Showing papers on "Mach–Zehnder interferometer published in 2000"
TL;DR: In this paper, a waveguide optical isolator based on non-reciprocal interference was proposed, which exhibits a 19 dB extinction ratio at λ=1.54 μm.
Abstract: A waveguide optical isolator based on nonreciprocal interference is demonstrated. Ridge waveguides are fabricated in a Mach–Zehnder configuration on a single film of bismuth-, lutetium-, neodymium-iron garnet. With this design, no polarizers are required to achieve extinction in the backward propagation direction. This isolator exhibits a 19 dB extinction ratio at λ=1.54 μm. A flat wavelength dependence, to within 2 dB, has been observed in the range between 1.49 and 1.57 μm.
224 citations
TL;DR: In this paper, the authors demonstrate a new heterodyne Michelson interferometer design for displacement measurements capable of fringe interpolation accuracy of one part in 36'000 using two acousto-optic modulators.
Abstract: We demonstrate a new heterodyne Michelson interferometer design for displacement measurements capable of fringe interpolation accuracy of one part in 36 000. Key to this level of accuracy are the use of two acousto-optic modulators for heterodyne frequency generation and digital signal processing demodulation electronics. We make a direct comparison of our interferometer to a commercial interferometer based on a Zeeman-stabilized laser, and show that the residual periodic errors in ours are two orders of magnitude lower than those in the commercial unit. We discuss electronically induced optical cross talk and optical feedback as sources of periodic error. Our new interferometer is simple, robust, and readily implemented.
184 citations
TL;DR: In this article, an all-active SOA-based Mach-Zehnder device, employed as a wavelength converter, is shown capable of improving the OSNR by more than 20 dB at this bit rate, thereby resulting in penalty reduction.
Abstract: All-optical 2R and 3R regeneration techniques are investigated at 40 Gb/s. It is shown that an all-active SOA-based Mach-Zehnder device, employed as a wavelength converter, is capable of improving the OSNR by more than 20 dB at this bit rate, thereby resulting in penalty reduction. Furthermore, simultaneous all-optical wavelength conversion and demultiplexing from 40 to 10 Gb/s is demonstrated showing that the scheme, which also has a 3R regeneration capability, is feasible in a combined OTDM/WDM network.
156 citations
NEC1
TL;DR: In this article, a hybrid-integrated symmetric Mach-Zehnder all-optical switch was developed for demultiplexing of 168-Gb/s data pulses at a repetition rate of 10 GHz with this switch.
Abstract: We have developed a hybrid-integrated symmetric Mach-Zehnder all-optical switch and evaluated the demultiplexing of 168-Gb/s data pulses at a repetition rate of 10 GHz with this switch. A compact, stable device was realized by assembling semiconductor optical amplifiers as nonlinear waveguides on a planar lightwave circuit in a self-aligned manner. A 6.0-ps switching window needed for 168-Gb/s demultiplexing was provided by the push-pull operation of the symmetric Mach-Zehnder all-optical switch. Demultiplexed signal light showed a high extinction ratio of better than 18 dB. Error-free demultiplexing with a bit error rate of 10/sup -11/ was achieved.
133 citations
TL;DR: A simple and highly sensitive phase-demodulation technique is proposed and its use for a fiber Bragg grating strain sensor is experimentally demonstrated, and strain sensing at as much as a 30-kHz sampling rate was obtained.
Abstract: A simple and highly sensitive phase-demodulation technique is proposed, and its use for a fiber Bragg grating strain sensor is experimentally demonstrated. Sampling a phase-modulated Mach–Zehnder output with controlled time delay produced two quadrature data streams that have relative quadrature phase difference (90°). The Bragg wavelength-dependent phase information is extracted by application of digital arctangent function and phase unwrapping to the quadrature signals. By use of this technique with a reference grating, strain sensing at as much as a 30-kHz sampling rate was obtained with strain resolution of 3.5 microstrains and 6 nanostrains/ Hzin quasi-static and dynamic strain measurements, respectively.
110 citations
TL;DR: In this paper, a Mach-Zehnder interferometer using Bose-Einstein condensed rubidium atoms and optical Bragg diffraction was constructed, which can be used to detect vortices or other topological condensate phases.
Abstract: We construct a Mach-Zehnder interferometer using Bose-Einstein condensed rubidium atoms and optical Bragg diffraction. In contrast to interferometers based on normal diffraction, where only a small percentage of the atoms contribute to the signal, our Bragg diffraction interferometer uses all the condensate atoms. The condensate coherence properties and high phase-space density result in an interference pattern of nearly 100% contrast. The two arms of the interferometer may be completely separated in space, making it an ideal tool that can be used to detect vortices or other topological condensate phases.
106 citations
TL;DR: In this paper, the authors present a fully integrated Mach-Zehnder interferometer in silicon-on-insulator (SiOI) technology, achieving a bandwidth in the 10 MHz range.
Abstract: We present a fully integrated Mach-Zehnder interferometer in silicon-on-insulator technology. Modulation of the index of refraction is achieved through the plasma dispersion effect resulting in a bandwidth in the 10 MHz range. A particular and innovative design makes this device completely compatible with CMOS technology allowing electronic functions to be integrated on the same substrate. Measurement results, limitations due to thermooptic effect and absorption related to charge injection together with further improvements are discussed.
105 citations
TL;DR: In this paper, an amplitude division soft-x-ray interferometer was used to generate high-contrast interferograms at the wavelength of any of the saturated soft x-ray lasers (5.6-46.9 nm) available at present.
Abstract: We report the demonstration of an amplitude-division soft-x-ray interferometer that can be used to generate high-contrast interferograms at the wavelength of any of the saturated soft-x-ray lasers (5.6-46.9 nm) that are available at present. The interferometer, which utilizes grazing-incidence diffraction gratings as beam splitters in a modified Mach-Zehnder configuration, was used in combination with a tabletop 46.9-nm laser to probe a large-scale (~2.7-mm-long) laser-created plasma.
95 citations
TL;DR: The Mach-Zehnder interferometer is a simple device for demonstrating interference by division of amplitude as discussed by the authors, where a light beam is first split into two parts by a beamsplitter and then recombined by a second beamplitter depending on the relative phase acquired by the beam along the two paths.
Abstract: The Mach-Zehnder interferometer is a particularly simple device for demonstrating interference by division of amplitude. A light beam is first split into two parts by a beamsplitter and then recombined by a second beamsplitter. Depending on the relative phase acquired by the beam along the two paths the second beamsplitter will reflect the beam with efficiency between 0 and 100%. The operation of a Mach-Zehnder interferometer is often used as an example in quantum mechanics because it shows a clear path-choice problem. However, it is not at all obvious at first glance that it works as claimed, until reflection phase shifts are considered in detail.
86 citations
TL;DR: In this article, the response of a Mach-Zehnder interferometer composed by two 3dB long period gratings (LPG) with different external refractive indices higher than that of silica (leaky configuration) was investigated.
84 citations
TL;DR: In this paper, a reversed-ridge PLZT film waveguide was fabricated on r-sapphire substrates with a patterned ITO spacer film by sol-gel deposition.
Abstract: We report the numerical analysis and the fabrication of a reversed-ridge PLZT film waveguide. It is single-mode, has low transmission loss, and has large transverse cross-section suitable for efficient coupling to single-mode optical fibers. We used this structure to fabricate Mach-Zehnder (MZ) waveguide modulators. The field distribution in the channel and Y branch waveguides was calculated using a beam propagation method to analyze the modal profiles and the propagation loss. The reversed-ridge waveguides and the MZ structures were fabricated on r-sapphire substrates with a patterned ITO spacer film by sol-gel deposition. At 1.55 /spl mu/m the propagation loss was 2.7 dB/cm. In the MZ, the half-wave modulation voltage was 8.5 V using 1.55 /spl mu/m light and electrode length of 3.5 mm.
TL;DR: In this paper, the performance of the NPL Jamin Differential Plane Mirror Interferometer when it is fitted with stabilized and unstabilized lasers was compared. But the results of the experiments were limited.
Abstract: The x-ray interferometer from the combined optical and x-ray interferometer (COXI) facility at NPL has been used to investigate the performance of the NPL Jamin Differential Plane Mirror Interferometer when it is fitted with stabilized and unstabilized lasers. This Jamin interferometer employs a common path design using a double pass configuration and one fringe is realized by a displacement of 158 nm between its two plane mirror retroreflectors. Displacements over ranges of several optical fringes were measured simultaneously using the COXI x-ray interferometer and the Jamin interferometer and the results were compared. In order to realize the highest measurement accuracy from the Jamin interferometer, the air paths were shielded to prevent effects from air turbulence and electrical signals generated by the photodetectors were analysed and corrected using an optimizing routine in order to subdivide the optical fringes accurately. When an unstabilized laser was used the maximum peak-to-peak difference between the two interferometers was 80 pm, compared with 20 pm when the stabilized laser was used.
TL;DR: In this article, the authors present a theoretical modeling of the propagation characteristics and surface sensitivity of the ARROW structure, which is based on an integrated Mach-Zehnder interferometer configuration.
Abstract: Silicon based antiresonant reflecting optical waveguides (ARROW's) have been designed in order to obtain a high sensitive optical transducer for sensing applications. The designed sensor has an integrated Mach-Zehnder interferometer configuration. The optical waveguides that form its structure have to verify two conditions: monomode behavior and high surface sensitivity. In this paper, we present a theoretical modeling of the propagation characteristics and surface sensitivity of the ARROW structure.
TL;DR: In this paper, the authors presented a new technique for fiber Bragg grating (FBG) sensor interrogation and multiplexing, which combines a scanning bandpass filter used to multiplex by wavelength multiple gratings in a single fiber, and an unbalanced Mach-Zehnder fiber interferometer made with a 3/spl times/3 coupler to detect straininduced wavelength shifts.
Abstract: We present a new technique for fiber Bragg grating (FBG) sensor interrogation and multiplexing. The technique combines a scanning bandpass filter used to multiplex by wavelength multiple gratings in a single fiber, and an unbalanced Mach-Zehnder fiber interferometer made with a 3/spl times/3 coupler to detect strain-induced wavelength shifts. A demonstration system interrogates four gratings in a single fiber at a sampling rate up to 20 kHz, with a noise floor measured at less than 10 n/spl epsiv///spl radic/(Hz) above 0.1 Hz.
TL;DR: In this article, a periodic multi/demultiplexer that has a square spectrum response with a 200 GHz free spectrum range was fabricated using a modified Mach-Zehnder interferometer with MMI couplers, a delay line, and a ring resonator.
Abstract: A periodic multi/demultiplexer that has a square spectrum response with a 200-GHz free spectrum range was fabricated using a modified Mach-Zehnder interferometer with MMI couplers, a delay line, and a ring resonator. A large enhancement of the FSR is obtained by using a deep ridge waveguide. The transmission bandwidths of 1 dB down and -15-dB rejection are about 75 GHz and over 50 GHz, respectively.
TL;DR: In this paper, a regenerative capability for 40-Gb/s optical time-division multiplexed (OTDM) data using a semiconductor optical amplifier (SOA) based, monolithic Mach-Zehnder interferometer (MZI) was demonstrated.
Abstract: We present a novel method for all-optical add-drop multiplexing having regenerative capability for 40-Gb/s optical time-division multiplexed (OTDM) data using a semiconductor optical amplifier (SOA) based, monolithic Mach-Zehnder interferometer (MZI). Simultaneous dropping of one 10-Gb/s channel out of 10-Gb/s OTDM data and perfect clearing of the corresponding time slot in the remaining 3/spl times/10 Gb/s data stream is demonstrated. Bit-error-rate measurements show a low penalty of 2 dB for each 10 Gb/s channel. No extra penalty was observed introducing a 10-Gb/s add channel through the device into the cleared time slot.
TL;DR: In this paper, a 160 Gbit/s all-optical demultiplexer based on gain-transparent cross-phase modulation in semiconductoroptical amplifiers is presented.
Abstract: The authors report on a 160 Gbit/s all-optical demultiplexer based on gain-transparent cross-phase modulation in semiconductor-optical amplifiers. The switch comprises a hybridly set up Mach-Zehnder interferometer with switching windows as short as 2.5 ps and an input power dynamic range of 50 dB.
TL;DR: In this paper, a self-testing teleportation configuration for photon qubits based on a Mach-Zehnder interferometer is proposed, where Bob can tell how well the input state has been teleported without knowing what that input state was.
Abstract: We suggest a self-testing teleportation configuration for photon qubits based on a Mach-Zehnder interferometer. That is, Bob can tell how well the input state has been teleported without knowing what that input state was. One could imagine building a ``locked'' teleporter based on this configuration. The analysis is performed for continuous variable teleportation but the arrangement could be applied equally to discrete manipulations.
24 Mar 2000
TL;DR: In this paper, a series of low-power phase-modulating devices fabricated in SIMOX material suitable for use in distributed sensing or as optical variable attenuators is presented.
Abstract: An investigation of a series of low-power thermo-optic phase-modulating devices fabricated in SIMOX material suitable for use in distributed sensing or as optical variable attenuators is presented. These devices are integrated in a balanced Mach-Zehnder Interferometer utilizing multi-micron vertical sidewall rib waveguides and exhibit low polarization dependence. The investigation highlights the power consumption of various lengths of devices with low-lateral heat diffusion operated by ohmic heating and quantifies the attainable modulation depths under quasi-static operation. Non-linear device behavior is demonstrated and explained with a proposal for these characteristics giving rise to devices which would operate with further power reductions. AC characteristics are also investigated, showing the modulation to have 3 dB bandwidths of approximately 40kHz. A second device geometry is presented which was fabricated utilizing an under-etching technique to suspend the arms of the Mach-Zehnder. Results indicate lower power operation with a corresponding reduction in bandwidth to approximately 1kHz. An improvement in overall device geometry provides modulation depths in excess of 99 percent, independent of both bandwidth and power.
TL;DR: In this article, the phase delay of a twisted nematic liquid crystal spatial light modulator (LCSLM) was measured using a lock-in amplifier and an electro-optic modulator.
28 Apr 2000
TL;DR: In this paper, the authors present a family of novel interferometer designs incorporating optical circulators, unbalanced couplers, and/or balanced detection which are designed to optimize optical power efficiency and system signal to noise ratio.
Abstract: The most straightforward interferometer for optical coherence tomography (OCT) is a simple Michelson interferometer. A low-coherence source illuminates the interferometer. The light is split by a 50/50 beamsplitter into a sample and a reference path. Light retro reflected from the reference and the sample is recombined at the beamsplitter and half is collected by a photodetetor in the detection arm of the interferometer. Half of the light is returned towards the source, where it is lost. In addition, the reference arm light is typically attenuated by orders of magnitude in order to improve signal to noise ratio. Thus, using this typical configuration, virtually 75 percent of the optical power supplied by the source is not used for image formation. We present a family of novel interferometer designs incorporating optical circulators, unbalanced couplers, and/or balanced detection which are designed to optimize optical power efficiency and circulators, unbalanced couplers, and/or balance detection which are designed to optimize optical power efficiency and system signal to noise ratio. We evaluate the expected performance of the novel interferometers as compared with the standard Michelson interferometer. We review signal and noise sources important for the design of OCT interferometers, and specify the design equations for evaluation and optimization of signal to noise ratio. This analysis, based on sound, experimentally verified literature, predicts improved sensitivity for all of the new interferometer designs.
Patent•
14 Feb 2000TL;DR: In this article, an integrated optical Mach Zehnder structure has an optical path length modifying heater (phase shifter) associated with a portion of the length of each interference arm of the MZEHnder.
Abstract: An integrated optical Mach Zehnder structure has an optical path length modifying heater (phase-shifter) associated with a portion of the length of each interference arm of the Mach Zehnder. The portion of the length of the interference arm associated with one of the heaters is flanked with trenches that provide that portion with a temperature coefficient of birefringence different from that of the corresponding portion of the other interference arm. The invention is applicable no only to stand-alone Mach Zehnders, but also to more complex Mach Zehnder structures having a series combination of two or more component Mach Zehnders that are close coupled by having the two outputs of one component Mach Zehnder of the complex structure constitute the two inputs of the next component Mach Zehnder of the complex structure.
TL;DR: A theoretical and experimental study of self-referencing fiber optic intensity sensors based on Michelson and on Mach-Zehnder configurations is conducted, and the definition of the measurement parameter R, sensor linearity and sensitivity are analyzed.
Abstract: A theoretical and experimental study of self-referencing fiber optic intensity sensors based on Michelson and on Mach-Zehnder configurations is conducted. Via the definition of the measurement parameter R, sensor linearity and sensitivity are analyzed. Theoretical and experimental results are compared, considering the problem of sensor design and optimization. The choice between the two configurations is addressed; the Michelson one is recommended for practical reasons.
TL;DR: In this paper, an all-active dual-order mode (DOMO) converter is presented which has been assessed experimentally at 10 Gbit/s showing almost wavelengthindependent performance for signal and CW wavelengths covering the entire EDFA window.
Abstract: An all-active dual-order mode (DOMO) converter is presented which has been assessed experimentally at 10 Gbit/s showing almost wavelength-independent performance for signal and CW wavelengths covering the entire EDFA window. In addition, the authors demonstrate, for the first time, wavelength conversion at 20 Gbit/s using this device structure.
TL;DR: In this article, the authors showed that spectral interferometry enables one to measure average roughness of the surfaces in the subscales of optical wavelengths using the correlation between two beams, in a two-beam interferometer, modifies the spectral characteristics of the light field.
TL;DR: In this article, three ways to combine two laser beams with equal linear polarizations and very closely spaced frequencies into a single output beam containing up to 100% of the input power of each beam were discussed.
Abstract: We discuss three ways to combine two laser beams with equal linear polarizations and very closely spaced frequencies into a single output beam containing up to 100% of the input power of each beam. One setup, a modified Mach–Zehnder interferometer, is examined in detail; it allows to adjust the combined output power electronically with the help of a simple servo loop. With off-the-shelf optical components we obtained a 98% efficiency.
TL;DR: In this paper, a 10 Gbit/s 2R regenerative wavelength up-and down-conversion using a monolithically integrated Mach-Zehnder interferometer module with semiconductor optical amplifiers (MZI-SOAs) is presented.
Abstract: A demonstration is presented of 10 Gbit/s 2R regenerative wavelength up- and down-conversion within the C-band as well as up-conversion to the L-band using a monolithically integrated Mach-Zehnder interferometer module with semiconductor optical amplifiers (MZI-SOAs). The converted output signals exhibit very low noise and chirp which is accompanied by a negative power penalty.
07 Mar 2000
TL;DR: In this article, an optical 3R regenerator combining semiconductor optical amplifier-based Mach Zehnder interferometers is assessed at 20 Gbit/s. Inserted in a recirculation loop including 110 mm of dispersion shifted fibre, more than 200 regenerators have been cascaded.
Abstract: An optical 3R regenerator combining semiconductor optical amplifier-based Mach Zehnder interferometers is assessed at 20 Gbit/s. Inserted in a recirculation loop including 110 mm of dispersion shifted fibre, more than 200 regenerators have been cascaded.
NEC1
TL;DR: In this paper, a symmetric-Mach-Zehnder-type switch was used for all-optical switching with a record high 168 GHz, 1.5-ps-wide, 10dB-extinction switch windows.
Abstract: We report on the ultrahigh-repetition all-optical switching of a semiconductor-optical-amplifier-based symmetric-Mach-Zehnder-type switch. Record high 168 GHz, 1.5-ps-wide, 10-dB-extinction switch windows were observed. This repetition rate is ten times higher than the semiconductor optical amplifier's cutoff frequency. The control optical pulse energy used was a record low 1 fJ (average power=170 µW). Clearly isolated 168 GHz components were also observed in the output pulses' optical spectrum, which was in contrast to the continuum-like spectrum of the input pulses.