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Journal articles on the topic 'Interferometerek'
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1
Pan, Xiaopei, Shri Kulkarni, Michael Shao, and M. Mark Colavita. "Narrow-Angle and Wide-Angle Astrometry via Long Baseline Optical/Infrared Interferometers." Symposium - International Astronomical Union 166 (1995): 13–18. http://dx.doi.org/10.1017/s0074180900227769.
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Long baseline optical/infrared interferometers, such as the Mark III Stellar Interferometer1 on Mt. Wilson and the ASEPS-0 Testbed Interferometer2 on Palomar Mountain, California, have good capabilities for narrow-angle and wide-angle astrometry with very high precision. Using the Mark III Interferometer many spectroscopic binaries became “visual” for the first time. The measurement accuracy of angular separation is 0.2 mas, the smallest separation measured between two components is 2 mas, the maximum magnitude difference is 4 mag, and the smallest semimajor axis is 4 mas. Such high angular resolution and dynamic range have been used to determine stellar masses with precision of 2% and differential stellar luminosities to better than 0.05 mag for separations of less than 0.″2. For some binary stars, not only have the systems been resolved, but also the diameter of the primary component has been determined, yielding direct measurements of stellar effective temperature with high accuracy. For parallax determination, the precision is 1 mas or better and is unaffected by interstellar extinction. For wide-angle astrometry with the Mark III interferometer, the observation results yielded average formal 1σ errors for FK5 stars of about 10 mas. Presently a new infrared interferometer, the ASEPS-0 Testbed Interferometer on Palomar Mountain is under construction, and is being optimized to perform high accuracy narrow-angle astrometry using long baseline observations at 2.2 μm, with phase referencing for increased sensitivity. The goal is to demonstrate differential astrometric accuracies of 0.06–0.1 mas3 in order to allow for detection of extra-solar planets in the near future.
2
Miyata, Kaoru, Hidekazu Oozeki, Hideyuki Nakagawa, Hiroki Masuda, and Hisayoshi Sakai. "Two-Wavelength Laser Interferometer System Which Reduces the Uncertainty Caused by the Fluctuation of the Refractive Index of Air." International Journal of Automation Technology 5, no. 2 (2011): 126–31. http://dx.doi.org/10.20965/ijat.2011.p0126.
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Laser interferometers are widely used to measure highly sensitive length and displacement, e.g., in which refractive index fluctuations of air adversely affect measurement accuracy. To compensate for these effects, the two-wavelength interferometer studied has not yet proved practical in industrial use. We studied the interferometer’s performance and practicality, using uncertainty analysis to extract its features. Based on our results, we developed a two-wavelengthMichelson interferometer with wavelengths of 1064 nm and 532 nm. It was calibrated and evaluated using a highprecision laser interferometer whose optical path was in a vacuum. Results confirmed measurement accuracy of 100 nm/50 mm (k=2) under unstable air conditions - superior to a traditional laser interferometer.
3
Rudenko, Valentin, Svetlana Andrusenko, Daniil Krichevskiy, and Gevorg Manucharyan. "GW Interferometer Euro-Asian Network: Detection Characteristics for Signals of Known Shape." Universe 6, no. 9 (2020): 140. http://dx.doi.org/10.3390/universe6090140.
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In this paper, we estimate efficiency of a conceivable Euro-Asian network of gravitational wave (GW) interferometers that might be realized having in mind a plan of construction of third generation interferometer in Novosibirsk region. Subsequently, some network would be composed, including four GW detectors. Among them there are the already active interferometers VIRGO (Italy) and KAGRA (Japan), Indian interferometer under construction—LIGO India and the interferometer in Siberia mentioned above. The quality of network in question is considered on the base of typical numerical criteria of efficiency for detecting GW signals of known structure—radiation of relativistic binary coalescence.
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Mamadjanov, A. I., A. Turgunov, and M. Umaraliyev. "INVESTIGATE THE DEPENDENCE OF THE LIGHT REFRACTIVE INDEX OF AN IDEAL GAS ON ITS PRESSURE USING INTERFEROMETERS." International Journal of Advanced Research 8, no. 12 (2020): 272–79. http://dx.doi.org/10.21474/ijar01/12147.
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This article analyzes the working principle of the Michelson interferometer and the ability to measure some physical quantities. Using the Michelson Interferometer, the ability to detect not only the light wave but also the full wavelength of radio waves was analyzed. Using the Mach-Zehnder and Michelson interferometers, it was determined that the refractive index of air depends on its pressure. The results obtained in two different interferometers were compared comparatively in the graphs.
5
Vu, Toan-Thang, Thanh-Tung Vu, Van-Doanh Tran, Thanh-Dong Nguyen, and Ngoc-Tam Bui. "A New Method to Verify the Measurement Speed and Accuracy of Frequency Modulated Interferometers." Applied Sciences 11, no. 13 (2021): 5787. http://dx.doi.org/10.3390/app11135787.
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The measurement speed and measurement accuracy of a displacement measuring interferometer are key parameters. To verify these parameters, a fast and high-accuracy motion is required. However, the displacement induced by a mechanical actuator generates disadvantageous features, such as slow motion, hysteresis, distortion, and vibration. This paper proposes a new method for a nonmechanical high-speed motion using an electro-optic modulator (EOM). The method is based on the principle that all displacement measuring interferometers measure the phase change to calculate the displacement. This means that the EOM can be used to accurately generate phase change rather than a mechanical actuator. The proposed method is then validated by placing the EOM into an arm of a frequency modulation interferometer. By using two lock-in amplifiers, the phase change in an EOM and, hence, the corresponding virtual displacement could be measured by the interferometer. The measurement showed that the system could achieve a displacement at 20 kHz, a speed of 6.08 mm/s, and a displacement noise level < 100 pm//√Hz above 2 kHz. The proposed virtual displacement can be applied to determine both the measurement speed and accuracy of displacement measuring interferometers, such as homodyne interferometers, heterodyne interferometers, and frequency modulated interferometers.
6
Polavarapu, Prasad L. "Double Polarization Modulation Interferometry." Applied Spectroscopy 51, no. 6 (1997): 770–77. http://dx.doi.org/10.1366/0003702971941197.
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The concepts of a double polarization modulation interferometer and the experimental measurements verifying these concepts are presented. This interferometer serves as an analytical tool for the characterization of polarization modulation devices. In addition, for polarization difference measurements this interferometer offers four times better efficiency over widely used amplitude-division interferometers.
7
Vu, Thanh Tung, Hong Hai Hoang, Toan Thang Vu, and Ngoc Tam Bui. "A Displacement Measuring Interferometer Based on a Frequency-Locked Laser Diode with High Modulation Frequency." Applied Sciences 10, no. 8 (2020): 2693. http://dx.doi.org/10.3390/app10082693.
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Laser interferometers can achieve a nanometer-order uncertainty of measurements when their frequencies are locked to the reference frequencies of the atom or molecule transitions. There are three types of displacement-measuring interferometers: homodyne, heterodyne, and frequency modulation (FM) interferometers. Among these types of interferometer, the FM interferometer has many advantageous features. The interference signal is a series of time-dependent harmonics of modulation frequency, so the phase shift can be detected accurately using the synchronous detection method. Moreover, the FM interferometer is the most suitable for combination with a frequency-locked laser because both require frequency modulation. In previous research, low modulation frequencies at some tens of kHz have been used to lock the frequency of laser diodes (LDs). The low modulation frequency for the laser source means that the maximum measurement speed of the FM interferometers is limited. This paper proposes a novel contribution regarding the application of a high-frequency modulation for an LD to improve both the frequency stability of the laser source and the measurement speed of the FM interferometer. The frequency of the LD was locked to an I2 hyperfine component at 1 MHz modulation frequency. A high bandwidth lock-in amplifier was utilized to detect the saturated absorption signals of the I2 hyperfine structure and induce the signal to lock the frequency of the LD. The locked LD was then used for an FM displacement measuring interferometer. Moreover, a suitable modulation amplitude that affected the signal-to-noise ratio of both the I2 absorption signal and the harmonic intensity of the interference signal was determined. In order to verify the measurement resolution of the proposed interferometer, the displacement induced by a piezo electric actuator was concurrently measured by the interferometer and a capacitive sensor. The difference of the displacement results was less than 20 nm. To evaluate the measurement speed, the interferometer was used to measure the axial error of a high-speed spindle at 500 rpm. The main conclusion of this study is that a stable displacement interferometer with high accuracy and a high measurement speed can be achieved using an LD frequency locked to an I2 hyperfine transition at a high modulation frequency.
8
Liu, X., Y. Gao, Suet To, and Wing Bun Lee. "Anti-Vibration Characteristics of a Lateral Shear Interferometer for On-Machine Surface Measurement." Key Engineering Materials 295-296 (October 2005): 411–16. http://dx.doi.org/10.4028/www.scientific.net/kem.295-296.411.
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Lateral shear interferometers have large measurement range and good anti-disturbance ability. They have similar accuracy compared with the reference based interferometers. Based on a specially designed shear generator, a new lateral shear interferometer is proposed. The new system has a complete common optical path and a simple mechanism. The optical model of the interferometer is presented and the anti-vibration characteristics are analyzed. To validate its antivibration ability for on-machine surface measurement, experimental tests have been conducted and results presented.
9
de Haan, Victor. "Asymmetric Mach–Zehnder fiber interferometer test of the anisotropy of the speed of light." Canadian Journal of Physics 87, no. 10 (2009): 1073–78. http://dx.doi.org/10.1139/p09-080.
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Two optical fiber Mach–Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer with a length of 2 m optical fiber in each arm with the main direction of the arms parallel to each other. A path (length 175 mm) filled with atmospheric air is inserted in one arm. Another interferometer with a length of 2 m optical fiber in each parallel arm acts as a control. In one of the arms in each interferometer, 1 m of fiber was wound around a ring made of piezo material enabling the control of the length of the arms by means of a voltage. The influence of rotation of the interferometers at the Earth's surface on the observed phase differences was determined. For one interferometer (with the air path) it was found that the phase difference depends on the azimuth of the interferometer. For the other one no relevant dependence on the azimuth has been measured.
10
Khokhlov, Dmitri. "Quantum non-demolition measurement in the interferometer." International Journal of Physical Research 9, no. 1 (2020): 7. http://dx.doi.org/10.14419/ijpr.v9i1.31243.
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The schemes of the arrangements based on the Mach-Zehnder interferometer and the interferometer with two polarizing beam splitters are considered. The interferometers in both the schemes are equipped with some devices, creating a Kerr medium, to perform the quantum non-demolition measurement of a single photon. Such a device gives which way information of the photon while preserving the work of the interferometer.
11
Kawashima, Natsumi, Tomoya Kitazaki, Kosuke Nogo, Akira Nishiyama, Kenji Wada, and Ichiro Ishimaru. "Superimposing interferogram method using a multi-slit array to enhance sensitivity and interference definition of spatial-phase-shift interferometers." Optical Review 27, no. 6 (2020): 530–41. http://dx.doi.org/10.1007/s10043-020-00626-4.
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Abstract We propose a superimposing interferogram method to enhance the sensitivity and interference definition of spatial-phase-shift interferometers. The proposed method uses a multi-slit array as a redesigned field stop for the spatial-phase-shift interferometer. The widths of the apertural and blocked areas correspond to half the wavelength of the fringe pattern on the imaging plane and determine the wavelength that improves the interference definition while eliminating those wavelengths that worsen it, thus improving the interference definition of the interferogram. Additionally, to improve the interferometer’s sensitivity, several apertural areas were aligned to increase the amount of incident light. We performed spectroscopic measurements and confirmed improvements in both the sensitivity and the interference definition using a prototype of a bean-sized mid-infrared spectroscopic imager based on a one-shot Fourier spectroscope and a prototype multi-slit array. Although mid-infrared light is absorbed well by water and its intensity is thus weak for detection using the array sensors of cameras, mid-infrared spectroscopic imagers that incorporate our proposed method can be used for biomedical measurements of samples containing water.
12
Samoylenko, O., O. Adamenko, and V. Kalynichenko. "The Method and the Results of the Direct Comparison of the Laser Interferometers Renishaw Xl-80." Metrology and instruments, no. 4 (August 30, 2018): 15–21. http://dx.doi.org/10.33955/2307-2180(4)2018.15-21.
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The method of the direct comparison of the laser interferometers and method processing of the interferometry measurement results by the least square method (LSM) is present. The additive part of the measurement error for each pair of the interferometers is evaluated and the multiplicative part of the measurement error for each interferometer is evaluated too by LSM. Uncertainty by A tape by LSM is evaluated for all parameters. Results of the comparison of the three interferometers are presented.
13
Pongrac, Blaž, Denis Đonlagic, Matej Njegovec, and Dušan Gleich. "THz Signal Generator Using a Single DFB Laser Diode and the Unbalanced Optical Fiber Interferometer." Sensors 20, no. 17 (2020): 4862. http://dx.doi.org/10.3390/s20174862.
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This paper presents a frequency-modulated optical signal generator in the THz band. The proposed method is based on a fast optical frequency sweep of a single narrowband laser diode used together with an optical fiber interferometer. The optical frequency sweep using a single laser diode is achieved by generating short current pulses with a high amplitude, which are driving the laser diode. Theoretical analysis showed that the modulation frequency could be changed by the optical path difference of the interferometer or optical frequency sweep rate of a laser diode. The efficiency of the optical signal generator with Michelson and Fabry–Perot interferometers is theoretically analyzed and experimentally evaluated for three different scenarios. Interferometers with different optical path differences and a fixed optical frequency sweep rate were used in the first scenario. Different optical frequency sweep rates and fixed optical path differences of the interferometers were used in the second scenario. This paper presents a method for optical chirp generation using a programmable current pulse waveform, which drives a laser diode to achieve nonlinear optical sweep with a fixed optical path difference of the interferometer. The experimental results showed that the proposed signals could be generated within a microwave (1–30 GHz) and THz band (0.1–0.3 THz).
14
Zhang, Yanqi, Adam S. Hines, Guillermo Valdes, and Felipe Guzman. "Investigation and Mitigation of Noise Contributions in a Compact Heterodyne Interferometer." Sensors 21, no. 17 (2021): 5788. http://dx.doi.org/10.3390/s21175788.
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We present a noise estimation and subtraction algorithm capable of increasing the sensitivity of heterodyne laser interferometers by one order of magnitude. The heterodyne interferometer is specially designed for dynamic measurements of a test mass in the application of sub-Hz inertial sensing. A noise floor of 3.31×10−11m/Hz at 100 mHz is achieved after applying our noise subtraction algorithm to a benchtop prototype interferometer that showed a noise level of 2.76×10−10m/Hz at 100 mHz when tested in vacuum at levels of 3×10−5 Torr. Based on the previous results, we investigated noise estimation and subtraction techniques of non-linear optical pathlength noise, laser frequency noise, and temperature fluctuations in heterodyne laser interferometers. For each noise source, we identified its contribution and removed it from the measurement by linear fitting or a spectral analysis algorithm. The noise correction algorithm we present in this article can be generally applied to heterodyne laser interferometers.
15
de Haan, Victor. "Mach–Zehnder fiber interferometer test of the anisotropy of the speed of light." Canadian Journal of Physics 87, no. 9 (2009): 999–1008. http://dx.doi.org/10.1139/p09-062.
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Two optical fiber Mach–Zehnder interferometers were constructed in an environment with a temperature stabilization of better than 1 mK per day. One interferometer consisted of a length of 12 m optical fiber in each arm, with the main direction of the arms perpendicular to each other while the other consisted of a length of 2 m optical fiber in each arm, where the main direction of the arms are parallel, and served as a control. In each arm, 1 m of fiber was wound around a ring made of piezo material, enabling the control of the length of the arms by means of an applied voltage. The influence of the temperature on the optical phase difference between the interferometer arms was measured. The temperature change induced a variation of the interaction region of the optical fiber couplers. Further, the influence of rotation of the interferometers at the Earth surface on the observed phase differences was determined. For one interferometer (with the long and perpendicular arms), it was found that the phase difference depends on the azimuth of the interferometer. For the other one (with the short and parallel arms), no relevant dependence on the azimuth has been measured.
16
Liu, Hengyi, Shi Qiu, and Wansheng Dong. "The Three-Dimensional Locating of VHF Broadband Lightning Interferometers." Atmosphere 9, no. 8 (2018): 317. http://dx.doi.org/10.3390/atmos9080317.
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VHF (Very High Frequency) lightning interferometers can locate and observe lightning discharges with a high time resolution. Especially the appearance of continuous interferometers makes the 2-D location of interferometers further improve in time resolution and completeness. However, there is uncertainty in the conclusion obtained by simply analyzing the 2-D locating information. Without the support of other 3-D total lightning locating networks, the 2-station interferometer becomes an option to obtain 3-D information. This paper introduces a 3-D lightning location method of a 2-station broadband interferometer, which uses the theodolite wind measurement method for reference, and gives the simulation results of the location accuracy. Finally, using the multi-baseline continuous 2-D locating method and the 3-D locating method, the locating results of one intra-cloud flash and the statistical results of the initiation heights of 61 cloud-to-ground flashes and 80 intra-cloud flashes are given. The results show that the two-station interferometer has high observation accuracy on both sides of the connection between the two sites. The locating accuracy will deteriorate as the distance between the radiation source and the two stations increases or the height decreases. The actual locating results are similar to those of the existing VHF TDOA (Time Difference of Arrival) lightning locating network.
17
SHAWHAN, PETER S. "THE SEARCH FOR GRAVITATIONAL WAVES WITH LIGO: STATUS AND PLANS." International Journal of Modern Physics A 16, supp01c (2001): 1028–30. http://dx.doi.org/10.1142/s0217751x01008795.
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The Laser Interferometer Gravitational-Wave Observatory (LIGO) project has been designed to detect gravitional waves directly using large interferometers at two widely separated sites. Construction of the observatory facilities is now complete, and commissioning of the interferometers is well underway. Following a series of engineering runs, science running is scheduled to begin in 2002. A parallel effort is underway to develop improved detector to achieve dramatically greater sensitivity in the future.
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Rodríguez, Luis F. "SpS1-Instrumentation for sub-millimeter spectroscopy." Proceedings of the International Astronomical Union 5, H15 (2009): 527–28. http://dx.doi.org/10.1017/s1743921310010525.
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The fields of millimeter and sub-millimeter interferometry have been developing for more than 30 years. At millimeter wavelengths the most important interferometers are the Combined Array for Research in Millimeter-Wave Astronomy (CARMA), the Plateau de Bure Interferometer (PdBI), and the Nobeyama Millimeter Array (NMA). At sub-millimeter wavelenghts, the most powerful interferometer is the SubMillimeter Array (SMA, for a detailed description, see Ho et al. 2004).
19
Englert, Berthold-Georg, Marian O. Scully, Georg Süssmann, and Herbert Walther. "Surrealistic Bohm Trajectories." Zeitschrift für Naturforschung A 47, no. 12 (1992): 1175–86. http://dx.doi.org/10.1515/zna-1992-1201.
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Abstract A study of interferometers with one-bit which-way detectors demonstrates that the trajectories, which David Bohm invented in his attempt at a realistic interpretation of quantum mechanics, are in fact surrealistic, because they may be macroscopically at variance with the observed track of the particle. We consider a two-slit interferometer and an incomplete Stern-Gerlach interferometer, and propose an experimentum crucis based on the latter.
20
Fiori, Irene, Federico Paoletti, Maria Concetta Tringali, et al. "The Hunt for Environmental Noise in Virgo during the Third Observing Run." Galaxies 8, no. 4 (2020): 82. http://dx.doi.org/10.3390/galaxies8040082.
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The first twenty years of operation of gravitational-wave interferometers have shown that these detectors are affected by physical disturbances from the surrounding environment. These are seismic, acoustic, or electromagnetic disturbances that are mainly produced by the experiment infrastructure itself. Ambient noise can limit the interferometer sensitivity or potentially generate transients of non-astrophysical origin. Between 1 April 2019 and 27 March 2020, the network of second generation interferometers—LIGO, Virgo and GEO—performed the third joined observing run, named O3, searching for gravitational signals from the deep universe. A thorough investigation has been done on each detector before and during data taking in order to optimize its sensitivity and duty cycle. In this paper, we first revisit typical sources of environmental noise and their coupling paths, and we then describe investigation methods and tools. Finally, we illustrate applications of these methods in the hunt for environmental noise at the Virgo interferometer during the O3 run and its preparation phase. In particular, we highlight investigation techniques that might be useful for the next observing runs and the future generation of terrestrial interferometers.
21
Ferreri, Alessandro, Matteo Santandrea, Michael Stefszky, et al. "Spectrally multimode integrated SU(1,1) interferometer." Quantum 5 (May 27, 2021): 461. http://dx.doi.org/10.22331/q-2021-05-27-461.
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Nonlinear SU(1,1) interferometers are fruitful and promising tools for spectral engineering and precise measurements with phase sensitivity below the classical bound. Such interferometers have been successfully realized in bulk and fiber-based configurations. However, rapidly developing integrated technologies provide higher efficiencies, smaller footprints, and pave the way to quantum-enhanced on-chip interferometry. In this work, we theoretically realised an integrated architecture of the multimode SU(1,1) interferometer which can be applied to various integrated platforms. The presented interferometer includes a polarization converter between two photon sources and utilizes a continuous-wave (CW) pump. Based on the potassium titanyl phosphate (KTP) platform, we show that this configuration results in almost perfect destructive interference at the output and supersensitivity regions below the classical limit. In addition, we discuss the fundamental difference between single-mode and highly multimode SU(1,1) interferometers in the properties of phase sensitivity and its limits. Finally, we explore how to improve the phase sensitivity by filtering the output radiation and using different seeding states in different modes with various detection strategies.
22
Vivekanand, M., and S. R. Kulkarni. "Self-noise in interferometers." International Astronomical Union Colloquium 131 (1991): 1–5. http://dx.doi.org/10.1017/s0252921100012975.
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AbstractWe study the distribution of noise in images synthesized by radio interferometers, focusing particularly on the noise due to source power fluctuations. For a total power interferometer, the r.m.s. fluctuation in the image consists of a term that is constant all over the map, which is the uncorrelated system noise divided by the number of telescopes in the interferometer, and a term that is the image itself. For a correlation interferometer the expression is not so simple but is qualitatively similar. Our results are consistent with intuitive expectations in various observing situations. We find similarities in self-noise at optical and radio wavelengths.
23
Guillen Bonilla, José Trinidad, Héctor Guillen Bonilla, Verónica María Rodríguez Betancourtt, et al. "Low-Finesse Fabry–Pérot Interferometers Applied in the Study of the Relation between the Optical Path Difference and Poles Location." Sensors 20, no. 2 (2020): 453. http://dx.doi.org/10.3390/s20020453.
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Interferometry sensors are frequently analyzed by applying the Fourier transform because the transformation separates all frequency components of its signal, making its study on a complex plane feasible. In this work, we study the relation between the optical path difference (OPD) and poles location theoretically and experimentally, using the Laplace transform and a pole-zero map. Theory and experiments are in concordance. For our study, only the cosine function was considered, which is filtered from the interference pattern. In experimental work, two unperturbed low-finesse Fabry–Pérot interferometers were used. First, a Fabry–Pérot interferometer that has a cavity length of ~ 1.6 mm was used. Its optical path difference was 2.33 mm and the poles were localized at points ± i 12 . rad/nm. Secondly, a Fabry–Pérot interferometer with a cavity length of ~ 5.2 mm was used, and its optical path difference was 7.59 mm and the poles were localized at points ± i 40.4 rad/nm. Experimental results confirmed the theoretical analysis. Our proposal finds practical application for interferometer analysis, signal processing of optical fiber sensors, communication system analysis, and multiplexing systems based on interferometers.
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Gusev, A. V., E. Majorana, V. N. Rudenko, and V. D. Yushkin. "Measurement of geophysical effects on the large-scale gravitational-wave interferometer." International Journal of Modern Physics D 29, no. 07 (2020): 2050050. http://dx.doi.org/10.1142/s0218271820500509.
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Geophysical application of large free-mass laser interferometers, which had been designed merely for the detection of gravitational radiation of an astrophysical nature, are considered. Despite the suspended mass-mirrors, these interferometers can be considered as two coordinate meters even at very low frequency ([Formula: see text][Formula: see text]Hz) are rather accurate two-coordinate distance meters. In this case, the measurement of geodynamic deformations looks like a parallel product of long-term observations dictated by the task of the blind search for gravitational waves (GW) of extraterrestrial origin. Compared to conventional laser strain meters, gravitational interferometers have the advantage of an increased absolute value of the deformation signal due to the 3–4[Formula: see text]km baseline. The magnitude of the tidal variations of the baseline is 150–200[Formula: see text]microns, leading to conceive the observation of the fine structure of geodynamic disturbances. This paper presents the results of processing geophysical measurements made on a Virgo interferometer during test (technical) series of observations in 2007–2009. The specific design of mass-mirrors suspensions in the Virgo gravitational interferometer also creates a unique possibility of separating gravitational and deformation perturbations through a recording mutual angular deviations of the suspensions of its central and end mirrors. It gives a measurement of the spatial derivative of the gravity acceleration along with the geoid of the Earth. In this mode, the physics of the interferometer is considered with estimates of the achievable sensitivity in the application to the classical problem of registration of oscillations of the inner Earth’s core.
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Shepherd, G. G., W. A. Gault, and R. A. Koehler. "The development of wide-angle Michelson interferometers in Canada." Canadian Journal of Physics 69, no. 8-9 (1991): 1175–83. http://dx.doi.org/10.1139/p91-178.
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The history of wide-angle Michelson interferometers in Canada began in 1961, in Paris. This will culminate with the launch of the WINDII (WIND Imaging Interferometer) instrument in 1991, precisely 30 years later. The intervening developments are reviewed, and possible future directions are described.
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CAPOZZIELLO, SALVATORE, and CHRISTIAN CORDA. "SCALAR GRAVITATIONAL WAVES FROM SCALAR-TENSOR GRAVITY: PRODUCTION AND RESPONSE OF INTERFEROMETERS." International Journal of Modern Physics D 15, no. 07 (2006): 1119–50. http://dx.doi.org/10.1142/s0218271806008814.
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Scalar-tensor gravity admits the existence of scalar modes of gravitational waves (SGWs). The mechanism of production and the response of interferometers to these scalar components of gravitational waves can be studied in three different gauges in the massless case: the transverse-traceless (TT) gauge, the so-called "Shibata, Nakao and Nakamura" (SNN) gauge, and the local Lorentz gauge. The response of interferometers to massless SGWs is invariant in these different gauges. Our work generalizes previous results which, in the study of the coupling between interferometers and massless SGWs, started from the assumption that the wavelength of the SGW is much larger than the distance between the test masses. Furthermore, considering situations motivated by string-dilaton gravity, the effect of a small mass term on the response of the interferometer is taken into account. In this case (massive SGW), we have a longitudinal effect, the response of an arm of an interferometer, which is aligned in the wave propagation direction is computed. The value of the longitudinal response function for non-relativistic massive SGW at high frequencies is very high: this fact opens the doors to the interesting possibility of detection of "massive" part of the signal, if advanced projects will achieve high sensitivities. Finally, by using previous results and the geometry of the system, the generalized coupling between interferometers (like VIRGO or LIGO) and massless SGWs is studied. The total frequency response function to massless SGWs incoming from arbitrary directions is studied.
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Spichtinger, Jan, Michael Schulz, and Gerd Ehret. "Absolute distance interferometry for subaperture stitching of large freeform optics." EPJ Web of Conferences 238 (2020): 06011. http://dx.doi.org/10.1051/epjconf/202023806011.
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We are developing a form measurement system for the surfaces of freeform optics and large conventional optics. The specifications of the optics are diameters up to 1.5 m and radii of curvature down to 10 m. This includes optics like telescope mirror segments and synchrotron optics. Using a Fizeau interferometer, we propose a subaperture stitching method that involves vertically aligning the interferometer’s optical axis to the local surface gradient and measuring the absolute distance from the interferometer’s reference flat to the specimen. Experimental results for the absolute distance measurement are shown.
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Grizbil, B. A., L. A. Maksimova, and V. P. Ryabukho. "Diffraction model of a laser speckle interferometer for measuring micro-displacements of objects with scattering surface." Computer Optics 44, no. 4 (2020): 568–77. http://dx.doi.org/10.18287/2412-6179-co-702.
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On the basis of diffraction transformations of an optical wave field a mathematical model for the formation of speckle modulated interference patterns and signals at the output of a speckle interferometer is developed, which allows us to identify their properties and quantitative parameters. Speckle interferometers based on a Michelson arrangement are considered, where objects with scattering surfaces are used instead of mirrors in the reference and object arms. Results of numerical simulation of speckle modulated interference patterns on the basis of diffraction transformations of wave fields in an interferometer are discussed. Simulated images obtained at the output of the interferometer when focusing laser beams on the scattering surfaces of the controlled and reference objects are considered. Experimental results of using a speckle interferometer with a digital matrix photodetector for measuring the temperature micro-displacements of an object with a scattering surface and a quantitative comparison of experimental data with the results obtained by a numerical experiment using a diffraction model of a speckle interferometer are presented.
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Zhan, Ming-Sheng, Jin Wang, Wei-Tou Ni, et al. "ZAIGA: Zhaoshan long-baseline atom interferometer gravitation antenna." International Journal of Modern Physics D 29, no. 04 (2019): 1940005. http://dx.doi.org/10.1142/s0218271819400054.
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The Zhaoshan long-baseline Atom Interferometer Gravitation Antenna (ZAIGA) is a new type of underground laser-linked interferometer facility, and is currently under construction. It is in the 200-m-on-average underground of a mountain named Zhaoshan which is about 80[Formula: see text]km southeast to Wuhan. ZAIGA will be equipped with long-baseline atom interferometers, high-precision atom clocks, and large-scale gyros. ZAIGA facility will take an equilateral triangle configuration with two 1-km-apart atom interferometers in each arm, a 300-m vertical tunnel with atom fountain and atom clocks mounted, and a tracking-and-ranging 1-km-arm-length prototype with lattice optical clocks linked by locked lasers. The ZAIGA facility will be used for experimental research on gravitation and related problems including gravitational wave detection, high-precision test of the equivalence principle of micro-particles, clock-based gravitational red-shift measurement, rotation measurement and gravitomagnetic effect.
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Shyu, Lih Horng, Yung Cheng Wang, and Jui Cheng Lin. "A Compact Signal Processing with Position Sensitive Detectors Utilized for Michelson Interferometer." Key Engineering Materials 437 (May 2010): 98–102. http://dx.doi.org/10.4028/www.scientific.net/kem.437.98.
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Interferometric signals of a homodyne Michelson interferometer appear in sinusoidal forms. In this investigation, new concepts for signal processing of Michelson interferometer are demonstrated. With the utilization of detection of position sensitive detector (PSD) and by the procedure of differential signals and the characteristic of symmetric waveform, a compact signal processing for homodyne Michelson interferometer has been developed. Its advantages include simplified procedure, fast processing and few electronic hardware. For experiment tests of the signal processing, a conventional homodyne Michelson interferometer has been constructed. Major components of the interferometer consist of laser light source, beam splitter, mirrors, PSD and piezo transducer for driving measurement mirror. To verify the performance of the signal processing, a commercial nanopositioning stage as reference standard has been utilized for comparison measurements. Through theoretical analysis and experiment tests, it can be proved that by the developed signal processing an interferometer possesses the optical resolution of 79 nm. With support of the developed signal processing, interferometers will possess the benefits of simply structure, few components and lower cost.
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Loriani, Sina, Alexander Friedrich, Christian Ufrecht, et al. "Interference of clocks: A quantum twin paradox." Science Advances 5, no. 10 (2019): eaax8966. http://dx.doi.org/10.1126/sciadv.aax8966.
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The phase of matter waves depends on proper time and is therefore susceptible to special-relativistic (kinematic) and gravitational (redshift) time dilation. Hence, it is conceivable that atom interferometers measure general-relativistic time-dilation effects. In contrast to this intuition, we show that (i) closed light-pulse interferometers without clock transitions during the pulse sequence are not sensitive to gravitational time dilation in a linear potential. (ii) They can constitute a quantum version of the special-relativistic twin paradox. (iii) Our proposed experimental geometry for a quantum-clock interferometer isolates this effect.
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Tokura, Yasuhiro. "Quantum Adiabatic Pumping in Rashba- Dresselhaus-Aharonov-Bohm Interferometer." Entropy 21, no. 9 (2019): 828. http://dx.doi.org/10.3390/e21090828.
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We investigate the quantum adiabatic pumping effect in an interferometer attached to two one-dimensional leads. The interferometer is subjected to an Aharonov-Bohm flux and Rashba-Dresselhaus spin-orbit interaction. Using Brouwer’s formula and rigorous scattering eigenstates, we obtained the general closed formula for the pumping Berry curvatures depending on spin for general interferometers when the external control parameters only modulate the scattering eigenstates and corresponding eigenvalues. In this situation, pumping effect is absent in the combination of the control parameters of Aharonov-Bohm flux and spin-orbit interaction strength. We have shown that finite pumping is possible by modulating both Rashba and Dresselhaus interaction strengths and explicitly demonstrated the spin-pumping effect in a diamond-shaped interferometer made of four sites.
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Shao, M., M. Colavita, D. Staelin, R. Simon, and K. Johnston. "Present Status and Future Plans for the Two Color Astrometric Interferometer Project." Symposium - International Astronomical Union 109 (1986): 331–40. http://dx.doi.org/10.1017/s0074180900076750.
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A 3-meter two telescope stellar interferometer has been used to observe fringes for the past year in order to study the feasibility of using long baseline interferometers for astrometry. We have demonstrated that two color fringe measurements are capable of significantly reducing the astrometric error due to atmospheric turbulence. Currently, we are investigating the thermal and mechanical sources of error in the instrument. The results of our study will be incorporated into the design of the 20 meter astrometric interferometer which will be built in the next 1–2 years. The key to the 20-meter interferometer is the laser system which we expect to monitor all the mechanical and thermal imperfections relevant to astrometry at the 10−3 to 10−4 arc sec level. A slight modification of this system could be used in a space based interferometer for 1 to 10 microarcsecond astrometry of faint objects.
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Chesneau, O., K. Rousselet-Perraut, and F. Vakili. "Interferometry and Stellar Magnetism." International Astronomical Union Colloquium 175 (2000): 174–77. http://dx.doi.org/10.1017/s0252921100055792.
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AbstractThe classical detection of magnetic fields in Be stars remains a challenge due to the sensitivity threshold and geometrical cancelation of the field effects. We propose to study the Zeeman effect using Spectro-Polarimetric INterferometry (SPIN) which consists of the simultaneous use of polarimetry and very high angular resolution provided by long baseline interferometers. As monitoring of the instrumental polarisation is mandatory in order to calibrate interferometric observations in any case, the polarised signal is a natural by-product of interferometers. This method will be tested on the GI2T interferometer thanks to its high spectral resolution and its polarimetric capabilities.
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Kol'tso, N. E., S. A. Grenkov, and L. V. Fedotov. "Comparison of Radio Interferometers with Analog and Digital Extraction of Recorded Signal." Journal of the Russian Universities. Radioelectronics 23, no. 2 (2020): 6–18. http://dx.doi.org/10.32603/1993-8985-2020-23-2-6-18.
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Introduction. Radio telescopes of Very Long Baseline Interferometry (VLBI) networks usually record several signals with relatively narrow (up to 32 MHz) bands, which are extracted by means of base band converters (BBC) from an analog noise signal of an intermediate frequency (IF) with bands up to 1 GHz. When processing data, frequency band synthesis is used. At new small radio telescopes (for example, RT-13), directly wideband IF signals are digitized. An ability to connect the RT-13 radio telescope to the “Quasar” VLBI complex and to international VLBI networks provides by a digital narrow-band signal extraction module developed in 2019.Aim. Determining the measuring accuracy of an interferometric group delay of a signal by a radio interferometer with a digital narrow-band signal extraction module and comparing the sensitivity of interferometers with analog and digital signal extraction systems.Materials and methods. Sensitivity losses of interferometers with different systems for detecting recorded signals were calculated. The accuracy of a multi-channel interferometer with the synthesis of a frequency band and of an interferometer with recording of digital broadband IF signals without band synthesis was compared. The results were confirmed by VLBI observations in the observatories of the “Quasar” complex.Results. When replacing the analog system of signal extraction with digital system the sensitivity losses of the interferometer were slightly reduced. The measurement accuracy of the interferometric group delay had not changed. Accuracy increased when digitally recording broadband IF signals and when synthesizing a frequency band significantly larger than the IF bandwidth. Conditions and minimum synthesized bands were determined under which the accuracy of the interferometer with the registration of narrowband signals can be higher than the accuracy of the interferometer with the registration of wideband IF signals.Conclusion. The problem of combining RT-13 radio telescopes with VLBI networks with recording of video frequency signals was solved. The efficiency of the installation of digital signal conversion systems at radio telescopes was shown.
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Zhuzhukin, A. I. "APPLICATION OF SPECKLE INTERFEROMETRY FOR THE INVESTIGATION OF VIBRATIONS AND STATIC DEFORMATIONS OF ELEMENTS OF ENERGY INSTALLATIONS." Vestnik of Samara University. Natural Science Series 19, no. 9.2 (2017): 80–86. http://dx.doi.org/10.18287/2541-7525-2013-19-9.2-80-86.
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The article deals with the development of digital speckle interferometer with superimposed bundles and speckle modulated reference wave for the study of vibration characteristics and deformation displacements of elements of energy installations excited by statistic loadings. It is experimentally established that at vibration studies thanks to the possibility of using in optical scheme of digital camera in speckle interferograms obtained with the use of interferometer showed that dispersion of speckle noise is from 2.5 up to 3.2 times lower than in speckle interferograms obtained with the traditionally used interferometers with separated bundles and smooth reference wave.
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Shih, Yi-Chieh, Pi-Cheng Tung, Wen-Yuh Jywe, Chung-Ping Chang, Lih-Horng Shyu, and Tung-Hsien Hsieh. "Investigation on the Differential Quadrature Fabry–Pérot Interferometer with Variable Measurement Mirrors." Applied Sciences 10, no. 18 (2020): 6191. http://dx.doi.org/10.3390/app10186191.
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Due to the common path structure being insensitive to the environmental disturbances, relevant Fabry–Pérot interferometers have been presented for displacement measurement. However, the discontinuous signal distribution exists in the conventional Fabry–Pérot interferometer. Although a polarized Fabry–Pérot interferometer with low finesse was subsequently proposed, the signal processing is complicated, and the nonlinearity error of sub-micrometer order occurs in this signal. Therefore, a differential quadrature Fabry–Pérot interferometer has been proposed for the first time. In this measurement system, the nonlinearity error can be improved effectively, and the DC offset during the measurement procedure can be eliminated. Furthermore, the proposed system also features rapid and convenient replacing the measurement mirrors to meet the inspection requirement in various measuring ranges. In the comparison result between the commercial and self-developed Fabry–Pérot interferometer, it reveals that the maximum standard deviation is less than 0.120 μm in the whole measuring range of 600 mm. According to these results, the developed differential Fabry–Pérot interferometer is feasible for precise displacement measurement.
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Pushin, D. A., M. G. Huber, M. Arif, et al. "Neutron Interferometry at the National Institute of Standards and Technology." Advances in High Energy Physics 2015 (2015): 1–7. http://dx.doi.org/10.1155/2015/687480.
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Neutron interferometry has proved to be a very precise technique for measuring the quantum mechanical phase of a neutron caused by a potential energy difference between two spatially separated neutron paths inside interferometer. The path length inside the interferometer can be many centimeters (and many centimeters apart) making it very practical to study a variety of samples, fields, potentials, and other macroscopic medium and quantum effects. The precision of neutron interferometry comes at a cost; neutron interferometers are very susceptible to environmental noise that is typically mitigated with large, active isolated enclosures. With recent advances in quantum information processing especially quantum error correction (QEC) codes we were able to demonstrate a neutron interferometer that is insensitive to vibrational noise. A facility at NIST’s Center for Neutron Research (NCNR) has just been commissioned with higher neutron flux than the NCNR’s older interferometer setup. This new facility is based on QEC neutron interferometer, thus improving the accessibility of neutron interferometry to the greater scientific community and expanding its applications to quantum computing, gravity, and material research.
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Liu, Chien-Sheng, Yu-Fan Pu, Yu-Ta Chen, and Yong-Tai Luo. "Design of a Measurement System for Simultaneously Measuring Six-Degree-Of-Freedom Geometric Errors of a Long Linear Stage." Sensors 18, no. 11 (2018): 3875. http://dx.doi.org/10.3390/s18113875.
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This study designs and characterizes a novel precise measurement system for simultaneously measuring six-degree-of-freedom geometric motion errors of a long linear stage of a machine tool. The proposed measurement system is based on a method combined with the geometrical optics method and laser interferometer method. In contrast to conventional laser interferometers using only the interferometer method, the proposed measurement system can simultaneously measure six-degree-of-freedom geometric motion errors of a long linear stage with lower cost and faster operational time. The proposed measurement system is characterized numerically using commercial software ZEMAX and mathematical modeling established by using a skew-ray tracing method, a homogeneous transformation matrix, and a first-order Taylor series expansion. The proposed measurement system is then verified experimentally using a laboratory-built prototype. The experimental results show that, compared to conventional laser interferometers, the proposed measurement system better achieves the ability to simultaneously measure six-degree-of-freedom geometric errors of a long linear stage (a traveling range of 250 mm).
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Liu, He-Shan, Zi-Ren Luo, and Wei Sha. "In-orbit performance of the laser interferometer of Taiji-1 experimental satellite." International Journal of Modern Physics A 36, no. 11n12 (2021): 2140004. http://dx.doi.org/10.1142/s0217751x21400042.
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Taiji-1, which is the first experimental satellite for space gravitational wave detection in China, relies on key technologies which include the laser interferometer, the gravitational reference sensor (GRS), the micro-thruster and the satellite platform. Similarly to the Laser Interferometer Space Antenna (LISA) pathfinder, except for the science interferometer, the optical bench (OB) of Taiji-1 contains reference and test mass (TM) interferometers. Limited by the lower mechanical strength of the carrier rocket and by the orbit environment, the OB of Taiji-1 is made of invar steel and fused silica, and it is aimed to achieve a sensitivity of the order of 100[Formula: see text]pm/[Formula: see text]. The experimental results from in-orbit tests of Taiji-1 demonstrate that the interferometer can reach a sensitivity of 30[Formula: see text]pm/[Formula: see text] in the frequency range of 0.01–10[Formula: see text]Hz, which satisfies the requirements of Taiji-1 mission.
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Budinski, Vedran, and Denis Donlagic. "A Miniature Fabry Perot Sensor for Twist/Rotation, Strain and Temperature Measurements Based on a Four-Core Fiber." Sensors 19, no. 7 (2019): 1574. http://dx.doi.org/10.3390/s19071574.
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In this article, a novel miniature Fabry-Perot twist/rotation sensor using a four core fiber and quadruple interferometer setup is presented and demonstrated. Detailed sensor modeling, analytical evaluation and test measurement assessment were conducted in this contribution. The sensor structure comprises a single lead-in multicore fiber, which has four eccentrically positioned cores, a special asymmetrical microstructure, and an inline semi-reflective mirror, all packed in a glass capillary housing. A four core fiber positioned in front of a special asymmetrical microstructure and the inline semi reflective mirror defines four Fabry-Perot interferometers. Rotation of the sensors’ asymmetrical microstructure around the axis of the in-line four core fibers´ modulates the path lengths of all four interferometers simultaneously. Proper processing of path length changes of all four interferometers allows for unambiguous and temperature independent determination of the sensor’s rotation angle.
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Thuering, T., and M. Stampanoni. "Performance and optimization of X-ray grating interferometry." Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 372, no. 2010 (2014): 20130027. http://dx.doi.org/10.1098/rsta.2013.0027.
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The monochromatic and polychromatic performance of a grating interferometer is theoretically analysed. The smallest detectable refraction angle is used as a metric for the efficiency in acquiring a differential phase-contrast image. Analytical formulae for the visibility and the smallest detectable refraction angle are derived for Talbot-type and Talbot–Lau-type interferometers, respectively, providing a framework for the optimization of the geometry. The polychromatic performance of a grating interferometer is investigated analytically by calculating the energy-dependent interference fringe visibility, the spectral acceptance and the polychromatic interference fringe visibility. The optimization of grating interferometry is a crucial step for the design of application-specific systems with maximum performance.
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Corrêa, Raul, Marina F. B. Cenni, and Pablo L. Saldanha. "Quantum Interference of Force." Quantum 2 (December 14, 2018): 112. http://dx.doi.org/10.22331/q-2018-12-14-112.
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We show that a quantum particle subjected to a positive force in one path of a Mach-Zehnder interferometer and a null force in the other path may receive a negative average momentum transfer when it leaves the interferometer by a particular exit. In this scenario, an ensemble of particles may receive an average momentum in the opposite direction of the applied force due to quantum interference, a behavior with no classical analogue. We discuss some experimental schemes that could verify the effect with current technology, with electrons or neutrons in Mach-Zehnder interferometers in free space and with atoms from a Bose-Einstein condensate.
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J Stevenson, Andrew, Malcolm B Gray, Charles C Harb, David E McClelland, and Hans-A. Bachor. "Interferometers with Internal and External Phase Modulation: Experimental and Analytical Comparison." Australian Journal of Physics 48, no. 6 (1995): 971. http://dx.doi.org/10.1071/ph950971.
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Optical intensity noise in a light source easily degrades the sensitivity of a shot-noise-limited interferometer which is directly detecting low frequency phase or displacement variations. In this paper we describe and compare two experimental methods in which we use high frequency optical phase modulation to shift low frequency phase signals in an interferometer to a shot noise limited region of the photocurrent spectrum. This phase modulation is applied either within the interferometer arms-internal modulation-or in a local oscillator beam tapped off the main interferometer and coherently recombined with the interferometer output-external modulation. he photocurrent is mixed electronically with the high frequency modulating waveform to extract the signal information free from laser intensity noise. In our experiments, we have been able to detect interferometrically low frequency signals with true shot-noise-limited sensitivity. We find, theoretically and experimentally, that the interferometric sensitivity achievable in each scheme depends critically on non-ideal factors, such as imperfect interferometric fringe contrast and electronic noise in the detectors or amplifiers. This paper examines the relative merits and operating requirements of both modulation schemes in practical interferometers.
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Ahmedov, Haci, Mehnet Celik, Recep Orhan, Beste Korutlu, Sahin Ersoy, and Ramiz Hamid. "A UME Kibble balance displacement measurement procedure." ACTA IMEKO 9, no. 3 (2020): 11. http://dx.doi.org/10.21014/acta_imeko.v9i3.766.
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<p>The redefinition of the kilogram in terms of Planck constant came into effect on 20 May 2019. The National Metrology Institute of Turkey (UME) realised the new definition by means of the oscillating magnet Kibble balance. The novel dynamical measurement procedure developed for Kibble balance in Turkey has the advantage of being less sensitive to environmental disturbances compared to the traditional Kibble balance experiments. Precise displacement measurements are performed either with Michelson or Fabry-Perot interferometers in worldwide Kibble balances. Moreover, most of them operate in a global vacuum. A commercial Michelson interferometer has been used in UME’s Kibble balance experiment. In this article, we determine the contribution of ultra-small oscillations to the Planck constant by taking simultaneous displacement measurements on two back-to-back mirrors attached to the piezoelectric transducer, undergoing an oscillatory motion with the Michelson and Fabry-Perot interferometers. The following novel measurement procedure makes such measurements possible in a regular laboratory environment. Otherwise, the experiment needs to be performed in a global vacuum. This is why we were required to investigate the resolution performances of these devices in laboratory conditions. As the expected relative uncertainty in the redefinition of kilogram is above the resolution uncertainties of both interferometers, we may conclude that a commercial Michelson interferometer will serve our purposes in our route to the redefinition of a kilogram by means of local vacuum.</p>
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Lucas, Robert. "Chemistry of Diffuse Clouds and Circumstellar Envelopes." Highlights of Astronomy 13 (2005): 822–24. http://dx.doi.org/10.1017/s153929960001724x.
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AbstractWe present and review recent millimeter-wave observations with interferometers, in particular, with the Plateau de Bure interferometer, that stress the importance of high-frequency resolution for studying the chemistry of diffuse interstellar clouds and of post main-sequence circumstellar envelopes. The future impact of new instruments, such as the Atacama Large Millimeter and submillimeter Array (ALMA), is also investigated.
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Ковалев, А. А. "Резонатор лазера с интерференционно-поляризационным фильтром на основе фазовых интерферометров". Журнал технической физики 126, № 4 (2019): 458. http://dx.doi.org/10.21883/os.2019.04.47516.175-18.
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AbstractIt is proposed to use the phase properties of a reflective interferometer upon oblique incidence for spectral selection in lasers. The effect is achieved due to the difference in phases of waves having different polarization and reflected from the reflective interferometer. A simple version in which the wave is incident at the Brewster angle on the reflective interferometer in the form of a plate with a single totally reflecting face is considered for several materials of the plate. It is shown that one such element can replace several plates of Lyot-type filters. A cavity with two reflective interferometers has been calculated; in this cavity, one can multiply increase the selectivity. A version of a cavity with a reflective interferometer in the form of a thin-layer coating is considered; for this cavity, a mechanism for a twofold increase in the free dispersion region due to inclusion of a metal layer into the coating is proposed. Results of calculating a specific device for a wavelength of 0.6 μm are presented.
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Gomes, André D., Marta S. Ferreira, Jörg Bierlich, et al. "Optical Harmonic Vernier Effect: A New Tool for High Performance Interferometric Fiber Sensors." Sensors 19, no. 24 (2019): 5431. http://dx.doi.org/10.3390/s19245431.
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The optical Vernier effect magnifies the sensing capabilities of an interferometer, allowing for unprecedented sensitivities and resolutions to be achieved. Just like a caliper uses two different scales to achieve higher resolution measurements, the optical Vernier effect is based on the overlap in the responses of two interferometers with slightly detuned interference signals. Here, we present a novel approach in detail, which introduces optical harmonics to the Vernier effect through Fabry–Perot interferometers, where the two interferometers can have very different frequencies in the interferometric pattern. We demonstrate not only a considerable enhancement compared to current methods, but also better control of the sensitivity magnification factor, which scales up with the order of the harmonics, allowing us to surpass the limits of the conventional Vernier effect as used today. In addition, this novel concept opens also new ways of dimensioning the sensing structures, together with improved fabrication tolerances.
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Nechaeva, M., D. Adamchik, Vl Bezrukovs, N. Dugin, I. Shmeld, and Y. Tikhomirov. "Measurements of Interferometer Parameters at Reception of GLONASS and GPS Signals." Latvian Journal of Physics and Technical Sciences 53, no. 5 (2016): 24–30. http://dx.doi.org/10.1515/lpts-2016-0033.
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Abstract The present paper deals with the calibration method of interferometers with antennas having a small effective area, on the quasinoise signals of GLONASS and GPS navigation satellites. Algorithms for calculation of antenna coordinates and instrumental delay from the analysis of correlation interferometer response to signals of satellites in the near field of the instrument were reviewed. The method was tested in VLBI experiments on interferometers with medium and large baselines that included radio telescopes of NIRFI and VIRAC. The values of the antenna coordinates and instrumental delay with an error within the limits of one discrete were obtained. The sources of measurement errors and ways to improve the accuracy of results were analysed.
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Fisher, Philip C., Joseph B. Houston, and Tilman W. Stuhlinger. "Infrared Interferometers for Observing Extra-Solar Planets." International Astronomical Union Colloquium 161 (January 1997): 367–73. http://dx.doi.org/10.1017/s0252921100014871.
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AbstractConcepts are outlined for ground - and space-based interferometers for observing nearby extra-solar earth-like planets (in the 8-20 μ range). The collecting elements are special coronagraphs, two of which constitute part of a Michelson interferometer. Performance characteristics are compared to those inferred for several competing systems. One conclusion is that one could construct a groundbased instrument that seems superior to the Keck interferometer system («superior» meaning up to a tenfold increase in angular resolution in each of two orthogonal directions, up to a tenfold increase in sensitivity, and a ten-fold lower cost). Space-based instruments of comparable/superior (?) performance to the Oases-1 and-2 systems might also be constructed.