Showing papers on "Mach–Zehnder interferometer published in 1983"
TL;DR: In this paper, a new ultrafast optical waveguide gate based on a nonlinear optical interaction in a waveguide interferometer is presented. Butler et al. used a modified Mach-Zehnder Interferometer, 2 cm long, fabricated in a LiNbO 3 substrate.
Abstract: We present a new ultrafast optical waveguide gate based on a nonlinear optical interaction in a waveguide interferometer. A train of signal pulses is gated by control pulses which change the refractive index in only one arm of the interferometer. The principle of operation is demonstrated using a modified Mach-Zehnder interferometer, 2 cm long, fabricated in a LiNbO 3 substrate. The experiments were performed with a near-infrared dye laser which produced 5 ps pulses at \lambda = 840 nm. A maximum modulation on the order of 10-3was obtained for a peak control power of 2 W. Experimentally, we determined the appropriate nonlinear coefficient of LiNbO 3 to be n_{2} = 3 \times 10^{-9} (MW/cm2)-1. As possible applications of the structure we describe an all-optical inverter, an XOR gate, and an AND gate. We conclude with a brief description of a random number generator encoder and decoder based on a few all-optical logic gates.
170 citations
TL;DR: In this article, an interferometer with a self-pumped phase-conjugating mirror was demonstrated, which eliminates the effects of turbulence or optical distortion in the beam path yet responds to any uniform phase change.
Abstract: An interferometer having a self-pumped phase-conjugating mirror is demonstrated. This device eliminates the effects of turbulence or optical distortion in the beam path yet responds to any uniform phase change.
116 citations
TL;DR: In this paper, a high-speed integrated-optic Ti:LiNbO3 Mach-Zehnder interferometric modulator for 0.83μm wavelength operation has been fabricated and characterized.
Abstract: A high‐speed integrated‐optic Ti:LiNbO3 Mach–Zehnder interferometric modulator for 0.83‐μm wavelength operation has been fabricated and characterized. The modulator exhibits smooth, resonance‐free frequency response with a 17‐GHz 3‐dB bandwidth. The modulator has a built‐in phase bias of π/2 for maximum linearity. Complete intensity modulation can be achieved with 120‐mW drive power. Optical modulation was measured up to 18 GHz directly by using a very high‐speed photodiode and indirectly using the swept frequency technique.
109 citations
TL;DR: In this paper, a demodulation technique suitable for use with fiber interferometric sensors is described, which employs a frequency switched diode laser and an unbalanced Mach-Zehnder interferometer.
Abstract: A demodulation technique suitable for use with fibre interferometric sensors is described The scheme employs a frequency switched diode laser and an unbalanced Mach-Zehnder interferometer Minimum phase sensitivity ≈ 2× 10-5 rad is obtainable, and can be shown to be limited by the laser phase noise
54 citations
01 Jan 1983
TL;DR: In this paper, the authors examined the quantum noise sources in a laser interferometer detection system for gravitational radiation and found that the quantum nature of the light is the dominant source of noise and contributes via what has been called the photon counting noise and indirectly via the fluctuating force the light exerts on the mirrors.
Abstract: In this paper I will examine the quantum noise sources in a laser interferometer detection system for gravitational radiation. The quantum noise sources will be of two basic forms — that due to the quantum nature of the light itself and that due to the damping in the mirror masses used as reflectors in the interferometers. We will find that the quantum nature of the light is the dominant source of noise and contributes via two mechanisms — directly as what has been called the photon counting noise and indirectly via the fluctuating force the light exerts on the mirrors. It will be shown that by setting up the initial state of the field entering the input port of the interferometer not being used by the laser in a generalised squeezed state, the effect of both of these noise sources can be made as small as desired. (The possibility for reducing the direct noise by a similar technique was shown by Caves for a simple single mode interferometer model). The noise introduced by the damping of the motion of the mirror masses will contribute significantly only if one does squeeze the state of the light beam and if the laser power is sufficiently large.
41 citations
TL;DR: In this article, a microwave-modulated optical waveguide interferometer formed in Ti-indiffused LiNbO 3 was used to produce a train of 19 ps FWHM pulses at a repetition rate of 20 GHz.
Abstract: Picosecond pulses have been produced from the CW output of a He-Ne laser using a microwave-modulated optical waveguide interferometer formed in Ti-indiffused LiNbO 3 . An experimental frequency spectrum demonstrating 97 percent modulation is presented along with theoretical predictions for the spectral components of signals produced by both ideal nonideal devices. A device modulated with 1 W of power at 10 GHz exhibited a spectrum corresponding to a train of 19 ps FWHM pulses produced at a repetition rate of 20 GHz. Applications of the device in signal processing operations utilizing sampling and demultiplexing schemes are discussed.
31 citations
TL;DR: In this paper, the successful experimental test of a two-crystal Bragg-case neutron interferometer that is topologically equivalent to Jamin interferometers is reported.
Abstract: The successful experimental test of a two-crystal Bragg-case neutron interferometer that is topologically equivalent to a Jamin interferometer is reported. The intensity distributions behind the interferometer are found to be in excellent agreement with those expected from dynamical diffraction theory. The distinguishing feature of this interferometer type is the absence of Borrmann spreading in one of the interfering beams. This would facilitate the use of very narrow beams in neutron interferometry.
21 citations
15 Nov 1983
TL;DR: In this paper, a heterodyne, Mach-Zehnder interferometer system has been developed for testing the wavefront quality of laser diode collimator pens, and the problems associated with testing laser diodes are discussed.
Abstract: A heterodyne, Mach-Zehnder interferometer system has been developed for testing the wavefront quality of laser diode collimator pens. The testing system is described and the problems associated with testing laser diodes are discussed.
19 citations
TL;DR: The feasibility of tuning these devices by modifying the propagation constant with Ta2O5 loading of Ti:LiNbO3 waveguides was studied and the intrinsic phase of a Mach-Zehnder modulator was adjusted.
Abstract: Unwanted path length variations cause integrated optical Mach-Zehnder modulators to have random intrinsic phase and directional couplers to have uncertain coupling lengths. The feasibility of tuning these devices by modifying the propagation constant with Ta2O5 loading of Ti:LiNbO3 waveguides was studied. The intrinsic phase of a Mach-Zehnder modulator was adjusted by this method.
18 citations
TL;DR: In this paper, a horizontal circular cylinder is moved vertically and also horizontally at constant velocity normal to its axis in density stratified brine which has a constant buoyancy frequency, N. The Reynolds numbers based on the cylinder diameter, D, are between 1 and 10 and the frequency parameter, DN/U, where U is the body velocity, is of order one.
Abstract: Experiments are described in which a horizontal circular cylinder is moved vertically and also horizontally at constant velocity normal to its axis in density stratified brine which has a constant buoyancy frequency, N. A six mirror Mach Zehnder interferometer is used to measure the density distributions within the far field wave systems. The Reynolds numbers based on the cylinder diameter, D, are between 1 and 10 and the frequency parameter, DN/U, where U is the body velocity, is of order one.
14 citations
TL;DR: These experiments demonstrated in principle that a number of multiline HF amplified beams can be recombined and phase-matched to produce a high beam quality output beam.
Abstract: Active phase matching of multiline HF laser beams by means of a phase-locked Mach-Zehnder interferometer was demonstrated by locking the interferometer to the central interference fringe at zero optical path length difference. The central fringe could be found by varying the spectral content of the input beam. Laser amplification in one leg of the interferometer decreased fringe visibility without adversely affecting locking. Single-line fringe patterns produced by an array spectrometer (while the interferometer was operated in its scanning mode) were analyzed to show that no significant dispersion occurred in the amplifier. The techniques developed have potential for measuring dispersion mismatch between larger parallel amplifiers. These experiments demonstrated in principle that a number of multiline HF amplified beams can be recombined and phase-matched to produce a high beam quality output beam.
Abstract: The nature of propagation of electromagnetic oscillations in a multimode waveguide is considered and it is shown in principle that such a waveguide can be used in a fiber-optic ring interferometer in combination with an optical radiation source characterized by a short coherence length A description is given of the apparatus and the results of an experimental investigation of such an interferometer are reported Ways of improving further the sensitivity of this interferometer are discussed
TL;DR: In this paper, the feasibility of using an integrated optics array of Mach-Zehnder dielectric-waveguide interferometers to measure the phase and amplitude across an optical wave front is demonstrated.
Abstract: First results are presented demonstrating the feasibility of using an integrated optics array of Mach–Zehnder dielectric‐waveguide interferometers to measure the phase and amplitude across an optical wave front. The interferometers are formed from single‐mode waveguides produced by Ti diffusion into LiNbO3. The spacing between the arms of the interferometer is 20 μm. The phase difference φ between the optical waves incident on the two interferometers arms is measured and compared with theory. The excellent and reproducible agreement between experiment and theory over a number of interferometers suggests that the accuracy of the wave front measurement sensor should be attractively high, limited only by signal statistics and noise considerations. As example, a sensor design is given for which the rms deviation (1σ) in the value of φ is less than 4.5° (the rms deviation in the optical path difference is less than λ/80).
Patent•
04 Mar 1983
TL;DR: In this article, an interferometer spectrometer aligning apparatus and method are disclosed, in which the laser beam generator, which is in the instrument to provide data controlling clock signals, is also used to accomplish initial (and as needed) alignment of the instrument.
Abstract: An interferometer spectrometer aligning apparatus and method are disclosed, in which the laser beam generator, which is in the instrument to provide data controlling clock signals, is also used to accomplish initial (and as needed) alignment of the instrument. The laser beam is directed through a target both on its way from the laser generator to the interferometer, and as it is reflected back from the interferometer, thereby validating the perpendicularity of the reflector to the axis of the interferometer. A semi-transparent mirror, i.e., a small beamsplitter, is used in the path of the laser beam ahead of the interferometer beamsplitter, thereby enabling portions of the laser beam to go into both the interferometer and the sample chamber. A second semi-transparent small mirror (beamsplitter) is also used in the path of the laser beam, for the purpose of providing two parallel laser beams both in the interferometer and in the sample chamber, the parallel beams being used for a plurality of optical checking and adjusting tasks.
TL;DR: In this article, a Fabry-Perot etalon with a Mach Zehnder interferometer (MZI) was used to deduce the index of refraction resonant dispersion curve near the center of an atomic line from the superimposed fringe system.
Abstract: A new experimental technique, namely, the combination of a Fabry-Perot etalon with a Mach Zehnder interferometer (MZI) makes it possible to deduce the index of refraction resonant dispersion curve near the center of an atomic line from the superimposed fringe system. A tunable pulsed dye laser as light source and a sodium seeded flame as test flow enabled us to verify the very large enhancement of sensitivity for refractive flow-visualization methods such as shadowgraph, schlieren and interferometry. The specific refractivity is a direct measure of the sensitivity, and that quantity increases from a non-resonant value of 4 × 10−3 m'/kg to a peak value of 189 m3/kg at the half-power points of the sodium D2-line.
19 Sep 1983
TL;DR: In this article, the evanescent wave directional coupler is used to split or combine guided optical waves and thus rgpl aces the bulk optic beam splitter, which allows compactness and offers a well defined optical path.
Abstract: During the last few years the sensitivities of fiber optic Sagnac gyroscopes and Mach Zehnder interferometer sensors have improved significantly. Part of this improvement is due to replacement of bulk devices with integrated optic and fiber optic devices.1 Guided wave devices reduce errors resulting from component motion and surface reflections. They allow compactness and offer a well defined optical path. One of the most commonly utilized guided wave devices is the evanescent wave directional coupler. This device can be used to split or combine guided optical waves and thus rgpl aces the bulk optic beam splitter. Veuions of directional couplers have been fabricated from optical fiber 4,;) and from integrated optical waveguides4.
19 Sep 1983
TL;DR: In this article, a passive stabilization scheme using a (3x3) fiber directional coupler in an all fiber Mach-Zehnder interferometer and suitable signal processing has been successfully demonstrated.
Abstract: A passive stabilization scheme using a (3x3) fiber directional coupler in an all fiber Mach-Zehnder interferometer and suitable signal processing has been successfully demonstrated. A stable output with large signal dynamic range and a minimum detectable phase shift in the microradian range has been achieved.© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
01 Mar 1983
TL;DR: A brief review of the laser-liquid interaction is presented in this article, where a 1 nanosecond duration nitrogen laser has been used as the light source for Mach Zehnder interferometry of the first few microseconds following the impact of a carbon dioxide laser pulse on water and partially transmitting cyclohexane.
Abstract: A brief review of the laser-liquid interaction is presented A 1 nanosecond duration nitrogen laser has been used as the light source for Mach Zehnder interferometry of the first few microseconds following the impact of a carbon dioxide laser pulse on water and partially transmitting cyclohexane Quantitative analysis of the interferograms using an Abel inversion procedure has been carried out Ultra violet laser induced cavitation has been observed© (1983) COPYRIGHT SPIE--The International Society for Optical Engineering Downloading of the abstract is permitted for personal use only
19 Sep 1983
TL;DR: In this paper, the authors proposed and demonstrated two broadband single mode fiber optic sensor systems for detection of ultrasonic waves propagating in fluids, one based on polarization modulation and the other based on phase modulation in the form of a two fiber Mach-Zehnder interferometer.
Abstract: Recently we have proposed and demonstrated two broadband single mode fiber optic sensor systems for detection of ultrasonic waves propagating in fluids. A review of such systems and their theoretical analysis is presented here. One such system is based on polarization modulation and only requires the use of a single fiber in a very simple configuration. This system has a frequency response from 0.7 MHz to 50 MHz, and a flat response between 11 MHz and 25 MHz. The other system is based on phase modulation, in the form of a two fiber Mach-Zehnder interferometer. The ultrasonic wave is detected through the pressure induced changes in the interference between the two optical beams propagating in the "ref-erence" and "sensing" fiber, i.e., the two arms of the interferometer. This system has a frequency response from 50 kHz to 50 MHz, with a flat response between 50 kHz and 1 MHz.
TL;DR: In this paper, the authors propose a method to improve the quality of the information provided by the user by using their own knowledge of the user's behavior. But they do not specify how to use this information.
Abstract: 法1),2)が検討 され てい る.光 フ ァイバ を セ ンサと して 使用 した場合,計 測対象 の状態 を光 信号 として取 り出 す光学的 なセンサで あるので,従 来の電気的なセ ンサ で は使用が 困難な計測対象(た とえば,電 磁環境下, 引火爆発性環境下 など)に おいても利 用でき る.本 研 究は光 ファイバの特徴を生か して単一 モー ド光 フ ァイ バを温度セ ンサ としての適用3)を 試み た.光 フ ァイバ 温度セ ンサ としては光 ファイバ その ものを センサ とし て機 能させ るセ ンサ素子形 と光 フ ァイバの端面の ほか の温度セ ンサを取 り付 け るセ ンサ伝送路形4)の 二つの 方式が考え られてい る.本 研究 はセ ンサ素子形の光 フ ァイバについて温度セ ンサ と しての可能性を明確 にす ることを主要 目的と し,温 度セ ンサ と しての感度を光 ファイバ中を伝播す る光 波の位相変化量 と して とらえ る光 位相信号 自動検出装置を製作 し,裸 フ ァイバ,被 覆 フ ァイバ などについて諸特性 を測定 し検討5)~6)を加 えた.
28 Nov 1983
TL;DR: In this article, a Ti-diffused lithium niobate, traveling wave modulator has been fabricated and tested using a Mach-Zehnder interferometer optical configuration and a coplanar waveguide electrical transmission line.
Abstract: A Ti-diffused lithium niobate, traveling wave modulator has been fabricated and tested. A Mach-Zehnder interferometer optical configuration and a coplanar waveguide electrical transmission line are used. For a 4mm interaction length, the modulator has a 3dB bandwidth of 13 GHz and requires only 2 volts to switch at λ = 840 nm. The frequency response is measured directly using an ultra-high speed photodiode, and the test set-up therefore constitutes the highest bandwidth electrooptical transmission system ever reported.