Showing papers on "Mach–Zehnder interferometer published in 1985"
TL;DR: A cyclic interferometers can be used for both lateral and radial shearing, and the working of a polarization phase shifting cyclic shear interferometer is demonstrated.
Abstract: A cyclic interferometer can be used for both lateral and radial shearing. Being common-path this interferometer is quite stable. The use of a cyclic shear interferometer for phase shifting interferometry is discussed. The phase shifting is provided here by polarization techniques. Some useful cyclic phase shifting interferometer arrangements are discussed, and the working of a polarization phase shifting cyclic shear interferometer is demonstrated.
112 citations
TL;DR: In this paper, a very high sensitivity non-contacting vibration analysis system based upon a monomode fiber optic Mach Zehnder interferometer incorporating an open air path is described.
Abstract: A very high sensitivity non-contacting vibration analysis system based upon a monomode fibre optic Mach Zehnder interferometer incorporating an open air path is described. The system was operated in both a closed loop limited tracking range (>105) homodyne mode and an effective infinite tracking range novel pseudo-heterodyne mode. For periodic signals, amplitude detection sensitivities of approximately 2*10-10 m at 10 Hz to 5*10-11 m at 10 kHz have been demonstrated for both modes of operation.
63 citations
TL;DR: In this article, a Mach-Zehnder rib waveguide interferometer with low loss Y branches and Schottky barrier electrodes was fabricated in n−/n+−GaAs by reactive ion etching.
Abstract: Electro‐optic Mach–Zehnder rib waveguide interferometers with low loss Y branches and Schottky barrier electrodes have been fabricated in n−/n+‐GaAs by reactive ion etching. With antireflection coating and optimized Y branches device losses of the interferometers at 1.3 μm were as low as 4 dB. In a push‐pull configuration drive voltages of only 13 V suffice to attain a modulation depth of 12.7 dB. The optical signal bandwidth of these interferometers was measured to exceed 4.5 GHz.
44 citations
TL;DR: In this paper, an optical multi/demultiplexer with spectrum selectivity of gigahertz order is proposed, which consists of a Mach-Zehnder interferometer and a feedback control circuit.
Abstract: An optical multi/demultiplexer with spectrum selectivity of gigahertz order is proposed. It consists of a Mach-Zehnder interferometer and a feedback control circuit. Its feasibility was experimentally demonstrated.
42 citations
TL;DR: A new type of all-optical logic gate is described that employs a single-mode waveguide, unequal-arm-length Mach-Zehnder interferometer fabricated using materials that exhibit an optical Kerr effect, suitable for digital signal processing.
Abstract: A new type of all-optical logic gate is described that employs a single-mode waveguide, unequal-arm-length Mach–Zehnder interferometer fabricated using materials that exhibit an optical Kerr effect. Because of the unique properties of the single-mode Y junction, there is no reflected light output from the element. This interferometer is therefore suitable for digital signal processing because an optical isolator is not needed for connection as a serial array to achieve sharp on–off characteristics.
35 citations
TL;DR: The rainbow schlieren apparatus is simpler, cheaper, and more easily built to large scale than the interferometer, but the accuracies of the two instruments are similar but only if refraction is properly accounted for in interferometry.
Abstract: The rainbow schlieren apparatus is simpler, cheaper, and more easily built to large scale than the interferometer. The accuracies of the two instruments are similar but only if refraction is properly accounted for in interferometry. The measurement thresholds of both instruments are similar. The rainbow schlieren device provides more detailed information because the detection threshold of the rainbow schlieren is an order of magnitude better than that of the interferometer.
23 citations
TL;DR: In this paper, a fast polarimeter based on heterodyne frequency mixing is presented and the time resolution achievable in principle is of the order of tens of nanoseconds and several versions of the basic structure providing different performances suitable to various applications are discussed.
22 citations
Patent•
22 May 1985
TL;DR: In this paper, a Mach Zehnder interferometer with arms of equal length is formed between two optic fibres by locating the lightly tensioned fibres in a generally parallel configuration and forming optical couplings between them at points (22,23) which lie on the centre-line of the configuration.
Abstract: A Mach Zehnder interferometer with arms (30,40) of equal length is formed between two optic fibres (3,4) This is achieved by locating the lightly tensioned fibres in a generally parallel configuration (Fig2(a), Fig2(b)) and forming optical couplings between them at points (22,23) which lie on the centre-line of the configuration Preferably the couplings are formed by a fused biconical tapering technique
16 citations
TL;DR: In this paper, a photothermal interference spectroscopy (PIS) was proposed, analyzed and demonstrated for the first time, where a sample under study is set in one of the arms of a Mach-Zehnder interferometer, and its refractive index is modulated by a periodically modulated pump laser beam.
Abstract: A new spectroscopic measuring scheme, photothermal interference spectroscopy (PIS), has been proposed, analyzed and demonstrated for the first time. A sample under study is set in one of the arms of a Mach-Zehnder interferometer, and its refractive index is modulated by a periodically modulated pump laser beam. A signal dependence on a sample concentration is proportional to the product of the trigonometric function and the Bessel function. Applications of this method to gas monitoring and to gas and liquid chromatographies are also discussed.
16 citations
Patent•
10 May 1985
TL;DR: In this article, a beam splitter is used to return a portion of the output beam of radiation to the interferometer as an incident beam, and a bandpass filter is used between the splitter and the detector.
Abstract: Apparatus and method for converting a conventional Michelson interferometer into a high resolution double-pass interferometer. The Michelson interferometer includes means for dividing an incident beam of radiation into first and second beams, means for propagating the first and second beams through first and second optical paths, respectively, means for recombining the first and second beams to form an output beam of radiation, and means for detecting an interference pattern in the output beam of radiation. The improvement comprises a beam splitter which is positioned to return a portion of the output beam of radiation to the interferometer as an incident beam of radiation, and a bandpass filter which is positioned between the beam splitter and the detector to filter from the output beam of radiation a portion which has been twice passed through the interferometer.
13 citations
Patent•
04 May 1985
TL;DR: The phase of modulation of an optical signal (Pin), in particular intensity modulation, is controlled to a predetermined value by applying the signal in a predetermined power split ratio to an unbalanced fibre Mach Zehnder interferometer which is sure that the signals applied to its output coupler are in-phase and quadrature (I, Q) as discussed by the authors.
Abstract: The phase of modulation of an optical signal (Pin), in particular intensity modulation, is controlled to a predetermined value by applying the signal in a predetermined power split ratio to an unbalanced fibre Mach Zehnder interferometer (10) which is sure that the signals applied to its output coupler (13) are in-phase and quadrature (I, Q), the phase of the output signal Pout 1 being determined by the power split ratio The predetermined power split ratio is achieved by causing an appropriate optical phase difference between the optical signals in the arms (3, 4) of fibre Mach Zehnder interferometer (1) If required the amplitude of the phase controlled Pout 1 signal can be controlled by a third fibre Mach Zehnder interferometer (17)
TL;DR: In this paper, the magnetic properties of the metal-coated fiber were measured using an M•H looper and its magnetostriction λ using the fiber magnetometer setup.
Abstract: The fiber optic magnetometer is a relatively new sensor concept which shows promise for high sensitivity measurements. It employs glass fibers which are configured in a Mach–Zehnder interferometer where the fringe pattern output is extremely sensitive to path length changes. The sensing leg is sensitized to magnetic fields by electroplating the fiber with magnetostrictive Ni‐Fe‐Co alloys. The magnetic M properties of the metal‐coated fiber are measured using an M‐H looper and its magnetostriction λ using the fiber magnetometer setup. Data for Ni‐Fe alloys are presented which compare the measurements of M and λ versus tension. From this data physical relationships between λ and M for the metal‐coated fibers are identified.
TL;DR: Realisation d'un attenuateur commande electriquement insensible a la polarisation pour systemes a fibres optiques monomodes.
Abstract: Realisation d'un attenuateur commande electriquement insensible a la polarisation pour systemes a fibres optiques monomodes
29 Jan 1985
TL;DR: In this article, the behavior of two kinds of channel waveguide modulators in Ti-indiffused LiNb03: Mach-Zehnder interferometers and directional couplers is compared.
Abstract: Theory and experiment at 1.3 μm are presented to describe and compare the behavior of two kinds of channel waveguide modulators in Ti-indiffused LiNb03: Mach-Zehnder interferometers and directional couplers. Each device can be operated as a linear modulator when biased to an appropriate point, either by passive geometrical means or by application of a DC voltage. However, the device voltage responses differ, being sinusoidal for an interferometer and varying as sin2x/x2 for a directional coupler. There is good agreement between calculated and measured device responses. The linear dynamic range of each kind of modulator is reported. We have measured linearity over 76 dB and voltage sensitivities of ~ 13 μV.
TL;DR: In this paper, simultaneous measurements of the electron density in a plasma focus by a Moire-Schlieren technique and Mach-Zehnder interferometry were carried out to investigate the unavoidable error in the inter-ferometry generated by refraction of the probe beam by the density gradient.
Abstract: Simultaneous measurements of the electron density in a plasma focus by a Moire-Schlieren technique and Mach-Zehnder interferometry were carried out to investigate the unavoidable error in the interferometry generated by refraction of the probe beam by the density gradient. The refraction angle was measured precisely by the Moire-Schlieren technique, and the spatial distribution of the electron density calculated from the refraction angle agreed well with that obtained by Mach-Zehnder interferometry. The error produced by the refraction is found to be negligible if an N2-laser is employed as the light source for the plasma focus.
TL;DR: A signal processor for simultaneous direction finding and spectral analysis of radio signals is described, utilizing acoustooptics and a Mach-Zehnder interferometer.
Abstract: A signal processor for simultaneous direction finding and spectral analysis of radio signals is described. This device utilizes acoustooptics and a Mach-Zehnder interferometer. The signal processor’s operational principles are analytically derived and experimentally demonstrated. Alternative acoustooptic signal processors are compared with this instrument.
TL;DR: A common path interferometers utilizing noncritically phase-matched frequency doubling crystals is presented, although the reference wave of the interferometer is flatter than predicted, and the two are compared in this paper.
Abstract: A common path interferometer utilizing noncritically phase-matched frequency doubling crystals is presented. The interference pattern is directly sensitive to the wave front shape (as the Mach-Zehnder interferometer) and is in the second harmonic of the laser source. This interferometer has twice the sensitivity of a two-beam interferometer. All the optics are 100% transmitting—no beam splitters, the contrast is adjustable, and the laser intensity pattern is not affected by the interferometer. This interferometer is similar in some ways to the point diffraction interferometer, and the two are compared in this paper. A theory of operation is given, although the reference wave of the interferometer is flatter than predicted. Several possible reasons for this are examined, but no conclusion was found.
TL;DR: In this paper, a Fabry-Perot interferometer with one phase-conjugate mirror was studied, and the performance of the cavity was analyzed under different conditions under which the cavity can act as a regenerative amplifier.
Abstract: We study theoretically a Fabry–Perot interferometer with one phase-conjugate mirror Comparisons with results previously obtained by Kastler [ Appl Opt1, 17 ( 1962)] for an ordinary Fabry–Perot interferometer are made Specifically, we discuss the field intensity of the light both outside and inside the interferometer We also study the intensity of the exterior field that is due to atoms radiating incoherently inside the interferometer The operating characteristics below the threshold of the interferometer when it is filled with a gain medium are also analyzed and are found to be different from those of the ordinary interferometer Finally, conditions are obtained under which the cavity can act as a regenerative amplifier
Patent•
26 Sep 1985TL;DR: In this article, an interferometer in Mach-Zehnder configuration comprises beamsplitters and mirrors, which divide an optical beam whose wavefront is to be monitored into an information component and a reference component, and recombine the information and reference components to form an interference pattern that changes dynamically at a spatial light modulator in response to dynamic variations in the atmosphere through which the beam passes.
Abstract: An interferometer in Mach-Zehnder configuration comprises beamsplitters (10, 12) and mirrors (11, 13), which divide an optical beam whose wavefront is to be monitored into an information component and a reference component, and which recombine the information and reference components to form an interference pattern that changes dynamically at a spatial light modulator (14) in response to dynamic variations in the atmosphere through which the beam passes. A spatial light filter (15) comprising a plate with a pin-hole aperture is positioned to transmit the reference component of the beam, but with second-order aberrations being removed from the reference component prior to recombination of the information and reference components. The wavefront of the reference component that recombines with the information component is a substantially unaberrated version of the wavefront of the beam whose wavefront is to be monitored. An acousto-optical beam-steering device (20) steers the reference component in real time so as to maintain substantially continuous alignment of a maximum-intensity centroid of the reference component with respect to the pin-hole aperture of the spatial light filter (15).
Patent•
12 Nov 1985
TL;DR: In this paper, a two-element spaced array (E1-E2) antenna is applied to Bragg cells (BC1-BC2) in a Mach-Zehnder interferometer to produce a first optical beam (P1) from one element of the array and a second beam(P2) which is a combination of the signal from the first element and the second element (E2), passing the beams through opto-electrical transducers (L1-L2) and linear photo detector (D1-D2) to a
Abstract: A method of and a means for acousto-optic signal processing for electronic support measures in which a signal is received on a two element spaced array (E1-E2) antenna and applied to Bragg cells (BC1-BC2) in a Mach-Zehnder interferometer to produce a first optical beam (P1) from one element of the array (E1), and a second beam (P2) which is a combination of the signal from the first element (E1) and the second element (E2) of the array, and passing the beams through opto-electrical transducers (L1-L2) and linear photo detector (D1-D2) to a computer.
TL;DR: In this article, a three-beam heterodyne interferometer was proposed for the measurement of optical phase, which was shown to be suitable for electronic measurement of phase change.
TL;DR: In this article, a fiber optic Mach-Zehnder interferometer was constructed using channel waveguides in LiNbO3 as splitters and combiners and integrating the phase-tracking component on the device.
Abstract: A fibre optic Mach-Zehnder interferometer has been constructed using channel waveguides in LiNbO3 as splitters and combiners and integrating the phase-tracking component on the LiNbO3 device. The results are discussed and improvements are suggested.
01 Jan 1985
TL;DR: In this paper, an integrated optics version of a Mach-Zehnder interferometer is presented, with the same sensitivity of the same order as with other MZ-ehnder concepts.
Abstract: An integrated optics version of a Mach-Zehnder interferometer is presented- Sensitivities of the same order as with other Mach-Zehnder concepts were reached.
TL;DR: In this article, a Mach-Zehnder waveguide frequency translator is used to assemble an optical frequency multiplex and the linearity of the process is reported and experimental measurements are compared with theory.
Abstract: A Mach-Zehnder waveguide frequency translator is used to assemble an optical frequency multiplex. The linearity of the process is reported and experimental measurements are compared with theory.
01 Feb 1985
TL;DR: In this paper, a soft x-ray scanning microscope is built on the NSLS xray ring's undulator beam line, which is expected to improve the resolution of scanning microscopy to the sub-1000A range and form pictures in seconds rather than minutes.
Abstract: A soft x-ray scanning microscope will be built on the NSLS x-ray ring's undulator beam line. It is expected that the beam line will provide more powerful coherent soft x-ray flux to improve the resolution of scanning microscopy to the sub-1000A range and form pictures in seconds rather than minutes. A laser interferometer has been developed for encoding the coordinates of the scanning plane of the soft x-ray microscope with 300A resolution. A pair of the optical fibers has been used as an interference fringe phase detector in the interferometer which can make the system phase adjustment simpler, more accurate, and polarization-independent. The last character is important because if the fringe phase detector is polarization dependent the interferometer's optical design will be complicated when the optical path of the interferometer has to include additional windows or mirrors which usually change the polarization situation. In the first section of this report we discuss the optical arrangement of the interferometer. In the following two sections we describe the schematic of the resolution extending unit and the interferometer's other possible applications.
TL;DR: In this article, the determination of a density field by means of digital imaging of a Mach-Zehnder interferogram and processing by a microcomputer was described, and the fringe count and the spatial locations of the fringes were calculated using basic programs.
Abstract: The determination of a density field by means of digital imaging of a Mach–Zehnder interferogram and processing by a microcomputer is described. The apparatus used in this study are an optical single‐bit digitizer, a microcomputer, and a dot matrix printer. Photographs of the interferograms are semiautomatically digitized by the apparatus. The fringe count and the spatial locations of the fringes are calculated using basic programs, and the density field is plotted as an output.
TL;DR: In this article, an analysis of the specific features of the operation of a multimode double-arm interferometer with an additional phase modulation in one of the arms is presented.
Abstract: An analysis is made of the specific features of the operation of a multimode double-arm interferometer with the aim of identifying the reasons for fading of the output signal and possible ways of suppressing this effect. This analysis is carried out for a most commonly used multimode Mach–Zehnder interferometer with an additional phase modulation in one of the arms. It is shown that fading of the output signal in a multimode variant is related to the possibility of interference of like waveguide modes traveling in the fiber arms and characterized by random phases. The result of such interference is zero mathematical expectation of the resultant output signal, but the variance of this signal is finite because its rms deviations may reach large values. Tuning and stabilization of this interferometer may be ensured by using a radiation source with a large coherence length and wide-band frequency tuning. The required tuning range is found from a theory of image transfer along multimode waveguides.
12 Jun 1985
TL;DR: In this article, a simple procedure, using holographic interferometry, for measuring diffusion in transparent liquids is presented, where a Mach-Zehnder interferometer and a CCD linear array are used to record the moving fringes, and the data is processed automatically on a micro computer.
Abstract: A simple procedure, using holographic interferometry, for measuring diffusion in transparent liquids is presented. A Mach-Zehnder interferometer and A CCD linear array are used to record the moving fringes, and the data is processed automatically on a micro computer. The diffusion constant is determined from the velocity of the fringes which are observed in real time. Results of measurements on NaCl solutions demonstrate the usefulness of this technique.
TL;DR: In this paper, a Mach-Zehnder interferometer with pulsed nitrogen laser was used for electronic density studies in the plasma focus device, where the light pulse duration of 2 ns enables interferometric measurements to be made at any instant during the plasma evolution in a 20 kJ (20 kV) device.
Abstract: A Mach-Zehnder interferometer with pulsed nitrogen laser used for electronic density studies in the plasma focus device is described. The light pulse duration of 2 ns enables interferometric measurements to be made at any instant during the plasma evolution in a 20 kJ (20 kV) device. A numerical method for interferogram processing and computation of the electronic density is presented. Some preliminary plasma studies are discussed.
01 Jan 1985
TL;DR: In this paper, the dependence of the coupling strength of Ti:LiNbO3 directional couplers on fabrication parameters has been investigated and an optical intensity modulator was built up with the Couplers.
Abstract: The dependence of the coupling strength of Ti:LiNbO3 directional couplers on fabrication parameters has been investigated. An optical intensity modulator was built up with the couplers.