational waves, is a ground-based power recycled Michelson interferometer, with 3 km long suspended Fabry -Perot cavities. The first Virgo scientific

  20. Lembit Michelsoni CV / Lembit Michelson

    Index Scriptorium Estoniae

    Michelson, Lembit, 1960-

    2011-01-01

    Fotograaf Lembit Michelson meenutab lapsepõlve- ja kooliaastaid, sõjaväeteenistust, tööd fotograafina nõukogude ajal. Viimased 15 aastat töötab oma foto- ja disainistuudios Akriibia. Erinevatest fotoseeriatest. Artiklile lisatud 7 Lembit Michelsoni kirjutatud luuletust

  1. Visualizing the phenomena of wave interference, phase-shifting and polarization by interactive computer simulations

    Science.gov (United States)

    Rivera-Ortega, Uriel; Dirckx, Joris

    2015-09-01

    In this manuscript a computer based simulation is proposed for teaching concepts of interference of light (under the scheme of a Michelson interferometer), phase-shifting and polarization states. The user can change some parameters of the interfering waves, such as their amplitude and phase difference in order to graphically represent the polarization state of a simulated travelling wave. Regarding to the interference simulation, the user is able to change the wavelength and type of the interfering waves by selecting combinations between planar and Gaussian profiles, as well as the optical path difference by translating or tilting one of the two mirrors in the interferometer setup, all of this via a graphical user interface (GUI) designed in MATLAB. A theoretical introduction and simulation results for each phenomenon will be shown. Due to the simulation characteristics, this GUI can be a very good non-formal learning resource.

  2. Characterization of a Piezoelectric Buzzer Using a Michelson Interferometer

    Science.gov (United States)

    Lloyd, S.; Paetkau, M.

    2010-01-01

    A piezoelectric material generates an electric potential across its surface when subjected to mechanical stress; conversely, the inverse piezoelectric effect describes the expansion or contraction of the material when subjected to some applied voltage. Piezoelectric materials are used in devices such as doorbell buzzers, barbeque igniters, and…

  3. Sideband ratio in double sideband receivers with a Michelson interferometer

    NARCIS (Netherlands)

    Romanini, M.; Baryshev, A. M.; Hesper, R.; Mena, F. P.; Wild, W.

    2007-01-01

    Terahertz heterodyne receivers typically use double sideband (DSB) mixers. The precise knowledge of the receiver sideband ratio (SBR) is a fundamental requirement for the calibration of the data taken with this type of receivers. At the moment the spectroscopic techniques developed for submillimeter

  4. Vapor Sensor Realized in an Ultracompact Polarization Interferometer Built of a Freestanding Porous-Silicon Form Birefringent Film

    National Research Council Canada - National Science Library

    O, Beom-Hoan; Liu, Rong; Li, Yang Y; Sailor, Michael J; Fainman, Yeshaiahu

    2005-01-01

    .... The simulation accurately predicts the polarization interference signal, which is used to estimate the effective refractive indexes characterizing the form birefringence of a porous-silicon film with 0.001 accuracy...

  5. Michelson mode selector for spectral range stabilization in a self-sweeping fiber laser.

    Science.gov (United States)

    Tkachenko, A Yu; Vladimirskaya, A D; Lobach, I A; Kablukov, S I

    2018-04-01

    We report on spectral range stabilization in a self-sweeping laser by adding a narrowband fiber Bragg grating (FBG) to the output mirror in the Michelson configuration. The effects of FBG reflectivity and optical path difference in the Michelson interferometer on the laser spectral dynamics are investigated. Optimization of the interferometer allows us to demonstrate broadband (over 16 nm) self-sweeping operation and reduction of the start and stop wavelength fluctuations by two orders and one order of magnitude (∼100 and 15 times) for start and stop bounds, respectively (down to several picometers). The proposed approaches significantly improve quality of the spectral dynamics and facilitate application of the self-sweeping lasers.

  6. Lock acquisition of a gravitational-wave interferometer.

    Science.gov (United States)

    Evans, M; Mavalvala, N; Fritschel, P; Bork, R; Bhawal, B; Gustafson, R; Kells, W; Landry, M; Sigg, D; Weiss, R; Whitcomb, S; Yamamoto, H

    2002-04-15

    Interferometric gravitational-wave detectors, such as the Laser Interferometer Gravitational Wave Observatory (LIGO) detectors currently under construction, are based on kilometer-scale Michelson interferometers, with sensitivity that is enhanced by addition of multiple coupled optical resonators. Reducing the relative optic motions to bring the system to the resonant operating point is a significant challenge. We present a new approach to lock acquisition, used to lock a LIGO interferometer, whereby the sensor transformation matrix is dynamically calculated to sequentially bring the cavities into resonance.

  7. Fourier Transform Fabry-Perot Interferometer

    Science.gov (United States)

    Snell, Hilary E.; Hays, Paul B.

    1992-01-01

    We are developing a compact, rugged, high-resolution remote sensing instrument with wide spectral scanning capabilities. This relatively new type of instrument, which we have chosen to call the Fourier-Transform Fabry-Perot Interferometer (FT-FPI), is accomplished by mechanically scanning the etalon plates of a Fabry-Perot interferometer (FPI) through a large optical distance while examining the concomitant signal with a Fourier-transform analysis technique similar to that employed by the Michelson interferometer. The FT-FPI will be used initially as a ground-based instrument to study near-infrared atmospheric absorption lines of trace gases using the techniques of solar absorption spectroscopy. Future plans include modifications to allow for measurements of trace gases in the stratosphere using spectral lines at terahertz frequencies.

  8. Modeling the Laser Interferometer Space Antenna Optics

    Science.gov (United States)

    Waluschka, Eugene; Pedersen, Tracy R.; McNamara, paul

    2005-01-01

    The Laser Interferometer Space Antenna (LISA), shown below, will detect gravitational waves produced by objects such as binary black holes or objects falling into black holes (extreme mass ratio inspirals) over a frequency range of l0(exp -4) to 0.1 Hz. Within the conceptual frame work of Newtonian physics, a gravitational wave produces a strain, (Delta)l/l, with magnitudes of the order of Earth based gravitational wave detectors, such as the Laser Interferometer Gravitational-Wave Observatory (LIGO) project, use Michelson interferometers with arm lengths l = 4 km to detect these strains. Earth induced seismic noise limits ground-based instruments detecting gravitational waves with frequencies lower than approx. 1 Hz.

  9. Pneumatic probe with laser interferometer

    International Nuclear Information System (INIS)

    Wilkens, P.H.

    1978-01-01

    Improvements to upgrade the accuracy of Rotacon probes by a complete redesign of probe to include a Michelson interferometer to replace the existing long-range capacity transducer are described. This has resulted in a compact and interchangeable probe cartridge with a 3 μin. resolution and accuracy; the cartridge can be installed and replaced in the Rotacon gauge with the minimum of realignment, which should reduce our dependence on operator skill. In addition, the stylus contact force can be reduced to 750 mg for the contacting types, but an alternative feature, which we are still developing, will use a gas jet cushion in place of the stylus to provide a noncontacting version of the same basic probe cartridge. This device is very sensitive to external vibration effects because it is virtually frictionless

  10. Improvement of input power dynamic range for 20 Gbit/s optical WDM switch nodes using an integrated Michelson wavelength converter

    DEFF Research Database (Denmark)

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

    1997-01-01

    be improved compared to switch blocks without IWCs. This is especially important at high bit rates where the cascadability of the SOA gates decreases. Here, more than 15 dB improvement of the input power dynamic range is achieved at 20 Gbit/s using a high-speed Michelson interferometer wavelength converter...

  11. Virgo an interferometer for gravitational wave detection

    International Nuclear Information System (INIS)

    Passaquieti, R.

    2000-01-01

    Gravitational waves propagating from rapidly accelerating star masses can be detected by means of interfer- ometric techniques. The Virgo detector is a Michelson interferometer, with two 3 km long Fabry-Perot cavities, that is going to be built in the countryside of Pisa (Italy). Principles of interferometric gravitational wave detection, and the main noise sources in the Virgo apparatus are treated. The Virgo optical scheme and its main components are also described. Finally, an overview on the status of works at the Virgo site is presented

  12. Sensing and control in dual-recycling laser interferometer gravitational-wave detectors.

    Science.gov (United States)

    Strain, Kenneth A; Müller, Guido; Delker, Tom; Reitze, David H; Tanner, David B; Mason, James E; Willems, Phil A; Shaddock, Daniel A; Gray, Malcolm B; Mow-Lowry, Conor; McClelland, David E

    2003-03-01

    We introduce length-sensing and control schemes for the dual-recycled cavity-enhanced Michelson interferometer configuration proposed for the Advanced Laser Interferometer Gravitational Wave Observatory (LIGO). We discuss the principles of this scheme and show methods that allow sensing and control signals to be derived. Experimental verification was carried out in three benchtop experiments that are introduced. We present the implications of the results from these experiments for Advanced LIGO and other future interferometric gravitational-wave detectors.

  13. An interferometer for high-resolution optical surveillance from GEO - internal metrology breadboard

    Science.gov (United States)

    Bonino, L.; Bresciani, F.; Piasini, G.; Pisani, M.; Cabral, A.; Rebordão, J.; Musso, F.

    2017-11-01

    This paper describes the internal metrology breadboard development activities performed in the frame of the EUCLID CEPA 9 RTP 9.9 "High Resolution Optical Satellite Sensor" project of the WEAO Research Cell by AAS-I and INETI. The Michelson Interferometer Testbed demonstrates the possibility of achieving a cophasing condition between two arms of the optical interferometer starting from a large initial white light Optical Path Difference (OPD) unbalance and of maintaining the fringe pattern stabilized in presence of disturbances.

  14. Evolved Stars: Interferometer Baby Food or Staple Diet?

    Science.gov (United States)

    Tuthill, Peter

    With their extreme red and infrared luminosities and large apparent diameters, evolved stars have nurtured generations of interferometers (beginning with Michelson's work on Betelgeuse) with unique science programs at attainable resolutions. Furthermore, the inflated photosphere and circumstellar material associated with dying stars presents complex targets with asymmetric structure on many scales encoding a wealth of poorly-understood astrophysics. A brief review the major past milestones and future prospects for interferometry's contribution to studies of circumstellar matter in evolved stars is presented.

  15. All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Malak, M.; Marty, F.; Bourouina, T. [Universite Paris-Est, Laboratoire ESYCOM, ESIEE Paris, Cite Descartes, 2 Boulevard Blaise Pascal, 93162 Noisy-le-Grand Cedex (France); Nouira, H.; Vailleau, G. [Laboratoire National de Metrologie et d' Essais, 1 rue Gaston Boissier, 75724 Paris Cedex 15 (France)

    2013-04-08

    A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

  16. All-silicon Michelson instrument on chip: Distance and surface profile measurement and prospects for visible light spectrometry

    International Nuclear Information System (INIS)

    Malak, M.; Marty, F.; Bourouina, T.; Nouira, H.; Vailleau, G.

    2013-01-01

    A miniature Michelson interferometer is analyzed theoretically and experimentally. The fabricated micro-interferometer is incorporated at the tip of a monolithic silicon probe to achieve contactless distance measurements and surface profilometry. For infrared operation, two approaches are studied, based on the use of monochromatic light and wavelength sweep, respectively. A theoretical model is devised to depict the system characteristics taking into account Gaussian beam divergence and light spot size. Furthermore, preliminary results using visible light demonstrate operation of the probe as a visible light spectrometer, despite silicon absorbance, thanks to the micrometer thickness involved in the beam splitter.

  17. Adaptive DFT-based Interferometer Fringe Tracking

    Science.gov (United States)

    Wilson, Edward; Pedretti, Ettore; Bregman, Jesse; Mah, Robert W.; Traub, Wesley A.

    2004-01-01

    An automatic interferometer fringe tracking system has been developed, implemented, and tested at the Infrared Optical Telescope Array (IOTA) observatory at Mt. Hopkins, Arizona. The system can minimize the optical path differences (OPDs) for all three baselines of the Michelson stellar interferometer at IOTA. Based on sliding window discrete Fourier transform (DFT) calculations that were optimized for computational efficiency and robustness to atmospheric disturbances, the algorithm has also been tested extensively on off-line data. Implemented in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time operating system, the algorithm runs in approximately 2.0 milliseconds per scan (including all three interferograms), using the science camera and piezo scanners to measure and correct the OPDs. The adaptive DFT-based tracking algorithm should be applicable to other systems where there is a need to detect or track a signal with an approximately constant-frequency carrier pulse.

  18. Development of a steel ball center alignment device based on Michelson interference concept.

    Science.gov (United States)

    Lee, Hau-Wei; Liu, Chien-Hung

    2014-09-01

    This study presents a ball center alignment method based on the Michelson interferometer where one of the reflecting mirrors is replaced by a lens and steel ball. By locating the ball away from the focal length of the lens, the beam is reflected as a spherical wave. The interference ring formed by the planar and spherical waves can be clearly observed using a camera without a lens. The distance of the offset of the ball center can be enhanced by more than 140% using this method. A fast ring profile fitting method can reduce circle fitting time to around a third of that needed for Hough transformation.

  19. CO laser interferometer for REB-plasma experiments

    International Nuclear Information System (INIS)

    Burmasov, V.S.; Kruglyakov, E.P.

    1996-01-01

    The Michelson carbon oxide laser interferometer for measuring plasma density in studies on REB-plasma interaction is described. A detail description of the interferometer and CO laser is presented. For a selection of a single wavelength laser operation the CaF 2 prism is applied. A Ge:Au photoconductor at 77 deg K is applied as the detector. The CO laser radiation at λ 5.34 μm coincides with the detector maximum sensitivity (of the order of 1000 V/W). This increases the interferometer sensitivity about ten times with respect to the He-Ne laser (λ = 3.39 μm) used as the source of light. The typical interferogram and time evolution of plasma density obtained at GOL-M device are presented. (author). 3 figs., 5 refs

  20. The POLIS interferometer for ponderomotive squeezed light generation

    Energy Technology Data Exchange (ETDEWEB)

    Calloni, Enrico [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Conte, Andrea [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); De Laurentis, Martina, E-mail: martina.delaurentis@na.infn.it [Dipartimento di Fisica, Università degli Studi di Napoli “Federico II”, Napoli (Italy); INFN, Sezione di Napoli (Italy); Naticchioni, Luca [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy); Puppo, Paola [INFN, Sezione di Roma1 (Italy); Ricci, Fulvio [Dipartimento di Fisica, Università di Roma “Sapienza”, Roma (Italy); INFN, Sezione di Roma1 (Italy)

    2016-07-11

    POLIS (POnderomotive LIght Squeezer) is a suspended interferometer, presently under construction, devoted to the generation of ponderomotive squeezed light and to the study of the interaction of non classical quantum states of light and macroscopic objects. The interferometer is a Michelson whose half-meter long arms are constituted by high-finesse cavities, suspended to a seismic isolation chain similar to the Virgo SuperAttenuator. The mass of the suspended cavity mirrors are chosen to be tens of grams: this value is sufficiently high to permit the use of the well-tested Virgo suspension techniques but also sufficiently small to generate the coupling among the two phase quadratures with a limited amount of light in the cavity, of the order of few tens of kW. In this short paper the main features of the interferometer are shown, together with the expected sensitivity and squeezing factor.

  1. The Newcomb & Michelson Velocity of Light Experiments

    Science.gov (United States)

    Carter, W. E.

    2002-05-01

    Simon Newcomb (1835-1909) is remembered as the leading American mathematical astronomer of the 19th century; Albert Michelson (1852-1931) as the leading optical experimentalist of his era, and the first American to win the Nobel Prize in physics (1907). Newcomb first became interested in measuring the velocity of light to better determine the scale of the solar system. Ensign Michelson began his velocity of light experiments while preparing to teach physics at the U.S. Naval Academy, in Annapolis, Maryland. Using private funding and Naval Academy facilities, in January 1879, Michelson obtained a value of 299,910 km/sec. In March of that same year Newcomb received an appropriation of five thousand dollars and Michelson was detailed to the U.S. Naval Observatory (USNO) to assist with experiments in Washington D. C. The instrument designed by Newcomb used a four-sided solid steel rotating mirror to avoid a failure of the type Michelson had experienced when a thin glass mirror failed from centrifugal force. The mirror was driven by compressed air operating on fan wheels at each end of the assembly. Rotation rates of 250 rev/sec were possible, in both directions, and the rate could be varied minutely by adjusting conflicting air jets. Ft. Meyers was selected for the primary station, and fixed mirror stations were placed at USNO (Foggy Bottom) and the Washington Monument. The U.S. Coast and Geodetic Survey (USC&GS) determined the distances from the rotating mirror to the fixed mirrors. They first established a few hundred meter long baseline on Analostan Island, in the Potomac River, using 4 meter long agate capped steel slide-rods. Triangulation was then used to extend the network to each of the reflector stations. Michelson participated in the Washington D.C. observations until September 1880, when he was granted a leave of absence by the Navy to study in Europe. Newcomb continued the experiments for two more years. In his final report, Newcomb gave two values for the

  2. A stellar interferometer on the Moon

    Science.gov (United States)

    Porro, Irene

    is produced by simulating the interference of the distorted wavefront with a plane wavefront. This interferogram is a means to represent the loss in the optical performance of the system. The interferograms produced by the simulation program are collected in an "atlas" (I present an extract of it as an independent appendix of this thesis) which will be used during the telescope alignment operation to help in diagnosing the error in the optics position. The initial part of the chapter is devoted to a brief introduction to the wavefront aberration theory (from Schroeder, 1987) and to the analysis of one of the IOTA telescopes when it is in auto-collimation mode (the configuration used for the alignment operation). On the basis of this analysis I derived the misalignment conditions which I studied by means of the simulation program. The third chapter (III) is devoted to the beamsplitter, a fundamental element for most Michelson optical stellar interferometers. The beamsplitter is the optical element by means of which the beams are made interfere. In the first part of the chapter I describe the characteristics of a beamsplitter for astronomical applications. This description is mainly based on a study that James D. Phillips accomplished within the project of the space interferometer POINTS. To my knowledge, this is the only study which deals with both the theoretical approach of the problem and the experimental aspect involved in the design of a beamsplitter for astronomical applications. In the second part of the chapter I present the original contribution on this subject, which consists in the analysis of the polarizations effects introduced by the beamsplitter. In particular I obtain the expression of the fringe intensity when considering the polarization effects. This expression contains a term which gives the visibility loss due to the phase difference between the polarization components of the interfering beams. Then I evaluate the loss in visibility for IOTA and

  3. Special relativity and interferometers

    Science.gov (United States)

    Han, D.; Kim, Y. S.

    1988-01-01

    A new generation of gravitational wave detectors is expected to be based on interferometers. Yurke et al. (1986) introduced a class of interferometers characterized by SU(1,1) which can in principle achieve a phase sensitivity approaching 1/N, where N is thte total number of photons entering the interferometer. It is shown here that the SU(1,1) interferometer can serve as an analog computer for Wigner's little group of the Poincare\\'| group.

  4. Theoretical Analysis of Interferometer Wave Front Tilt and Fringe Radiant Flux on a Rectangular Photodetector

    Directory of Open Access Journals (Sweden)

    Franz Konstantin Fuss

    2013-09-01

    Full Text Available This paper is a theoretical analysis of mirror tilt in a Michelson interferometer and its effect on the radiant flux over the active area of a rectangular photodetector or image sensor pixel. It is relevant to sensor applications using homodyne interferometry where these opto-electronic devices are employed for partial fringe counting. Formulas are derived for radiant flux across the detector for variable location within the fringe pattern and with varying wave front angle. The results indicate that the flux is a damped sine function of the wave front angle, with a decay constant of the ratio of wavelength to detector width. The modulation amplitude of the dynamic fringe pattern reduces to zero at wave front angles that are an integer multiple of this ratio and the results show that the polarity of the radiant flux changes exclusively at these multiples. Varying tilt angle causes radiant flux oscillations under an envelope curve, the frequency of which is dependent on the location of the detector with the fringe pattern. It is also shown that a fringe count of zero can be obtained for specific photodetector locations and wave front angles where the combined effect of fringe contraction and fringe tilt can have equal and opposite effects. Fringe tilt as a result of a wave front angle of 0.05° can introduce a phase measurement difference of 16° between a photodetector/pixel located 20 mm and one located 100 mm from the optical origin.

  5. White light spectral interferometer for measuring dispersion in the visible-near infrared

    Science.gov (United States)

    Arosa, Yago; Rodríguez Fernández, Carlos Damian; Algnamat, Bilal S.; López-Lago, Elena; de la Fuente, Raul

    2017-08-01

    We have designed a spectrally resolved interferometer to measure the refractive index of transparent samples over a wide spectral band from 400 to 1550 nm. The measuring device consists of a Michelson interferometer whose output is analyzed by means of three fiber spectrometers. The first one is a homemade prism spectrometer, which obtains the interferogram produced by the sample over 400 to 1050 nm; the second one is a homemade transmission grating spectrometer thought to measure the interferogram in the near infrared spectral band from 950 to 1550 nm; the last one is a commercial Czerny-Turner spectrometer used to make high precision measurements of the displacement between the Michelson mirrors also using white light interferometry. The whole system is illuminated by a white light source with an emission spectrum similar to black body. We have tested the instrument with solid and liquids samples achieving accuracy to the fourth decimal on the refractive index after fitting it to a Cauchy formula

  6. Analytic models of spectral responses of fiber-grating-based interferometers on FMC theory.

    Science.gov (United States)

    Zeng, Xiangkai; Wei, Lai; Pan, Yingjun; Liu, Shengping; Shi, Xiaohui

    2012-02-13

    In this paper the analytic models (AMs) of the spectral responses of fiber-grating-based interferometers are derived from the Fourier mode coupling (FMC) theory proposed recently. The interferometers include Fabry-Perot cavity, Mach-Zehnder and Michelson interferometers, which are constructed by uniform fiber Bragg gratings and long-period fiber gratings, and also by Gaussian-apodized ones. The calculated spectra based on the analytic models are achieved, and compared with the measured cases and those on the transfer matrix (TM) method. The calculations and comparisons have confirmed that the AM-based spectrum is in excellent agreement with the TM-based one and the measured case, of which the efficiency is improved up to ~2990 times that of the TM method for non-uniform-grating-based in-fiber interferometers.

  7. Michelson wide-field stellar interferometry : Principles and experimental verification

    NARCIS (Netherlands)

    Montilla, I.; Pereira, S.F.; Braat, J.J.M.

    2005-01-01

    A new interferometric technique for Michelson wide-field interferometry is presented that consists of a Michelson pupil-plane combination scheme in which a wide field of view can be achieved in one shot. This technique uses a stair-shaped mirror in the intermediate image plane of each telescope in

  8. Adaptive DFT-Based Interferometer Fringe Tracking

    Directory of Open Access Journals (Sweden)

    Pedretti Ettore

    2005-01-01

    Full Text Available An automatic interferometer fringe tracking system has been developed, implemented, and tested at the Infrared Optical Telescope Array (IOTA Observatory at Mount Hopkins, Arizona. The system can minimize the optical path differences (OPDs for all three baselines of the Michelson stellar interferometer at IOTA. Based on sliding window discrete Fourier-transform (DFT calculations that were optimized for computational efficiency and robustness to atmospheric disturbances, the algorithm has also been tested extensively on offline data. Implemented in ANSI C on the 266 MHz PowerPC processor running the VxWorks real-time operating system, the algorithm runs in approximately milliseconds per scan (including all three interferograms, using the science camera and piezo scanners to measure and correct the OPDs. The adaptive DFT-based tracking algorithm should be applicable to other systems where there is a need to detect or track a signal with an approximately constant-frequency carrier pulse. One example of such an application might be to the field of thin-film measurement by ellipsometry, using a broadband light source and a Fourier-transform spectrometer to detect the resulting fringe patterns.

  9. Navigation with Atom Interferometers

    Science.gov (United States)

    2017-03-20

    Navigation with Atom Interferometers Mary F. Locke and Frank A. Narducci Avionics Department Naval Air Systems Command Patuxent River, Md...20670 Abstract: In this article, we review the basic physics of an atom interferometer. We highlight the usefulness of atom interferometers for...inertial navigation due to their high phase sensitivity to both linear acceleration and angular rotation, but also the drawback that a single atom

  10. Variations of interferometer types

    International Nuclear Information System (INIS)

    Graeff, W.

    1978-01-01

    The search for other interferometer configurations than the LLL interferometer that has been proved to work satisfactorily, has two reasons: first some disadvantages of the LLL interferometer like the smearins of the beams over the Borrmann fan or the loss of half of the intensity in the Laue case mirror may be overcome by changing the geometry. Secondly, problems of neutron optics like details of wave propagation in perfect and nearly perfect crystals coherence etc. can be investigated by varying the properties of the interferometer components. The discussion is restricted to those inteferometer types where Bragg diffracting single crystals are used for beam handling

  11. Atom Wave Interferometers

    National Research Council Canada - National Science Library

    Pritchard, David

    1999-01-01

    Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

  12. Achieving resonance in the Advanced LIGO gravitational-wave interferometer

    International Nuclear Information System (INIS)

    Staley, A; Martynov, D; Abbott, R; Adhikari, R X; Arai, K; Brooks, A F; Ballmer, S; Barsotti, L; Evans, M; Fritschel, P; DeRosa, R T; Effler, A; Dwyer, S; Gray, C; Izumi, K; Frolov, V V; Guido, C J; Heintze, M; Gustafson, R; Hoak, D

    2014-01-01

    Interferometric gravitational-wave detectors are complex instruments comprised of a Michelson interferometer enhanced by multiple coupled cavities. Active feedback control is required to operate these instruments and keep the cavities locked on resonance. The optical response is highly nonlinear until a good operating point is reached. The linear operating range is between 0.01% and 1% of a fringe for each degree of freedom. The resonance lock has to be achieved in all five degrees of freedom simultaneously, making the acquisition difficult. Furthermore, the cavity linewidth seen by the laser is only ∼1 Hz, which is four orders of magnitude smaller than the linewidth of the free running laser. The arm length stabilization system is a new technique used for arm cavity locking in Advanced LIGO. Together with a modulation technique utilizing third harmonics to lock the central Michelson interferometer, the Advanced LIGO detector has been successfully locked and brought to an operating point where detecting gravitational-waves becomes feasible. (paper)

  13. The Narrabri Stellar Intensity Interferometer: a 50th birthday tribute

    Science.gov (United States)

    Tuthill, Peter G.

    2014-07-01

    This year marks the 50th anniversary since the first scientific measurements were produced with the Narrabri Stellar Intensity Interferometer, which was constructed in the early 1960's by Robert Hanbury Brown and Richard Twiss. A collaboration between the Universities of Sydney and Manchester, the interferometer was the culmination of a series of experiments which pioneered the technique of intensity interferometry. The immediate controversy surrounding the quantum implications of the technique enveloped some of the most eminent physicists of the day, sparking a debate about nonlocal effects and optical coherence. A full explanation of the workings of the intensity interferometer in a quantum context was finally put forward by Roy Glauber, ultimately earning him the 2005 Nobel Prize in Physics. The intensity interferometer rekindled the field of high resolution stellar imaging, which had been extinguished for a half century (following the failure of Pease's 50-foot beam on Mt Wilson), while delivering the first ever measurements of the sizes of normal stars - establishing an effective temperature scaling relationship which has underpinned stellar astronomy for 50 years. This directly paved the way for the next generation of Michelson Stellar Interferometers. Intensity interferometry itself has found application in several fields (notably particle physics), and plans are in active development for modern reprises within stellar interferometry. However undoubtedly the greatest legacy lies in the Hanbury Brown Twiss (HBT) effect being the foundational experiment for what is now known as Quantum Optics - a field which underpins a huge sector of the technology which enables our modern world. This invited review discuses the development of the interferometer, including the controversy that its underlying principles generated within the contemporary physics community. The core scientific output generated by the instrument is presented, together with the impact of the

  14. Polarization-sensitive optical coherence tomography for imaging of biological tissues

    Science.gov (United States)

    Chen, Xiaodong; Wang, Yi; Li, Wanhui; Yu, Daoyin

    2006-09-01

    Polarization sensitive optical coherence tomography (PS-OCT) is a new non-contact and non-invasive method for measuring the change of birefringence in biological tissues caused by pathological changes of body. It has great potential in imaging the structural properties of turbid biological media because the polarization state of light backscattered from biological tissues is influenced by the birefringence of fibrous structures. The arrangement is based on a Michelson interferometer with use of quarter-wave plates and polarimeter. Through the detection of light backscattered from biological tissues and reflected from a reference mirror, the optical phase delay between orthogonal polarization compositions propagating in the birefringence media can be measured. PS-OCT is a powerful tool for research of tendon, dentin, lesions, which have strong polarization effective. We in this paper describe the experimental scheme and its mathematical representation, along with the theory of PS-OCT imaging. Besides, we introduce a fiber-based PS-OCT system for measuring the tissue birefringence.

  15. Correlations of mesospheric winds with subtle motion of the Arctic polar vortex

    Directory of Open Access Journals (Sweden)

    Y. Bhattacharya

    2010-01-01

    Full Text Available This paper investigates the relationship between high latitude upper mesospheric winds and the state of the stratospheric polar vortex in the absence of major sudden stratospheric warmings. A ground based Michelson Interferometer stationed at Resolute Bay (74°43' N, 94°58' W in the Canadian High Arctic is used to measure mesopause region neutral winds using the hydroxyl (OH Meinel-band airglow emission (central altitude of ~85 km. These observed winds are compared to analysis winds in the upper stratosphere during November and December of 1995 and 1996; years characterized as cold, stable polar vortex periods. Correlation of mesopause wind speeds with those from the upper stratosphere is found to be significant for the 1996 season when the polar vortex is subtly displaced off its initial location by a strong Aleutian High. These mesopause winds are observed to lead stratospheric winds by approximately two days with increasing (decreasing mesospheric winds predictive of decreasing (increasing stratospheric winds. No statistically significant correlations are found for the 1995 season when there is no such displacement of the polar vortex.

  16. Multi-user distribution of polarization entangled photon pairs

    Energy Technology Data Exchange (ETDEWEB)

    Trapateau, J.; Orieux, A.; Diamanti, E.; Zaquine, I., E-mail: isabelle.zaquine@telecom-paristech.fr [LTCI, CNRS, Télécom ParisTech, Université Paris-Saclay, 75013 Paris (France); Ghalbouni, J. [Applied Physics Laboratory, Faculty of Sciences 2, Lebanese University, Campus Fanar, BP 90656 Jdeidet (Lebanon)

    2015-10-14

    We experimentally demonstrate multi-user distribution of polarization entanglement using commercial telecom wavelength division demultiplexers. The entangled photon pairs are generated from a broadband source based on spontaneous parametric down conversion in a periodically poled lithium niobate crystal using a double path setup employing a Michelson interferometer and active phase stabilisation. We test and compare demultiplexers based on various technologies and analyze the effect of their characteristics, such as losses and polarization dependence, on the quality of the distributed entanglement for three channel pairs of each demultiplexer. In all cases, we obtain a Bell inequality violation, whose value depends on the demultiplexer features. This demonstrates that entanglement can be distributed to at least three user pairs of a network from a single source. Additionally, we verify for the best demultiplexer that the violation is maintained when the pairs are distributed over a total channel attenuation corresponding to 20 km of optical fiber. These techniques are therefore suitable for resource-efficient practical implementations of entanglement-based quantum key distribution and other quantum communication network applications.

  17. Warm Vapor Atom Interferometer

    Science.gov (United States)

    Biedermann, Grant; Wheeler, David; Jau, Yuan-Yu; McGuinness, Hayden

    2014-05-01

    We present a light pulse atom interferometer using room temperature rubidium vapor. Doppler sensitive stimulated Raman transitions forming the atom optical elements inherently select a cold velocity group for the interferometer. The interferometer is configured to be sensitive to accelerations. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  18. Simulation tools for future interferometers

    OpenAIRE

    Yamamoto, H.; Barton, M.; Bhawal, B.; Evans, M.; Yoshida, S.

    2006-01-01

    For the design and commissioning of the LIGO interferometer, simulation tools have been used explicitly and implicitly. The requirement of the advanced LIGO interferometer is much more demanding than the first generation interferometer. Development of revised simulation tools for future interferometers are underway in the LIGO Laboratory. The outline of those simulation tools and applications are discussed.

  19. Michelson-Morley Experiment within the Quantum Mechanics Framework

    International Nuclear Information System (INIS)

    Khokhlov, D.L.

    2008-01-01

    It is revisited the Michelson-Morley experiment within the quantum mechanics framework. One can define the wave function of photon in the whole space at a given moment of time. The phase difference between the source and receiver is a distance between the source and receiver at the time of reception hence it does not depend on the velocity of the frame. Then one can explain the null result of the Michelson-Morley experiment within the quantum mechanics framework. (author)

  20. Vibration compensated high-resolution scanning white-light Linnik-interferometer

    Science.gov (United States)

    Tereschenko, Stanislav; Lehmann, Peter; Gollor, Pascal; Kuehnhold, Peter

    2017-06-01

    We present a high-resolution Linnik scanning white-light interferometer (SWLI) with integrated distance measuring interferometer (DMI) for close-to-machine applications in the presence of environmental vibrations. The distance, measured by DMI during the depth-scan, is used for vibration compensation of SWLI signals. The reconstruction of the white-light interference signals takes place after measurement by reordering the captured images in accordance with their real positions obtained by the DMI and subsequent trigonometrical approximation. This system is the further development of our previously presented Michelson-interferometer. We are able to compensate for arbitrary vibrations with frequencies up to several kilohertz and amplitudes in the lower micrometer range. Completely distorted SWLI signals can be reconstructed and the surface topography can be obtained with high accuracy. We demonstrate the feasibility of the method by examples of practical measurements with and without vibrational disturbances.

  1. Design and Status of the Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII): An Interferometer at the Edge of Space

    Science.gov (United States)

    Rinehart, Stephen A.; Barclay, Richard B.; Barry, R. K.; Benford, D. J.; Calhoun, P. C.; Fixsen, D. J.; Gorman, E. T.; Jackson, M. L.; Jhabvala, C. A.; Leisawitz, D. T.; hide

    2012-01-01

    The Balloon Experimental Twin Telescope for Infrared Interferometry (BETTII) is an 8-meter baseline far-infraredinterferometer designed to fly on a high altitude balloon. BETTII uses a double-Fourier Michelson interferometer tosimultaneously obtain spatial and spectral information on science targets; the long baseline permits subarcsecond angular resolution, a capability unmatched by other far-infrared facilities. Here, we present key aspects of the overall design of the mission and provide an overview of the current status of the project. We also discuss briefly the implications of this experiment for future space-based far-infrared interferometers.

  2. Fizeau plasma interferometer

    International Nuclear Information System (INIS)

    Frank, A.M.

    1980-01-01

    This paper describes a technique by which the sensitivity of plasma interferometers can be increased. Stabilization and fractional fringe measurement techniques have improved to the point where additional optical sensitivity could be useful

  3. Atom Wave Interferometers

    National Research Council Canada - National Science Library

    Pritchard, David

    2000-01-01

    Long-term research objective: Matter wave interferometers, in which de Broglie waves are coherently split and then recombined to produce interference fringes, have opened exciting new possibilities for precision and fundamental...

  4. Local electron density measurements in a screw pinch by means of a Michelson interferometer

    International Nuclear Information System (INIS)

    Hoekzema, J.A.; Busch, P.J.; Mastop, W.J.

    1976-06-01

    The time-dependent density profile of a toroidal screw-pinch plasma is determined from successive measurements of the line density along different sections of a line through the plasma. The pathlength is varied by the introduction of a hollow quartz tube into the plasma

  5. Generation of a femtosecond electron microbunch train from a photocathode using twofold Michelson interferometer

    Science.gov (United States)

    Shevelev, M.; Aryshev, A.; Terunuma, N.; Urakawa, J.

    2017-10-01

    The interest in producing ultrashort electron bunches has risen sharply among scientists working on the design of high-gradient wakefield accelerators. One attractive approach generating electron bunches is to illuminate a photocathode with a train of femtosecond laser pulses. In this paper we describe the design and testing of a laser system for an rf gun based on a commercial titanium-sapphire laser technology. The technology allows the production of four femtosecond laser pulses with a continuously variable pulse delay. We also use the designed system to demonstrate the experimental generation of an electron microbunch train obtained by illuminating a cesium-telluride semiconductor photocathode. We use conventional diagnostics to characterize the electron microbunches produced and confirm that it may be possible to control the main parameter of an electron microbunch train.

  6. High Temperature Testing with Sapphire Fiber White-Light Michelson Interferometers

    Science.gov (United States)

    Barnes, A.; Pedrazzani, J.; May, R.; Murphy, K.; Tran, T.; Coate, J.

    1996-01-01

    In the design of new aerospace materials, developmental testing is conducted to characterize the behavior of the material under severe environmental conditions of high stress, temperature, and vibration. But to test these materials under extreme conditions requires sensors that can perform in harsh environments. Current sensors can only monitor high temperature test samples using long throw instrumentation, but this is inherently less accurate than a surface mounted sensor, and provides no means for fabrication process monitoring. A promising alternative is the use of sapphire optical fiber sensors. Sapphire is an incredibly rugged material, being extremely hard (9 mhos), chemically inert, and having a melting temperature (over 2000 C). Additionally, there is a extensive background of optical fiber sensors upon which to draw for sapphire sensor configurations.

  7. Generation of a femtosecond electron microbunch train from a photocathode using twofold Michelson interferometer

    Directory of Open Access Journals (Sweden)

    M. Shevelev

    2017-10-01

    Full Text Available The interest in producing ultrashort electron bunches has risen sharply among scientists working on the design of high-gradient wakefield accelerators. One attractive approach generating electron bunches is to illuminate a photocathode with a train of femtosecond laser pulses. In this paper we describe the design and testing of a laser system for an rf gun based on a commercial titanium-sapphire laser technology. The technology allows the production of four femtosecond laser pulses with a continuously variable pulse delay. We also use the designed system to demonstrate the experimental generation of an electron microbunch train obtained by illuminating a cesium-telluride semiconductor photocathode. We use conventional diagnostics to characterize the electron microbunches produced and confirm that it may be possible to control the main parameter of an electron microbunch train.

  8. Calibration and validation of the advanced E-Region Wind Interferometer

    Directory of Open Access Journals (Sweden)

    S. K. Kristoffersen

    2013-07-01

    Full Text Available The advanced E-Region Wind Interferometer (ERWIN II combines the imaging capabilities of a CCD detector with the wide field associated with field-widened Michelson interferometry. This instrument is capable of simultaneous multi-directional wind observations for three different airglow emissions (oxygen green line (O(1S at a height of ~97 km, the PQ(7 and P(7 emission lines in the O2(0–1 atmospheric band at ~93 km and P1(3 emission line in the (6, 2 hydroxyl Meinel band at ~87 km on a three minute cadence. In each direction, for 45 s measurements for typical airglow volume emission rates, the instrument is capable of line-of-sight wind precisions of ~1 m s−1 for hydroxyl and O(1S and ~4 m s−1 for O2. This precision is achieved using a new data analysis algorithm which takes advantage of the imaging capabilities of the CCD detector along with knowledge of the instrument phase variation as a function of pixel location across the detector. This instrument is currently located in Eureka, Nunavut as part of the Polar Environment Atmospheric Research Laboratory (PEARL (80°N, 86° W. The details of the physical configuration, the data analysis algorithm, the measurement calibration and validation of the observations from December 2008 and January 2009 are described. Field measurements which demonstrate the capabilities of this instrument are presented. To our knowledge, the wind determinations with this instrument are the most accurate and have the highest observational cadence for airglow wind observations of this region of the atmosphere and match the capabilities of other wind-measuring techniques.

  9. Sagnac interferometer as a speed-meter-type, quantum-nondemolition gravitational-wave detector

    International Nuclear Information System (INIS)

    Chen Yanbei

    2003-01-01

    According to quantum measurement theory, 'speed meters' - devices that measure the momentum, or speed, of free test masses - are immune to the standard quantum limit (SQL). It is shown that a Sagnac-interferometer gravitational-wave detector is a speed meter and therefore in principle it can beat the SQL by large amounts over a wide band of frequencies. It is shown, further, that, when one ignores optical losses, a signal-recycled Sag nac interferometer with Fabry-Perot arm cavities has precisely the same performance, for the same circulating light power, as the Michelson speed-meter interferometer recently invented and studied by Purdue and the author. The influence of optical losses is not studied, but it is plausible that they be fairly unimportant for the Sag nac interferometer, as for other speed meters. With squeezed vacuum (squeeze factor e -2R =0.1) injected into its dark port, the recycled Sag nac interferometer can beat the SQL by a factor √(10)≅3 over the frequency band 10 Hz c ∼820 kw as is to be used by the (quantum limited) second-generation Advanced LIGO interferometers--if other noise sources are made sufficiently small. It is concluded that the Sag nac optical configuration, with signal recycling and squeezed-vacuum injection, is an attractive candidate for third-generation interferometric gravitational-wave detectors (LIGO-III and EURO)

  10. Progress on multi-object exoplanet search spectral interferometer

    Science.gov (United States)

    Zhang, Kai; Zhu, Yongtian; Wang, Lei; Yue, Zhongyu; Chen, Yi; Tang, Jin; Hu, Zhongwen

    2012-09-01

    It's a very important point that fully open up power of Gou Shoujing telescope (LAMOST) in exoplanet detection field by developing a multi-exoplanet survey system. But it's an indisputable truth in the present astronomy that a traditional type of multi-object high resolution spectrograph is almost impossible to be developed. External Dispersed Interferometry is an effective way to improve the radial velocity measuring accuracy of medium resolution spectrograph. With the using of this technique, Multi-object Exoplanet Search Spectral Interferometer (MESSI) is an exploratory system with medium measuring accuracy based on LAMOST low resolution spectrograph works in medium-resolution mode (R=5,000 - 10,000). And it's believed that will bring some feasible way in the future development of multi-object medium/high resolution spectrograph. After prototype experiment in 2010, a complete configuration is under the development, including a multi-object fixed-delay Michelson interferometer, an iodine cell with multi-fiber optical coupling system and a multi-terminal switching system in an efficient fiber physical coupling way. By some effective improvement, the interferometer has smaller cross section and more stable interference component. Moreover, based on physical and optical fiber coupling technique, it's possible for the iodine cell and the switching system to simultaneously and identically coupling 25 pairs of fibers. In paper, all of the progress is given in detail.

  11. Design of a speed meter interferometer proof-of-principle experiment

    International Nuclear Information System (INIS)

    Gräf, C; Barr, B W; Bell, A S; Campbell, F; Cumming, A V; Gordon, N A; Hammond, G D; Hennig, J; Houston, E A; Huttner, S H; Jones, R A; Leavey, S S; Macarthur, J; Marwick, M; Rigby, S; Sorazu, B; Spencer, A; Danilishin, S L; Lück, H; Schilling, R

    2014-01-01

    The second generation of large scale interferometric gravitational wave (GW) detectors will be limited by quantum noise over a wide frequency range in their detection band. Further sensitivity improvements for future upgrades or new detectors beyond the second generation motivate the development of measurement schemes to mitigate the impact of quantum noise in these instruments. Two strands of development are being pursued to reach this goal, focusing both on modifications of the well-established Michelson detector configuration and development of different detector topologies. In this paper, we present the design of the world's first Sagnac speed meter (SSM) interferometer, which is currently being constructed at the University of Glasgow. With this proof-of-principle experiment we aim to demonstrate the theoretically predicted lower quantum noise in a Sagnac interferometer compared to an equivalent Michelson interferometer, to qualify SSM for further research towards an implementation in a future generation large scale GW detector, such as the planned Einstein telescope observatory. (paper)

  12. Camera-based micro interferometer for distance sensing

    Science.gov (United States)

    Will, Matthias; Schädel, Martin; Ortlepp, Thomas

    2017-12-01

    Interference of light provides a high precision, non-contact and fast method for measurement method for distances. Therefore this technology dominates in high precision systems. However, in the field of compact sensors capacitive, resistive or inductive methods dominates. The reason is, that the interferometric system has to be precise adjusted and needs a high mechanical stability. As a result, we have usual high-priced complex systems not suitable in the field of compact sensors. To overcome these we developed a new concept for a very small interferometric sensing setup. We combine a miniaturized laser unit, a low cost pixel detector and machine vision routines to realize a demonstrator for a Michelson type micro interferometer. We demonstrate a low cost sensor smaller 1cm3 including all electronics and demonstrate distance sensing up to 30 cm and resolution in nm range.

  13. Highly accurate Michelson type wavelength meter that uses a rubidium stabilized 1560 nm diode laser as a wavelength reference

    International Nuclear Information System (INIS)

    Masuda, Shin; Kanoh, Eiji; Irisawa, Akiyoshi; Niki, Shoji

    2009-01-01

    We investigated the accuracy limitation of a wavelength meter installed in a vacuum chamber to enable us to develop a highly accurate meter based on a Michelson interferometer in 1550 nm optical communication bands. We found that an error of parts per million order could not be avoided using famous wavelength compensation equations. Chromatic dispersion of the refractive index in air can almost be disregarded when a 1560 nm wavelength produced by a rubidium (Rb) stabilized distributed feedback (DFB) diode laser is used as a reference wavelength. We describe a novel dual-wavelength self-calibration scheme that maintains high accuracy of the wavelength meter. The method uses the fundamental and second-harmonic wavelengths of an Rb-stabilized DFB diode laser. Consequently, a highly accurate Michelson type wavelength meter with an absolute accuracy of 5x10 -8 (10 MHz, 0.08 pm) over a wide wavelength range including optical communication bands was achieved without the need for a vacuum chamber.

  14. Astrophysical Adaptation of Points, the Precision Optical Interferometer in Space

    Science.gov (United States)

    Reasenberg, Robert D.; Babcock, Robert W.; Murison, Marc A.; Noecker, M. Charles; Phillips, James D.; Schumaker, Bonny L.; Ulvestad, James S.; McKinley, William; Zielinski, Robert J.; Lillie, Charles F.

    1996-01-01

    POINTS (Precision Optical INTerferometer in Space) would perform microarcsecond optical astrometric measurements from space, yielding submicroarcsecond astrometric results from the mission. It comprises a pair of independent Michelson stellar interferometers and a laser metrology system that measures both the critical starlight paths and the angle between the baselines. The instrument has two baselines of 2 m, each with two subapertures of 35 cm; by articulating the angle between the baselines, it observes targets separated by 87 to 93 deg. POINTS does global astrometry, i.e., it measures widely separated targets, which yields closure calibration, numerous bright reference stars, and absolute parallax. Simplicity, stability, and the mitigation of systematic error are the central design themes. The instrument has only three moving-part mechanisms, and only one of these must move with sub-milliradian precision; the other two can tolerate a precision of several tenths of a degree. Optical surfaces preceding the beamsplitter or its fold flat are interferometrically critical; on each side of the interferometer, there are only three such. Thus, light loss and wavefront distortion are minimized. POINTS represents a minimalistic design developed ab initio for space. Since it is intended for astrometry, and therefore does not require the u-v-plane coverage of an imaging, instrument, each interferometer need have only two subapertures. The design relies on articulation of the angle between the interferometers and body pointing to select targets; the observations are restricted to the 'instrument plane.' That plane, which is fixed in the pointed instrument, is defined by the sensitive direction for the two interferometers. Thus, there is no need for siderostats and moving delay lines, which would have added many precision mechanisms with rolling and sliding parts that would be required to function throughout the mission. Further, there is no need for a third interferometer

  15. Spatially translatable optical fiber-coupled heterodyne interferometer

    Science.gov (United States)

    Seo, Byonghoon; Bellan, Paul M.

    2017-12-01

    An interferometer is a useful diagnostic tool for measuring line-averaged electron density but is limited in its use because it generally measures at a fixed location. We report here a spatially translatable fiber-coupled interferometer that measures the density of a high-speed MHD-driven plasma jet colliding with a target cloud. The interferometer uses a He-Ne laser coupled to a polarization-maintaining single mode optical fiber having a vacuum feedthrough. The interferometer provides a measure of the spatial-temporal profile of the line-averaged electron density from which the change in jet velocity as a result of its collision with the target cloud can be deduced.

  16. The millimeter-wave bolometric interferometer

    Science.gov (United States)

    Gault, Amanda Charlotte

    The Millimeter-wave Bolometric Interferometer (MBI) is a technology demonstrator for future searches for the B-mode polarization of the Cosmic Microwave Background (CMB). If observed, B-modes would be a direct probe of the energy scale of inflation, an energy scale that is impossible to reach with even the most sophisticated particle accelerators. In this thesis, I outline the technology differences between MBI and conventional interferometers, including the Faraday effect phase modulators (FPM) used both to control systematic effects and to allow for phase sensitive detection of signals. MBI is a four element adding interferometer with a Fizeau optical beam combiner. This allows simple scaling of the instrument to a large numbers of baselines without requiring complicated pair-wise correlations of signals. Interferometers have an advantage over imaging telescopes when measuring the CMB power spectrum as each baseline is sensitive to a single Fourier mode (angular scale) on the sky. Recovering individual baseline information with this combination scheme requires phase modulating the signal from each antenna. MBI performs this modulation with Faraday effect phase modulators. In these novel cryogenic devices a modulated magnetic field switches the phase of a millimeter-wave RF signal by +/- 90 degrees at frequencies up to a few Hertz. MBI's second season of observations occurred in the winter of 2009 at Pine Bluff Observatory a few miles west of Madsion, WI. We successfully observed interference fringes of a microwave test source located in the far field of the instrument that agree well with those expected from simulations. MBI has inspired a second generation bolometric interferometer, QUBIC, which will have hundreds of antennas and thousands of detectors. When it deploys in 2015, it will be sensitive enough to search for B-mode signals from the CMB.

  17. Sagnac interferometer as a speed-meter-type, quantum-nondemolition gravitational-wave detector

    Science.gov (United States)

    Chen, Yanbei

    2003-06-01

    According to quantum measurement theory, “speed meters”—devices that measure the momentum, or speed, of free test masses—are immune to the standard quantum limit (SQL). It is shown that a Sagnac-interferometer gravitational-wave detector is a speed meter and therefore in principle it can beat the SQL by large amounts over a wide band of frequencies. It is shown, further, that, when one ignores optical losses, a signal-recycled Sagnac interferometer with Fabry-Perot arm cavities has precisely the same performance, for the same circulating light power, as the Michelson speed-meter interferometer recently invented and studied by Purdue and the author. The influence of optical losses is not studied, but it is plausible that they be fairly unimportant for the Sagnac interferometer, as for other speed meters. With squeezed vacuum (squeeze factor e-2R=0.1) injected into its dark port, the recycled Sagnac interferometer can beat the SQL by a factor (10)≃3 over the frequency band 10 Hz≲f≲150 Hz using the same circulating power Ic˜820 kW as is to be used by the (quantum limited) second-generation Advanced LIGO interferometers—if other noise sources are made sufficiently small. It is concluded that the Sagnac optical configuration, with signal recycling and squeezed-vacuum injection, is an attractive candidate for third-generation interferometric gravitational-wave detectors (LIGO-III and EURO).

  18. Multiple Josephson contact interferometer

    International Nuclear Information System (INIS)

    Zappe, H.H.

    1978-01-01

    The interferometer (quantum interference between two parallel contacts) displays a mid connector and contacts of the same size, or contacts at which the middle one is twice the size as the other two, or a double connector and three contacts by which the middle contact carries twice the current as the other two. Also there can be provided interferometers with three and four contacts as well as with symmetrical double current connectors and the same largest Josephson current through all contacts. Because all contacts display the same phase state in the voltage free switching state, the amplification property can be increased and current dissipation can be decreased in a way that logic circuits with high integration degree and high switching velocities can be designed. (DG) [de

  19. Atomic-resolution measurements with a new tunable diode laser-based interferometer

    DEFF Research Database (Denmark)

    Silver, R.M.; Zou, H.; Gonda, S.

    2004-01-01

    We develop a new implementation of a Michelson interferometer designed to make measurements with an uncertainty of less than 20 pm. This new method uses a tunable diode laser as the light source, with the diode laser wavelength continuously tuned to fix the number of fringes in the measured optical...... path. The diode laser frequency is measured by beating against a reference laser. High-speed, accurate frequency measurements of the beat frequency signal enables the diode laser wavelength to be measured with nominally 20-pm accuracy for the measurements described. The new interferometer design...... is lightweight and is mounted directly on an ultra-high vacuum scanning tunneling microscope capable of atomic resolution. We report the simultaneous acquisition of an atomic resolution image, while the relative lateral displacement of the tip along the sample distance is measured with the new tunable diode...

  20. Ground-based airglow imaging interferometer. Part 1: instrument and observation.

    Science.gov (United States)

    Gao, Haiyang; Tang, Yuanhe; Hua, Dengxin; Liu, Hanchen; Cao, Xiangang; Duan, Xiaodong; Jia, Qijie; Qu, Ouyang; Wu, Yong

    2013-12-20

    A ground-based airglow imaging interferometer (GBAII) is proposed to measure simultaneously the temperature and wind in the mesopause region by using airglow emissions of the O2(0-1) band. Since it employs a wide angle Michelson interferometer with a large air gap, combined with the rotational temperature measurement, both the phase and spectral information can be obtained from the imaging results. Based on the optimization and calibrations for the optical system in the laboratory, we developed and assembled a prototype of a GBAII, and carried out one observation at the observatory of Xi'an University of Technology on 12 June 2012. The observed temperatures fall mainly on the range of 167-196 K, while both the zonal and meridional winds faintly show the feature of half-day oscillation. The consistent trends between the observation results and the standard atmospheric models suggest that the GBAII has achieved our basic design goals.

  1. Feedback-stabilized fractional fringe laser interferometer for plasma density measurements

    International Nuclear Information System (INIS)

    Schneider, J.; Robertson, S.

    1979-01-01

    A feedback stabilization technique is described for a fractional fringe interferometer measuring plasma electron densities. Using this technique, a CO 2 laser Michelson interferometer with a pyroelectric detector exhibited a sensitivity of 3.4 x 10 -4 fringe on a 1-ms time scale and, due to acoustic pickup, 1.8 x 10 -2 fringe on a 10-ms time scale. The rise time is 45 μs. Stabilization against slow drifts in mirror distances is achieved by an electromechanically translated mirror driven by a servo system having a 0.2-s response time. A mechanical chopper in one of the two beam paths generates the signal which drives the servo system

  2. The Experiment of Michelson and Morley

    Indian Academy of Sciences (India)

    sible for the production of both light and heat. Before Newton,. Huygens had given the hypothesis of light being a longitudinal wave like sound, travelling through ether. This idea was rejected as it could not account for the two polarizations of light. Fresnel, on the other hand, introduced the wave theory of light, with light.

  3. Absolute metrology for space interferometers

    Science.gov (United States)

    Salvadé, Yves; Courteville, Alain; Dändliker, René

    2017-11-01

    The crucial issue of space-based interferometers is the laser interferometric metrology systems to monitor with very high accuracy optical path differences. Although classical high-resolution laser interferometers using a single wavelength are well developed, this type of incremental interferometer has a severe drawback: any interruption of the interferometer signal results in the loss of the zero reference, which requires a new calibration, starting at zero optical path difference. We propose in this paper an absolute metrology system based on multiplewavelength interferometry.

  4. A novel method for polarization squeezing with Photonic Crystal Fibers

    DEFF Research Database (Denmark)

    Milanovic, Josip; Lassen, Mikael Østergaard; Andersen, Ulrik Lund

    2010-01-01

    fiber squeezing experiments. Explicit we produce squeezed states in counter propagating pulses along the same fiber axis to achieve near identical dispersion properties. This enables the production of polarization squeezing through interference in a polarization type Sagnac interferometer. We observe...

  5. Demonstration of a refractometric sensor based on an optical micro-fiber three-beam interferometer.

    Science.gov (United States)

    Han, Chunyang; Ding, Hui; Lv, Fangxing

    2014-12-16

    With diameter close to the wavelength of the guided light and high index contrast between the fiber and the surrounding, an optical micro-fiber shows a variety of interesting waveguiding properties, including widely tailorable optical confinement, strong evanescent fields and waveguide dispersion. Among various micro-fiber applications, optical sensing has been attracting increasing research interest due to its possibilities of realizing miniaturized fiber optic sensors with small footprint, high sensitivity, and low optical power consumption. Typical micro-fiber based sensing structures, including Michelson interferometer, Mach-Zenhder interferometer, Fabry-Perot interferometer, micro-fiber ring resonator, have been proposed. The sensitivity of these structures heavily related to the fraction of evanescent field outside micro-fiber. In this paper, we report the first theoretical and experimental study of a new type of refractometric sensor based on micro-fiber three-beam interferometer. Theoretical and experimental analysis reveals that the sensitivity is not only determined by the fraction of evanescent field outside the micro-fiber but also related to the values of interferometric arms. The sensitivity can be enhanced significantly when the effective lengths of the interferometric arms tends to be equal. We argue that this has great potential for increasing the sensitivity of refractive index detection.

  6. A prototype imaging second harmonic interferometer

    International Nuclear Information System (INIS)

    Jobes, F.C.; Bretz, N.L.

    1997-01-01

    We have built a prototype imaging second harmonic interferometer, which is intended to test critical elements of a design for a tangential array interferometer on C-Mod 6 . The prototype uses a pulsed, 35 mJ, 10 Hz multimode, Nd:YAG laser, LiB 3 O 5 doublers, a fan beam created by a cylindrical lens, four retroreflector elements, and a CCD camera as a detector. The prototype also uses a polarization scheme in which the interference information is eventually carried by two second harmonic beams with crossed polarization. These are vector summed and differenced, and separated, by a Wollaston prism, to give two spots on the CCD. There is a pair of these spots for each retroreflector used. The phase information is directly available as the ratio of the difference to sum the intensities of the two spots. We have tested a single channel configuration of this prototype, varying the phase by changing the pressure in an air cell, and we have obtained a 5:1 light to dark ratio, and a clear sinusoidal variation of the ratio as a function of pressure change. copyright 1997 American Institute of Physics

  7. Lukewarm lithium recoil interferometer

    Science.gov (United States)

    Copenhaver, Eric; Cassella, Kayleigh; Estey, Brian; Feng, Yanying; Lai, Chen; Holger, Müller

    2017-04-01

    We demonstrate recoil-sensitive atom interferometry with laser-cooled lithium-7 at 50 times the recoil temperature. The large bandwidth of 160-ns beam-splitter pulses drives conjugate interferometers simultaneously with nearly equal contrast. Two-photon Raman transitions spectrally resolve the outputs, which thermally expand too quickly to be spatially resolved. Two images captured during a single exposure of a camera with slow readout detects both output ports. Optical pumping to a magnetically insensitive state using the well-resolved D1 line suppresses magnetic dephasing and extends coherence time. Sensitivity comparable to interferometers utilizing large momentum transfer pulses is attainable at interrogation times on the order of 10 ms due to lithium's high recoil frequency and the increased available atom number. Vibration noise is mitigated at this time scale and is converted to amplitude noise in our detection scheme, isolating the recoil frequency from what is conventionally phase noise. These techniques relax requirements for cooling in recoil-sensitive interferometry, broadening the choice of species to particles that remain difficult to trap and cool, like electrons.

  8. The Michelson Era in American Science, 1870--1930

    International Nuclear Information System (INIS)

    Goldberg, S.; Stuewer, R.H.

    1988-01-01

    The articles in this volume relate, in one way or another, to a single experiment: the Michelson-Morley ether-drift experiment of 1887. About one-half of the articles in the collection are based on papers delivered at a two-day symposium ''The Michelson Era in American Science: 1870--1930,'' held a Case Western Reserve University in Cleveland, Ohio, 28--29 October 1987, commemorating the centennial of the experiment. The Michelson-Morley experiment was designed to detect the motion of the earth through the luminiferous ether. At the time, physicists did not question the existence of the ether. The experiment, like many physical probes of nature, was simple in conception, yet uncompromisingly demanding of the art of contemporary craftsmanship. The state of the mechanical arts and its relationship to the pursuit of physical science in late nineteenth- century America is well documented in Section I, which also addresses the more general question of the link between state-of-the-art shop practice and engineering theory

  9. Diffraction-grating neutron interferometers

    International Nuclear Information System (INIS)

    Ioffe, A.I.

    1988-01-01

    Aberration distortions of wavefronts in a very cold neutron interferometer using diffraction gratings are analyzed. Aberrations that considerably reduce the efficiency of a two-grating interferometer are shown to be fully compensable by adding a third diffraction grating, which also permits the interferometer to operate with a non-collimated and non-monochromatized illuminating beam thereby raising its efficiency. A fourth diffraction grating additionally permits compensation of effects of the terrestrial rotation that affect performance of a large interferometer in which the spatial separation of beams can be of the order of a few meters. It is demonstrated to be practically possible to implement an interferometer for neutrons having a wavelength λ = 20 A and to use it in experiments aimed at finding the electric charge of the neutron at the level of 10 -23 to 10 -22 of the electronic charge. (orig.)

  10. Neutron interferometers with diffraction gratings

    International Nuclear Information System (INIS)

    Ioffe, A.I.

    1983-01-01

    A neutron interferometer is described in which the amplitude coherent division of the wave fronts is realized by means of neutron diffraction gratings. Photolithographic gratings on glass with a rectangular surface relief profile with a 58 Ni sprayed layer 2000 A thick are used as gratings. In contrast to perfect-crystal neutron interferometers the designed interferometer is capable of operating in the longwave neutron spectrum region. Variation of the value of spatial division of the interfering beams (up to 50 cm) and rather a high efficiency of the amergent beam together with the elemination of neutron beam passage through the interferometer coherent divosor material in such an interferometer permit to use it for solving problems of the solid-state physics and nuclear physics, for example, foA searching for the Yang Mills long-range field

  11. Spin filtering in a Rashba–Dresselhaus–Aharonov–Bohm double-dot interferometer

    International Nuclear Information System (INIS)

    Matityahu, Shlomi; Aharony, Amnon; Entin-Wohlman, Ora; Tarucha, Seigo

    2013-01-01

    We study the spin-dependent transport of spin-1/2 electrons through an interferometer made of two elongated quantum dots or quantum nanowires, which are subject to both an Aharonov–Bohm flux and (Rashba and Dresselhaus) spin–orbit interactions. Similar to the diamond interferometer proposed in our previous papers (Aharony et al 2011 Phys. Rev. B 84 035323; Matityahu et al 2013 Phys. Rev. B 87 205438), we show that the double-dot interferometer can serve as a perfect spin filter due to a spin interference effect. By appropriately tuning the external electric and magnetic fields which determine the Aharonov–Casher and Aharonov–Bohm phases, and with some relations between the various hopping amplitudes and site energies, the interferometer blocks electrons with a specific spin polarization, independent of their energy. The blocked polarization and the polarization of the outgoing electrons is controlled solely by the external electric and magnetic fields and do not depend on the energy of the electrons. Furthermore, the spin filtering conditions become simpler in the linear-response regime, in which the electrons have a fixed energy. Unlike the diamond interferometer, spin filtering in the double-dot interferometer does not require high symmetry between the hopping amplitudes and site energies of the two branches of the interferometer and thus may be more appealing from an experimental point of view. (paper)

  12. Improvement of interferometric measurements on FIR polarimeter/interferometer systems

    International Nuclear Information System (INIS)

    Barry, S.; Nieswald, C.; Buehlmann, F.; Prunty, S.L.; Mansfield, H.M.

    1996-03-01

    On many tokamaks the reconstruction of the magnetic field structure in the plasma is supported by polarimetric measurements. Recent proposed and realized methods are based on a far-infrared laser beam with a rotating polarization ellipse. The same instrument usually performs as an interferometer measuring the line integrated plasma density. It has been shown that the rotating polarization ellipse disturbs the interferometric measurements. A method based on the principle of a rotating polarization in which the interferometric measurement is unaffected is proposed. Bench test results are presented which show the feasibility of this method. (author) 4 figs., 13 refs

  13. The Fizeau Interferometer Testbed

    Science.gov (United States)

    Zhang, Xiaolei; Carpenter, Kenneth G.; Lyon, Richard G,; Huet, Hubert; Marzouk, Joe; Solyar, Gregory

    2003-01-01

    The Fizeau Interferometer Testbed (FIT) is a collaborative effort between NASA's Goddard Space Flight Center, the Naval Research Laboratory, Sigma Space Corporation, and the University of Maryland. The testbed will be used to explore the principles of and the requirements for the full, as well as the pathfinder, Stellar Imager mission concept. It has a long term goal of demonstrating closed-loop control of a sparse array of numerous articulated mirrors to keep optical beams in phase and optimize interferometric synthesis imaging. In this paper we present the optical and data acquisition system design of the testbed, and discuss the wavefront sensing and control algorithms to be used. Currently we have completed the initial design and hardware procurement for the FIT. The assembly and testing of the Testbed will be underway at Goddard's Instrument Development Lab in the coming months.

  14. Microscopy of non-birefringent transmissive phase samples using Sagnac laser interferometer.

    Science.gov (United States)

    Sarkar, Sanjukta; Bhattacharya, K

    2014-11-01

    A cyclic interferometer, appropriately combined with a long working distance microscope objective, is adapted for quantitative phase microscopy. In such an arrangement, the sample information, in terms of the diffracted orders emerging from the sample, is carried by both the counter propagating beams within the cyclic interferometer. However, positioning the sample close to the input/output cube beam splitter and use of a suitably converging laser beam of light as the input to the interferometer ensure that only one of the counter propagating beams carries the object information to the objective while the other beam, which serves as the reference, allows only the undiffracted component to contribute to the process of image formation. Use of suitable polarization optics renders the interferometer its polarization phase shifting property. Using the proposed arrangement, the experimental results showing the quantitative 3D phase rendering of polystyrene microspheres and micro-wells etched in glass are presented. Copyright © 2014 Elsevier Ltd. All rights reserved.

  15. Maurice Car̊me'i lihtsad laulud lastele / Helle Michelson

    Index Scriptorium Estoniae

    Michelson, Helle, 1929-

    2003-01-01

    Car̊me, Maurice. Muinasjutud Caprine'ile / tõlkinud Helle Michelson. [Tallinn] : Tiritamm, 2002 ; Car̊me, Maurice. Naeruhull kirsipuu : [luuletused] / prantsuse keelest tõlkinud Helvi Jürisson. [Tallinn] : Tiritamm, 2002 ; Car̊me, Maurice. Margareetapäev : [jutustused] / tõlkinud Helle Michelson. [Tallinn] : Varrak, 2000

  16. Applications of Optical Interferometer Techniques for Precision Measurements of Changes in Temperature, Growth and Refractive Index of Materials

    Directory of Open Access Journals (Sweden)

    Rami Reddy Bommareddi

    2014-05-01

    Full Text Available Optical metrology techniques used to measure changes in thickness; temperature and refractive index are surveyed. Optical heterodyne detection principle and its applications for precision measurements of changes in thickness and temperature are discussed. Theoretical formulations are developed to estimate crystal growth rate, surface roughness and laser cooling/heating of solids. Applications of Michelson and Mach-Zehnder interferometers to measure temperature changes in laser heating of solids are described. A Mach-Zehnder interferometer is used to measure refractive index and concentration variations of solutions in crystal growth experiments. Additionally, fluorescence lifetime sensing and fluorescence ratio method are described for temperature measurement. For all the above techniques, uncertainty calculations are included.

  17. Surface profiling interferometer

    Science.gov (United States)

    Takacs, Peter Z.; Qian, Shi-Nan

    1989-01-01

    The design of a long-trace surface profiler for the non-contact measurement of surface profile, slope error and curvature on cylindrical synchrotron radiation (SR) mirrors. The optical system is based upon the concept of a pencil-beam interferometer with an inherent large depth-of-field. The key feature of the optical system is the zero-path-difference beam splitter, which separates the laser beam into two colinear, variable-separation probe beams. A linear array detector is used to record the interference fringe in the image, and analysis of the fringe location as a function of scan position allows one to reconstruct the surface profile. The optical head is mounted on an air bearing slide with the capability to measure long aspheric optics, typical of those encountered in SR applications. A novel feature of the optical system is the use of a transverse "outrigger" beam which provides information on the relative alignment of the scan axis to the cylinder optic symmetry axis.

  18. Development of the measurement system with interferometers for ultraprecise X-ray mirror

    CERN Document Server

    Yamauchi, K; Mimura, H

    2003-01-01

    A figure measurement system with a stitching method has been developed for evaluation and fabrication of the ultraprecise hard X-ray mirror optics. This system was constructed by two interferometers. One is the Michelson-type microscopic interferometer which is improved to keep the focus distance within 0.1 mu m. Another is the Fizeau's interferometer employed to compensate stitching error in the long spatial wavelength range. To estimate the absolute accuracy in this figure measurement system, the reflection X-ray intensity distributions of flat and aspherical mirrors, which are fabricated by us, were predicted by wave-optical simulation based on measured profile an compared with actually observed distributions. As the result, they are in good agreements. These agreements prove that the developed system has sub-nanometer absolute accuracy in all the spatial wavelength range longer than 0.5mm, because sub-nanometer figure error in those spatial wavelength ranges are known to affect reflection X-ray intensity ...

  19. Statistics of polarization speckle: theory versus experiment

    DEFF Research Database (Denmark)

    Wang, Wei; Hanson, Steen Grüner; Takeda, Mitsuo

    2010-01-01

    In this paper, we reviewed our recent work on the statistical properties of polarization speckle, described by stochastic Stokes parameters fluctuating in space. Based on the Gaussian assumption for the random electric field components and polar-interferometer, we investigated theoretically...... and experimentally the statistics of Stokes parameters of polarization speckle, including probability density function of Stokes parameters with the spatial degree of polarization, autocorrelation of Stokes vector and statistics of spatial derivatives for Stokes parameters....

  20. Quasi-quadrature interferometer for plasma density radial profile measurements

    International Nuclear Information System (INIS)

    Lowenthal, D.D.; Hoffman, A.L.

    1979-01-01

    A cw Mach Zehnder multichannel interferometer has been developed to measure time-dependent fractional fringe shifts with an accuracy of one-fortieth fringe. The design is quasi-quadrature in that known phase shifts, introduced in the reference beam, are time multiplexed with the normal reference beam. This technique requires only one detector per interferometer channel as compared to two detectors for most quadrature designs. The quadrature information makes the sense of density changes unambiguous, it automatically calibrates the instrument during the plasma event, and it makes fringe shift measurements virtually independent of fringe contrast fluctuations caused by plasma refractive and/or absorptive effects. The interferometer optical design is novel in that the electro-optic crystal used to introduce the 90 0 phase shifts is located in the common 2-mm-diam HeNe entrance beam to the interferometer, by exploiting polarization techniques, rather than in the expanded 1--2-cm reference beam itself. This arrangement greatly reduces the size, cost, and high-voltage requirements for the phase modulating crystal

  1. Ultra-sensitive wide dynamic range temperature sensor based on in-fiber Lyot interferometer

    Science.gov (United States)

    Nikbakht, Hamed; Poorghdiri Isfahani, Mohamad Hosein; Latifi, Hamid

    2017-04-01

    An in-fiber Lyot interferometer for temperature measurement is presented. The sensor utilizes high temperature-dependence of the birefringence in Panda polarization maintaining fibers to achieve high resolution in temperature measurements. Temperature variation modulates the phase difference between the polarization modes propagating in different modes of the Panda fiber. The Lyot interferometer produces a spectrum which varies with the phase difference. Therefore, by monitoring this spectrum a high resolution of 0.003°C was achieved. A fiber Bragg grating is added to the setup to expand its dynamic range. This sensor does not need complicated fabrication process and can be implemented in many applications.

  2. Sensitivity improvement of a laser interferometer limited by inelastic back-scattering, employing dual readout

    International Nuclear Information System (INIS)

    Meinders, Melanie; Schnabel, Roman

    2015-01-01

    Inelastic back-scattering of stray light is a long-standing and fundamental problem in high-sensitivity interferometric measurements and a potential limitation for advanced gravitational-wave (GW) detectors. The emerging parasitic interferences cannot be distinguished from a scientific signal via conventional single readout. In this work, we propose the subtraction of inelastic back-scatter signals by employing dual homodyne detection on the output light, and demonstrate it for a table-top Michelson interferometer. The additional readout contains solely parasitic signals and is used to model the scatter source. Subtraction of the scatter signal reduces the noise spectral density and thus improves the measurement sensitivity. Our scheme is qualitatively different from the previously demonstrated vetoing of scatter signals and opens a new path for improving the sensitivity of future GW detectors and other back-scatter limited devices. (paper)

  3. Controlling the opto-mechanics of a cantilever in an interferometer via cavity loss

    Energy Technology Data Exchange (ETDEWEB)

    Schmidsfeld, A. von, E-mail: avonschm@uos.de; Reichling, M., E-mail: reichling@uos.de [Fachbereich Physik, Universität Osnabrück, Barbarastraße 7, 49076 Osnabrück (Germany)

    2015-09-21

    In a non-contact atomic force microscope, based on interferometric cantilever displacement detection, the optical return loss of the system is tunable via the distance between the fiber end and the cantilever. We utilize this for tuning the interferometer from a predominant Michelson to a predominant Fabry-Pérot characteristics and introduce the Fabry-Pérot enhancement factor as a quantitative measure for multibeam interference in the cavity. This experimentally easily accessible and adjustable parameter provides a control of the opto-mechanical interaction between the cavity light field and the cantilever. The quantitative assessment of the light pressure acting on the cantilever oscillating in the cavity via the frequency shift allows an in-situ measurement of the cantilever stiffness with remarkable precision.

  4. Handheld White Light Interferometer for Measuring Defect Depth in Windows

    Science.gov (United States)

    Youngquist, Robert; Simmons, Stephen; Cox, Robert

    2010-01-01

    Accurate quantification of defects (scratches and impacts) is vital to the certification of flight hardware and other critical components. The amount of damage to a particular component contributes to the performance, reliability, and safety of a system, which ultimately affects the success or failure of a mission or test. The launch-commit criteria on a Space Shuttle Orbiter window are governed by the depth of the defects that are identified by a visual inspection. This measurement of a defect is not easy to obtain given the environment, size of the defect, and location of the window(s). The determination of depth has typically been performed by taking a mold impression and measuring the impression with an optical profiling instrument. Another method of obtaining an estimate of the depth is by using a refocus microscope. To use a refocus microscope, the surface of the glass and bottom of the defect are, in turn, brought into focus by the operator. The amount of movement between the two points corresponds to the depth of the defect. The refocus microscope requires a skilled operator and has been proven to be unreliable when used on Orbiter windows. White light interferometry was chosen as a candidate to replace the refocus microscope. The White Light Interferometer (WLI) was developed to replace the refocus microscope as the instrument used for measuring the depth of defects in Orbiter windows. The WLI consists of a broadband illumination source, interferometer, detector, motion control, displacement sensor, mechanical housing, and support electronics. The illumination source for the WLI is typically a visible light emitting diode (LED) or a near-infrared superluminescent diode (SLD) with power levels of less than a milliwatt. The interferometer is a Michelson configuration consisting of a 1-in. (2.5-cm) cube beam splitter, a 0.5-in. (1.3-cm) optical window as a movable leg (used to closely match the return intensity of the fixed leg from the window), and a

  5. Standing waves in fiber-optic interferometers

    NARCIS (Netherlands)

    De Haan, V.; Santbergen, R.; Tijssen, M.; Zeman, M.

    2011-01-01

    A study is presented giving the response of three types of fiber-optic interferometers by which a standing wave through an object is investigated. The three types are a Sagnac, Mach–Zehnder and Michelson–Morley interferometer. The response of the Mach–Zehnder interferometer is similar to the Sagnac

  6. Polarization-independent, differential-phase-shift, quantum-key distribution system using upconversion detectors.

    Science.gov (United States)

    Iwai, Yuki; Honjo, Toshimori; Inoue, Kyo; Kamada, Hidehiko; Nishida, Yoshiki; Tadanaga, Osamu; Asobe, Masaki

    2009-05-15

    We propose and demonstrate a polarization-independent, differential-phase-shift, quantum-key distribution system with upconversion detectors. Even though the detectors have polarization dependency, use of alternative polarization modulation and a two-bit delay interferometer achieves polarization-insensitive operation. In an experiment, sifted key bits were polarization-independently generated over 50 km fiber.

  7. Helical wavefront and beam shape modulated by advanced liquid crystal q-plate fabricated via photoalignment and analyzed by Michelson's interference.

    Science.gov (United States)

    Huang, Yao-Han; Li, Ming-Shian; Ko, Shih-Wei; Fuh, Andy Y-G

    2013-09-10

    In this study, electrically tunable advanced liquid crystal q-plates (ALCQPs) that combine two q values in one device to generate optical vortex beams were fabricated using a photoalignment method that involves the use of azo dye, a surfactant alignment material. The electrically tunable ALCQP device could be modulated to control the shape and polarization of a circularly polarized Gaussian laser beam that propagated through the device. A Gaussian beam modulated by an ALCQP under suitable applied voltage showed a variation beam shape with helical wavefront, as demonstrated by Michelson's interference. This helical wavefront beam carries an orbital angular momentum and can be used in an optical tweezers system to trap, move, and rotate particles simultaneously.

  8. The TEXT upgrade vertical interferometer

    International Nuclear Information System (INIS)

    Hallock, G.A.; Gartman, M.L.; Li, W.; Chiang, K.; Shin, S.; Castles, R.L.; Chatterjee, R.; Rahman, A.S.

    1992-01-01

    A far-infrared interferometer has been installed on TEXT upgrade to obtain electron density profiles. The primary system views the plasma vertically through a set of large (60-cm radialx7.62-cm toroidal) diagnostic ports. A 1-cm channel spacing (59 channels total) and fast electronic time response is used, to provide high resolution for radial profiles and perturbation experiments. Initial operation of the vertical system was obtained late in 1991, with six operating channels

  9. Stellar Interferometer Technology Experiment (SITE)

    Science.gov (United States)

    Crawley, Edward F.; Miller, David; Laskin, Robert; Shao, Michael

    1995-01-01

    The MIT Space Engineering Research Center and the Jet Propulsion Laboratory stand ready to advance science sensor technology for discrete-aperture astronomical instruments such as space-based optical interferometers. The objective of the Stellar Interferometer Technology Experiment (SITE) is to demonstrate system-level functionality of a space-based stellar interferometer through the use of enabling and enhancing Controlled-Structures Technologies (CST). SITE mounts to the Mission Peculiar Experiment Support System inside the Shuttle payload bay. Starlight, entering through two apertures, is steered to a combining plate where it is interferred. Interference requires 27 nanometer pathlength (phasing) and 0.29 archsecond wavefront-tilt (pointing) control. The resulting 15 milli-archsecond angular resolution exceeds that of current earth-orbiting telescopes while maintaining low cost by exploiting active optics and structural control technologies. With these technologies, unforeseen and time-varying disturbances can be rejected while relaxing reliance on ground alignment and calibration. SITE will reduce the risk and cost of advanced optical space systems by validating critical technologies in their operational environment. Moreover, these technologies are directly applicable to commercially driven applications such as precision matching, optical scanning, and vibration and noise control systems for the aerospace, medical, and automotive sectors. The SITE team consists of experienced university, government, and industry researchers, scientists, and engineers with extensive expertise in optical interferometry, nano-precision opto-mechanical control and spaceflight experimentation. The experience exists and the technology is mature. SITE will validate these technologies on a functioning interferometer science sensor in order to confirm definitely their readiness to be baselined for future science missions.

  10. A new high sensitivity far-infrared laser interferometer for the HL-2A tokamak

    Science.gov (United States)

    Li, Y. G.; Zhou, Y.; Li, Y.; Deng, Z. C.; Wang, H. X.; Yi, J.

    2017-08-01

    A new four-chord Michelson-type formic acid (HCOOH, λ = 432.5 μm) laser interferometer has been successfully commissioned on the HL-2A tokamak to measure the electron density and density fluctuations. Due to the employment of the two-laser heterodyne technique, the time resolution of the interferometer reached 1.0 microseconds (μs). Four chords of line electron densities with a line-averaged density resolution 2 × 1016/m3 were obtained in a recent HL-2A experimental campaign, and detailed electron density fluctuations, caused by events such as edge localized mode, sawtooth precursor-oscillations, and energetic particle driven instabilities, were distinctly measured. In particular, the high-frequency electron density fluctuations (up to 500 kHz) caused by the reversed shear Alfvénic eigenmode were observed by the internal two interferometry channels, and their fluctuation location could be approximately identified from the spectra characteristics of multi-chord line electron densities.

  11. Phase-modulation interferometer for ICF-target characterization

    International Nuclear Information System (INIS)

    Cooper, D.E.

    1981-01-01

    Characterization requirements for high gain laser fusion targets are severe. We are required to detect defects on the surfaces of opaque and transparent shells with an amplitude resolution of +- 5 nm and a spatial resolution of 1 to 10 μm. To achieve this we have developed a laser-illuminated phase-modulation interferometer. This instrument is based on a photoelastic polarization modulation technique which allows one to convert phase information into an intensity modulation which can be easily and sensitively measured using ac signal processing techniques. This interferometer has detected path length changes as small as 1 nm and the required spatial resolution is assured by using a microscope objective to focus the probe laser beam down to a small (approx. 1 μm) spot on the surface of a microballoon. The interferometer will soon be coupled to an LSI-11 controlled 4π sphere manipulator which will allow us to automatically inspect the entire surface area of a target sphere

  12. A multichannel 118.8 μm-CH3OH laser interferometer for electron density profile measurements in LHD

    International Nuclear Information System (INIS)

    Kawahata, K.; Tanaka, K.; Tokuzawa, T.; Ito, Y.; Ejiri, A.; Okajima, S.

    2001-01-01

    A 13-channel far infrared laser interferometer has been developed and routinely operated for the measurements of the spatial and temporal behaviours of the electron density in the Large Helical Device (LHD). The optical configuration is of the Michelson interferometer type with a heterodyne detection system. The light source is a highly stable twin 118.8-μm CH 3 OH laser pumped by a cw CO 2 laser, which is developed in NIFS. All the optical components of the interferometer except laser sources are mounted on a massive stainless steel frame, which encircles the plasma vacuum vessel and is placed on three vibration-isolating mounts. The observed fringe shifts caused by the mechanical vibrations of the system is 1/100 fringes for the high frequency components of f > 1 Hz and 1/50 fringes for the low frequency components. The phase-shift measurement is made with an accuracy of 1/100 of a fringe, corresponding to a minimum measurable line-averaged density of 5.6 x 10 16 m -3 at the central chord. (author)

  13. Wavelength switchable flat-top all-fiber comb filter based on a double-loop Mach-Zehnder interferometer.

    Science.gov (United States)

    Luo, Ai-Ping; Luo, Zhi-Chao; Xu, Wen-Cheng; Cui, Hu

    2010-03-15

    A wavelength switchable all-fiber comb filter with flat-top spectral response based on a double-loop Mach-Zehnder (M-Z) interferometer is proposed and demonstrated. The proposed flat-top filter consists of a rotatable polarizer and a double-loop M-Z interferometer composed of two fiber couplers with a polarization controller (PC) in the first loop. In the theoretical analysis, when the second coupler of the M-Z interferometer is a non-3dB one, with proper settings of the polarization state of the input light and the PC, the wavelength switchable comb filter with flat-top passband can be obtained. Theoretical prediction was verified by experimental demonstration. The measured 1 dB bandwidth was 0.51 nm with a channel spacing of 0.98 nm, indicating that the flat-top passband of 1 dB bandwidth extends to about 50% of the comb spacing.

  14. A variable partially polarizing beam splitter

    Science.gov (United States)

    Flórez, Jefferson; Carlson, Nathan J.; Nacke, Codey H.; Giner, Lambert; Lundeen, Jeff S.

    2018-02-01

    We present designs for variably polarizing beam splitters. These are beam splitters allowing the complete and independent control of the horizontal and vertical polarization splitting ratios. They have quantum optics and quantum information applications, such as quantum logic gates for quantum computing and non-local measurements for quantum state estimation. At the heart of each design is an interferometer. We experimentally demonstrate one particular implementation, a displaced Sagnac interferometer configuration, that provides an inherent instability to air currents and vibrations. Furthermore, this design does not require any custom-made optics but only common components which can be easily found in an optics laboratory.

  15. Nanoscale Tilt Measurement Using a Cyclic Interferometer with Phase Stepping and Multiple Reflections

    Science.gov (United States)

    Naderishahab, Tahereh

    High accuracy tilt or roll angle measurement is required for a variety of engineering and scientific applications. Optical interferometry is normally used because it is non-contact and can measure tilt with a very high degree of accuracy. In this thesis, a cyclic interferometer has been developed with four mirrors to measure tilt angles as small as a few nanoradians. To measure the phase, a novel and simple method of phase shift by polarization was developed to enhance measurement sensitivity and accuracy. Since the cyclic interferometer is insensitive to external vibrations and turbulences, polarization phase step was accomplished with relative ease. To introduce the phase shift, a quarter wave plate and a half wave plate were used with a polarized laser beam. Multiple reflections were also introduced in the cyclic interferometer to enhance tilt measurement capability. A new method was developed to evaluate phase and eventually measure the tilt even in the case of changing fringe visibility. The results of these studies show that the multiple reflection cyclic interferometer can be used to measure object tilts in the order of 0.2 nanoradians or 10. (-5) arc second.

  16. Stabilization of a Fabry-Perot interferometer using a suspension-point interferometer

    International Nuclear Information System (INIS)

    Aso, Y.; Ando, M.; Kawabe, K.; Otsuka, S.; Tsubono, K.

    2004-01-01

    A suspension-point interferometer (SPI) is an auxiliary interferometer for active vibration isolation, implemented at the suspension points of the mirrors of an interferometric gravitational wave detector. We constructed a prototype Fabry-Perot interferometer equipped with an SPI and observed vibration isolation in both the spectrum and transfer function. The noise spectrum of the main interferometer was reduced by 40 dB below 1 Hz. Transfer function measurements showed that the SPI also produced good vibration suppression above 1 Hz. These results indicate that SPI can improve both the sensitivity and the stability of the interferometer

  17. A novel super-high extinction ratio comb-filter based on cascaded Mach-Zehnder Gires-Tournois interferometers with dispersion compensation.

    Science.gov (United States)

    Zhang, Yu; Huang, Wencai; Wang, Xiulin; Xu, Huiying; Cai, Zhiping

    2009-08-03

    In this paper, we propose a novel Mach-Zehnder Gires- Tournois interferometer (MZGTI) and a scheme to realize super high extinction ratio flat-top comb filter based on cascaded MZGTIs. Two sets of novel multi-cavity transmissive Gires-Tournois etalon (MCT-GTE) composed of cascaded Mach-Zehnder interferometer loops are added to the two arms of Mach-Zehnder interferometer (MZI) respectively, which forms a new MZI, i.e., MZGTI. MZGTI has the same characteristics as Michelson-Gires-Tournois interferometer (MGTI), which is suitable for dense wavelength division multiplexing systems. The super-high extinction ratio comb filter (SHERCF) we proposed has good passband flatness and wide bandwidth (passband or stopband bandwidth) when the extinction ratio is fairly high, which is quite superior to MGTI or MZGTI. For the severe chromatic dispersion problems, we propose a set of multi-cavity ring resonator (MC-RR) as a tunable dispersion compensator (TDC) for MZGTI, which is a set of cascaded ring resonators. Moreover, we demonstrate that a set of cascaded MC-RRs is an efficient dispersion compensator for SHERCF with the optimized results.

  18. Combination of a fast white-light interferometer with a phase shifting interferometric line sensor for form measurements of precision components

    Science.gov (United States)

    Laubach, Sören; Ehret, Gerd; Riebling, Jörg; Lehmann, Peter

    2017-06-01

    By means of an interferometric line sensor system, the form of a specimen can be measured by stitching several overlapping circular subapertures to form one 3D topography. This concept is very flexible and can be adapted to many different specimen geometries. The sensor is based on a Michelson interferometer configuration that consists of a rapidly oscillating reference mirror in combination with a high-speed line-scan camera. Due to the overlapping areas, movement errors of the scan axes can be corrected. In order to automatically adjust the line sensor in such a way that it is perpendicular to the measurement surface at a fixed working distance, a white-light interferometer was included in the line-based form-measuring system. By means of a fast white-light scan, the optimum angle of the sensor (with respect to the surface of the specimen) is determined in advance, before scanning the specimen using the line-based sinusoidal phase shifting interferometer. This produces accurate measurement results and makes it possible to also measure non-rotational specimens. In this paper, the setup of the line-based form-measuring system is introduced and the measurement strategy of the sensor adjustment using an additional white-light interferometer is presented. Furthermore, the traceability chain of the system and the main error influences are discussed. Examples of form measurement results are shown.

  19. Overall comparison of subpicosecond electron beam diagnostics by the polychromator, the interferometer and the femtosecond streak camera

    CERN Document Server

    Watanabe, T; Yoshimatsu, T; Sasaki, S; Sugiyama, Y; Ishi, K; Shibata, Y; Kondo, Y; Yoshii, K; Ueda, T; Uesaka, M

    2002-01-01

    Measurements of longitudinal bunch length of subpicosecond and picosecond electron beams have been performed by three methods with three radiation sources at the 35 MeV S-band twin liner accelerators at Nuclear Engineering Research Laboratory, University of Tokyo. The methods we adopt are the femtosecond streak camera with a nondispersive reflective optics, the coherent transition radiation (CTR) Michelson interferometer and the 10 ch polychromator that detects the spectrum of CTR and coherent diffraction radiation (CDR). The measurements by the two CTR methods were independently done with the streak camera and their results were consistent with one another. As a result, the reliability of the polychromator for the diagnostics of less than picosecond electron bunch and the usefulness of the diagnostics for the single shot measurement were verified. Furthermore, perfect nondestructive diagnostics for subpicosecond bunches was performed utilizing CDR interferometry. Then the good agreement between CDR interfero...

  20. Gravitational Wave Polarizations in f (R Gravity and Scalar-Tensor Theory

    Directory of Open Access Journals (Sweden)

    Gong Yungui

    2018-01-01

    Full Text Available The detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory opens a new era to use gravitational waves to test alternative theories of gravity. We investigate the polarizations of gravitational waves in f (R gravity and Horndeski theory, both containing scalar modes. These theories predict that in addition to the familiar + and × polarizations, there are transverse breathing and longitudinal polarizations excited by the massive scalar mode and the new polarization is a single mixed state. It would be very difficult to detect the longitudinal polarization by interferometers, while pulsar timing array may be the better tool to detect the longitudinal polarization.

  1. Gravitational Wave Polarizations in f (R) Gravity and Scalar-Tensor Theory

    Science.gov (United States)

    Gong, Yungui; Hou, Shaoqi

    2018-01-01

    The detection of gravitational waves by the Laser Interferometer Gravitational-Wave Observatory opens a new era to use gravitational waves to test alternative theories of gravity. We investigate the polarizations of gravitational waves in f (R) gravity and Horndeski theory, both containing scalar modes. These theories predict that in addition to the familiar + and × polarizations, there are transverse breathing and longitudinal polarizations excited by the massive scalar mode and the new polarization is a single mixed state. It would be very difficult to detect the longitudinal polarization by interferometers, while pulsar timing array may be the better tool to detect the longitudinal polarization.

  2. Lifetime and production rate of NOx in the upper stratosphere and lower mesosphere in the polar spring/summer after the solar proton event in October–November 2003

    Directory of Open Access Journals (Sweden)

    F. Friederich

    2013-03-01

    Full Text Available We present altitude-dependent lifetimes of NOx, determined with MIPAS/ENVISAT (the Michelson Interferometer for Passive Atmospheric Sounding/the European Environment Satellite, for the Southern polar region after the solar proton event in October–November 2003. Between 50° S and 90° S and decreasing in altitude they range from about two days at 64 km to about 20 days at 44 km. The lifetimes are controlled by transport, mixing and photochemistry. We infer estimates of dynamical lifetimes by comparison of the observed decay to photochemical lifetimes calculated with the SLIMCAT 3-D Model. Photochemical loss contributes to the observed NOx depletion by 0.1% at 44 km, increasing with altitude to 45% at 64 km. In addition, we show the correlation of modelled ionization rates and observed NOx densities under consideration of the determined lifetimes of NOx, and calculate altitude-dependent effective production rates of NOx due to ionization. For that we compare ionization rates of the AIMOS data base with the MIPAS measurements from 15 October–31 December 2003. We derive effective NOx-production rates to be applied to the AIMOS ionization rates which range from about 0.2 NOx-molecules per ion pair at 44 km to 0.7 NOx-molecules per ion pair at 62 km. These effective production rates are considerably lower than predicted by box model simulations which could hint at an overestimation of the modelled ionization rates.

  3. The LTP interferometer and phasemeter

    International Nuclear Information System (INIS)

    Heinzel, G; Wand, V; GarcIa, A; Jennrich, O; Braxmaier, C; Robertson, D; Middleton, K; Hoyland, D; Ruediger, A; Schilling, R; Johann, U; Danzmann, K

    2004-01-01

    The LISA Technology Package (LTP), to be launched by ESA in 2006/2007, is a technology demonstration mission in preparation for the LISA space-borne gravitational wave detector. A central part of the LTP is the optical metrology package (heterodyne interferometer with phasemeter) which monitors the distance between two test masses with a noise level of 10 pm Hz -1/2 between 3 mHz and 30 mHz. It has a dynamic range of >100 μm without any actuators for the pathlength. In addition to the longitudinal measurements, it provides alignment measurements with an expected noise level of -1/2 . While the basic design has been described previously by Heinzel et al (2003 Class. Quantum Grav. 20 S153-61), this paper gives new details on the laser stabilization, the phasemeter and recent prototype results

  4. Dispersion cancellation in a triple Laue interferometer

    International Nuclear Information System (INIS)

    Lemmel, Hartmut

    2014-01-01

    The concept of dispersion cancellation has been established in light optics to improve the resolution of interferometric measurements on dispersive media. Odd order dispersion cancellation allows to measure phase shifts without defocusing the interferometer due to wave packet displacements, while even order dispersion cancellation allows to measure time lags without losing resolution due to wave packet spreading. We report that either type of dispersion cancellation can be realized very easily in a triple Laue interferometer. Such interferometers are Mach–Zehnder interferometers based on Bragg diffraction, and are commonly used for neutrons and x-rays. Although the first x-ray interferometer was built nearly five decades ago, the feature of dispersion cancellation hasn't been recognized so far because the concept was hardly known in the neutron and x-ray community. However, it explains right away the surprising decoupling of phase shift and spatial displacement that we have discovered recently in neutron interferometry (Lemmel and Wagh 2010 Phys. Rev. A 82 033626). Furthermore, this article might inspire the light optics community to consider whether a triple Laue interferometer for laser light would be useful and feasible. We explain how dispersion cancellation works in neutron interferometry, and we describe the setup rigorously by solving the Schrödinger equation and by calculating the path integral. We point out, that the latter has to be evaluated with special care since in our setup the beam trajectory moves with respect to the crystal lattice of the interferometer. (paper)

  5. Geometric phases in singlemode fiber lightguides and fiber ring interferometers

    International Nuclear Information System (INIS)

    Malykin, Grigorii B; Pozdnyakova, Vera I

    2004-01-01

    We consider various geometric phases (GPs) in singlemode fiber lightguides (SMFs) and in fiber ring interferometers (FRIs): the Pancharatnam phase stemming from the cyclic evolution of the polarization state of radiation (RP state) in SMF, the Rytov-Vladimirskii phase (RV phase) stemming from the Rytov effect (specifically, rotation of the polarization plane due to noncoplanar winding of SMFs), as well as the nonreciprocal phase difference of counterpropagating waves (NPDCW) and nonreciprocal geometric phase of counterpropagating waves (NGPCW), which are caused by polarization nonreciprocity (PN) in FRIs. We show that in the general case, the Pancharatnam phase for an arbitrary RP state is inconsistent with the real phase change of light fluctuations in media that possess not only circular but also linear birefringence. We show that the RV phase, having a geometric origin, can in principle be considered as a dynamic phase (DP). We also show that the NGPCW can be considered as an effect of the evolution of the RP state mapped on the Poincare sphere in Ginzburg's orthogonal screw polarization modes (GSPMs) of SMFs in the FRI contour. We analyze a number of experiments in which geometric phases were detected in FRIs: changing the RV phase and Rytov's angle (RA) in response to change of the pitch of helicoidal winding of SMFs. (methodological notes)

  6. Comparative Sensitivities of Gravitational Wave Detectors Based on Atom Interferometers and Light Interferometers

    Science.gov (United States)

    Baker, John G.; Thorpe, J. I.

    2012-01-01

    We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe. Whether this potential advantage outweighs the additional complexity associated with including atom interferometers will require further study.

  7. Turbulence-Free Double-slit Interferometer

    Science.gov (United States)

    Smith, Thomas A.; Shih, Yanhua

    2018-02-01

    Optical turbulence can be detrimental for optical observations. For instance, atmospheric turbulence may reduce the visibility or completely blur out the interference produced by an interferometer in open air. However, a simple two-photon interference theory based on Einstein's granularity picture of light makes a turbulence-free interferometer possible; i.e., any refraction index, length, or phase variations along the optical paths of the interferometer do not have any effect on its interference. Applying this mechanism, the reported experiment demonstrates a two-photon double-slit interference that is insensitive to atmospheric turbulence. The turbulence-free mechanism and especially the turbulence-free interferometer would be helpful in optical observations that require high sensitivity and stability such as for gravitational-wave detection.

  8. Turbulence-Free Double-slit Interferometer.

    Science.gov (United States)

    Smith, Thomas A; Shih, Yanhua

    2018-02-09

    Optical turbulence can be detrimental for optical observations. For instance, atmospheric turbulence may reduce the visibility or completely blur out the interference produced by an interferometer in open air. However, a simple two-photon interference theory based on Einstein's granularity picture of light makes a turbulence-free interferometer possible; i.e., any refraction index, length, or phase variations along the optical paths of the interferometer do not have any effect on its interference. Applying this mechanism, the reported experiment demonstrates a two-photon double-slit interference that is insensitive to atmospheric turbulence. The turbulence-free mechanism and especially the turbulence-free interferometer would be helpful in optical observations that require high sensitivity and stability such as for gravitational-wave detection.

  9. Interferometer Designs for the Terrestrial Planet Finder

    Science.gov (United States)

    Lawson, P. R.; Dumont, P. J.; Colavita, M. M.

    2000-01-01

    The Terrestrial Planet Finder (TPF) is a space-based infrared interferometer that will combine high sensitivity and spatial resolution to detect and characterize planetary systems within 15 pc of our sun. TPF is a key element in NASA's Origins Program and is currently un- der study in its Pre-Project Phase. We review some of the interferometer designs that have been considered for starlight nulling, with particular attention to the architecture and subsystems of the central beam-combiner.

  10. QUBIC, a bolometric interferometer to measure the B modes of the CMB

    OpenAIRE

    Kaplan, Jean; collaboration, for the QUBIC

    2009-01-01

    Measuring the B modes of the CMB polarization fluctuations would provide very strong constraints on inflation. The main challenge in this measurement is the treatment of systematic effects. CMB observations with imagers and interferometers, subject to very different systematics, are complementary in this respect. Interferometry provides direct access to the Fourier transform of the sky signal. In bolometric interferometry, the interference pattern produced by the sky through a few hundred hor...

  11. Polarization Optics

    OpenAIRE

    Fressengeas, Nicolas

    2010-01-01

    The physics of polarization optics *Polarized light propagation *Partially polarized light; DEA; After a brief introduction to polarization optics, this lecture reviews the basic formalisms for dealing with it: Jones Calculus for totally polarized light and Stokes parameters associated to Mueller Calculus for partially polarized light.

  12. Testing a Model of Planck-Scale Quantum Geometry With Broadband Correlation of Colocated 40m Interferometers

    Energy Technology Data Exchange (ETDEWEB)

    McCuller, Lee Patrick [Univ. of Chicago, IL (United States)

    2015-12-01

    The Holometer is designed to test for a Planck diffractive-scaling uncertainty in long-baseline position measurements due to an underlying noncommutative geometry normalized to relate Black hole entropy bounds of the Holographic principle to the now-finite number of position states. The experiment overlaps two independent 40 meter optical Michelson interferometers to detect the proposed uncertainty as a common broadband length fluctuation. 150 hours of instrument cross-correlation data are analyzed to test the prediction of a correlated noise magnitude of $7\\times10^{−21}$ m/$\\sqrt{\\rm Hz}$ with an effective bandwidth of 750kHz. The interferometers each have a quantum-limited sensitivity of $2.5\\times 10^{−18}$ m/$\\sqrt{\\rm Hz}$, but their correlation with a time-bandwidth product of $4\\times 10^{11}$ digs between the noise floors in search for the covarying geometric jitter. The data presents an exclusion of 5 standard deviations for the tested model. This exclusion is defended through analysis of the calibration methods for the instrument as well as further sub shot noise characterization of the optical systems to limit spurious background-correlations from undermining the signal.

  13. A cryogenic optical feedthrough using polarization maintaining fibers.

    Science.gov (United States)

    Nelson, M J; Collins, C J; Speake, C C

    2016-03-01

    Polarization maintaining optical fibers can be used to transmit linearly polarized light over long distances but their use in cryogenic environments has been limited by their sensitivity to temperature changes and associated mechanical stress. We investigate experimentally how thermal stresses affect the polarization maintaining fibers and model the observations with Jones matrices. We describe the design, construction, and testing of a feedthrough and fiber termination assembly that uses polarization maintaining fiber to transmit light from a 633 nm HeNe laser at room temperature to a homodyne polarization-based interferometer in a cryogenic vacuum. We report on the efficiency of the polarization maintaining properties of the feedthrough assembly. We also report that, at cryogenic temperatures, the interferometer can achieve a sensitivity of 8 × 10(-10) rad/√Hz at 0.05 Hz using this feedthrough.

  14. Comparison of Atom Interferometers and Light Interferometers as Space-Based Gravitational Wave Detectors

    Science.gov (United States)

    Baker, John G.

    2012-01-01

    We consider a class of proposed gravitational wave detectors based on multiple atomic interferometers separated by large baselines and referenced by common laser systems. We compute the sensitivity limits of these detectors due to intrinsic phase noise of the light sources, non-inertial motion of the light sources, and atomic shot noise and compare them to sensitivity limits for traditional light interferometers. We find that atom interferometers and light interferometers are limited in a nearly identical way by intrinsic phase noise and that both require similar mitigation strategies (e.g. multiple arm instruments) to reach interesting sensitivities. The sensitivity limit from motion of the light sources is slightly different and favors the atom interferometers in the low-frequency limit, although the limit in both cases is severe.

  15. Q-switched operation with Fox-Smith-Michelson laser cavity

    International Nuclear Information System (INIS)

    Huang, X; Huang, L; Gong, M

    2008-01-01

    A new kind of three-mirror composite cavity, Fox-Smith-Michelson cavity has been configured. This laser cavity is capable of high power output, owing to the low threshold of Michelson cavity. Also, thanks to the mode selection function of Fox-Smith cavity, stable pulses at high repetition rate can be generated. In our experiment, 15.54 W CW output at 1064 nm has been achieved, with an optic-to-optic conversion efficiency of 42.2%. At the Q-switching repetition rate of 100 kHz, the average output power is 11.92 W, with an optic-to-optic conversion efficiency of 38.2%. For Q-switching frequency from 30 kHz to 100 kHz, the pulse width variation is below 4.4% and the amplitude variation is below 4.8%

  16. Demonstration of the Wide-Field Imaging Interferometer Testbed Using a Calibrated Hyperspectral Image Projector

    Science.gov (United States)

    Bolcar, Matthew R.; Leisawitz, David; Maher, Steve; Rinehart, Stephen

    2012-01-01

    The Wide-field Imaging Interferometer testbed (WIIT) at NASA's Goddard Space Flight Center uses a dual-Michelson interferometric technique. The WIIT combines stellar interferometry with Fourier-transform interferometry to produce high-resolution spatial-spectral data over a large field-of-view. This combined technique could be employed on future NASA missions such as the Space Infrared Interferometric Telescope (SPIRIT) and the Sub-millimeter Probe of the Evolution of Cosmic Structure (SPECS). While both SPIRIT and SPECS would operate at far-infrared wavelengths, the WIIT demonstrates the dual-interferometry technique at visible wavelengths. The WIIT will produce hyperspectral image data, so a true hyperspectral object is necessary. A calibrated hyperspectral image projector (CHIP) has been constructed to provide such an object. The CHIP uses Digital Light Processing (DLP) technology to produce customized, spectrally-diverse scenes. CHIP scenes will have approximately 1.6-micron spatial resolution and the capability of . producing arbitrary spectra in the band between 380 nm and 1.6 microns, with approximately 5-nm spectral resolution. Each pixel in the scene can take on a unique spectrum. Spectral calibration is achieved with an onboard fiber-coupled spectrometer. In this paper we describe the operation of the CHIP. Results from the WIIT observations of CHIP scenes will also be presented.

  17. Dynamic spectro-polarimeter based on a modified Michelson interferometric scheme.

    Science.gov (United States)

    Dembele, Vamara; Jin, Moonseob; Baek, Byung-Joon; Kim, Daesuk

    2016-06-27

    A simple dynamic spectro-polarimeter based on a modified Michelson interferometric scheme is described. The proposed system can extract a spectral Stokes vector of a transmissive anisotropic object. Detail theoretical background is derived and experiments are conducted to verify the feasibility of the proposed novel snapshot spectro-polarimeter. The proposed dynamic spectro-polarimeter enables us to extract highly accurate spectral Stokes vector of any transmissive anisotropic object with a frame rate of more than 20Hz.

  18. Perfect crystal interferometer and its applications

    Energy Technology Data Exchange (ETDEWEB)

    Hasegawa, Yuji [Atominstitut der Oesterreichischen Universitaeten, Vienna (Austria)

    1996-08-01

    The interferometry with angstrom scale wavelength has developed steadily, and various types of interferometers have been investigated. Among them, LLL interferometers are widely used. The first neutron interferometry was achieved in 1962 by Maier-Leibnitz et al. A new type of neutron interferometers was constructed with a perfect crystal, and experimentally performed in 1974 by Rauch et al. The precise measurements with LLL neutron interferometers were performed on scattering length, gravitational effect, coherence, Fizeau effects, spin superposition, complementarity, and post-selection effects. Since the early stage of quantum physics, the double-slit experiment has served as the example of the epistemologically strange features of quantum phenomena, and its course of study is described. The time-delayed interferometry with nuclear resonant scattering of synchrotron radiation and phase transfer in time-delayed interferometry with nuclear resonant scattering were experimented, and are briefly reported. A geometric phase factor was derived for a split beam experiment as an example of cyclic evolution. The geometric phase was observed with a two-loop neutron interferometer. All the experimental results showed complete agreement with the theoretical treatment. (K.I.)

  19. Aerosol absorption measurement with a sinusoidal phase modulating fiber optic photo thermal interferometer

    Science.gov (United States)

    Li, Shuwang; Shao, Shiyong; Mei, Haiping; Rao, Ruizhong

    2016-10-01

    Aerosol light absorption plays an important role in the earth's atmosphere direct and semi-direct radiate forcing, simultaneously, it also has a huge influence on the visibility impairment and laser engineering application. Although various methods have been developed for measuring aerosol light absorption, huge challenge still remains in precision, accuracy and temporal resolution. The main reason is that, as a part of aerosol light extinction, aerosol light absorption always generates synchronously with aerosol light scattering, and unfortunately aerosol light scattering is much stronger in most cases. Here, a novel photo-thermal interferometry is proposed only for aerosol absorption measurement without disturbance from aerosol scattering. The photo-thermal interferometry consists of a sinusoidal phase-modulating single mode fiber-optic interferometer. The thermal dissipation, caused by aerosol energy from photo-thermal conversion when irritated by pump laser through interferometer, is detected. This approach is completely insensitive to aerosol scattering, and the single mode fiber-optic interferometer is compact, low-cost and insensitive to the polarization shading. The theory of this technique is illustrated, followed by the basic structure of the sinusoidal phase-modulating fiber-optic interferometer and demodulation algorithms. Qualitative and quantitative analysis results show that the new photo-thermal interference is a potential approach for aerosol absorption detection and environmental pollution detection.

  20. A heterodyne interferometer for angle metrology

    International Nuclear Information System (INIS)

    Hahn, Inseob; Weilert, M.; Wang, X.; Goullioud, R.

    2010-01-01

    We have developed a compact, high-resolution, angle measurement instrument based on a heterodyne interferometer. Common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer set up, an optical mask is used to sample the laser beam reflecting back from four areas on a target surface. From the relative displacement measurements of the target surface areas, we can simultaneously determine angular rotations around two orthogonal axes in a plane perpendicular to the measurement beam propagation direction. The device is used in a testbed for a tracking telescope system where pitch and yaw angle measurements of a flat mirror are performed. Angle noise measurement of the device shows 0.1 nrad/√(Hz) at 1 Hz, at a working distance of 1 m. The operation range and nonlinearity of the device when used with a flat mirror is approximately ±0.15 mrad, and 3 μrad rms, respectively.

  1. Streak camera recording of interferometer fringes

    International Nuclear Information System (INIS)

    Parker, N.L.; Chau, H.H.

    1977-01-01

    The use of an electronic high-speed camera in the streaking mode to record interference fringe motion from a velocity interferometer is discussed. Advantages of this method over the photomultiplier tube-oscilloscope approach are delineated. Performance testing and data for the electronic streak camera are discussed. The velocity profile of a mylar flyer accelerated by an electrically exploded bridge, and the jump-off velocity of metal targets struck by these mylar flyers are measured in the camera tests. Advantages of the streak camera include portability, low cost, ease of operation and maintenance, simplified interferometer optics, and rapid data analysis

  2. Superconducting on-chip microwave interferometers

    Energy Technology Data Exchange (ETDEWEB)

    Menzel, Edwin P.; Fischer, Michael; Schneider, Christian; Baust, Alexander; Eder, Peter; Goetz, Jan; Haeberlein, Max; Schwarz, Manuel; Wulschner, Karl Friedrich; Xie, Edwar; Zhong, Ling; Deppe, Frank; Fedorov, Kirill; Huebl, Hans; Marx, Achim; Gross, Rudolf [Walther-Meissner-Institut, Bayerische Akademie der Wissenschaften, Garching (Germany); Physik-Department, TU Muenchen, Garching (Germany); Nanosystems Initiative Munich (NIM), Muenchen (Germany)

    2015-07-01

    In the realm of all-microwave quantum computation, information is encoded in itinerant microwave photons propagating along transmission lines. In such a system unitary operations are implemented by linear elements such as beam splitters or interferometers. However, for two-qubit operations non-linear gates, e.g., c-phase gates are required. In this work, we investigate superconducting interferometers as a building block of a c-phase gate. We experimentally characterize their scattering properties and compare them to simulation results. Finally, we discuss our progress towards the realization of a c-phase gate.

  3. Quantum Spin Transport in Mesoscopic Interferometer

    Directory of Open Access Journals (Sweden)

    Zein W. A.

    2007-10-01

    Full Text Available Spin-dependent conductance of ballistic mesoscopic interferometer is investigated. The quantum interferometer is in the form of ring, in which a quantum dot is embedded in one arm. This quantum dot is connected to one lead via tunnel barrier. Both Aharonov- Casher and Aharonov-Bohm e ects are studied. Our results confirm the interplay of spin-orbit coupling and quantum interference e ects in such confined quantum systems. This investigation is valuable for spintronics application, for example, quantum information processing.

  4. The study of interferometer spectrometer based on DSP and linear CCD

    Science.gov (United States)

    Kang, Hua; Peng, Yuexiang; Xu, Xinchen; Xing, Xiaoqiao

    2010-11-01

    In this paper, general theory of Fourier-transform spectrometer and polarization interferometer is presented. A new design is proposed for Fourier-transform spectrometer based on polarization interferometer with Wollaston prisms and linear CCD. Firstly, measured light is changed into linear polarization light by polarization plate. And then the light can be split into ordinary and extraordinary lights by going through one Wollaston prism. At last, after going through another Wollaston prism and analyzer, interfering fringes can be formed on linear CCD behind the analyzer. The linear CCD is driven by CPLD to output amplitude of interfering fringes and synchronous signals of frames and pixels respectively. DSP is used to collect interference pattern signals from CCD and the digital data of interfering fringes are processed by using 2048-point-FFT. Finally, optical spectrum of measured light can be display on LCD connected to DSP with RS232. The spectrometer will possess the features of firmness, portability and the ability of real-time analyzing. The work will provide a convenient and significant foundation for application of more high accuracy of Fourier-transform spectrometer.

  5. Method and device for aligning and interferometer

    NARCIS (Netherlands)

    Somers, P.A.A.

    2005-01-01

    Method and device for the alignment of an interferometer arrangement, which comprises an object beam part (4), a beam splitting part (5) and a beam combination part (6). A detector unit (2) is arranged to detect an interference pattern for two beams that can be differentiated, via each of n optical

  6. Background reduction in a young interferometer biosensor

    NARCIS (Netherlands)

    Mulder, H. K P; Subramaniam, V.; Kanger, J. S.

    2014-01-01

    Integrated optical Young interferometer (IOYI) biosensors are among the most sensitive label-free biosensors. Detection limits are in the range of 20 fg/mm2. The applicability of these sensors is however strongly hampered by the large background that originates from both bulk refractive index

  7. Smart photogalvanic running-grating interferometer

    DEFF Research Database (Denmark)

    Kukhtarev, N. V.; Kukhtareva, T.; Edwards, M. E.

    2005-01-01

    Photogalvanic effect produces actuation of periodic motion of macroscopic LiNbO3 crystal. This effect was applied to the development of an all-optical moving-grating interferometer usable for optical trapping and transport of algae chlorella microorganisms diluted in water with a concentration...

  8. Plasmonic interferometers: From physics to biosensing applications

    Science.gov (United States)

    Zeng, Xie

    Optical interferometry has a long history and wide range of applications. In recent years, plasmonic interferometer arouses great interest due to its compact size and enhanced light-matter interaction. They have demonstrated attractive applications in biomolecule sensing, optical modulation/switching, and material characterization, etc. In this work, we first propose a practical far-field method to extract the intrinsic phase dispersion, revealing important phase information during interactions among free-space light, nanostructure, and SPs. The proposed approach is confirmed by both simulation and experiment. Then we design novel plasmonic interferometer structure for sensitive optical sensing applications. To overcome two major limitations suffered by previously reported double-slit plasmonic Mach-Zehnder interferometer (PMZI), two new schemes are proposed and investigated. (1) A PMZI based on end-fire coupling improves the SP coupling efficiency and enhance the interference contrast more than 50 times. (2) In another design, a multi-layered metal-insulator-metal PMZI releases the requirement for single-slit illumination, which enables sensitive, high-throughput sensing applications based on intensity modulation. We develop a sensitive, low-cost and high-throughput biosensing platform based on intensity modulation using ring-hole plasmonic interferometers. This biosensor is then integrated with cell-phone-based microscope, which is promising to develop a portable sensor for point-of-care diagnostics, epidemic disease control and food safety monitoring.

  9. Absolute distance metrology for space interferometers

    NARCIS (Netherlands)

    Swinkels, B.L.; Latoui, A.; Bhattacharya, N.; Wielders, A.A.; Braat, J.J.M.

    2005-01-01

    Future space missions, among which the Darwin Space Interferometer, will consist of several free flying satellites. A complex metrology system is required to have all the components fly accurately in formation and have it operate as a single instrument. Our work focuses on a possible implementation

  10. Thermal Noise in the Initial LIGO Interferometers

    Science.gov (United States)

    Gillespie, Aaron D.

    1995-01-01

    Gravitational wave detectors capable of detecting broadband gravitational wave bursts with a strain amplitude sensitivity near 10^{-21} at frequencies around 100 Hz are currently under construction by the LIGO (Laser Interferometer Gravitational-wave Observatory) and VIRGO groups. One challenge facing these groups is how to detect the motion of the center of an inertial mass to a precision of 10^{-18} m when the mass consists of atoms each of which individually moves much more than that due to thermal energy. The uncertainty in the interferometer's measurement due to these thermal motions is called thermal noise. This thesis describes the thermal noise of the initial LIGO detectors. The thermal noise was analyzed by modelling the normal modes of the test mass suspension system as harmonic oscillators with dissipation and applying the fluctuation dissipation theorem. The dissipation of all modes which contribute significant thermal noise to the interferometer was measured and from these measurements the total thermal noise was estimated. The frequency dependence of the dissipation of the pendulum mode was characterized from measurements of the violin modes. A steel music wire suspension system was found to meet the goals of the initial LIGO detectors. A mathematical technique was developed which relates the energy in each vibrational mode to the motion of the mirror surface measured by the interferometer. Modes with acoustic wavelengths greater than the laser beam spot size can contribute significant thermal noise to the interferometer measurements. The dissipation of the test masses of LIGO's 40 -m interferometer at Caltech was investigated, and a technique for suspending and controlling the test masses which lowered the dissipation and met the thermal noise goals of the initial LIGO detector was developed. New test masses were installed in the 40-m interferometer resulting in improved noise performance. The implications of thermal noise to detecting gravitational

  11. Measuring Earth: Current status of the GRACE Follow-On Laser Ranging Interferometer

    Science.gov (United States)

    Schütze, Daniel; LRI Team

    2016-05-01

    The GRACE mission that was launched in 2002 has impressively proven the feasibility of low-orbit satellite-to-satellite tracking for Earth gravity observations. Especially mass transport related to Earth's hydrological system could be well resolved both spatially and temporally. This allows to study processes such as polar ice sheet decline and ground water depletion in great detail. Owing to GRACE's success, NASA and GFZ will launch the successor mission GRACE Follow-On in 2017. In addition to the microwave ranging system, GRACE Follow-On will be the first mission to use a Laser Ranging Interferometer as technology demonstrator to track intersatellite distance changes with unprecedented precision. This new ranging device inherits some of the technologies which have been developed for the future spaceborne gravitational wave detector LISA. I will present the architecture of the Laser Ranging Interferometer, point out similarities and differences to LISA, and conclude with the current status of the flight hardware production.

  12. A generalized, periodic nonlinearity-reduced interferometer for straightness measurements

    International Nuclear Information System (INIS)

    Wu Chienming

    2008-01-01

    Periodic nonlinearity is a systematic error limiting the accuracy of displacement measurements at the nanometer level. However, an interferometer with a displacement measurement accuracy of less than 1 nm is required in nanometrology and in fundamental scientific research. To meet this requirement, a generalized, periodic nonlinearity-reduced interferometer, based on three construction principles has been developed for straightness measurements. These three construction principles have resulted in an interferometer with a highly stable design with reduced periodic nonlinearity. Verifications by a straightness interferometer have demonstrated that the periodic nonlinearity was less than 40 pm. The results also demonstrate that the interferometer design is capable of subnanometer accuracy and is useful in nanometrology

  13. State-labeling Wannier-Stark atomic interferometers

    Science.gov (United States)

    Pelle, B.; Hilico, A.; Tackmann, G.; Beaufils, Q.; Pereira dos Santos, F.

    2013-02-01

    Using cold 87Rb atoms trapped in a one-dimensional (1D)-optical lattice, atomic interferometers involving coherent superpositions between different Wannier-Stark atomic states are realized. Two different kinds of trapped interferometer schemes are presented: a Ramsey-type interferometer sensitive both to clock frequency and external forces, and a symmetric accordion-type interferometer, sensitive to external forces only. We evaluate the limits in terms of sensitivity and accuracy of those schemes and discuss their application as force sensors. As a first step, we apply these interferometers to the measurement of the Bloch frequency and the demonstration of a compact gravimeter.

  14. Non magnetic neutron spin quantum precession using multilayer spin splitter and a phase-spin echo interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Ebisawa, T.; Tasaki, S.; Kawai, T.; Akiyoshi, T. [Kyoto Univ., Kumatori, Osaka (Japan). Research Reactor Inst.; Achiwa, N.; Hino, M.; Otake, Y.; Funahashi, H.

    1996-08-01

    The authors have developed cold neutron optics and interferometry using multilayer mirrors. The advantages of the multilayer mirrors are their applicability to long wavelength neutrons and a great variety of the mirror performance. The idea of the present spin interferometry is based on nonmagnetic neutron spin quantum precession using multilayer spin splitters. The equation for polarized neutrons means that the polarized neutrons are equivalent to the coherent superposition of two parallel spin eigenstates. The structure and principle of a multilayer spin splitter are explained, and the nonmagnetic gap layer of the multilayer spin splitter gives rise to neutron spin quantum precession. The performance test of the multilayer spin splitter were made with a new spin interferometer, which is analogous optically to a spin echo system with vertical precession field. The spin interferometers were installed at Kyoto University research reactor and the JRR-3. The testing method and the results are reported. The performance tests on a new phase-spin echo interferometer are described, and its applications to the development of a high resolution spin echo system and a Jamin type cold neutron interferometer are proposed. (K.I.)

  15. Einstein, the exponential metric, and a proposed gravitational Michelson-Morley experiment

    International Nuclear Information System (INIS)

    Yilmaz, H.

    1979-01-01

    An early but potentially important remark of Einstein on the exponential nature of time-dilation is discussed. Using the same argument for the length-contraction, plus two alternative kinematical assumptions, the Schwarzschild and exponential metrics are derived. A gravitational Michelson-Morley experiment with one arm directed along the vertical is proposed to test the metrics. The experiment may be considered as a laboratory test of the Schwarzschild field and possibly a test of the black-hole interpretation of collapsed matter

  16. A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations

    Directory of Open Access Journals (Sweden)

    R. Spang

    2018-04-01

    Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS instrument aboard the European Space Agency (ESA Envisat satellite operated from July 2002 to April 2012. The infrared limb emission measurements provide a unique dataset of day and night observations of polar stratospheric clouds (PSCs up to both poles. A recent classification method for PSC types in infrared (IR limb spectra using spectral measurements in different atmospheric window regions has been applied to the complete mission period of MIPAS. The method uses a simple probabilistic classifier based on Bayes' theorem with a strong independence assumption on a combination of a well-established two-colour ratio method and multiple 2-D probability density functions of brightness temperature differences. The Bayesian classifier distinguishes between solid particles of ice, nitric acid trihydrate (NAT, and liquid droplets of supercooled ternary solution (STS, as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been compiled. Comparisons with results from the classification scheme of the spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations (CALIPSO satellite show excellent correspondence in the spatial and temporal evolution for the area of PSC coverage (APSC even for each PSC class. Probability density functions of the PSC temperature, retrieved for each class with respect to equilibrium temperature of ice and based on coincident temperatures from meteorological reanalyses, are in accordance with the microphysical knowledge of the formation processes with respect to temperature for all three PSC types.This paper represents unprecedented pole-covering day- and nighttime climatology of the PSC distributions and their composition of different particle types. The dataset allows analyses on the temporal and spatial development of the PSC formation

  17. A climatology of polar stratospheric cloud composition between 2002 and 2012 based on MIPAS/Envisat observations

    Science.gov (United States)

    Spang, Reinhold; Hoffmann, Lars; Müller, Rolf; Grooß, Jens-Uwe; Tritscher, Ines; Höpfner, Michael; Pitts, Michael; Orr, Andrew; Riese, Martin

    2018-04-01

    The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) instrument aboard the European Space Agency (ESA) Envisat satellite operated from July 2002 to April 2012. The infrared limb emission measurements provide a unique dataset of day and night observations of polar stratospheric clouds (PSCs) up to both poles. A recent classification method for PSC types in infrared (IR) limb spectra using spectral measurements in different atmospheric window regions has been applied to the complete mission period of MIPAS. The method uses a simple probabilistic classifier based on Bayes' theorem with a strong independence assumption on a combination of a well-established two-colour ratio method and multiple 2-D probability density functions of brightness temperature differences. The Bayesian classifier distinguishes between solid particles of ice, nitric acid trihydrate (NAT), and liquid droplets of supercooled ternary solution (STS), as well as mixed types. A climatology of MIPAS PSC occurrence and specific PSC classes has been compiled. Comparisons with results from the classification scheme of the spaceborne lidar Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) on the Cloud-Aerosol-Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite show excellent correspondence in the spatial and temporal evolution for the area of PSC coverage (APSC) even for each PSC class. Probability density functions of the PSC temperature, retrieved for each class with respect to equilibrium temperature of ice and based on coincident temperatures from meteorological reanalyses, are in accordance with the microphysical knowledge of the formation processes with respect to temperature for all three PSC types.This paper represents unprecedented pole-covering day- and nighttime climatology of the PSC distributions and their composition of different particle types. The dataset allows analyses on the temporal and spatial development of the PSC formation process over

  18. Direct-reading type microwave interferometer

    International Nuclear Information System (INIS)

    Matsuura, Kiyokata; Fujita, Junji; Ogata, Atsushi; Haba, Kiichiro.

    1977-10-01

    A new microwave interferometer has been developed and applied to the electron density measurement on JIPP T-II plasma device. The interferometer generates an output voltage proportional to the number of fringe shifts and also output pulses which indicate the change of electron density for the convenience of data processing, where the resolution is a quarter of fringe shift. The principle is based on the digitization of fringe shifts utilizing the phase detection of microwave signals with two-level modulation of source frequency. With this system and 70 GHz microwave source, a change of electron density as rapid as about 2 x 10 13 cm -3 in 1 ms has been measured at the tokamak operation of JIPP T-II. (auth.)

  19. Dynamics of pi-junction interferometer circuits

    DEFF Research Database (Denmark)

    Kornkev, V.K.; Mozhaev, P.B.; Borisenko, I.V.

    2002-01-01

    The pi-junction superconducting circuit dynamics was studied by means of numerical simulation technique. Parallel arrays consisting of Josephson junctions of both 0- and pi-type were studied as a model of high-T-c grain-boundary Josephson junction. The array dynamics and the critical current...... dependence on magnetic field are discussed. Experimental results for dc interferometers with 0 and pi high-T-c bi-crystal Josephson junctions are reported and discussed in comparison with numerical simulation....

  20. Model-based phase-shifting interferometer

    Science.gov (United States)

    Liu, Dong; Zhang, Lei; Shi, Tu; Yang, Yongying; Chong, Shiyao; Miao, Liang; Huang, Wei; Shen, Yibing; Bai, Jian

    2015-10-01

    A model-based phase-shifting interferometer (MPI) is developed, in which a novel calculation technique is proposed instead of the traditional complicated system structure, to achieve versatile, high precision and quantitative surface tests. In the MPI, the partial null lens (PNL) is employed to implement the non-null test. With some alternative PNLs, similar as the transmission spheres in ZYGO interferometers, the MPI provides a flexible test for general spherical and aspherical surfaces. Based on modern computer modeling technique, a reverse iterative optimizing construction (ROR) method is employed for the retrace error correction of non-null test, as well as figure error reconstruction. A self-compiled ray-tracing program is set up for the accurate system modeling and reverse ray tracing. The surface figure error then can be easily extracted from the wavefront data in forms of Zernike polynomials by the ROR method. Experiments of the spherical and aspherical tests are presented to validate the flexibility and accuracy. The test results are compared with those of Zygo interferometer (null tests), which demonstrates the high accuracy of the MPI. With such accuracy and flexibility, the MPI would possess large potential in modern optical shop testing.

  1. Fine art of computing nulling interferometer maps

    Science.gov (United States)

    Hénault, F.

    2008-07-01

    Spaceborne nulling interferometers are often characterized by means of their nulling ratio, which is defined as the deepest possible extinction of one target star supposed to harbor an extra-solar system. Herein is shown that another parameter, which is the transmitting efficiency of nearby bright fringes, is also of prime importance. More generally, "nulling maps" formed by the whole destructive and constructive fringe pattern projected on-sky, are found to be very sensitive on the design of some subsystems constituting the interferometer. In particular, we consider Spatial Filtering (SF) and Achromatic Phase Shifter (APS) devices, both required achieving planet detection and characterization. Consequences of the SF choice (pinhole or single-mode optical fiber) and APS properties (with or without induced pupil-flip) are discussed, for both monochromatic and polychromatic cases. Examples of numerical simulations are provided for single Bracewell interferometer, Angel cross and X-array configurations, demonstrating noticeable differences in the aspect of resulting nulling maps. It is concluded that both FS and APS designs exhibit variable capacities for serendipitous planet discovery.

  2. Polarization preserving ultra fast optical shutter for quantum information processing

    OpenAIRE

    Spagnolo, Nicolo'; Vitelli, Chiara; Giacomini, Sandro; Sciarrino, Fabio; De Martini, Francesco

    2008-01-01

    We present the realization of a ultra fast shutter for optical fields, which allows to preserve a generic polarization state, based on a self-stabilized interferometer. It exhibits high (or low) transmittivity when turned on (or inactive), while the fidelity of the polarization state is high. The shutter is realized through two beam displacing prisms and a longitudinal Pockels cell. This can represent a useful tool for controlling light-atom interfaces in quantum information processing.

  3. Three Phase-Grating Moiré Neutron Interferometer for Large Interferometer Area Applications

    Science.gov (United States)

    Sarenac, D.; Pushin, D. A.; Huber, M. G.; Hussey, D. S.; Miao, H.; Arif, M.; Cory, D. G.; Cronin, A. D.; Heacock, B.; Jacobson, D. L.; LaManna, J. M.; Wen, H.

    2018-03-01

    We demonstrate a three phase-grating moiré neutron interferometer in a highly intense neutron beam as a robust candidate for large area interferometry applications and for the characterization of materials. This novel far-field moiré technique allows for broad wavelength acceptance and relaxed requirements related to fabrication and alignment, thus circumventing the main obstacles associated with perfect crystal neutron interferometry. We observed interference fringes with an interferometer length of 4 m and examined the effects of an aluminum 6061 alloy sample on the coherence of the system. Experiments to measure the autocorrelation length of samples and the universal gravitational constant are proposed and discussed.

  4. Gravitational Wave Detection with Single-Laser Atom Interferometers

    Science.gov (United States)

    Yu, Nan; Tinto, Massimo

    2011-01-01

    A new design for a broadband detector of gravitational radiation relies on two atom interferometers separated by a distance L. In this scheme, only one arm and one laser are used for operating the two atom interferometers. The innovation here involves the fact that the atoms in the atom interferometers are not only considered as perfect test masses, but also as highly stable clocks. Atomic coherence is intrinsically stable, and can be many orders of magnitude more stable than a laser.

  5. SHIMS -- A Spatial Heterodyne Interferometer for Methane Sounding, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This project develops the Spatial Heterodyne Interferometer for Methane Sounding (SHIMS), a lightweight, compact, robust spectrometer system for remote sensing of...

  6. CAMEX-3 ATMOSPHERIC EMITTED RADIANCE INTERFEROMETER (AERI) V1

    Data.gov (United States)

    National Aeronautics and Space Administration — The Atmospheric Emitted Radiance Interferometer (AERI) was used to make atmospheric temperature and moisture retrievals. AERI provides absolutely calibrated...

  7. Snapshot imaging spectrometry with a heterodyned Savart plate interferometer

    Science.gov (United States)

    Maione, Bryan; Brickson, Leandra; Escuti, Michael; Kudenov, Michael

    2017-08-01

    Imaging spectrometers are frequently used in remote sensing for their increased target discrimination capabilities over conventional imaging. Increasing the spectral resolution of these sensors further enables the system's ability to discriminate certain targets and adds the potential for monitoring narrow-line spectral features. We describe a high spectral resolution (Δλ=1.1 nm full-width at half maximum) snapshot imaging spectrometer capable of distinguishing two narrowly separated bands in the red-visible spectrum. A theoretical model is provided to detail the first polarization grating-based spatial heterodyning of a Savart plate interferometer. Following this discussion, the experimental conditions of the narrow-line imaging spectrometer (NLIS) are provided. Finally, calibration and target identification methods are applied and quantified. Ultimately it is demonstrated that in a full spectral acquisition the NLIS sensor is capable of less than 3.5% error in reconstruction. Additionally, it is demonstrated that neural networks provide greater than 99% reduction in crosstalk when compared to pseudoinversion and expectation maximization in single target identification.

  8. Comparison of blind imaging performance of Fizeau and Michelson type arrays for a partially resolved object

    NARCIS (Netherlands)

    Van der Avoort, C.; Den Herder, J.W.; Braat, J.

    2005-01-01

    This paper compares two well-known types of interferometer arrays for optical aperture synthesis. An analytical model for both types describes the expected output, in terms of photon counts. The goal is to characterize the performance of both types of array for blind imaging of a wide-field or

  9. X-ray speckle correlation interferometer

    International Nuclear Information System (INIS)

    Eisenhower, Rachel; Materlik, Gerhard

    2000-01-01

    Speckle Pattern Correlation Interferometry (SPCI) is a well-established technique in the visible-light regime for observing surface disturbances. Although not a direct imaging technique, SPCI gives full-field, high-resolution information about an object's motion. Since x-ray synchrotron radiation beamlines with high coherent flux have allowed the observation of x-ray speckle, x-ray SPCI could provide a means to measure strains and other quasi-static motions in disordered systems. This paper therefore examines the feasibility of an x-ray speckle correlation interferometer

  10. Phase-shifting interferometer for surface inspection

    Science.gov (United States)

    Tam, Siu Chung; Low, Beng-Yew; Chua, Hock-Chuan; Ho, Anthony T. S.; Neo, Wah-Peng

    1997-08-01

    A phase-shifting Twyman-Green interferometer has been constructed. Using three consecutively captured interferograms, the phase profile of a reflective surface can be determined. Results using various fringe processing techniques are compared. These methods include uniform averaging, Gaussian mask and spin filtering. For simulated fringes superimposed with random noise and fixed-pattern noise, it has been observed that a combination of weighted averaging and spin filtering could generate the best results. The computerized system has been applied to the measurement of the form errors of a silicon wafer and a cosmetic mirror, respectively. The root-mean-square error of the wafer is determined to be 11.13 nm.

  11. Multichannel far-infrared interferometer/polarimeter

    International Nuclear Information System (INIS)

    Young, P.E.

    1984-01-01

    Studies of the time development of the current density profile in a tokamak plasma have been incomplete due to the lack of adequate, direct measurements of the internal magnetic field. Experimental confirmation of anomalous current penetration during the startup phase of a tokamak discharge and the detailed study of major disruptions and their relation to the presence of tearing modes are needed to complete the understanding of tokamak confinement properties. The major obstacle to studies of the tokamak current density profile has been the lack of a reliable, nonperturbing diagnostic. This dissertation describes a multichannel interferometer/polarimeter that was developed for this purpose

  12. Asymmetrical transverse structures in nonlinear interferometers

    CERN Document Server

    Romanov, O G

    2003-01-01

    The work presents a novel type of optical instability, which leads to the spontaneous formation of a stationary or pulsating asymmetrical structure in the problem of interaction between two counterpropagating waves in a ring cavity with Kerr-like nonlinearity. Linear stability analysis of interferometer transmission stationary states enabled: (1) to mark out typical bifurcations for this system: self- and cross-modulational instabilities, (2) to determine the range of parameters for which the symmetry breaking of transverse structures and complex temporal behaviour of the light field could be observed. The predictions of linear stability analysis have been verified with numerical modelling of coupled-modes equations.

  13. A reliable, compact and low-cost Michelson wavemeter for laser wavelength measurement

    International Nuclear Information System (INIS)

    Fox, P.J.; Scholten, R.E.; Walkiewicz, M.R.; Drullinger, R.E.

    1998-01-01

    We describe the construction and operation of a simple, compact and cost effective Michelson wavemeter with picometer accuracy. The low cost of the device means that it can form the basis of an undergraduate laboratory experiment, yet it is sufficiently reliable and accurate that it has become an important tool in our research laboratory, where it is regularly used to tune lasers to atomic transitions. The usefulness and accuracy of the wavemeter is demonstrated by tuning two separate extended cavity diode lasers to achieve two-step excitation of the Rb 5 2 D state, observed by detecting 420 nm blue fluorescence from the 5 2 D → 6 2 P → 5 2 S decay path. (authors)

  14. Effect of imperfect Faraday mirrors on the security of a Faraday–Michelson quantum cryptography system

    International Nuclear Information System (INIS)

    Wang, Wei-Long; Gao, Ming; Ma, Zhi

    2013-01-01

    The one-way Faraday–Michelson system is a very useful practical quantum cryptography system where Faraday mirrors (FMs) play an important role. In this paper we analyze the security of this system against imperfect FMs. We consider the security loophole caused by imperfect FMs in Alice’s and Bob’s security zones. Then we implement a passive FM attack in this system. By changing the values of the imperfection parameters of Alice’s FMs, we calculate the quantum bit error rate between Alice and Bob induced by Eve and the probability that Eve obtains outcomes successfully. It is shown that the imperfection of one of Alice’s two FMs makes the system sensitive to an attack. Finally we give a modified key rate as a function of the FM imperfections. The security analysis indicates that both Alice’s and Bob’s imperfect FMs can compromise the secure key. (paper)

  15. Polarization developments

    International Nuclear Information System (INIS)

    Prescott, C.Y.

    1993-07-01

    Recent developments in laser-driven photoemission sources of polarized electrons have made prospects for highly polarized electron beams in a future linear collider very promising. This talk discusses the experiences with the SLC polarized electron source, the recent progress with research into gallium arsenide and strained gallium arsenide as a photocathode material, and the suitability of these cathode materials for a future linear collider based on the parameters of the several linear collider designs that exist

  16. Calibration of the VIRGO experiment: from the testing of the detector to the search of coalescing binaries with the central interferometer; Calibration de l'experience VIRGO: de l'etalonnage du detecteur a la recherche de signaux de coalescences binaires avec l'interferometre central

    Energy Technology Data Exchange (ETDEWEB)

    Veziant, O

    2003-05-01

    The aim of the VIRGO experiment is the detection of gravitational waves. The detector is based on a Michelson interferometer with three-kilometer long arms. Before the availability of the complete detector, most of the technical choices have been tested on a small scale interferometer (central interferometer or CITF). This allowed to record the first technical data of the experiment. The calibration of the CITF data has been studied in this thesis. This work involved some local operations such as the calibration of the electronics of the detection system, and also some more global operation such as the characterisation of the detector response function. The latter is used to unfold the data from experimental effects and to estimate the detector sensitivity. A monitoring procedure of this response function has been applied to produce a time series of reconstructed data, i.e. data free from experimental distortions. The implementation of VIRGO will make use of an optical calibrator using the radiation pressure of a laser beam to act on the interferometer mirrors and characterize its response. The optical calibrator has been designed and assembled in laboratory and its performances have been measured. The physics analysis following the calibration step was tackled through a coalescing binary search algorithm. The latter was applied both on simulated data and on CITF data in order to estimate the detector noise level and to check the effects of the reconstruction procedure. (author)

  17. Electrically controlled phases of partially polarized light and orientational Kerr effect in liquid crystal ferroelectrics

    Science.gov (United States)

    Kiselev, Alexei D.; Kesaev, Vladimir V.; Pozhidaev, Evgeny P.

    2017-10-01

    We study the electro-optic properties of subwavelength-pitch deformed-helix ferroelectric liquid crystals illuminated with partially polarized light. In an experimental setup based on the Mach-Zehnder interferometer, it is found that the interference pattern crucially depends on the degree of polarization of the incident light. We evaluate the electric field dependence of both the Pancharatnam relative phase and the geometric phase for the general case of nonunitarily evolving mixed polarization states.

  18. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The proposed interferometer set-up is quite suitable for performing optical test studies on phase (transparent) objects in real-time. Recording schemes for the formation of holographic optical elements and the related technique for the realization of the interferometer set-up along with the experimental results have been ...

  19. Silicon Carbide Mounts for Fabry-Perot Interferometers

    Science.gov (United States)

    Lindemann, Scott

    2011-01-01

    Etalon mounts for tunable Fabry- Perot interferometers can now be fabricated from reaction-bonded silicon carbide structural components. These mounts are rigid, lightweight, and thermally stable. The fabrication of these mounts involves the exploitation of post-casting capabilities that (1) enable creation of monolithic structures having reduced (in comparison with prior such structures) degrees of material inhomogeneity and (2) reduce the need for fastening hardware and accommodations. Such silicon carbide mounts could be used to make lightweight Fabry-Perot interferometers or could be modified for use as general lightweight optical mounts. Heretofore, tunable Fabry-Perot interferometer structures, including mounting hardware, have been made from the low-thermal-expansion material Invar (a nickel/iron alloy) in order to obtain the thermal stability required for spectroscopic applications for which such interferometers are typically designed. However, the high mass density of Invar structures is disadvantageous in applications in which there are requirements to minimize mass. Silicon carbide etalon mounts have been incorporated into a tunable Fabry-Perot interferometer of a prior design that originally called for Invar structural components. The strength, thermal stability, and survivability of the interferometer as thus modified are similar to those of the interferometer as originally designed, but the mass of the modified interferometer is significantly less than the mass of the original version.

  20. Discrete interferometer with individual trapped atoms

    Science.gov (United States)

    Steffen, Andreas; Alberti, Andrea; Alt, Wolfgang; Belmechri, Noomen; Hild, Sebastian; Karski, Michal; Widera, Artur; Meschede, Dieter; Quantum Technology Team

    2011-05-01

    Coherent control and delocalization of individual atoms is a pivotal challenge in quantum technologies. As a new step on this road, we present an individual atom interferometer that is capable of splitting a trapped Cs atom by up to 10 μm , allowing us to measure potential gradients on the microscale. The atom is confined in a 1D optical lattice, which is capable of performing discrete state-dependent shifts to split the atom by the desired number of sites. We establish a high degree of control, as the initial atom position, vibrational state and spin state can all be prepared with above 95% fidelity. To unravel decoherence effects and phase influences, we have explored several basic interferometer geometries, among other things demonstrating a positional spin echo to cancel background effects. As a test case, an inertial force has been applied and successfully measured using the atomic phase. This will offer us a new tool to investigate the interaction between two atoms in a controlled model system.

  1. Multichannel microwave interferometer for the levitated dipole experiment

    Energy Technology Data Exchange (ETDEWEB)

    Boxer, Alexander C. [Plasma Science and Fusion Center, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Garnier, Darren T.; Mauel, Michael E. [Department of Applied Physics and Applied Mathematics, Columbia University, New York, New York 10027 (United States)

    2009-04-15

    A four-channel microwave interferometer (center frequency: 60 GHz) has been constructed to measure plasma density profiles in the levitated dipole experiment (LDX). The LDX interferometer has a unique design owing to the unique geometry of LDX. The main design features of the interferometer are: (1) the transmitted beam traverses the plasma entirely in O-mode; (2) the interferometer is a heterodyne system employing two free-running oscillators; (3) four signals of data are received from just on transmitted beam; (4) phase shifts are detected in quadrature. Calibration tests demonstrate that the interferometer measures phase shifts with an uncertainty of approximately 5 deg. Plasma densities in LDX corresponding to phase shifts of up to 5{pi} are routinely and successfully measured.

  2. Polar stratospheric cloud observations by MIPAS on ENVISAT: detection method, validation and analysis of the northern hemisphere winter 2002/2003

    Directory of Open Access Journals (Sweden)

    R. Spang

    2005-01-01

    Full Text Available The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS on ENVISAT has made extensive measurements of polar stratospheric clouds (PSCs in the northern hemisphere winter 2002/2003. A PSC detection method based on a ratio of radiances (the cloud index has been implemented for MIPAS and is validated in this study with respect to ground-based lidar and space borne occultation measurements. A very good correspondence in PSC sighting and cloud altitude between MIPAS detections and those of other instruments is found for cloud index values of less than four. Comparisons with data from the Stratospheric Aerosol and Gas Experiment (SAGE III are used to further show that the sensitivity of the MIPAS detection method for this threshold value of cloud index is approximately equivalent to an extinction limit of 10-3km-1 at 1022nm, a wavelength used by solar occultation experiments. The MIPAS cloud index data are subsequently used to examine, for the first time with any technique, the evolution of PSCs throughout the Arctic polar vortex up to a latitude close to 90° north on a near-daily basis. We find that the winter of 2002/2003 is characterised by three phases of very different PSC activity. First, an unusual, extremely cold phase in the first three weeks of December resulted in high PSC occurrence rates. This was followed by a second phase of only moderate PSC activity from 5-13 January, separated from the first phase by a minor warming event. Finally there was a third phase from February to the end of March where only sporadic and mostly weak PSC events took place. The composition of PSCs during the winter period has also been examined, exploiting in particular an infra-red spectral signature which is probably characteristic of NAT. The MIPAS observations show the presence of these particles on a number of occasions in December but very rarely in January. The PSC type differentiation from MIPAS indicates that future comparisons of PSC

  3. Polarization, political

    NARCIS (Netherlands)

    Wojcieszak, M.; Mazzoleni, G.; Barnhurst, K.G.; Ikeda, K.; Maia, R.C.M.; Wessler, H.

    2015-01-01

    Polarization has been studied in three different forms: on a social, group, and individual level. This entry first focuses on the undisputed phenomenon of elite polarization (i.e., increasing adherence of policy positions among the elites) and also outlines different approaches to assessing mass

  4. Polarization holography

    DEFF Research Database (Denmark)

    Nikolova, L.; Ramanujam, P.S.

    Current research into holography is concerned with applications in optically storing, retrieving, and processing information. Polarization holography has many unique properties compared to conventional holography. It gives results in high efficiency, achromaticity, and special polarization...... properties. This books reviews the research carried out in this field over the last 15 years. The authors provide basic concepts in polarization and the propagation of light through anisotropic materials, before presenting a sound theoretical basis for polarization holography. The fabrication...... and characterization of azobenzene based materials, which remain the most efficient for the purpose, is described in detail. This is followed by a description of other materials that are used in polarization holography. An in-depth description of various applications, including display holography and optical storage...

  5. Characterization of spatial polarization fluctuations in scattered field

    International Nuclear Information System (INIS)

    Kumar Singh, Rakesh; Naik, Dinesh N; Itou, Hitoshi; Miyamoto, Yoko; Takeda, Mitsuo

    2014-01-01

    We extend the concept of Poincare vector correlations for the characterization of spatial polarization fluctuations of scattered fields. Spatial (rather than temporal) dynamics of polarization in the scattered field is investigated experimentally by detecting instantaneous polarization with a specially designed polarization interferometer. Use of the Poincare-vector correlation in characterization is demonstrated by determining polarization dynamics of three different cases of scattered fields. This confirms usefulness of the proposed technique in diagnosis of scatterers. Under the condition of spatial ergodicity and Gaussian statistics of the scattered field, we replace the ensemble average of the instantaneous field with the space average, and estimate generalized Stokes parameters (GSPs) of the polarization speckles. Results of GSPs are used to obtain spatial correlation of the Poincare vectors. (paper)

  6. Thermal effects in the Input Optics of the Enhanced Laser Interferometer Gravitational-Wave Observatory interferometers.

    Science.gov (United States)

    Dooley, Katherine L; Arain, Muzammil A; Feldbaum, David; Frolov, Valery V; Heintze, Matthew; Hoak, Daniel; Khazanov, Efim A; Lucianetti, Antonio; Martin, Rodica M; Mueller, Guido; Palashov, Oleg; Quetschke, Volker; Reitze, David H; Savage, R L; Tanner, D B; Williams, Luke F; Wu, Wan

    2012-03-01

    We present the design and performance of the LIGO Input Optics subsystem as implemented for the sixth science run of the LIGO interferometers. The Initial LIGO Input Optics experienced thermal side effects when operating with 7 W input power. We designed, built, and implemented improved versions of the Input Optics for Enhanced LIGO, an incremental upgrade to the Initial LIGO interferometers, designed to run with 30 W input power. At four times the power of Initial LIGO, the Enhanced LIGO Input Optics demonstrated improved performance including better optical isolation, less thermal drift, minimal thermal lensing, and higher optical efficiency. The success of the Input Optics design fosters confidence for its ability to perform well in Advanced LIGO.

  7. Polar Bears

    Science.gov (United States)

    Amstrup, Steven C.; Douglas, David C.; Reynolds, Patricia E.; Rhode, E.B.

    2002-01-01

    Polar bears (Ursus maritimus) are hunted throughout most of their range. In addition to hunting polar bears of the Beaufort Sea region are exposed to mineral and petroleum extraction and related human activities such as shipping road-building, and seismic testing (Stirling 1990).Little was known at the start of this project about how polar bears move about in their environment, and although it was understood that many bears travel across political borders, the boundaries of populations had not been delineated (Amstrup 1986, Amstrup et al. 1986, Amstrup and DeMaster 1988, Garner et al. 1994, Amstrup 1995, Amstrup et al. 1995, Amstrup 2000).As human populations increase and demands for polar bears and other arctic resources escalate, managers must know the sizes and distributions of the polar bear populations. Resource managers also need reliable estimates of breeding rates, reproductive intervals, litter sizes, and survival of young and adults.Our objectives for this research were 1) to determine the seasonal and annual movements of polar bears in the Beaufort Sea, 2) to define the boundaries of the population(s) using this region, 3) to determine the size and status of the Beaufort Sea polar bear population, and 4) to establish reproduction and survival rates (Amstrup 2000).

  8. Gravitational waves interferometer and the VIRGO project

    CERN Document Server

    Gaddi, A

    2002-01-01

    Radio, optical and X-rays telescopes are improving our knowledge of deep space. All these telescopes detect electromagnetic radiation at various frequencies. But a different kind of radiation is generated in the deeper space; it is the gravitational one. Gravitational waves change the space-time metric. As a consequence, GW telescopes should detect an extremely small strain (h < 10/sup -21/) of the geometry of a reference frame; if the frame has a reference dimension (L) of some kilometers, the deformation amplitude ( Delta L = h * L) is limited to 10/sup -16/ meters. Laser interferometers are the most suitable devices to make precise measurements of distances. Their resolution is limited by the laser wavelength ( lambda = 10/sup -6/ meters) and by the light wave-shift detection capability ( Delta Phi = 1 ppb). These theoretical limits are strongly degraded by different noise sources, which reduce the actual resolution by several orders of magnitude. Applied physicists and engineers are working together to...

  9. Projection moire interferometer for research in otology

    Science.gov (United States)

    Dirckx, Joris J.; Decraemer, Willem F.

    1999-02-01

    A moire interferometer is presented which was specially designed for the study of middle ear mechanics. The apparatus is based on phase shift projection moire interferometry, and allows full field quantitative measurement of the shape and deformation of three-dimensional surfaces. Phase shifting and grating noise removal is obtained by piezo-actuated movements of the gratings in the projection and the viewing optical path, respectively. Object shape is then calculated from the recordings of four phase shift moire topograms. The angle between projection and viewing direction is very small, so that observation of the eardrum is possible with minimal shadow problems caused by the bony structures in the vicinity of the eardrum. Measurements obtained on a calibration object and on in-vitro middle ear preparations are presented.

  10. FIR interferometer and scattering measurements of ATF

    International Nuclear Information System (INIS)

    Ma, C.H.; Hutchinson, D.P.; Fockedey, Y.; Vander Sluis, K.L.; Bennett, C.A.

    1989-01-01

    A 15-channel far-infrared (FIR) interferometer system has been constructed to measure the electron densities on the ATF plasmas. The system consists of a pair of cw 214-μm difluoromethane (CH 2 F 2 ) lasers, optically pumped by separate CO 2 lasers. The large number of channels is achieved by the use of reflective beam expansion optics to create a beam of 2 cm /times/ 45 cm. After passing through the plasma discharge, the elongated beam produced by the cylindrical mirrors is dissected by an array of 15 off-axis paraboloid reflectors, each of which illuminates a single Schottky-diode detector. The use of the beam expanding optics system reduces the number of optical elements required for the interferometer to approximately 2-3 per channel. The FIR laser beams are transported from the laser room to the experimental area by 25 mm i.d. dielectric waveguides purged with dry nitrogen. The system can also be operated at a wavelength of 119-μm by changing the gas in FIR laser cavities to methanol for high density experiments. Details of the system are described. A study is underway to determine the optimum design of a FIR scattering system for the ATF. This scattering system will be used to investigate density fluctuations with scale lengths from 0.1 cm to the plasma radius. The laser for this scattering system may be operated at wavelengths of 447, 307, 214, 184, and 119 μm with power levels of 100 to 500 mW. A summary of the study is presented. 6 refs., 1 fig

  11. Michelson-Morley analogue for electrons using trapped ions to test Lorentz symmetry.

    Science.gov (United States)

    Pruttivarasin, T; Ramm, M; Porsev, S G; Tupitsyn, I I; Safronova, M S; Hohensee, M A; Häffner, H

    2015-01-29

    All evidence so far suggests that the absolute spatial orientation of an experiment never affects its outcome. This is reflected in the standard model of particle physics by requiring all particles and fields to be invariant under Lorentz transformations. The best-known tests of this important cornerstone of physics are Michelson-Morley-type experiments verifying the isotropy of the speed of light. For matter, Hughes-Drever-type experiments test whether the kinetic energy of particles is independent of the direction of their velocity, that is, whether their dispersion relations are isotropic. To provide more guidance for physics beyond the standard model, refined experimental verifications of Lorentz symmetry are desirable. Here we search for violation of Lorentz symmetry for electrons by performing an electronic analogue of a Michelson-Morley experiment. We split an electron wave packet bound inside a calcium ion into two parts with different orientations and recombine them after a time evolution of 95 milliseconds. As the Earth rotates, the absolute spatial orientation of the two parts of the wave packet changes, and anisotropies in the electron dispersion will modify the phase of the interference signal. To remove noise, we prepare a pair of calcium ions in a superposition of two decoherence-free states, thereby rejecting magnetic field fluctuations common to both ions. After a 23-hour measurement, we find a limit of h × 11 millihertz (h is Planck's constant) on the energy variations, verifying the isotropy of the electron's dispersion relation at the level of one part in 10(18), a 100-fold improvement on previous work. Alternatively, we can interpret our result as testing the rotational invariance of the Coulomb potential. Assuming that Lorentz symmetry holds for electrons and that the photon dispersion relation governs the Coulomb force, we obtain a fivefold-improved limit on anisotropies in the speed of light. Our result probes Lorentz symmetry violation

  12. Test of an intensity-compensated Fabry-Perot interferometer

    International Nuclear Information System (INIS)

    Kamiyama, Hiroshi; Okano, Shoichi

    1977-01-01

    In measurement of the heating effect when high-energy charged particles fall into the ultra-high atmosphere, the Doppler width of auroral bright lines was measured with a Fabry-Perot interferometer. To overcome the difficulty in directly measuring auroral temperature with a Fabry-Perot interferometer, in the intensity-compensated type, the quantity aF/I is recorded: I the intensity of small part of the light entering the interferometer, F the detected output, and a constant. The width of the bright lines can be obtained with high accuracy. (Mori, K.)

  13. Using the Talbot_Lau_interferometer_parameters Spreadsheet

    Energy Technology Data Exchange (ETDEWEB)

    Kallman, Jeffrey S. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-06-04

    Talbot-Lau interferometers allow incoherent X-ray sources to be used for phase contrast imaging. A spreadsheet for exploring the parameter space of Talbot and Talbot-Lau interferometers has been assembled. This spreadsheet allows the user to examine the consequences of choosing phase grating pitch, source energy, and source location on the overall geometry of a Talbot or Talbot-Lau X-ray interferometer. For the X-ray energies required to penetrate scanned luggage the spacing between gratings is large enough that the mechanical tolerances for amplitude grating positioning are unlikely to be met.

  14. Development of holographic interferometer for non-destructive testing

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Baik, Sung Hoon; Shin, Jang Soo; Cho, Jai Wan; Kim, Duk Hyeon; Hong, Suck Kyoung; Lee, Sang Kil; Kim, Heon Jun; Park, Chang Jin

    1993-02-01

    This project sets the goal at development of holographic interferometer. In this interferometer, fringe localization and imaging of object are considered. And collimated beam and wedge are used for the high-speed recording and formation of carrier fringes, respectively. With this real-time holographic interferometer, not only experiments were conducted on natural convection and flame jet, but also on high speed flow phenomena such as shock wave propagation. Visualization of high-speed flow is recorded in high-speed camera with framing rate ∼ 35000f/s. And to analyze axis symmetric phase object, analysis program was developed. (Author)

  15. DESIGN AND CHARACTERIZATION OF THERMALLY ACTUATED BIMETALLIC MEMBRANES BY MICHELSON INTERFEROMETRY

    Directory of Open Access Journals (Sweden)

    JULIO ENRIQUE DUARTE

    2011-01-01

    Full Text Available En el presente trabajo se describen el diseño y la caracterización de membranas bimetálicas de Al-Si, con actuación térmica. El diseño se realizó empleando el método de los Elementos Finitos y se concentró en optimizar la relación de los espesores de las capas de aluminio y silicio. La defl exión de las membranas se determinó aplicando la técnica del Interferómetro de Michelson. En la etapa experimental se utilizaron membranas cuadradas de 5 mm de lado, con un espesor de 10 mm para el silicio y espesores de 4 y 1 mm para el aluminio. La caracterización entregó un desplazamiento máximo de 14 mm para la membrana con 4 mm de Al, lo cual es consistente con los resultados obtenidos numéricamente.

  16. Micromachined Fabry-Perot Interferometer for Motion Detection

    National Research Council Canada - National Science Library

    Waters, Richard L; Aklufi, Monti E

    2002-01-01

    The monolithic integration of a Fabry-Perot interferometer and a (100) silicon photodiode is reported for use as a highly sensitive transduction method in the detection of minute displacements of a proof mass attached to a spring...

  17. Herriott Cell Augmentation of a Quadrature Heterodyne Interferometer

    National Research Council Canada - National Science Library

    Antonsen, Erik

    2002-01-01

    A quadrature heterodyne interferometer is augmented with a Herriott Cell multi-pass reflector to increase instrument resolution and enable a separation of the phase shift due to neutral density from room vibrations...

  18. Slow-Light-Enhanced Spectral Interferometers, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — We proposoe a research program aimed at developing spectral interferometers with dramatically enhanced performance. A key aspect of our approach is to place a highly...

  19. UARS Wind Imaging Interferometer (WINDII) Level 3AL V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Wind Imaging Interferometer (WINDII) Level 3AL data product consists of daily, 4 degree increment latitude-ordered vertical profiles of meridional and zonal wind...

  20. UARS Wind Imaging Interferometer (WINDII) Level 3AT V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Wind Imaging Interferometer (WINDII) Level 3AT data product consists of daily, 65.536 second interval time-ordered vertical profiles of meridional and zonal wind...

  1. Development of an HCN dual laser for the interferometer on EAST

    Science.gov (United States)

    Li, Gen; Wei, Xuechao; Liu, Haiqing; Shen, Junjie; Jie, Yinxian; Lian, Hui; Zeng, Long; Zou, Zhiyong; Zhang, Jibo; Wang, Shouxin

    2017-08-01

    A two-color continuous wave (CW) discharge-pumped far-infrared (FIR) hydrogen cyanide (HCN) laser was developed as the source of an interferometer for measuring the line-averaged electron density in the Experimental Advanced Superconducting Tokamak (EAST). The output power of the dual laser system was about 120 mW from each laser on the 337 μm (0.89 THz) line. The polarization of each output beam was fixed using thin tungsten filaments and oscillated in the EH11 mode. Different megahertz intermediate frequencies (IF) and a slight frequency offset (˜1 MHz) were generated in this system to replace the traditional rotating grating with ˜10 kHz IF, and this can improve the time resolution of the interferometer significantly. The experimental result showed that different IF signals were obtained by successfully adjusting the cavity length. In particular, the beat frequency was captured at ˜1.3 MHz by a Schottky mixer when the length of the resonant cavities was changed by 5 μm by an automatic adjustment system. In order to study the character of IF, a long time record of the IF signal was carried out, and the IF signal could be stabilized for a few minutes in the range of 2 MHz to 3 MHz. A real-time IF stability control system was initially designed for long pulse discharge experiments on the EAST. The ˜MHz frequency response and good phase sensitivity of the dual laser HCN interferometer will allow the system to track fast density profiles and resolve fast MHD events, such as tearing/neoclassical tearing, disruptions, etc. Contributed paper, published as part of the Proceedings of the 3rd Domestic Electromagnetic Plasma Diagnostics Workshop, September 2016, Hefei, China.

  2. A surface plasmon resonance interferometer based on spatial phase modulation for protein array detection

    Science.gov (United States)

    Yu, Xinglong; Ding, Xiang; Liu, Fangfang; Wei, Xing; Wang, Dingxin

    2008-01-01

    Thousands of kinds of proteins exist in a single cell. Proteomics research aims to characterize these proteins and simultaneously analyse modifications and interactions on a large scale. Here we present a label-free surface plasmon resonance (SPR) imaging interferometer based on spatial phase modulation, which can be useful in this field. It consists of a light source, a SPR sensing unit, a special phase modulator, a photoelectric conversion unit and a computer. Collimated light is projected into a prism and reflected at the gold-glass interface. The p- and s-polarized components of the reflected light pass through a one-dimensional beam expander and a Wollaston prism, and form an interference pattern on a CCD. Interference images are acquired and transferred to the computer for data processing. Protein interaction on the gold surface leads to a local refractive index change and results in interference fringe phase shift. By calculating the phase shift, interaction information can be obtained. It is demonstrated that this technique can detect different concentrations of NaCl solutions, and the phase change generated by a 0.9% NaCl solution is about 10°. In protein-protein interaction experiments, a model system of rabbit IgG and goat-anti-rabbit IgG is tested. The maximum phase change is up to 12°. The phase resolution of the system is 0.2°, equivalent to the refractive index resolution of 3 × 10-5 RIU, and this value can be improved to 2 × 10-6 RIU just by increasing the gold thickness of the sensing chip. It is concluded that the sensitivity of the interferometer is enough to achieve larger capacity than that detected by the present protein micro-array products. These results suggest that the SPR interferometer based on spatial phase modulation provides a potential facility to meet the requirements in proteomics research.

  3. Fast-scanning far-infrared Fabry--Perot interferometer

    International Nuclear Information System (INIS)

    Komm, D.S.; Blanken, R.A.; Brossier, P.

    1975-01-01

    A scanning Fabry--Perot interferometer for use in the far ir (100 μ m less than lambda less than 2 mm) has been developed capable of scanning a free spectral range in a few milliseconds. A commercial loudspeaker was used as a drive, and mirrors were fabricated from electroformed copper mesh. Primary limitations of the instrument were due to vibrations of the interferometer frame. (U.S.)

  4. Fiber Fabry-Perot interferometer with controllable temperature sensitivity.

    Science.gov (United States)

    Zhang, Xinpu; Peng, Wei; Zhang, Yang

    2015-12-01

    We proposed a fiber taper based on the Fabry-Perot (FP) interferometer structure with controllable temperature sensitivity. The FP interferometer is formed by inserting a segment of tapered fiber tip into the capillary and subsequently splicing the other end of the capillary to a single-mode fiber (SMF), the tapered fiber endface, and the spliced face form the FP cavity. Through controlling the inserted tapered fiber length, a series of FP interferometers were made. Because the inserted taper tip has the degree of freedom along the fiber axial, when the FP interferometer is subjected to temperature variation, the thermal expansion of the fiber taper tip will resist the FP cavity length change caused by the evolution of capillary length, and we can control the temperature sensitivity by adjusting the inserted taper length. In this structure, the equivalent thermal expansion coefficient of the FP interferometer can be defined; it was used to evaluate the temperature sensitivity of the FP interferometer, which provides an effective method to eliminate the temperature effect and to enhance other measurement accuracy. We fabricated the FP interferometers and calibrated their temperature characters by measuring the wavelength shift of the resonance dips in the reflection spectrum. In a temperature range of 50°C to 150°C, the corresponding temperature sensitivities can be controlled between 0 and 1.97 pm/°C when the inserted taper is between 75 and 160 μm. Because of its controllable temperature sensitivity, ease of fabrication, and low cost, this FP interferometer can meet different temperature sensitivity requirements in various application areas, especially in the fields which need temperature insensitivity.

  5. Automatic Alignment of Displacement-Measuring Interferometer

    Science.gov (United States)

    Halverson, Peter; Regehr, Martin; Spero, Robert; Alvarez-Salazar, Oscar; Loya, Frank; Logan, Jennifer

    2006-01-01

    A control system strives to maintain the correct alignment of a laser beam in an interferometer dedicated to measuring the displacement or distance between two fiducial corner-cube reflectors. The correct alignment of the laser beam is parallel to the line between the corner points of the corner-cube reflectors: Any deviation from parallelism changes the length of the optical path between the reflectors, thereby introducing a displacement or distance measurement error. On the basis of the geometrical optics of corner-cube reflectors, the length of the optical path can be shown to be L = L(sub 0)cos theta, where L(sub 0) is the distance between the corner points and theta is the misalignment angle. Therefore, the measurement error is given by DeltaL = L(sub 0)(cos theta - 1). In the usual case in which the misalignment is small, this error can be approximated as DeltaL approximately equal to -L(sub 0)theta sup 2/2. The control system (see figure) is implemented partly in hardware and partly in software. The control system includes three piezoelectric actuators for rapid, fine adjustment of the direction of the laser beam. The voltages applied to the piezoelectric actuators include components designed to scan the beam in a circular pattern so that the beam traces out a narrow cone (60 microradians wide in the initial application) about the direction in which it is nominally aimed. This scan is performed at a frequency (2.5 Hz in the initial application) well below the resonance frequency of any vibration of the interferometer. The laser beam makes a round trip to both corner-cube reflectors and then interferes with the launched beam. The interference is detected on a photodiode. The length of the optical path is measured by a heterodyne technique: A 100- kHz frequency shift between the launched beam and a reference beam imposes, on the detected signal, an interferometric phase shift proportional to the length of the optical path. A phase meter comprising analog

  6. Experimental implementation of phase locking in a nonlinear interferometer

    Science.gov (United States)

    Wang, Hailong; Marino, A. M.; Jing, Jietai

    2015-09-01

    Based upon two cascade four-wave mixing processes in two identical hot rubidium vapor cells, a nonlinear interferometer has been experimentally realized [Jing et al., Appl. Phys. Lett. 99, 011110 (2011); Hudelist et al., Nat. Commun. 5, 3049 (2014)]. It has a higher degree of phase sensitivity than a traditional linear interferometer and has many potential applications in quantum metrology. Phase locking of the nonlinear interferometer is needed before it can find its way into applications. In this letter, we investigate the experimental implementation of phase locking of the relative phase between the three beams at different frequencies involved in such a nonlinear interferometer. We have utilized two different methods, namely, beat note locking and coherent modulation locking. We find that coherent modulation locking can achieve much better phase stability than beat note locking in our system. Our results pave the way for real applications of a nonlinear interferometer in precision measurement and quantum manipulation, for example, phase control in phase-sensitive N-wave mixing process, N-port nonlinear interferometer and quantum-enhanced real-time phase tracking.

  7. Effects of stray lights on Faraday rotation measurement for polarimeter-interferometer system on EAST

    Science.gov (United States)

    Zou, Z. Y.; Liu, H. Q.; Ding, W. X.; Chen, J.; Brower, D. L.; Lian, H.; Wang, S. X.; Li, W. M.; Yao, Y.; Zeng, L.; Jie, Y. X.

    2018-01-01

    A double-pass radially view 11 chords polarimeter-interferometer system has been operated on the experimental advanced superconducting tokamak and provides important current profile information for plasma control. Stray light originating from spurious reflections along the optical path (unwanted reflections from various optical components/mounts and transmissive optical elements such as windows, waveplates, and lens as well as the detectors) and also direct feedback from the retro-reflector used to realize the double-pass configuration can both contribute to contamination of the Faraday rotation measurement accuracy. Modulation of the Faraday rotation signal due to the interference from multiple reflections is observable when the interferometer phase (plasma density) varies with time. Direct reflection from the detector itself can be suppressed by employing an optical isolator consisting of a λ/4-waveplate and polarizer positioned in front of the mixer. A Faraday angle oscillation during the density ramping up (or down) can be reduced from 5°-10° to 1°-2° by eliminating reflections from the detector. Residual modulation arising from misalignment and stray light from other sources must be minimized to achieve accurate measurements of Faraday rotation.

  8. First results of the J-TEXT high-resolution 3-wave polarimeter-interferometer system

    Science.gov (United States)

    Zhuang, G.; Chen, J.; Li, Q.; Gao, L.; Wang, Z. J.; Liu, Y.; Chen, W.

    2013-10-01

    A far-infrared laser polarimeter-interferometer system based on Three-wave technique has been established on the J-TEXT tokamak. The system determines Faraday angle by measuring phase difference between two collinear, counter-rotating, circularly polarized laser beams, and acquires line-integrated electron density simultaneously by phase comparison between the two beams and a third local oscilate (LO) beam. Three seperately pumped HCOOH lasers at 432 μm are adopted as sources, suppling more than 100 mW power output in sum. Parabolic mirrors are used to expand probe beams to 450 mm wide, covering ~ 80% of plasma cross section, which allows profile measurement with high spatial resolution. First experimental results of the polarimeter-interferometer have been obtained. 12 chords (3 cm chord spacing) simultaneous polarimetric and interferometric measurements are achieved, with phase resolution up to 0.1° at bandwidth of 50 kHz. With the high temporal and phase resolution, perturbations associated with the sawtooth cycle and MHD activity have been observed.

  9. A radio frequency interferometer (RIF) system

    International Nuclear Information System (INIS)

    Goldwire, H.C. Jr.

    1993-01-01

    The authors describe a radio frequency interferometer (RFI) system developed and tested by Lawrence Livermore National Laboratory over the last several years. The basic theory of operation, sample data, and analyzed results are presented and compared to results obtained by conventional TDR means (CORRTEX). A typical shock location measurement used for hydro-yield determination or for energy flow diagnostics comprises a coaxial sensing cable extending from the detonation region to a CORRTEX recording instrument. The single digitizer-based RFI system uses an identical sensing cable installation technique. Recording equipment consists of a CAMAC digitizer module, which produces a sinusoidal probing signal (the signal sent downhole) for each sensing channel (cable), while also coherently sampling the phase of the reflected signal. Each channel is recorded using a single digitizer, providing maximal temporal and spatial resolution, but independent of channel gain or quadruture errors inherent to dual digitizer systems. Interpolation software with suitable look-ahead logic permits determination of complete quadruture information using a single digitizer. This RFI system provides several times better spatial resolution and two orders of magnitude better temporal sampling density than does CORRTEX. It also is less susceptible to electromagnetic pulse distortion and provides a direct means for identifying (and rejecting) any data so contaminated

  10. Interferometer observations of cluster formation in Serpens

    Science.gov (United States)

    Williams, Jonathan

    1999-10-01

    One of the primary science goals of the Atacama Large Millimeter Array is to image star forming regions in unprecedented detail and sensitivity. Here, we present BIMA observations of a young embedded stellar group in Serpens that demonstrate some of the issues in this field that ALMA may address in the future. The high resolution of the interferometer enables us to to follow the structure, dynamics, and chemistry of the overall cluster forming cloud down to the scale of individual star forming cores. There is an approximately equal mix of cores with and without continuum sources suggesting that new stars are continually being added to the group. There is evidence for large scale collapse onto the cluster with concentrations toward regions where the velocity dispersion is at a local minimum. There are also significant differences in relative abundances throughout the cluster indicating that molecule formation and depletion timescales are comparable to or less than dynamical timescales for core formation and that chemistry may be used as a signature of their evolution. We discuss a scenario for cluster formation through the condensation and collapse of individual cores via turbulent dissipation and point out a few ways in which ALMA may contribute to future studies.

  11. Political polarization

    OpenAIRE

    Dixit, Avinash K.; Weibull, Jörgen W.

    2007-01-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  12. Political polarization.

    Science.gov (United States)

    Dixit, Avinash K; Weibull, Jörgen W

    2007-05-01

    Failures of government policies often provoke opposite reactions from citizens; some call for a reversal of the policy, whereas others favor its continuation in stronger form. We offer an explanation of such polarization, based on a natural bimodality of preferences in political and economic contexts and consistent with Bayesian rationality.

  13. Self-referencing Mach-Zehnder interferometer as a laser system diagnostic: Active and adaptive optical systems

    International Nuclear Information System (INIS)

    Feldman, M.; Mockler, D.J.; English, R.E. Jr.; Byrd, J.L.; Salmon, J.T.

    1991-01-01

    We are incorporating a novel self-referencing Mach-Zehnder interferometer into a large scale laser system as a real time, interactive diagnostic tool for wavefront measurement. The instrument is capable of absolute wavefront measurements accurate to better than λ/10 pv over a wavelength range > 300 nm without readjustment of the optical components. This performance is achieved through the design of both refractive optics and catadioptric collimator to achromatize the Mach-Zehnder reference arm. Other features include polarization insensitivity through the use of low angles of incidence on all beamsplitters as well as an equal path length configuration that allows measurement of either broad-band or closely spaced laser-line sources. Instrument accuracy is periodically monitored in place by means of a thermally and mechanically stable wavefront reference source that is calibrated off-line with a phase conjugate interferometer. Video interferograms are analyzed using Fourier transform techniques on a computer that includes dedicated array processor. Computer and video networks maintain distributed interferometers under the control of a single analysis computer with multiple user access. 7 refs., 11 figs

  14. Sensor System Performance Evaluation and Benefits from the NPOESS Airborne Sounder Testbed-Interferometer (NAST-I)

    Science.gov (United States)

    Larar, A.; Zhou, D.; Smith, W.

    2009-01-01

    Advanced satellite sensors are tasked with improving global-scale measurements of the Earth's atmosphere, clouds, and surface to enable enhancements in weather prediction, climate monitoring, and environmental change detection. Validation of the entire measurement system is crucial to achieving this goal and thus maximizing research and operational utility of resultant data. Field campaigns employing satellite under-flights with well-calibrated FTS sensors aboard high-altitude aircraft are an essential part of this validation task. The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed-Interferometer (NAST-I) has been a fundamental contributor in this area by providing coincident high spectral/spatial resolution observations of infrared spectral radiances along with independently-retrieved geophysical products for comparison with like products from satellite sensors being validated. This paper focuses on some of the challenges associated with validating advanced atmospheric sounders and the benefits obtained from employing airborne interferometers such as the NAST-I. Select results from underflights of the Aqua Atmospheric InfraRed Sounder (AIRS) and the Infrared Atmospheric Sounding Interferometer (IASI) obtained during recent field campaigns will be presented.

  15. Suppression of interference noise caused by Fresnel reflection in all-fiber white-light interferometer.

    Science.gov (United States)

    Yuan, Yonggui; Cheng, Yongqing; Yang, Jun; Zhang, Haoliang; Lu, Dongchuan; Lv, Yan; Peng, Feng; Li, Hanyang; Zhang, Xiaojun; Jiang, Fuqiang; Yuan, Libo

    2017-11-01

    We propose methods to suppress the interference noise (IN) of an all-fiber white-light interferometer (WLI), which is caused by the residual Fresnel reflective beam. The methods are proposed to ensure a wide dynamic range and enhance the accuracy of measurement. IN can cause misjudgment of the realistic optical characteristic parameters, such as the fault diagnosis and polarization coupling of the optical devices under test. In addition, IN can reduce the dynamic range of the WLI. The optical path mismatch (OPM) method and the intensity suppression (IS) method by changing the positions and intensity of the IN are presented. The two suppression methods can successfully restrain IN caused by the Fresnel reflection beams. The experimental results show that IN is successfully suppressed by the OPM method or restrained by IS method in interferograms, and the dynamic range can achieve 85 dB without IN.

  16. The first observations of wide-band interferometers and the spectra of relic gravitons

    CERN Document Server

    Giovannini, Massimo

    2016-01-01

    Stochastic backgrounds of relic gravitons of cosmological origin extend from frequencies of the order of the aHz up to the GHz range. Since the temperature and polarization anisotropies constrain the low frequency normalization of the spectra, in the concordance paradigm the strain amplitude corresponding to the frequency window of wide-band interferometers turns out to be, approximately, nine orders of magnitude smaller than the astounding signal recently reported and attributed to a binary black hole merger. The backgrounds of relic gravitons expected from the early Universe are compared with the stochastic foregrounds stemming from the estimated multiplicity of the astrophysical sources. It is suggested that while the astrophysical foregrounds are likely to dominate between few Hz and 10 kHz, relic gravitons with frequencies exceeding 100 kHz represent a potentially uncontaminated signal for the next generation of high-frequency detectors currently under scrutiny.

  17. 3D Reconfigurable NoC Multiprocessor Imaging Interferometer for Space Climate

    Science.gov (United States)

    Dekoulis, George

    2016-07-01

    This paper describes the development of an imaging interferometer for long-term observations of solar activity related events. Heliospheric physics phenomena are responsible for causing irregularities to the ionospheric-magnetospheric plasmasphere. Distinct signatures of these events are captured and studied over long periods of time deducting crucial conclusions about the short-term Space Weather and in the long run about Space Climate. The new prototype features an eight-channel implementation. The available hardware resources permit a 256- channel configuration for accurate beam scanning of the Earth's plasmasphere. A dual-polarization scheme has been implemented for obtaining accurate measurements. The system is based on state-of-the-art three-dimensional reconfigurable logic and exhibits a performance increase in the range of 70% compared to similar instruments in operation. Special circuits allow measurements of the most intense heliospheric physics events to be fully captured and analyzed.

  18. QUBIC, a bolometric interferometer to measure the B-modes of the CMB

    Science.gov (United States)

    Hamilton, J.-C.; Charlassier, R.

    The quest for the B-modes in the CMB polarization is one of the main challenges of modern cosmology as it would allow to give sharp constraints on the inflationary period. One of the main challenges of B modes detection is the treatment of systematic errors. Comparison of observations subject to different systematics is crucial. Interferometers offer such an alternative to imagers. However, to obtain the required sensitivity, a very large number of baselines is needed, which is extremely difficult to achieve with heterodyne interferometry. Bolometric interferometry copes with this problem using a new technique: the interference pattern produced by a few hundred horns is imaged on a bolometer array, and a time modulation of phase shifts insures the separation of visibilities while coherently adding redundant ones. The QUBIC collaboration proposes to build such an instrument.

  19. Study of a Linear Acoustooptic Laser Modulator Based on All-Fibre Sagnac Interferometer

    Directory of Open Access Journals (Sweden)

    G. Trinidad García

    2016-01-01

    Full Text Available The feasibility of polarization-maintaining photonic crystal fibre (PM-PCF strategy for acoustooptic modulation using all-fibre Sagnac interferometer is demonstrated. The principal constraint to apply the strategy is defined by a linear laser acoustooptic modulator (AOM for 1550 nm. The intensity of incident acoustic waves over the PM-PCF loop segment affected the signal interference transmission; here, modulation by birefringence variation around 7.6×10-4±Δni was observed. It is discovered that, through mathematical analysis, two operation points in the spectrum, TSI(λ, operate in a linear region, and expressions for spectral gain and sensibility are also discovered. AOM has a bandwidth from 0.1 Hz to 20 kHz, and its dynamic range is from 0.0 to 43.5 dB.

  20. Uranium hydrogeochemical and stream-sediment reconnaissance of the Mt. Michelson NTMS quadrangle, Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Zinkl, R.J.; Shettel, D.L. Jr.; Langfeldt, S.L.; Hardy, L.C.; D' Andrea, R.F. Jr. (comps.)

    1982-04-01

    This report presents results of a Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the Mt. Michelson NTMS quadrangle, Alaska. In addition to this abbreviated data release, more complete data are available to the public in machine-readable form. These machine-readable data, as well as quarterly or semiannual program progress reports containing further information on the HSSR program in general, or on the Los Alamos National Laboratory (LANL) portion of the program in particular, are available from DOE's Technical Library at its Grand Junction Area Office. Presented in this data release are location data, field analyses, and laboratory analyses of several different sample media. For the sake of brevity, many field site observations have not been included in this volume; these data are, however, available on the magnetic tape. Appendices A and B describe the sample media and summarize the analytical results for each medium. The data have been subdivided by one of the Los Alamos National Laboratory sorting programs of Zinkl and others (1981a) into groups of stream-sediment and lake-sediment samples. For each group which contains a sufficient number of observations, statistical tables, tables of raw data, and 1:1,000,000 scale maps of pertinent elements have been included in this report. Also included are maps showing results of multivariate statistical analyses. Information on the field and analytical procedures used by the Los Alamos National Laboratory during sample collection and analysis may be found in any HSSR data release prepared by the Laboratory and will not be included in this report.

  1. "First Light" for the VLT Interferometer

    Science.gov (United States)

    2001-03-01

    Excellent Fringes From Bright Stars Prove VLTI Concept Summary Following the "First Light" for the fourth of the 8.2-m telescopes of the VLT Observatory on Paranal in September 2000, ESO scientists and engineers have just successfully accomplished the next major step of this large project. On March 17, 2001, "First Fringes" were obtained with the VLT Interferometer (VLTI) - this important event corresponds to the "First Light" for an astronomical telescope. At the VLTI, it occurred when the infrared light from the bright star Sirius was captured by two small telescopes and the two beams were successfully combined in the subterranean Interferometric Laboratory to form the typical pattern of dark and bright lines known as " interferometric fringes ". This proves the success of the robust VLTI concept, in particular of the "Delay Line". On the next night, the VLTI was used to perform a scientific measurement of the angular diameter of another comparatively bright star, Alpha Hydrae ( Alphard ); it was found to be 0.00929±0.00017 arcsec . This corresponds to the angular distance between the two headlights of a car as seen from a distance of approx. 35,000 kilometres. The excellent result was obtained during a series of observations, each lasting 2 minutes, and fully confirming the impressive predicted abilities of the VLTI . This first observation with the VLTI is a monumental technological achievement, especially in terms of accuracy and stability . It crucially depends on the proper combination and functioning of a large number of individual opto-mechnical and electronic elements. This includes the test telescopes that capture the starlight, continuous and extremely precise adjustment of the various mirrors that deflect the light beams as well as the automatic positioning and motion of the Delay Line carriages and, not least, the optimal tuning of the VLT INterferometer Commissionning Instrument (VINCI). These initial observations prove the overall concept for the

  2. Wideband polarization splitter and rotator with large fabrication tolerance and simple fabrication process

    DEFF Research Database (Denmark)

    Ding, Yunhong; Ou, Haiyan; Peucheret, Christophe

    2013-01-01

    We propose and demonstrate a polarization splitter and rotator (PSR) built on a silicon-on-insulator platform. The PSR is constructed with a tapered waveguide followed by a 2×2 multimode interferometer and can be simply fabricated in a single lithography and etching step. A low insertion loss (....5  dB with minimum insertion loss of 0.6 dB) and a low polarization crosstalk (fabrication tolerance (>50  nm) are experimentally demonstrated....

  3. A-train CALIOP and MLS observations of early winter Antarctic polar stratospheric clouds and nitric acid in 2008

    Directory of Open Access Journals (Sweden)

    A. Lambert

    2012-03-01

    Full Text Available A-train Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP and Microwave Limb Sounder (MLS observations are used to investigate the development of polar stratospheric clouds (PSCs and the gas-phase nitric acid distribution in the early 2008 Antarctic winter. Observational evidence of gravity-wave activity is provided by Atmospheric Infrared Sounder (AIRS radiances and infrared spectroscopic detection of nitric acid trihydrate (NAT in PSCs is obtained from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS. Goddard Earth Observing System Data Assimilation System (GEOS-5 DAS analyses are used to derive Lagrangian trajectories and to determine temperature-time histories of air parcels. We use CALIOP backscatter and depolarization measurements to classify PSCs and the MLS measurements to determine the corresponding gas-phase HNO3 as a function of temperature. For liquid PSCs the uptake of HNO3 follows the theoretical equilibrium curve for supercooled ternary solutions (STS, but at temperatures about 1 K lower as determined from GEOS-5. In the presence of solid phase PSCs, above the ice frost-point, the HNO3 depletion occurs over a wider range of temperatures (+2 to −7 K distributed about the NAT equilibrium curve. Rapid gas-phase HNO3 depletion is first seen by MLS from from 23–25 May 2008, consisting of a decrease in the volume mixing ratio from 14 ppbv (parts per billion by volume to 7 ppbv on the 46–32 hPa (hectopascal pressure levels and accompanied by a 2–3 ppbv increase by renitrification at the 68 hPa pressure level. The observed region of depleted HNO3 is substantially smaller than the region bounded by the NAT existence temperature threshold. Temperature-time histories of air parcels demonstrate that the depletion is more clearly correlated with prior exposure to temperatures a few kelvin above the frost-point. From the combined data we infer the presence

  4. Sensitivity curves for spaceborne gravitational wave interferometers

    OpenAIRE

    Larson, Shane L.; Hiscock, William A.; Hellings, Ronald W.

    1999-01-01

    To determine whether particular sources of gravitational radiation will be detectable by a specific gravitational wave detector, it is necessary to know the sensitivity limits of the instrument. These instrumental sensitivities are often depicted (after averaging over source position and polarization) by graphing the minimal values of the gravitational wave amplitude detectable by the instrument versus the frequency of the gravitational wave. This paper describes in detail how to compute such...

  5. Polarized differential-phase laser scanning microscope

    International Nuclear Information System (INIS)

    Chou Chien; Lyu, C.-W.; Peng, L.-C.

    2001-01-01

    A polarized differential-phase laser scanning microscope, which combines a polarized optical heterodyne Mach-Zehnder interferometer and a differential amplifier to scan the topographic image of a surface, is proposed. In the experiment the differential amplifier, which acts as a PM-AM converter, in the experiment, converting phase modulation (PM) into amplitude modulation (AM). Then a novel, to our knowledge, phase demodulator was proposed and implemented for the differential-phase laser scanning microscope. An optical grating (1800 lp/mm) was imaged. The lateral and the depth resolutions of the imaging system were 0.5 μm and 1 nm, respectively. The detection accuracy, which was limited by the reflectivity variation of the test surface, is discussed

  6. ON THE ROTATION OF SUNSPOTS AND THEIR MAGNETIC POLARITY

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Jianchuan; Yang, Zhiliang; Guo, Kaiming [Department of Astronomy, Beijing Normal University, Beijing 100875 (China); Wang, Haimin; Wang, Shuo, E-mail: zlyang@bnu.edu.cn [Space Weather Research Laboratory, New Jersey Institute of Technology, University Heights, Newark, NJ 07102-1982 (United States)

    2016-07-20

    The rotation of sunspots of 2 yr in two different solar cycles is studied with the data from the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory and the Michelson Doppler Imager instrument on board the Solar and Heliospheric Observataory . We choose the α sunspot groups and the relatively large and stable sunspots of complex active regions in our sample. In the year of 2003, the α sunspot groups and the preceding sunspots tend to rotate counterclockwise and have positive magnetic polarity in the northern hemisphere. In the southern hemisphere, the magnetic polarity and rotational tendency of the α sunspot groups and the preceding sunspots are opposite to the northern hemisphere. The average rotational speed of these sunspots in 2003 is about 0.°65 hr{sup 1}. From 2014 January to 2015 February, the α sunspot groups and the preceding sunspots tend to rotate clockwise and have negative magnetic polarity in the northern hemisphere. The patterns of rotation and magnetic polarity of the southern hemisphere are also opposite to those of the northern hemisphere. The average rotational speed of these sunspots in 2014/2015 is about 1.°49 hr{sup 1}. The rotation of the relatively large and stable preceding sunspots and that of the α sunspot groups located in the same hemisphere have opposite rotational direction in 2003 and 2014/2015.

  7. Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics

    Science.gov (United States)

    Kimble, H. J.; Levin, Yuri; Matsko, Andrey B.; Thorne, Kip S.; Vyatchanin, Sergey P.

    2002-01-01

    The LIGO-II gravitational-wave interferometers (ca. 2006-2008) are designed to have sensitivities near the standard quantum limit (SQL) in the vicinity of 100 Hz. This paper describes and analyzes possible designs for subsequent LIGO-III interferometers that can beat the SQL. These designs are identical to a conventional broad band interferometer (without signal recycling), except for new input and/or output optics. Three designs are analyzed: (i) a squeezed-input interferometer (conceived by Unruh based on earlier work of Caves) in which squeezed vacuum with frequency-dependent (FD) squeeze angle is injected into the interferometer's dark port; (ii) a variational-output interferometer (conceived in a different form by Vyatchanin, Matsko and Zubova), in which homodyne detection with FD homodyne phase is performed on the output light; and (iii) a squeezed-variational interferometer with squeezed input and FD-homodyne output. It is shown that the FD squeezed-input light can be produced by sending ordinary squeezed light through two successive Fabry-Pérot filter cavities before injection into the interferometer, and FD-homodyne detection can be achieved by sending the output light through two filter cavities before ordinary homodyne detection. With anticipated technology (power squeeze factor e-2R=0.1 for input squeezed vacuum and net fractional loss of signal power in arm cavities and output optical train ɛ*=0.01) and using an input laser power Io in units of that required to reach the SQL (the planned LIGO-II power, ISQL), the three types of interferometer could beat the amplitude SQL at 100 Hz by the following amounts μ≡(Sh)/(SSQLh) and with the following corresponding increase V=1/μ3 in the volume of the universe that can be searched for a given noncosmological source: Squeezed input-μ~=(e-2R)~=0.3 and V~=1/0.33~=30 using Io/ISQL=1. Variational-output-μ~=ɛ1/4*~=0.3 and V~=30 but only if the optics can handle a ten times larger power: Io/ISQL~=1/(ɛ*)=10

  8. Conversion of conventional gravitational-wave interferometers into quantum nondemolition interferometers by modifying their input and/or output optics

    International Nuclear Information System (INIS)

    Kimble, H.J.; Levin, Yuri; Thorne, Kip S.; Matsko, Andrey B.; Vyatchanin, Sergey P.

    2002-01-01

    The LIGO-II gravitational-wave interferometers (ca. 2006-2008) are designed to have sensitivities near the standard quantum limit (SQL) in the vicinity of 100 Hz. This paper describes and analyzes possible designs for subsequent LIGO-III interferometers that can beat the SQL. These designs are identical to a conventional broad band interferometer (without signal recycling), except for new input and/or output optics. Three designs are analyzed: (i) a squeezed-input interferometer (conceived by Unruh based on earlier work of Caves) in which squeezed vacuum with frequency-dependent (FD) squeeze angle is injected into the interferometer's dark port; (ii) a variational-output interferometer (conceived in a different form by Vyatchanin, Matsko and Zubova), in which homodyne detection with FD homodyne phase is performed on the output light; and (iii) a squeezed-variational interferometer with squeezed input and FD-homodyne output. It is shown that the FD squeezed-input light can be produced by sending ordinary squeezed light through two successive Fabry-Perot filter cavities before injection into the interferometer, and FD-homodyne detection can be achieved by sending the output light through two filter cavities before ordinary homodyne detection. With anticipated technology (power squeeze factor e -2R =0.1 for input squeezed vacuum and net fractional loss of signal power in arm cavities and output optical train ε * =0.01) and using an input laser power I o in units of that required to reach the SQL (the planned LIGO-II power, I SQL ), the three types of interferometer could beat the amplitude SQL at 100 Hz by the following amounts μ≡√(S h )/√(S h SQL ) and with the following corresponding increase V=1/μ 3 in the volume of the universe that can be searched for a given noncosmological source: Squeezed input--μ≅√(e -2R )≅0.3 and V≅1/0.3 3 ≅30 using I o /I SQL =1. Variational-output--μ≅ε * 1/4 ≅0.3 and V≅30 but only if the optics can handle a ten

  9. QUBIC: The QU bolometric interferometer for cosmology

    Science.gov (United States)

    Qubic Collaboration; Battistelli, E.; Baú, A.; Bennett, D.; Bergé, L.; Bernard, J.-Ph.; de Bernardis, P.; Bordier, G.; Bounab, A.; Bréelle, É.; Bunn, E. F.; Calvo, M.; Charlassier, R.; Collin, S.; Coppolecchia, A.; Cruciani, A.; Curran, G.; de Petris, M.; Dumoulin, L.; Gault, A.; Gervasi, M.; Ghribi, A.; Giard, M.; Giordano, C.; Giraud-Héraud, Y.; Gradziel, M.; Guglielmi, L.; Hamilton, J.-Ch.; Haynes, V.; Kaplan, J.; Korotkov, A.; Landé, J.; Maffei, B.; Maiello, M.; Malu, S.; Marnieros, S.; Martino, J.; Masi, S.; Murphy, A.; Nati, F.; O'Sullivan, C.; Pajot, F.; Passerini, A.; Peterzen, S.; Piacentini, F.; Piat, M.; Piccirillo, L.; Pisano, G.; Polenta, G.; Prêle, D.; Romano, D.; Rosset, C.; Salatino, M.; Schillaci, A.; Sironi, G.; Sordini, R.; Spinelli, S.; Tartari, A.; Timbie, P.; Tucker, G.; Vibert, L.; Voisin, F.; Watson, R. A.; Zannoni, M.; QUBIC Collaboration

    2011-04-01

    One of the major challenges of modern cosmology is the detection of B-mode polarization anisotropies in the Cosmic Microwave Background. These originate from tensor fluctuations of the metric produced during the inflationary phase. Their detection would therefore constitute a major step towards understanding the primordial Universe. The expected level of these anisotropies is however so small that it requires a new generation of instruments with high sensitivity and extremely good control of systematic effects.We propose the QUBIC instrument based on the novel concept of bolometric interferometry, bringing together the sensitivity advantages of bolometric detectors with the systematics effects advantages of interferometry.The instrument will directly observe the sky through an array of entry horns whose signals will be combined together using an optical combiner. The whole set-up is located inside a cryostat. Polarization modulation will be achieved using a rotating half-wave plate and the images of the interference fringes will be formed on two focal planes (separated by a polarizing grid) tiled with bolometers.We show that QUBIC can be considered as a synthetic imager, exactly similar to a usual imager but with a synthesized beam formed by the array of entry horns. Scanning the sky provides an additional modulation of the signal and improve the sky coverage shape. The usual techniques of map-making and power spectrum estimation can then be applied. We show that the sensitivity of such an instrument is comparable with that of an imager with the same number of horns. We anticipate a low level of beam-related systematics thanks to the fact that the synthesized beam is determined by the location of the primary horns. Other systematics should be under good control thanks to an autocalibration technique, specific to our concept, that will permit the accurate determination of most of the instrumental parameters that would otherwise lead to systematics.

  10. Operational Experience with the Navy Prototype Optical Interferometer

    Science.gov (United States)

    White, Nathaniel M.; Mozurkewich, David; Hutter, Donald J.; Benson, James A.; Hummel, Christian A.; Clark, James H., III

    2002-12-01

    A review of operational procedures and requirements evolving at the Navy Prototype Optical Interferometer (NPOI) provides some useful insights for the automation, maintenance and operation of large optical interferometers even as construction and instrument development continues. Automation is essential for efficient, single operator observing. It is important to integrate ease of operation and maintenance into the instrument design from the start. In final form, the Navy Prototype Optical Interferometer, NPOI, will use six portable siderostats for imaging stars and narrow angle astrometry of multiple stars as well as four fixed siderostats designed for all sky astrometry. Currently all four astrometric siderostats and two transportable siderostats are operational. All six beams from the siderostats now in use have been combined coherently to form images of multiple stars at milliseconds of arc resolution.

  11. 30-lens interferometer for high energy x-rays

    International Nuclear Information System (INIS)

    Lyubomirskiy, M.; Snigireva, I.; Vaughan, G.; Kohn, V.; Kuznetsov, S.; Yunkin, V.; Snigirev, A.

    2016-01-01

    We report a hard X-ray multilens interferometer consisting of 30 parallel compound refractive lenses. Under coherent illumination each CRL creates a diffraction limited focal spot - secondary source. An overlapping of coherent beams from these sources resulting in the interference pattern which has a rich longitudinal structure in accordance with the Talbot imaging formalism. The proposed interferometer was experimentally tested at ID11 ESRF beamline for the photon energies 32 keV and 65 keV. The fundamental and fractional Talbot images were recorded with the high resolution CCD camera. An effective source size in the order of 15 µm was determined from the first Talbot image proving that the multilens interferometer can be used as a high resolution beam diagnostic tool.

  12. Micro wishbone interferometer for Fourier transform infrared spectrometry

    International Nuclear Information System (INIS)

    Lee, Young-Min; Toda, Masaya; Ono, Takahito; Esashi, Masayoshi

    2011-01-01

    A miniature wishbone-type Si interferometer with electrically actuated rotary comb drive actuators is designed and fabricated to apply a Fourier transform infrared (FTIR) spectrometer. Corner cube mirrors are mounted on the end of the Si interferometer that is formed on a glass substrate. The total size of the interferometer is approximately 8 mm × 8 mm. The corner cube mirrors with sharp edges with a size of approximately 1 × 1 × 0.5 mm 3 are fabricated using an indentation technique. The rotation angle of rotary comb drive actuators is approximately 11° with an applied voltage of 180 V. Hereby, the maximum optical path difference of approximately 2640 µm is achieved, which corresponds to the highest resolution of ∼4 cm −1 as a spectrometer

  13. Optimum design of a microwave interferometer for plasma density measurement

    International Nuclear Information System (INIS)

    Lindberg, L.; Eriksson, A.

    1980-11-01

    Theoretical and practical problems arising in the application of microwave interferometry to density measurements on transient plasmas are discussed. The conditions for unambiquous measurements in a density range as wide as possible are analyzed. It is shown that the initial zero adjustment of the interferometer bridge recommended in many text books is the worst possible choice of initial condition when the aim is high initial sensitivity at low densities. The analytic expressions needed for unambiquous evaluation of any phase shift from a few degrees to several times π (counting of fringes) are derived. The practical design of the interferometer circuit and its inherent error sources due to reflexions and non-ideal component properties are discussed. The results are applied to an interferometer operating at 80 GHz used on a pulsed plasma experiment. The minimum measurable phase shift is 2deg and the range of linear densities that have been measured is = 1 . 10 16 - 3 . 10 18 m -2

  14. The Virgo gravitational wave interferometer: status and perspectives

    CERN Multimedia

    CERN. Geneva

    2018-01-01

    The first recording of a signal from a binary neutron star system by the Advanced LIGO and Advanced Virgo interferometers, and the observation of its remnants by telescopes in all bands of the electromagnetic spectrum, marked the beginning of multimessenger astronomy with gravitational waves. This followed the detection of gravitational wave signals by the LIGO interferometers in 2015, which started the detailed study of highly curved space time. These achievements come after decades of work spent understanding how to measure the tiny space time strain (h ~ 10-21) carried by gravitational waves. In the future, detectors will able to extract much more precise information from these events, or record signals from fainter sources, providing a new view of the Universe. After a presentation of the Virgo interferometer, the main results obtained from binary black hole and neutron star detection are reviewed. The focus will then shift on the perspective offered by a further reduction of noise in ground based interf...

  15. Parallel Wavefront Analysis for a 4D Interferometer

    Science.gov (United States)

    Rao, Shanti R.

    2011-01-01

    This software provides a programming interface for automating data collection with a PhaseCam interferometer from 4D Technology, and distributing the image-processing algorithm across a cluster of general-purpose computers. Multiple instances of 4Sight (4D Technology s proprietary software) run on a networked cluster of computers. Each connects to a single server (the controller) and waits for instructions. The controller directs the interferometer to several images, then assigns each image to a different computer for processing. When the image processing is finished, the server directs one of the computers to collate and combine the processed images, saving the resulting measurement in a file on a disk. The available software captures approximately 100 images and analyzes them immediately. This software separates the capture and analysis processes, so that analysis can be done at a different time and faster by running the algorithm in parallel across several processors. The PhaseCam family of interferometers can measure an optical system in milliseconds, but it takes many seconds to process the data so that it is usable. In characterizing an adaptive optics system, like the next generation of astronomical observatories, thousands of measurements are required, and the processing time quickly becomes excessive. A programming interface distributes data processing for a PhaseCam interferometer across a Windows computing cluster. A scriptable controller program coordinates data acquisition from the interferometer, storage on networked hard disks, and parallel processing. Idle time of the interferometer is minimized. This architecture is implemented in Python and JavaScript, and may be altered to fit a customer s needs.

  16. Local readout enhancement for detuned signal-recycling interferometers

    International Nuclear Information System (INIS)

    Rehbein, Henning; Mueller-Ebhardt, Helge; Schnabel, Roman; Danzmann, Karsten; Somiya, Kentaro; Chen Yanbei; Li Chao

    2007-01-01

    High power detuned signal-recycling interferometers currently planned for second-generation interferometric gravitational-wave detectors (for example Advanced LIGO) are characterized by two resonances in the detection band, an optical resonance and an optomechanical resonance which is upshifted from the suspension pendulum frequency due to the so-called optical-spring effect. The detector's sensitivity is enhanced around these two resonances. However, at frequencies below the optomechanical resonance frequency, the sensitivity of such interferometers is significantly lower than non-optical-spring configurations with comparable circulating power; such a drawback can also compromise high-frequency sensitivity, when an optimization is performed on the overall sensitivity of the interferometer to a class of sources. In this paper, we clarify the reason for such a low sensitivity, and propose a way to fix this problem. Motivated by the optical-bar scheme of Braginsky, Gorodetsky, and Khalili, we propose to add a local readout scheme which measures the motion of the arm-cavity front mirror, which at low frequencies moves together with the arm-cavity end mirror, under the influence of gravitational waves. This scheme improves the low-frequency quantum-noise-limited sensitivity of optical-spring interferometers significantly and can be considered as an incorporation of the optical-bar scheme into currently planned second-generation interferometers. On the other hand it can be regarded as an extension of the optical-bar scheme. Taking compact binary inspiral signals as an example, we illustrate how this scheme can be used to improve the sensitivity of the planned Advanced LIGO interferometer, in various scenarios, using a realistic classical-noise budget. We also discuss how this scheme can be implemented in Advanced LIGO with relative ease

  17. A Fiber Optic PD Sensor Using a Balanced Sagnac Interferometer and an EDFA-Based DOP Tunable Fiber Ring Laser

    Science.gov (United States)

    Wang, Lutang; Fang, Nian; Wu, Chunxu; Qin, Haijuan; Huang, Zhaoming

    2014-01-01

    A novel fiber-optic acoustic sensor using an erbium-doped fiber amplifier (EDFA)-based fiber ring laser and a balanced Sagnac interferometer for acoustic sensing of the partial discharge (PD) in power transformers is proposed and demonstrated. As a technical background, an experimental investigation on how the variations of the fiber birefringence affect the sensor performances was carried out, and the results are discussed. The operation principles are described, and the relevant formulas are derived. The analytical results show that an EDFA-based fiber ring laser operating in chaotic mode can provide a degree of polarization (DOP) tunable light beam for effectively suppressing polarization fading noises. The balanced Sagnac interferometer can eliminate command intensity noises and enhance the signal-to-noise ratio (SNR). Furthermore, it inherently operates at the quadrature point of the response curve without any active stabilizations. Several experiments are conducted for evaluating the performances of the sensor system, as well as for investigating the ability of the detection of high-frequency acoustic emission signals. The experimental results demonstrate that the DOP of the laser beam can be continuously tuned from 0.2% to 100%, and the power fluctuation in the whole DOP tuning range is less than 0.05 dBm. A high-frequency response up to 300 kHz is reached, and the high sensing sensitivity for detections of weak corona discharges, as well as partial discharges also is verified. PMID:24824371

  18. Absolute sensitivity of phase measurement in an SU(1,1) type interferometer

    Science.gov (United States)

    Du, Wei; Jia, Jun; Chen, J. F.; Ou, Z. Y.; Zhang, Weiping

    2018-03-01

    Absolute sensitivity is measured for the phase measurement in an SU(1,1) type interferometer and the results are compared to that of a Mach-Zehnder interferometer operated under the condition of the same intra-interferometer intensity. The interferometer is phase locked to a point with the largest quantum noise cancellation, and a simulated phase modulation is added in one arm of SU(1,1) interferometer. Both the signal and noise level are estimated at the same frequency range, and we obtain 3dB improvement in sensitivity for the SU(1,1) interferometer over the Mach-Zehnder interferometer. Our results demonstrate a direct phase estimation, and may pave the way for practical applications of nonlinear interferometer.

  19. Applications of the lateral shearing interferometer in measurement of synchrotron radiation optical elements

    International Nuclear Information System (INIS)

    Liu, Wu-ming; Takacs, P.Z.; Siddons, D.P.

    1987-11-01

    The use of a single plate shearing, or Murty, interferometer for measuring the surface quality of several optical elements is reviewed and several results are given. The principle of the Murty interferometer is also explained

  20. Absolute sensitivity of phase measurement in an SU(1,1) type interferometer.

    Science.gov (United States)

    Du, Wei; Jia, Jun; Chen, J F; Ou, Z Y; Zhang, Weiping

    2018-03-01

    Absolute sensitivity is measured for the phase measurement in an SU(1,1) type interferometer, and the results are compared to that of a Mach-Zehnder interferometer operated under the condition of the same intra-interferometer intensity. The interferometer is phase locked to a point with the largest quantum noise cancellation, and a simulated phase modulation is added in one arm of the SU(1,1) interferometer. Both the signal and noise level are estimated at the same frequency range, and we obtained 3 dB improvement in sensitivity for the SU(1,1) interferometer over the Mach-Zehnder interferometer. Our results demonstrate a direct phase estimation and may pave the way for practical applications of a nonlinear interferometer.

  1. Study on avalanche photodiode influence on heterodyne laser interferometer linearity

    Science.gov (United States)

    Budzyn, Grzegorz; Podzorny, Tomasz

    2016-06-01

    In the paper we analyze factors reducing the possible accuracy of the heterodyne laser interferometers. The analysis is performed for the avalanche-photodiode input stages but is in main points valid also for stages with other type of photodetectors. Instrumental error originating from optical, electronic and digital signal processing factors is taken into consideration. We stress factors which are critical and those which can be neglected at certain accuracy requirements. In the work we prove that it is possible to reduce errors of the laser instrument below 1 nm point for multiaxial APD based interferometers by precise control of incident optical power and the temperature of the photodiode.

  2. An intensity interferometer for soft x-rays

    Energy Technology Data Exchange (ETDEWEB)

    Yang, L.; McNulty, I.; Gluskin, E.

    1994-07-15

    We designed and built an intensity interferometer to characterize the spatial coherence of a soft x-ray undulator beam. The beam source size and shape can be determined from the measured coherence function. The instrument is 400 mm long and is mounted on a standard 204-mm diameter flange. This compact design is readily adaptable to other beamlines with sources of sufficient spectral brightness. Details of the interferometer design and performance are presented. We anticipate that when this technique is mature, it will provide a useful diagnostic for high brightness x-ray beams.

  3. Rational choices for the wavelengths of a two color interferometer

    International Nuclear Information System (INIS)

    Jobes, F.C.

    1995-07-01

    If in a two color interferometer for plasma density measurements, the two wavelengths are chosen to have a ratio that is a rational number, and if the signals from each of the wavelengths are multiplied in frequency by the appropriate integer of the rational number and then heterodyned together, the resultant signal will have all effects of component motion nulled out. A phase measurement of this signal will have only plasma density information in it. With CO 2 lasers, it is possible to find suitable wavelength pairs which are close enough to rational numbers to produce an improvement of about 100 in density resolution, compared to standard two color interferometers

  4. Electrooptic modulation in thin film barium titanate plasmonic interferometers.

    Science.gov (United States)

    Dicken, Matthew J; Sweatlock, Luke A; Pacifici, Domenico; Lezec, Henri J; Bhattacharya, Kaushik; Atwater, Harry A

    2008-11-01

    We demonstrate control of the surface plasmon polariton wavevector in an active metal-dielectric plasmonic interferometer by utilizing electrooptic barium titanate as the dielectric layer. Arrays of subwavelength interferometers were fabricated from pairs of parallel slits milled in silver on barium titanate thin films. Plasmon-mediated transmission of incident light through the subwavelength slits is modulated by an external voltage applied across the barium titanate thin film. Transmitted light modulation is ascribed to two effects, electrically induced domain switching and electrooptic modulation of the barium titanate index.

  5. Noise-Immune Conjugate Large-Area Atom Interferometers

    Science.gov (United States)

    Chiow, Sheng-Wey; Herrmann, Sven; Chu, Steven; Müller, Holger

    2009-07-01

    We present a pair of simultaneous conjugate Ramsey-Bordé atom interferometers using large (20ℏk)-momentum transfer beam splitters, where ℏk is the photon momentum. Simultaneous operation allows for common-mode rejection of vibrational noise. This allows us to surpass the enclosed space-time area of previous interferometers with a splitting of 20ℏk by a factor of 2500. Using a splitting of 10ℏk, we demonstrate a 3.4 ppb resolution in the measurement of the fine structure constant. Examples for applications in tests of fundamental laws of physics are given.

  6. An active interferometer-stabilization scheme with linear phase control

    DEFF Research Database (Denmark)

    Vardhan Krishnamachari, Vishnu; Andresen, Esben Ravn; Potma, Eric Olaf

    2006-01-01

    We report a simple and robust computer-based active interferometer stabilization scheme which does not require modulation of the interfering beams and relies on an error signal which is linearly related to the optical path difference. In this setup, a non-collinearly propagating reference laser...... beam stabilizes the interference output of the laser light propagating collinearly through the interferometer. This stabilization scheme enables adjustable phase control with 20 ms switching times in the range from 0.02π radians to 6π radians at 632.8 nm....

  7. Detectability of periodic gravitational waves by initial interferometers

    International Nuclear Information System (INIS)

    Owen, Benjamin J

    2006-01-01

    I review three recent theoretical developments in neutron star physics predicting that rotating neutron stars could be very strong emitters of periodic gravitational waves. These imply a small but nonzero chance that ground-based interferometers could detect their first periodic signal in the next few years rather than after advanced upgrades. They also imply that upper limits will become astrophysically interesting before advanced upgrades. I discuss the implications for near-future searches and for the astrophysical payoffs of proposed small upgrades to initial interferometers

  8. Measurement of quantum states in a neutron interferometer

    International Nuclear Information System (INIS)

    Baron, M.

    2005-03-01

    The characterization of quantum states of neutrons in an interferometer is the main topic of this thesis. All related experiments were performed at the instrument S18 of the Institut Laue Langevin (ILL) in Grenoble, France. This instrument is dedicated to neutron interferometry as well as Ultra Small Angle Neutron Scattering (USANS). In principle, the properties of the quantum states entering the interferometer are mainly affected by the neutron-guide (super mirror guide H25) and the perfect crystal monochromator. A coherence volume can be assigned to these states where phase relations are fixed and interference occurs. The coherence behaviour is strongly anisotropic, since only transversal momentum distribution is influenced by dynamical diffraction. The longitudinal and vertical directions remain unaffected. The neutron interferometer is a unique tool for probing the coherence properties. It allows us to split a neutron beam in two coherent paths, separated by several centimeters and to recombine them afterwards. Due to introduction of a longitudinal or a vertical phase shift, respectively, it was possible to measure the related coherence function, which is determined by the auto-correlation function of the wave-function. By inserting a phase shifter in one of the two beam paths, the initial state is converted to a new state by superposition with the phase shifted state. This causes a change in the momentum distribution, which can be measured behind the interferometer with an additional crystal. With this analyzer-crystal the smoothed out interference properties at high interference orders can be restored behind the interferometer, if proper spectral filtering is applied. To measure the spatial distribution of this newly created state, a 2-loop-interferometer is needed. This kind of interferometer permits to create any state in the first loop and analyze it in the second loop. Therefore, it is possible for the first time to measure the spatial and the momentum

  9. Results from a multi aperture Fizeau interferometer ground testbed: demonstrator for a future space-based interferometer

    Science.gov (United States)

    Baccichet, Nicola; Caillat, Amandine; Rakotonimbahy, Eddy; Dohlen, Kjetil; Savini, Giorgio; Marcos, Michel

    2016-08-01

    In the framework of the European FP7-FISICA (Far Infrared Space Interferometer Critical Assessment) program, we developed a miniaturized version of the hyper-telescope to demonstrate multi-aperture interferometry on ground. This setup would be ultimately integrated into a CubeSat platform, therefore providing the first real demonstrator of a multi aperture Fizeau interferometer in space. In this paper, we describe the optical design of the ground testbed and the data processing pipeline implemented to reconstruct the object image from interferometric data. As a scientific application, we measured the Sun diameter by fitting a limb-darkening model to our data. Finally, we present the design of a CubeSat platform carrying this miniature Fizeau interferometer, which could be used to monitor the Sun diameter over a long in-orbit period.

  10. Strategic Polarization.

    Science.gov (United States)

    Kalai, Adam; Kalai, Ehud

    2001-08-01

    In joint decision making, similarly minded people may take opposite positions. Consider the example of a marriage in which one spouse gives generously to charity while the other donates nothing. Such "polarization" may misrepresent what is, in actuality, a small discrepancy in preferences. It may be that the donating spouse would like to see 10% of their combined income go to charity each year, while the apparently frugal spouse would like to see 8% donated. A simple game-theoretic analysis suggests that the spouses will end up donating 10% and 0%, respectively. By generalizing this argument to a larger class of games, we provide strategic justification for polarization in many situations such as debates, shared living accommodations, and disciplining children. In some of these examples, an arbitrarily small disagreement in preferences leads to an arbitrarily large loss in utility for all participants. Such small disagreements may also destabilize what, from game-theoretic point of view, is a very stable equilibrium. Copyright 2001 Academic Press.

  11. On open electromagnetic resonators: relation between interferometers and resonators

    International Nuclear Information System (INIS)

    Manenkov, Aleksandr A; Bykov, Vladimir P; Kuleshov, N V

    2010-01-01

    The physical difference between the concepts 'Fabry-Perot interferometer' and 'open resonator' is discussed. It is shown that the use of the term 'Fabry-Perot resonator' for open laser resonators is incorrect both from the historical viewpoint and from the viewpoint of the physical meaning of the processes occurring in these resonators. (laser beams and resonators)

  12. Finite mass beam splitter in high power interferometers

    International Nuclear Information System (INIS)

    Harms, Jan; Schnabel, Roman; Danzmann, Karsten

    2004-01-01

    The beam splitter in high-power interferometers is subject to significant radiation-pressure fluctuations. As a consequence, the phase relations which appear in the beam splitter coupling equations oscillate and phase modulation fields are generated which add to the reflected fields. In this paper, the transfer function of the various input fields impinging on the beam splitter from all four ports onto the output field is presented including radiation-pressure effects. We apply the general solution of the coupling equations to evaluate the input-output relations of the dual-recycled laser-interferometer topology of the gravitational-wave detector GEO 600 and the power-recycling, signal-extraction topology of advanced LIGO. We show that the input-output relation exhibits a bright-port dark-port coupling. This mechanism is responsible for bright port contributions to the noise density of the output field and technical laser noise is expected to decrease the interferometer's sensitivity at low frequencies. It is shown quantitatively that the issue of technical laser noise is unimportant in this context if the interferometer contains arm cavities

  13. Drift correction in a multichannel integrated optical Young interferometer

    NARCIS (Netherlands)

    Ymeti, Aurel; Greve, Jan; Lambeck, Paul; Wijn, Robert Raimond; Heideman, Rene; Kanger, Johannes S.

    2005-01-01

    We demonstrate that in a sensor based on a multichannel Young interferometer, the phase information obtained for different pairs of channels can be used to correct the long-term instability (drift) due to temperature differences between measuring and reference channels, the drift in the alignment of

  14. Improving the performances of current optical interferometers & future designs

    Science.gov (United States)

    Arnold, L.; Le Coroller, H.; Surdej, J.

    2014-04-01

    The number of astrophysical studies making use of interferometers has steadily increased during the past 15 years. Nevertheless, the performances of interferometers are still limited: their sensitivity does not exceed magnitude V=12, and their imaging capability could yet be improved by increasing the number of telescopes/sub-apertures. In the context of the ELTs, it is not certain how future interferometry projects will be financed. However, interferometry remains the only way to observe compact astrophysical objects at very high angular resolution (integrated optic, pupil densifier, etc.); fringe tracking systems; laser telemetry applied to interferometry; heterodyne interferometry; progress in heterodyne detection using new technologies (laser comb, time propagation technologies, etc.); progress in image reconstruction techniques; progress in nulling interferometry; and important science cases that could benefit from progress in interferometry (report of observations at the limit of current interferometers). Nearly 50 oral presentations have been delivered, followed by very lively discussions which eventually emerged with the proposition to organize the "Planet Formation Interferometer/Imager" (PFI) project. The present proceedings reflect most of the highlights of this international colloquium.

  15. Switching behaviour of nonlinear Mach–Zehnder interferometer ...

    Indian Academy of Sciences (India)

    Switching behaviour of nonlinear Mach–Zehnder interferometer based on photonic crystal geometry. MAN MOHAN GUPTA and S MEDHEKAR. ∗. Centre for Applied Physics, Central University of Jharkhand, Ranchi 835 205, India. ∗. Corresponding author. E-mail: smedhekarbit@gmail.com. MS received 23 April 2013; ...

  16. Measurements from a novel interferometer for EUVL mirror substrates

    NARCIS (Netherlands)

    Krieg, M.L.; Braat, J.J.M.

    2005-01-01

    A previously reported interferometer without intermediate optics is used to perform measurements on an aspherical extreme ultraviolet lithography mirror substrate. Acousto-optic modulation based phase shifting is used together with a novel phase retrieval algorithm to retrieve the phase distribution

  17. Modelling of Extrinsic Fiber Optic Sagnac Ultrasound Interferometer ...

    African Journals Online (AJOL)

    Ultrasonic waves are used extensively in nondestructive testing both for characterization of material properties, in this paper, we describe a fiber optic sensor suitable for detection of ultrasonic waves. This sensor is based on an extrinsic fiber optic sagnac interferometer. The proposed sensor model can act as a conventional ...

  18. Realization of an optical interferometer based on holographic optics ...

    Indian Academy of Sciences (India)

    The paper describes a simple and cost effective method for the realization of an optical interferometer based on holographic optics, which use minimal bulk optical components. The optical arrangement in the proposed method involves a very simple alignment procedure and inexpensive holographic recording material is ...

  19. Precessing deuteron polarization

    International Nuclear Information System (INIS)

    Sitnik, I.M.; Volkov, V.I.; Kirillov, D.A.; Piskunov, N.M.; Plis, Yu.A.

    2002-01-01

    The feasibility of the acceleration in the Nuclotron of deuterons polarized in the horizontal plane is considered. This horizontal polarization is named precessing polarization. The effects of the main magnetic field and synchrotron oscillations are included. The precessing polarization is supposed to be used in studying the polarization parameters of the elastic dp back-scattering and other experiments

  20. Fabry-Perot interferometer utilized for displacement measurement in a large measuring range

    International Nuclear Information System (INIS)

    Wang, Yung-Cheng; Shyu, Lih-Horng; Chang, Chung-Ping

    2010-01-01

    The optical configuration of a Fabry-Perot interferometer is uncomplicated. This has already been applied in different measurement systems. For the displacement measurement with the Fabry-Perot interferometer, the result is significantly influenced by the tilt angles of the measurement mirror in the interferometer. Hence, only for the rather small measuring range, the Fabry-Perot interferometer is available. The goal of this investigation is to enhance the measuring range of Fabry-Perot interferometer by compensating the tilt angles. To verify the measuring characteristic of the self-developed Fabry-Perot interferometer, some comparison measurements with a reference standard have been performed. The maximum deviation of comparison experiments is less than 0.3 μm in the traveling range of 30 mm. The experimental results show that the Fabry-Perot interferometer is highly stable, insensitive to environment effects, and can meet the measuring requirement of the submicrometer order.

  1. Kilohertz generation of high contrast polarization states for visible femtosecond pulses via phase-locked acousto-optic pulse shapers

    Energy Technology Data Exchange (ETDEWEB)

    Seiler, Hélène; Walsh, Brenna; Palato, Samuel; Kambhampati, Patanjali, E-mail: pat.kambhampati@mcgill.ca [Department of Chemistry, McGill University, Montreal, Quebec H3A 0B8 (Canada); Thai, Alexandre; Forget, Nicolas [Fastlite, 1900 route des Crêtes, 06560 Valbonne (France); Crozatier, Vincent [Fastlite, Centre Scientifique d' Orsay, Bât.503, Plateau du Moulon, BP 45 Orsay (France)

    2015-09-14

    We present a detailed analysis of a setup capable of arbitrary amplitude, phase, and polarization shaping of broadband visible femtosecond pulses at 1 kHz via a pair of actively phase stabilized acousto-optic programmable dispersive filters arranged in a Mach-Zehnder interferometer geometry. The setup features phase stability values around λ/225 at 580 nm as well as degrees of polarization of at least 0.9 for any polarization state. Both numbers are important metrics to evaluate a setup's potential for applications based on polarization-shaped femtosecond pulses, such as fully coherent multi-dimensional electronic spectroscopy.

  2. No surgery required: the future of feline sterilization: An overview of the Michelson Prize & Grants in Reproductive Biology.

    Science.gov (United States)

    Johnston, Shirley; Rhodes, Linda

    2015-09-01

    For many years, researchers have been studying reproduction of cats and dogs, including approaches to non-surgical sterilization, but scant funding has been available for this work. Recognizing the need to fund research and to attract researchers from the biomedical community to apply their expertise to this area, the Michelson Prize & Grants (MPG) in Reproductive Biology program was founded. Since 2009, it has funded 34 research projects in seven countries toward discovery of a safe single-administration lifetime non-surgical sterilant in male and female cats and dogs. The goal of the MPG program is the reduction or elimination of the approximately 2.7 million deaths of healthy shelter cats and dogs in the US every year. The successful product is expected to be a single-dose injectable product approved by the US Food and Drug Administration as a veterinary prescription item. The most optimistic prediction is that such a product will reach the hands of practicing veterinarians within the next decade. Active research is in progress using approaches such as immunocontraception with a single-administration vaccine against gonadotropin releasing hormone (GnRH). Long-term therapy with GnRH agonists such as deslorelin administered in controlled-release devices is also being studied. Other scientists are targeting cells in the brain or gonads with cytotoxins, such as are used in cancer chemotherapy. Gene therapy expressing proteins that suppress reproduction and gene silencing of peptides essential to reproduction are further avenues of research. Findings are available at www.michelsonprizeandgrants.org/michelson-grants/research-findings. © The Author(s) 2015.

  3. Polare maskuliniteter

    Directory of Open Access Journals (Sweden)

    Marit Anne Hauan

    2012-05-01

    Full Text Available In this paper my aim is to read and understand the journal of Gerrit de Veer from the last journey of William Barents to the Arctic Regions in 1596 and the journal of captain Junge on his hunting trip from Tromsø to Svalbard in 1834.It is nearly 240 years between this to voyages. The first journal is known as the earliest report from the arctic era. Gerrit de Veer adds instructive copper engravings to his text and give us insight in the crews meeting with this new land. Captain Junges journal is found together with his dead crew in a house in a fjord nearby Ny-Ålesund and has no drawings, but word. Both of these journals may be read as sources of the knowledge and understanding of the polar region. They might also unveil the ideas of how to deal with and survive under the challenges that is given. In addition one can ask if the sources can tell us more about how men describe their challenges. Can the way they expressed themselves in the journals give us an understanding of masculinity? And not least help us to create good questions of the change in the ideas of masculinities which is said to follow the change in understanding of the wilderness.

  4. Modeling Gravitational Waves to Test GR Dispersion and Polarization

    Science.gov (United States)

    Tso, Rhondale; Chen, Yanbei; Isi, Maximilliano

    2017-01-01

    Given continued observation runs from the Laser Interferometer Gravitational-Wave Observatory Scientific Collaboration, further gravitational wave (GW) events will provide added constraints on beyond-general relativity (b-GR) theories. One approach, independent of the GW generation mechanism at the source, is to look at modification to the GW dispersion and propagation, which can accumulate over vast distances. Generic modification of GW propagation can also, in certain b-GR theories, impact the polarization content of GWs. To this end, a comprehensive approach to testing the dispersion and polarization content is developed by modeling anisotropic deformations to the waveforms' phase, along with birefringence effects and corollary consequences for b-GR polarizations, i.e., breathing, vector, and longitudinal modes. Such an approach can be mapped to specific theories like Lorentz violation, amplitude birefringence in Chern-Simons, and provide hints at additional theories to be included. An overview of data analysis routines to be implemented will also be discussed.

  5. Multimode simulations of a wide field of view double-Fourier far-infrared spatio-spectral interferometer

    Science.gov (United States)

    Bracken, Colm P.; Lightfoot, John; O'Sullivan, Creidhe; Murphy, J. Anthony; Donohoe, Anthony; Savini, Giorgio; Juanola-Parramon, Roser; The Fisica Consortium, On Behalf Of

    2018-01-01

    In the absence of 50-m class space-based observatories, subarcsecond astronomy spanning the full far-infrared wavelength range will require space-based long-baseline interferometry. The long baselines of up to tens of meters are necessary to achieve subarcsecond resolution demanded by science goals. Also, practical observing times command a field of view toward an arcminute (1‧) or so, not achievable with a single on-axis coherent detector. This paper is concerned with an application of an end-to-end instrument simulator PyFIInS, developed as part of the FISICA project under funding from the European Commission's seventh Framework Programme for Research and Technological Development (FP7). Predicted results of wide field of view spatio-spectral interferometry through simulations of a long-baseline, double-Fourier, far-infrared interferometer concept are presented and analyzed. It is shown how such an interferometer, illuminated by a multimode detector can recover a large field of view at subarcsecond angular resolution, resulting in similar image quality as that achieved by illuminating the system with an array of coherent detectors. Through careful analysis, the importance of accounting for the correct number of higher-order optical modes is demonstrated, as well as accounting for both orthogonal polarizations. Given that it is very difficult to manufacture waveguide and feed structures at sub-mm wavelengths, the larger multimode design is recommended over the array of smaller single mode detectors. A brief note is provided in the conclusion of this paper addressing a more elegant solution to modeling far-infrared interferometers, which holds promise for improving the computational efficiency of the simulations presented here.

  6. Processing of Signals from Fiber Bragg Gratings Using Unbalanced Interferometers

    Science.gov (United States)

    Adamovsky, Grigory; Juergens, Jeff; Floyd, Bertram

    2005-01-01

    Fiber Bragg gratings (FBG) have become preferred sensory structures in fiber optic sensing system. High sensitivity, embedability, and multiplexing capabilities make FBGs superior to other sensor configurations. The main feature of FBGs is that they respond in the wavelength domain with the wavelength of the returned signal as the indicator of the measured parameter. The wavelength is then converted to optical intensity by a photodetector to detect corresponding changes in intensity. This wavelength-to-intensity conversion is a crucial part in any FBG-based sensing system. Among the various types of wavelength-to-intensity converters, unbalanced interferometers are especially attractive because of their small weight and volume, lack of moving parts, easy integration, and good stability. In this paper we investigate the applicability of unbalanced interferometers to analyze signals reflected from Bragg gratings. Analytical and experimental data are presented.

  7. Behavior of electronic interferometers in the nonlinear regime.

    Science.gov (United States)

    Neder, I; Ginossar, E

    2008-05-16

    We investigate theoretically the behavior of the current oscillations in an electronic Mach-Zehnder interferometer (MZI) as a function of its source bias. Recently, the MZI visibility data showed an unexplained lobe pattern with a peculiar phase rigidity. Moreover, the effect did not depend on the MZI path length difference. We argue that these effects may be a new many-body manifestation of particle-wave duality in quantum mechanics. When biasing the interferometer sources so much that multiple electrons are on each arm at any instant in time, quantum shot noise (a particle phenomena) must affect the interference pattern of the electrons that create it. A solution to the interaction Hamiltonian presented here shows that the interference visibility has a lobe pattern with applied bias that has a period proportional to the average path length and independent of the path length difference, together with a phase rigidity.

  8. Report on the set-up of a holographic interferometer

    International Nuclear Information System (INIS)

    Koster, J.N.

    1977-10-01

    Holographic interferometry is well suited for visualizing temperature, density, pressure and concentration fields in transparent fluids. The holographic real-time interferometer allows a continuous observation of stationary and instationary flow processes. After the explanation of the measuring technique, the problems arising during the interferometer set-up as well as the necessary adjusting operations are described. For heat transfer problems new possibilities for the application of holographic interferometry are revealed. Convection in boxes, temperature fields around heated or cooled bodies, concentration and diffusion processes in two phase-flows, mixtures and solutions as well as melting and freezing processes may be investigated. On the basis of particular examples some applications are presented. (orig.) [de

  9. Application principle of Sagnac interferometer in optical fiber gyroscopic system

    Directory of Open Access Journals (Sweden)

    Michal Márton

    2016-12-01

    Full Text Available Gyroscopes are widely used in various applications for decades, but the idea to construct a gyroscopic system, able to exploit the properties of the gyroscope and also monitor the status information arose later. The expansion of the optical fiber technology also touch the subject, with the development of such interferometer measuring means to explore a variety of non-optical parameters led to the idea of the application of this knowledge to the already known systems. This optical system has been constructed on a fundamental principle of the gyroscope, but we can’t talk about pure gyroscope, because there is an optical interferometer that uses its features. So it was named as fiber optic gyroscopes. In this article we describe fiber optic gyro system, design and testing experimental measurements with this gyroscope system.

  10. A microwave interferometer for small and tenuous plasma density measurements

    International Nuclear Information System (INIS)

    Tudisco, O.; Falcetta, C.; De Angelis, R.; Florean, M.; Neri, C.; Mazzotta, C.; Pollastrone, F.; Rocchi, G.; Tuccillo, A. A.; Lucca Fabris, A.; Manente, M.; Ferri, F.; Tasinato, L.; Trezzolani, F.; Accatino, L.; Pavarin, D.; Selmo, A.

    2013-01-01

    The non-intrusive density measurement of the thin plasma produced by a mini-helicon space thruster (HPH.com project) is a challenge, due to the broad density range (between 10 16 m −3 and 10 19 m −3 ) and the small size of the plasma source (2 cm of diameter). A microwave interferometer has been developed for this purpose. Due to the small size of plasma, the probing beam wavelength must be small (λ= 4 mm), thus a very high sensitivity interferometer is required in order to observe the lower density values. A low noise digital phase detector with a phase noise of 0.02° has been used, corresponding to a density of 0.5 × 10 16 m −3 .

  11. QUBIC: A Fizeau Interferometer Targeting Primordial B-Modes

    Science.gov (United States)

    Tartari, A.; Aumont, J.; Banfi, S.; Battaglia, P.; Battistelli, E. S.; Baù, A.; Bélier, B.; Bennett, D.; Bergé, L.; Bernard, J. Ph.; Bersanelli, M.; Bigot-Sazy, M. A.; Bleurvacq, N.; Bordier, G.; Brossard, J.; Bunn, E. F.; Buzi, D.; Cammilleri, D.; Cavaliere, F.; Chanial, P.; Chapron, C.; Coppolecchia, A.; D'Alessandro, G.; De Bernardis, P.; Decourcelle, T.; Del Torto, F.; De Petris, M.; Dumoulin, L.; Franceschet, C.; Gault, A.; Gayer, D.; Gervasi, M.; Ghribi, A.; Giard, M.; Giraud-Héraud, Y.; Gradziel, M.; Grandsire, L.; Hamilton, J. Ch.; Haynes, V.; Holtzer, N.; Kaplan, J.; Korotkov, A.; Lande, J.; Lowitz, A.; Maffei, B.; Marnieros, S.; Martino, J.; Masi, S.; McCulloch, M.; Melhuish, S.; Mennella, A.; Montier, L.; Murphy, A.; Néel, D.; Ng, M. W.; O'Sullivan, C.; Pajot, F.; Passerini, A.; Perbost, C.; Piacentini, F.; Piat, M.; Piccirillo, L.; Pisano, G.; Prêle, D.; Rambaud, D.; Rigaut, O.; Salatino, M.; Schillaci, A.; Scully, S.; Stolpovskiy, M. M.; Timbie, P.; Tucker, G.; Viganò, D.; Voisin, F.; Watson, B.; Zannoni, M.

    2016-08-01

    Q and U Bolometric Interferometer for Cosmology (QUBIC) is a Fizeau interferometer sensitive to linear polarisation, to be deployed at the Antarctic station of Dome C. This experiment in its final configuration will be operated at 97, 150 and 220 GHz and is intended to target CMB primordial B-modes in a multipole window 20QUBIC interferometric configuration can be considered equivalent to a pupil-plane filtered imaging system. In this context, we show how our instrument can be self-calibrated. Finally, we conclude by showing an overview of the first dual-band module (150/220 GHz), which will serve also as a demonstrator for the subsequent units, and review the technological choices we made for each subsystem, with particular emphasis on the detection system.

  12. QUBIC: the Q&U Bolometric Interferometer for Cosmology

    Science.gov (United States)

    Piat, M.; Battistelli, E.; Baù, A.; Bennett, D.; Bergé, L.; Bernard, J.-P.; de Bernardis, P.; Bigot-Sazy, M.-A.; Bordier, G.; Bounab, A.; Bréelle, E.; Bunn, E. F.; Calvo, M.; Charlassier, R.; Collin, S.; Cruciani, A.; Curran, G.; Dumoulin, L.; Gault, A.; Gervasi, M.; Ghribi, A.; Giard, M.; Giordano, C.; Giraud-Héraud, Y.; Gradziel, M.; Guglielmi, L.; Hamilton, J.-C.; Haynes, V.; Kaplan, J.; Korotkov, A.; Landé, J.; Maffei, B.; Maiello, M.; Malu, S.; Marnieros, S.; Martino, J.; Masi, S.; Montier, L.; Murphy, A.; Nati, F.; O'Sullivan, C.; Pajot, F.; Parisel, C.; Passerini, A.; Peterzen, S.; Piacentini, F.; Piccirillo, L.; Pisano, G.; Polenta, G.; Prêle, D.; Romano, D.; Rosset, C.; Salatino, M.; Schillaci, A.; Sironi, G.; Sordini, R.; Spinelli, S.; Tartari, A.; Timbie, P.; Tucker, G.; Vibert, L.; Voisin, F.; Watson, R. A.; Zannoni, M.

    2012-06-01

    The primordial B-mode polarisation of the Cosmic Microwave Background is the imprints of the gravitational wave background generated by inflation. Observing the B-mode is up to now the most direct way to constrain the physics of the primordial Universe, especially inflation. To detect these B-modes, high sensitivity is required as well as an exquisite control of systematics effects. To comply with these requirements, we propose a new instrument called QUBIC (Q and U Bolometric Interferometer for Cosmology) based on bolometric interferometry. The control of systematics is obtained with a close-packed interferometer while bolometers cooled to very low temperature allow for high sensitivity. We present the architecture of this new instrument, the status of the project and the self-calibration technique which allows accurate measurement of the instrumental systematic effects.

  13. Towards a FPGA-controlled deep phase modulation interferometer

    Science.gov (United States)

    Terán, M.; Martín, V.; Gesa, Ll; Mateos, I.; Gibert, F.; Karnesis, N.; Ramos-Castro, J.; Schwarze, T. S.; Gerberding, O.; Heinzel, G.; Guzmán, F.; Nofrarias, M.

    2015-05-01

    Deep phase modulation interferometry was proposed as a method to enhance homodyne interferometers to work over many fringes. In this scheme, a sinusoidal phase modulation is applied in one arm while the demodulation takes place as a post-processing step. In this contribution we report on the development to implement this scheme in a fiber coupled interferometer controlled by means of a FPGA, which includes a LEON3 soft-core processor. The latter acts as a CPU and executes a custom made application to communicate with a host PC. In contrast to usual FPGA-based designs, this implementation allows a real-time fine tuning of the parameters involved in the setup, from the control to the post-processing parameters.

  14. A Fiber Interferometer for the Magnetized Shock Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Christian [Los Alamos National Laboratory

    2012-08-30

    The Magnetized Shock Experiment (MSX) at Los Alamos National Laboratory requires remote diagnostics of plasma density. Laser interferometry can be used to determine the line-integrated density of the plasma. A multi-chord heterodyne fiber optic Mach-Zehnder interferometer is being assembled and integrated into the experiment. The advantage of the fiber coupling is that many different view chords can be easily obtained by simply moving transmit and receive fiber couplers. Several such fiber sets will be implemented to provide a time history of line-averaged density for several chords at once. The multiple chord data can then be Abel inverted to provide radially resolved spatial profiles of density. We describe the design and execution of this multiple fiber interferometer.

  15. Measurement of Local Gravity via a Cold Atom Interferometer

    International Nuclear Information System (INIS)

    Zhou Lin; Xiong Zong-Yuan; Yang Wei; Tang Biao; Peng Wen-Cui; Wang Yi-Bo; Xu Peng; Wang Jin; Zhan Ming-Sheng

    2011-01-01

    We demonstrate a precision measurement of local gravity acceleration g in Wuhan by a compact cold atom interferometer. The atom interferometer is in vertical Mach—Zehnder configuration realized using a π/2 - π - π/2 Raman pulse sequence. Cold atoms were prepared in a magneto-optical trap, launched upward to form an atom fountain, and then coherently manipulated to interfere by stimulated Raman transition. Population signal vs Raman laser phase was recorded as interference fringes, and the local gravity was deduced from the interference signal. We have obtained a resolution of 7 × 10 −9 g after an integration time of 236s under the best vibrational environment conditions. The absolute g value was derived from the chirp rate with a difference of 1.5 × 10 −7 g compared to the gravity reference value. The tidal phenomenon was observed by continuously monitoring the local gravity over 123 h. (atomic and molecular physics)

  16. Abstract passive interferometers with applications to conservative logic

    Science.gov (United States)

    Qian, Lei; Caulfield, H. John

    2005-08-01

    Interferometers with two complex inputs and two complex outputs can be viewed as state machines over a 4-D hyperspace, where the relationship between outputs and inputs are transition functions. In the simplest case, there is full symmetry between inputs and between outputs. The nonzero inputs, the origin and the outputs define a 2-D plane in the 4-D space. The interferometer rotates the input vectors by [pi]/4 in the hyperspace. Cascading the symmetric units defines a simple Hamiltonian path of length 8 in a 2-D subspace. Breaking symmetry by introducing a relative phase shift in the input leads to more complex Hamiltonian paths that can require all four dimensions to describe. The special symmetry breaking caused by a phase shift in one of the input arms leads to outputs which, upon detection, are recognizable as Boolean and other simple operations on properly encrypted and interpreted inputs!

  17. Parametric Instability in Advanced Laser Interferometer Gravitational Wave Detectors

    International Nuclear Information System (INIS)

    Ju, L; Grass, S; Zhao, C; Degallaix, J; Blair, D G

    2006-01-01

    High frequency parametric instabilities in optical cavities are radiation pressure induced interactions between test mass mechanical modes and cavity optical modes. The parametric gain depends on the cavity power and the quality factor of the test mass internal modes (usually in ultrasonic frequency range), as well as the overlap integral for the mechanical and optical modes. In advanced laser interferometers which require high optical power and very low acoustic loss test masses, parametric instabilities could prevent interferometer operation if not suppressed. Here we review the problem of parametric instabilities in advanced detector configurations for different combinations of sapphire and fused silica test masses, and compare three methods for control or suppression of parametric instabilities-thermal tuning, surface damping and active feedback

  18. Femto-second synchronisation with a waveguide interferometer

    Science.gov (United States)

    Dexter, A. C.; Smith, S. J.; Woolley, B. J.; Grudiev, A.

    2018-03-01

    CERN's compact linear collider CLIC requires crab cavities on opposing linacs to rotate bunches of particles into alignment at the interaction point (IP). These cavities are located approximately 25 metres either side of the IP. The luminosity target requires synchronisation of their RF phases to better than 5 fs r.m.s. This is to be achieved by powering both cavities from one high power RF source, splitting the power and delivering it along two waveguide paths that are controlled to be identical in length to within a micrometre. The waveguide will be operated as an interferometer. A high power phase shifter for adjusting path lengths has been successfully developed and operated in an interferometer. The synchronisation target has been achieved in a low power prototype system.

  19. 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.

  20. A new dispersion interferometer on HL-2A

    Science.gov (United States)

    Wang, H. X.; Zhou, Y.; Li, Y.; Li, Y. G.; Yi, J.; Deng, Z. C.; Gao, Z.; Wu, T. Y.; Yin, Z. J.; Akiyama, T.

    2017-10-01

    In order to avoid a fringe jump caused by high plasma density and pellet injection [Y. Zhou et al., Rev. Sci. Instrum. 87, 11E107 (2016)], a new CO2 dispersion interferometer is designed and commissioned on HL-2A for average line-density measurement and density feedback control. The second harmonic technology in this system eliminates the phase shift caused by mechanical vibration. Signals are processed by a digital phase comparator and can be monitored in real time. A series of experiments are conducted to study the characteristics of the system such as a second harmonic coefficient and long-term stability. The resolution of density measurement is less than 8 × 1017/m3, and the experiment result on HL-2A demonstrates the interferometer's capability to track plasma density evolution with rapid change. The system also shows good stability against mechanical vibrations.