Showing papers on "Mach–Zehnder interferometer published in 1995"
TL;DR: In this paper, an all-fiber Mach-Zehnder interferometer with photo-induced Bragg gratings was used to drop/insert a single wavelength channel from/into a multiple-wavelength transmission link with 100 GHz channel-spacing at 1550 nm.
Abstract: A wavelength multiplexing/demultiplexing device is fabricated and used to drop/insert a single wavelength channel from/into a multiple wavelength transmission link with 100 GHz channel-spacing at 1550 nm. The device consists of an all-fiber Mach-Zehnder interferometer with photoinduced Bragg gratings. The following performances were measured: extraction/coupling efficiency =99.4%, excess loss 20 dB, and return loss >23 dB. >
219 citations
TL;DR: A soft x-ray interferometer is developed and used for the first time to probe a large laser-produced plasma with micron spatial resolutions and shows good agreement near the ablation surface but some discrepancy exists at lower densities.
Abstract: We have developed and used for the first time a soft x-ray interferometer to probe a large laser-produced plasma with micron spatial resolutions. A neonlike yttrium x-ray laser operating at 155 A was combined with a multilayer coated Mach-Zehnder interferometer to obtain electron density profiles in a plasma produced by laser irradiation of a CH target. The measured electron density profile has been compared to hydrodynamic simulations and shows good agreement near the ablation surface but some discrepancy exists at lower densities.
168 citations
TL;DR: In this paper, a polarization-discriminating Mach-Zehnder (PDMZ) all-optical switch is proposed, which is not limited by the slow relaxation time of highly efficient incoherent nonlinearities.
Abstract: We propose a polarization‐discriminating Mach‐Zehnder (PDMZ) all‐optical switch The switching speed of this PDMZ all‐optical switch is not limited by the slow relaxation time of highly efficient incoherent nonlinearities We demonstrate a squarelike modulation characteristic, which is necessary in most switching applications, at a switching speed (on‐off time) of 40 ps We also demonstrate ultrafast switching at a detector limited speed of ∼8 ps
103 citations
TL;DR: In this paper, the MZ interferometers were fabricated by using KOH anisotropic etching and their insertion losses and modulation depths were measured to be 4.81 dB and 98% respectively, at the wavelength of 1.3 μm when a forward bias voltage applied to a p+n junction is 0.95 V and the active zone length of the interferometer was 816.0 μm.
Abstract: Mach–Zehnder (MZ) waveguide interferometers integrated on SOI (silicon on insulator) for 1.3 μm operation are studied on the basis of the large cross‐section single‐mode rib waveguide condition and the free‐carrier plasma dispersion effect in Si wafer direct bonding SOI by back‐polishing. And the MZ interferometers are fabricated by using KOH anisotropic etching. Their insertion losses and modulation depths are measured to be 4.81 dB and 98%, respectively, at the wavelength of 1.3 μm when a forward bias voltage applied to a p+n junction is 0.95 V and the active zone length of the MZ interferometers is 816.0 μm.
89 citations
TL;DR: In this paper, the authors demonstrate all-optical error-free demultiplexing of 10, 20 and 40 Gbit/s data signals by using a monolithically integrated Mach-Zehnder interferometer with two semiconductor laser amplifiers.
Abstract: The authors demonstrate all-optical error-free demultiplexing of 10, 20 and 40 Gbit/s to 5 Gbit/s data signals by using a monolithically integrated Mach-Zehnder interferometer with two semiconductor laser amplifiers.
83 citations
TL;DR: An all-optical wavelength-converter based on monolithic integration of a Mach-Zehnder interferometer and integrated semiconductor optical amplifiers was demonstrated in this article.
Abstract: An all-optical wavelength-converter based on monolithic integration of a Mach-Zehnder interferometer and integrated semiconductor optical amplifiers was demonstrated. This device exhibited high stability, penalty-free conversion at 5 Gbit/s (at a BER of 10/sup 9/), no-excess penalty after a transmission over 60 km on standard fiber, and low signal-polarization dependency. The device operated in a 26-nm-wide optical window. >
76 citations
TL;DR: In this article, the authors demonstrate 40 GHz soliton pulse train generation using nonlinear compression of the output of a Mach-Zehnder modulator, and demonstrate transform-limited pulses at twice the RF drive frequency.
Abstract: We demonstrate 40-GHz soliton pulse train generation using nonlinear compression of the output of a Mach-Zehnder modulator. This source generates transform-limited pulses at twice the RF drive frequency, requires less than V/sub /spl pi// drive level, is tunable in wavelength (over the entire EDFA bandwidth), and is tunable in repetition rate. >
68 citations
TL;DR: All-optical switching with a contrast ratio of 7:1 based on the cascaded second-order nonlinearity is demonstrated, for the first time to the authors' knowledge, in a nonlinear hybrid Mach–Zehnder interferometer.
Abstract: We demonstrate, for the first time to our knowledge, all-optical switching with a contrast ratio of 7:1 based on the cascaded second-order nonlinearity. We performed the switching experiments in a nonlinear hybrid Mach–Zehnder interferometer, using a nonuniformly temperature-tuned lithium niobate channel waveguide in an operating regime of small fundamental depletion.
66 citations
TL;DR: In this paper, a three-part Mach-Zehnder configuration for wavelength conversion using semiconductor optical amplifiers monolithically integrated in a three part Mach-zero configuration for data rates of 1 and 2.5 Gb/s is presented.
Abstract: Wavelength conversion using semiconductor optical amplifiers monolithically integrated in a three-part Mach-Zehnder configuration is achieved for data rates of 1 and 2.5 Gb/s. The three-port configuration allows efficient use of pump signal power, as well as counter-propagation of pump and converted signals, eliminating the need for a filter. Operation of the device at 5 Gb/s in a two-port configuration is also achieved. Dynamic extinction ratios larger than 13 dB, as well as both data-inverting and noninverting operation are demonstrated. >
61 citations
TL;DR: The dependence of the transmission performance of 10 Gb/s systems on the splitting ratio of the Y-branch waveguides in a lithium niobate Mach-Zehnder modulator is assessed theoretically for single arm and dual arm modulation formats in this paper.
Abstract: The dependence of the transmission performance of 10 Gb/s systems on the splitting ratio of the Y-branch waveguides in a lithium niobate Mach-Zehnder modulator is assessed theoretically for single arm and dual arm modulation formats. When the splitting ratio is optimized, dual arm modulation using a push-pull configuration offers better dispersion limited performance than a conventional negative chirp modulator with symmetric Y-branch waveguides and single arm modulation (/spl alpha/ parameter of -1). The push-pull configuration also has the advantage of reducing the requirement on the amplitude of the modulating signals. >
48 citations
TL;DR: In this paper, a linearized solution for a series cascade of three Mach Zehnder interferometers separated by directional couplers is obtained that eliminates both the third and fifth order coefficients of the Taylor series representation of the transfer function.
Abstract: A linearized solution for a series cascade of three Mach Zehnder interferometers separated by directional couplers is obtained that eliminates both the third and fifth order coefficients of the Taylor series representation of the transfer function The device is characterized in terms of harmonic distortion with a three tone signal /spl sim/20-dB improvement in third harmonic distortion is obtained compared to a two section device >
TL;DR: In this article, the dark soliton data are generated by an AND gate and T-flip-flop circuits and detected by using a one-bit-shifting technique with a Mach-Zehnder interferometer.
Abstract: New schemes are described for the generation and detection of a dark soliton pseudorandom data train. The dark soliton data are generated by an AND gate and T-flip-flop circuits. The dark soliton is detected by using a one-bit-shifting technique with a Mach-Zehnder interferometer, which converts the dark soliton signal into a non-return-to-zero (NRZ) signal.
TL;DR: In this article, a three-port MZI wavelength converter enables strong improvement of extinction ratios up to 11 dB in dynamic operation and signal chirp reduction by optical crossphase modulation.
Abstract: 2.5 Gbit/s all-optical wavelength conversion is reported with a novel monolithically integrated Mach-Zehnder interferometer realised in InGaAs/InP MQW technology. The three-port MZI wavelength converter enables strong improvement of extinction ratios up to 11 dB in dynamic operation and signal chirp reduction by optical crossphase modulation. This improvement of signal quality by wavelength conversion is confirmed by a gain of 2.3 dB in system sensitivity after transmission over 100 km (nondispersion-shifted) fibre compared to the standard 2.5 Gbit/s direct modulation performance of a DFB laser. >
TL;DR: This investigation investigated the fringe visibility produced by a Mach-Zehnder interferometer illuminated by a collisionally pumped yttrium x-ray laser operating at 15.5 nm, yielding a gain-narrowed linewidth of 1.3 pm for the 15-nm laser transition and spatial coherence consistent with an effective source size of approximately 220 microm +/- 50% at the x- Ray laser output.
Abstract: We investigated the fringe visibility produced by a Mach–Zehnder interferometer illuminated by a collisionally pumped yttrium x-ray laser operating at 15.5 nm. Fringe visibility varied as a function both of relative path delay and of relative spatial overlap of the beams. This visibility information was extracted quantitatively from several interferograms and analyzed to produce a characterization of the temporal coherence, yielding a gain-narrowed linewidth of 1.3 pm for the 15.5-nm laser transition and spatial coherence consistent with an effective source size of ≈220 μm ± 50% at the x-ray laser output.
Patent•
25 May 1995TL;DR: In this article, the optical power splitting ratio between the two arms of the interferometer is adjusted to achieve the optimum distance and bit rate with low drive power. But the modulating voltage is supplied to a single arm or alternatively to both arms in a push-pull configuration.
Abstract: A Mach-Zehnder optical modulator in which the chirp parameter can be varied by adjusting the optical power splitting ratio between the two arms of the interferometer. The modulating voltage is supplied to a single arm or alternatively to both arms in a push-pull configuration. For an appropriate power splitting ratio negative chirp is achieved with approximately equal push-pull modulating drive voltage. This results in optimum distance and bit rate characteristics with low drive power.
TL;DR: In this article, a simple optimization method for determining the transmittance characteristics of an MZ filter gain equalizer required for optical networks using 980-nm or 1480-nm pumped EDFA cascades is introduced.
Abstract: This paper introduces a simple optimization method for determining the transmittance characteristics of an MZ filter gain equalizer required for optical networks using 980-nm or 1480-nm pumped EDFA cascades. This approach is shown capable of supporting 10 WDM signals spaced 2 nm apart over a 20-nm optical bandwidth (1540-1560 nm) up to a cascade of 10 amplifiers, allowing a total system gain of more than 150 dB with inter-channel power differences of less than 5 dB.
TL;DR: In this paper, two poled nonlinear optical side-chain polymers based on the dye Disperse Red 1, one with a glass transition temperature T g of 131 °C and the other with a t g of 228 °C, were used as the active layers in these devices.
Abstract: Polymeric 2×2 electro‐optic switches based on the balanced bridge, or Mach–Zehnder, design are presented. Two poled nonlinear optical side‐chain polymers based on the dye Disperse Red 1, one with a glass transition temperature T g of 131 °C and the other with a T g of 228 °C, were used as the active layers in these devices. The switch designs incorporated traveling‐wave electrodes in the phase shift sections and, for the lower T g polymerdevice, electrically adjustable 3 dB couplers. At the 1.32 μm operating wavelength, extinction ratios of at least 28 dB were achieved in all four states of the lower T g switch with a propagation loss of 1.6 dB/cm and a small signal 3 dB modulation bandwidth of over 2 GHz.
TL;DR: In this paper, fast 2/spl times/2 Mach-Zehnder optical space switches were achieved by using quantum confined Stark effect in InGaAsP-InP multiquantum-well structures that are ultracompact and require low voltages.
Abstract: We report fast 2/spl times/2 Mach-Zehnder optical space switches by using quantum confined Stark effect in InGaAsP-InP multiquantum-well structures that are ultracompact, require low voltages, and employ a simple RF drive with RC time-constant limited lumped electrodes. Cut-off frequencies in excess of 10 GHz are observed suitable for a variety of fast optical switching applications. >
TL;DR: In this article, a symmetric Mach-Zehnder (SMZ) all-optical switch was used to investigate the high-repetition switching capabilities of a recently developed symmetric MAC.
Abstract: The high‐repetition switching capabilities of a recently developed symmetric Mach–Zehnder (SMZ) all‐optical switch are experimentally investigated. Using a series of four control pulses at intervals of 100 or 25 ps, nearly full switching is achieved at the corresponding intervals. The results experimentally show that the repetition rate, as well as the switching speed, of the SMZ all‐optical switch is not restricted by the slow relaxation of the utilized high‐efficiency band‐filling effect.
TL;DR: In this article, the impact of thermal noise in the fiber on the noise power and signal-to-noise ratio (SNR) of fiber-optic sensors is investigated, and sensors based on the Sagnac and the Mach-Zehnder interferometers are compared.
Abstract: The impact of thermal noise in the fiber on the noise power and signal-to-noise ratio (SNR) of fiber-optic sensors is investigated, and sensors based on the Sagnac and the Mach-Zehnder interferometers are compared. The SNR is almost the same for the two interferometers; the Mach-Zehnder interferometer has slightly higher SNR at low frequencies, whereas the Sagnac interferometer may have a few dB higher SNR at high frequencies. It is also shown that thermal noise may dominate over shot noise for realistic system parameters, in which case a Sagnac interferometer has several advantages over a Mach-Zehnder interferometer. >
TL;DR: The first monolithically integrated DFB laser/Mach-Zehnder interferometric modulator fabricated by the selective area low pressure MOVPE growth technique is reported in this article.
Abstract: The first monolithically integrated DFB laser/Mach-Zehnder interferometric modulator fabricated by the selective area low pressure MOVPE growth technique is reported. A near 3-dB power divider at the Y-branches of the interferometer has been reproducibly achieved by a photolithographically defined dielectric mask used in the selective area growth technology and confirmed by an infrared near field imaging technique. A modulation depth of over 12 dB was achieved both in the forward and reverse bias to the arms of the phase modulator. >
TL;DR: In this paper, the real and imaginary parts of the linear electrooptic constants of four dyes, i.e., N,Ndimethylaminonitrostilbene (DANS), 4,[N,(2]-hydroxyethyl)‐N‐ethyl]amino‐4’−nitroazo‐ benzene [disperse red 1 (DR1)], N, Ndimentylindoaniline [phenol blue (PB)], and 1,1',3,3-3-5', 3'
Abstract: The real and imaginary parts of the linear electro‐optic (EO) constants of four dyes, i.e., N,N‐dimethylaminonitrostilbene (DANS), 4‐[N‐(2‐hydroxyethyl)‐N‐ethyl]amino‐4’‐nitroazo‐ benzene [disperse red 1 (DR1)], N,N‐dimentylindoaniline [phenol blue (PB)], and 1,1’,3,3,3’,3’‐hexamethylindotricarbocyanine iodide (HITCI) in polymethylmethacrylate (PMMA) films were determined using a Mach–Zehnder interferometer. The electronic transitions of DANS, DR1, PB, and HITCI are off‐resonant, near‐resonant, and resonant on the higher and lower energy sides with a He‐Ne laser wavelength (632.8 nm), respectively. The different ratios of the real and imaginary parts of the EO constants of four dyes including their signs are successfully explained in terms of detuning energy.
TL;DR: In this article, the authors examined the dispersion compensating schemes for 10 Gb/s lightwave systems based on a semiconductor Mach-Zehnder modulator and showed that the combination of an asymmetric input Y-branch waveguide push-pull operation of the optical modulator, and dispersion compensated fiber offers the best dispersion limited transmission performance.
Abstract: For 10 Gb/s lightwave systems based on a semiconductor Mach-Zehnder modulator, the following dispersion compensating schemes are examined theoretically; asymmetry in the splitting ratio of the modulator input Y-branch waveguide, linear equalization using an analog delay line equalizer, dispersion compensating fiber, and direct prechirping for NRZ signals. It is shown that the combination of an asymmetric input Y-branch waveguide push-pull operation of the optical modulator, and dispersion compensating fiber offers the best dispersion limited transmission performance. With dispersion compensating fiber, a larger portion of the optical power is applied to the arm of the modulator with more absorption, whereas without dispersion compensating fiber. A larger portion of the optical power is applied to the arm of the modulator with less absorption. >
TL;DR: In this paper, students in upper-division/graduate optics laboratory course assemble a Mach-Zehnder interferometer from simple components and use it to learn about interferometric principles and to visualize the phase-front geometries of light waves.
Abstract: Students in our upper‐division/graduate optics laboratory course assemble a Mach–Zehnder interferometer from simple components and use it to learn about interferometric principles and to visualize the phase‐front geometries of light waves. Here we describe the experimental procedures, specify the equipment needed, and make suggestions for follow‐up experiments.
TL;DR: In this article, it is shown that the wavelength converter has a strong influence on the intensity noise of the converted channel and ways of improving the noise performance of the converter are discussed.
Abstract: Wavelength conversion using semiconductor optical amplifiers in a Mach-Zehnder configuration is analyzed. It is shown that the wavelength converter has strong influence on the intensity noise of the converted channel. Ways of improving the noise performance of the wavelength converter are discussed. >
TL;DR: A new type of optical-fiber Mach-Zehnder interferometer whose output depends on phase differentials or the time rate of change of the unknown phase-modulating signal is introduced.
Abstract: We introduce a new type of optical-fiber Mach–Zehnder interferometer whose output depends on phase differentials or the time rate of change of the unknown phase-modulating signal. Whereas the actual phase excursion introduced by the signal could cause interference over several fringes in a conventional Mach–Zehnder interferometer, the differential phase shifts may be restricted to the linear range of the phase detector. Being of simple construction, the interferometer can be operated without active biasing, additional phase modulation, or complex signal-processing techniques. We analyze a prototype architecture to explain the principle of operation of the system and to derive design formulas. This is followed by experimental evaluation of a more practical configuration.
TL;DR: In this article, the phase shift in realistic experiments is addressed and two different estimations are suggested, and the conditional probability is given by the experimentally observable dependence of the measured probability on phase shift.
Abstract: The estimation of phase shift in realistic experiments is addressed here. Provided that the phase concept is not ideal, the phase shift should always be inferred from the performed measurement. Particulary, two different estimations are suggested. The conditional probability is given by the experimentally observable dependence of the measured probability on the phase shift. As an explicit example, the accuracy of the phase measurement on the Mach-Zehnder interferometer is evaluated using different methods for comparison.
TL;DR: In this article, the authors developed a new interpretation of MMI couplers for optical switching and for wavelength filtering, they are shown to work as active or passive integrated prisms.
Abstract: To simplify the driving conditions as well as to improve the wavelength response of multileg Mach-Zehnder interferometers (MZI) based on multimode interference (MMI) couplers we develop a new interpretation of these devices. Used for optical switching and for wavelength filtering, they are shown to work as active or passive integrated prisms. This analogy greatly facilitates the design of such components and simplifies the understanding of their functionality. The driving conditions of optical switches based on such multileg MZI are easility studied and will be reduced to basic active phase shifts. For wavelength filtering applications using such elements, a new design of the phased waveguide array is proposed which improves the characteristics of the filters.
01 Jan 1995
TL;DR: In this article, a novel type of wavelength demultiplexer is presented based on a generalized multimode interference/Mach Zehnder interferometer (MMI-MZI) configuration, which combines the potential of low loss and high uniformity of the output channels with a small device size.
Abstract: A novel type of wavelength demultiplexer is presented based on a generalized multimode interference/Mach Zehnder interferometer (MMI-MZI) configuration. This device combines the potential of low loss and high uniformity of the output channels with a small device size. Feasibility of the novel concept is demonstrated experimentally for a 4-channel demultiplexer with 4 nm channel spacing. Dimensions are 2800*106 mu m, which is the smallest device size reported so far