Showing papers on "Mach–Zehnder interferometer published in 2005"
TL;DR: The generalization of optical Mach-Zehnder interferometry, performed in qubit phase space, provides an alternative means to manipulate and characterize the qubit in the strongly driven regime.
Abstract: We demonstrate Mach-Zehnder-type interferometry in a superconducting flux qubit. The qubit is a tunable artificial atom, the ground and excited states of which exhibit an avoided crossing. Strongly driving the qubit with harmonic excitation sweeps it through the avoided crossing two times per period. Because the induced Landau-Zener transitions act as coherent beamsplitters, the accumulated phase between transitions, which varies with microwave amplitude, results in quantum interference fringes for n = 1 to 20 photon transitions. The generalization of optical Mach-Zehnder interferometry, performed in qubit phase space, provides an alternative means to manipulate and characterize the qubit in the strongly driven regime.
380 citations
TL;DR: In this article, a method of generating an electromagnetic Gaussian Schell-model source from two coherent linearly polarized plane waves is described, which involves two mutually correlated phase-only liquid-crystal spatial light modulators placed in the arms of a Mach-Zehnder interferometer.
Abstract: A method of generating an electromagnetic Gaussian Schell-model source from two coherent linearly polarized plane waves is described. This method involves two mutually correlated phase-only liquid-crystal spatial light modulators placed in the arms of a Mach–Zehnder interferometer. The sources produced by this method can be used to generate a wide class of electromagnetic beams with prescribed coherence and polarization properties.
130 citations
TL;DR: The optical phase sensitivity of fiber based on poly(methyl methacrylate) under near-single-mode conditions at 632.8 nm wavelength is measured, consistent with the values expected on the basis of the bulk polymer properties.
Abstract: We report experimental measurements of the strain and temperature sensitivity of the optical phase in a singlemode polymer optical fibre. These values were obtained by measuring optical path length change using a Mach-Zender interferometer.
117 citations
TL;DR: An InGaAsP-InP optical switch geometry based on electrical control of waveguide-resonator coupling is demonstrated, which enables a substantial reduction of the switching power, to a value of 26 mW in comparison with 40 mW for a conventional Mach-Zehnder interferometer switch.
Abstract: An InGaAsP-InP optical switch geometry based on electrical control of waveguide-resonator coupling is demonstrated. Thermooptic tuning of a Mach-Zehnder interferometer integrated with a racetrack resonator is shown to result in switching with ON-OFF contrast up to 18.5 dB. The optical characteristics of this unique design enable a substantial reduction of the switching power, to a value of 26 mW in comparison with 40 mW for a conventional Mach-Zehnder interferometer switch. Modulation response measurements reveal a 3 dB bandwidth of 400 kHz and a rise time of 1.8 µs, comparing favorably with current state-of-the-art thermooptic switches.
116 citations
TL;DR: The performance of all-optical XOR gate based on quantum-dot (QD) SOA MZI has been simulated and XOR operation at ~ 250 Gb/s is feasible using QD based Mach-Zehnder interferometers.
Abstract: The performance of all-optical XOR gate based on quantum-dot (QD) SOA MZI has been simulated. The saturation power, optical gain and phase response of a QD SOA has been analyzed numerically using a rate equation model of quantum dots embedded in a wetting layer. The calculated response is used to model the XOR performance. For the parameters used here, XOR operation at ~250 Gb/s is feasible using QD based Mach-Zehnder interferometers. The speed is limited by the relaxation time from wetting layer to the quantum dots.
100 citations
TL;DR: A simple microresonator scheme for a Mach-Zehnder interferometer in which a microResonator is side coupled to one arm and a phase shifter is introduced into the other arm, to produce an asymmetric Fano-resonance line shape is proposed.
Abstract: We propose a simple microresonator scheme for a Mach-Zehnder interferometer in which a microresonator is side coupled to one arm and a phase shifter is introduced into the other arm, to produce an asymmetric Fano-resonance line shape. In this system, a phase shifter is used to control the variation of the asymmetric line shape, with another reverse resonance next to a resonance minimum over a very narrow frequency range, which results from the interference between a direct channel and a high-Q resonance indirect channel. We also theoretically investigate the novel bistability characteristic based on these shapes.
81 citations
TL;DR: The phase-shifting system combines the advantages of a Twyman-Green and a Mach-Zehnder interferometer and permits full characterization of the aberrations of microlenses as well as radius of curvature and focal length measurements.
Abstract: A new interferometer design for microlens testing is presented. The phase-shifting system combines the advantages of a Twyman-Green and a Mach-Zehnder interferometer and permits full characterization of the aberrations of microlenses as well as radius of curvature and focal length measurements. The Twyman-Green system is applied to surface testing in reflection (single reflection), whereas the Mach-Zehnder system is used for lens testing in transmission (single pass). Both measurements are performed without removal of the test part, allowing for combination of the results without confusion of the actual lens and without an azimuthal orientation error. The interferometer setup is explained, the test procedure is described, and experimental results are given.
56 citations
Patent•
12 Jan 2005
TL;DR: In this article, the authors present devices and techniques for achieving signal filtering in RF or microwave frequencies by optical filtering using two separate optical paths, each optical path may include one or more optical resonators to achieve desired optical filtering.
Abstract: Devices and techniques for achieving signal filtering in RF or microwave frequencies by optical filtering using two separate optical paths. Each optical path may include one or more optical resonators to achieve desired optical filtering.
54 citations
TL;DR: In this article, the authors investigated the visibility of the current and shot-noise correlations of electrical analogs of the optical Mach-Zehnder interferometer and the Hanbury Brown Twiss interFERometer.
Abstract: We investigate the visibility of the current and shot-noise correlations of electrical analogs of the optical Mach-Zehnder interferometer and the Hanbury Brown Twiss interferometer. The electrical analogs are discussed in conductors subject to high magnetic fields where electron motion is along edge states. The transport quantities are modulated with the help of an Aharonov-Bohm flux. We discuss the conductance (current) visibility and shot noise visibility as a function of temperature and applied voltage. Dephasing is introduced with the help of fictitious voltage probes. Comparison of these two interferometers is of interest since the Mach-Zehnder interferometer is an amplitude (single-particle) interferometer, whereas the Hanbury Brown Twiss interferometer is an intensity (two-particle) interferometer. A direct comparison is only possible for the shot noise of the two interferometers. We find that the visibility of shot noise correlations of the Hanbury Brown Twiss interferometer as a function of temperature, voltage or dephasing, is qualitatively similar to the visibility of the first harmonic of the shot noise correlation of the Mach-Zehnder interferometer. In contrast, the second harmonic of the shot noise visibility of the Mach-Zehnder interferometer decreases much more rapidly with increasing temperature, voltage or dephasing rate.
53 citations
TL;DR: In this paper, a Mach-Zehnder delay interferometer was used for the first time to convert from NRZ to RZ using a 1.40 Gbit/s signal format.
48 citations
01 Jan 2005
TL;DR: In this article, a novel method of all-optical wavelength conversion of DPSK signal is presented, which demonstrates wavelength conversion for 40-Gb/s DPSK signals with a large dynamic range of input OSNR, and significant reduction of phase fluctuations.
Abstract: A novel method of all-optical wavelength conversion of DPSK signal is presented. We demonstrate wavelength conversion of 40-Gb/s DPSK signals with a large dynamic range of input OSNR, and significant reduction of phase fluctuations. (2 pages)
TL;DR: A study is presented of a Mach-Zehnder interferometer for the measurement of phasing errors of the type found in segmented telescopes and shows that with a pinhole much larger than the Airy disk and an optical path difference between the arms equal to a quarter of the wavelength, the interferometric signal is related to the second derivative of the wave front.
Abstract: A study is presented of a Mach-Zehnder interferometer for the measurement of phasing errors of the type found in segmented telescopes. We show that with a pinhole much larger than the Airy disk and an optical path difference between the arms equal to a quarter of the wavelength, the interferometric signal is related to the second derivative of the wave front. In this condition the signal is produced mostly by the segmentation errors and is marginally sensitive to other aberrations including atmospheric turbulence. The signal has distinguishable symmetric and antisymmetric properties that are related to segment aberrations. We suggest using the antisymmetric component of the signal to retrieve piston, tip, and tilt. The symmetric component of the signal serves as an estimate of the measurement error. In this way we proceed with a study of the errors associated with the misalignment of the interferometer, the segment edge imperfections, and the nonaveraged atmospheric perturbations. The entire study is performed on a theoretical basis, and numerical simulations are used to cross check the analytical results.
TL;DR: The experimental results show optical bistable operation for a latching device with an on-off contrast ratio of 11 dB that employs set and reset pulses of less than 250 pJ, although the energy of these pulses could be greatly reduced by optical integration of the whole device.
Abstract: A novel architecture for an all-optical flip-flop is validated experimentally. The architecture comprises a single semiconductor optical amplifier-based Mach-Zehnder interferometer with an external feedback loop. The experimental results show optical bistable operation for a latching device with an on-off contrast ratio of 11 dB that employs set and reset pulses of less than 250 pJ, although the energy of these pulses could be greatly reduced by optical integration of the whole device.
TL;DR: In this paper, the authors demonstrate that networks of locally connected processing units with a primitive learning capability exhibit a behavior that is usually only attributed to quantum systems, and describe networks that simulate single-photon beam splitter and Mach-Zehnder interferometer experiments on a causal, event-by-event basis and demonstrate that the simulation results are in excellent agreement with quantum theory.
Abstract: We demonstrate that networks of locally connected processing units with a primitive learning capability exhibit a behavior that is usually only attributed to quantum systems. We describe networks that simulate single-photon beam splitter and Mach-Zehnder interferometer experiments on a causal, event-by-event basis and demonstrate that the simulation results are in excellent agreement with quantum theory.
TL;DR: A single theory is shown to describe decoherence due to scattering either atoms or photons in a Mach-Zehnder atom interferometer, and predictions from this theory are tested by experiments with different species of background gas, and by experiment with different collimation restrictions on an atom beam interferometers.
Abstract: Decoherence due to scattering from background gas particles is observed for the first time in a Mach-Zehnder atom interferometer, and compared with decoherence due to scattering photons. A single theory is shown to describe decoherence due to scattering either atoms or photons. Predictions from this theory are tested by experiments with different species of background gas, and also by experiments with different collimation restrictions on an atom beam interferometer.
TL;DR: QD lasers are thus superior to QW lasers for any system or network, and Quantum dot semiconductor optical amplifiers (QD SOAs) demonstrate gain recovery times of 120–140 fs, 4–7 times faster than bulk/QW SOAs, and a net gain larger than 0.4 dB/(mm×QD layer) providing us with novel types of booster amplifiers and Mach–Zehnder interferometers.
TL;DR: In this article, the performance of a Mach-Zehnder interferometer consisting of two coupled-cavity waveguides with different lengths created in a two-dimensional photonic crystal is theoretically analyzed.
Abstract: Photonic crystal technology allows the creation of optical waveguides with low sharp-bending losses as well as ultra-low group velocity This last property is particularly interesting to develop highly-compact optical devices based on the controlled modification of the optical phase of the signals traveling through the waveguides Among these devices, the Mach–Zehnder interferometer acquires fundamental importance because it can be used as a building block of more complex optical devices and functionalities such as optical filters, wavelength demultiplexers, channels interleavers, intensity modulators, switches and optical gates In this paper, the performance of a Mach–Zehnder interferometer consisting of two coupled-cavity waveguides with different lengths created in a two-dimensional photonic crystal is theoretically analyzed We also provide simulation results using a finite-difference time-domain code that confirm the theoretical analysis The main limitations in the performance of the structure are addressed and discussed
06 Mar 2005
TL;DR: In this article, signal predistortion using a dual-drive Mach-Zehnder modulator and nonlinear digital filters was proposed, achieving compensation of 13600 ps/nm, equivalent to 800 km of standard single mode fiber at 10 Gbit/s.
Abstract: We propose the technique of signal predistortion using a dual-drive Mach-Zehnder modulator and nonlinear digital filters, and demonstrate compensation of 13600 ps/nm, equivalent to 800 km of standard single mode fibre, at 10 Gbit/s.
TL;DR: In this paper, a Hong-Ou-Mandel experiment with coherent photons is reported, where pairs of degenerate photons at telecommunication wavelength are created by parametric down-conversion in a periodically poled lithium niobate waveguide.
Abstract: To show the feasibility of a long-distance partial Bell-state measurement, a Hong-Ou-Mandel experiment with coherent photons is reported. Pairs of degenerate photons at telecommunication wavelength are created by parametric down-conversion in a periodically poled lithium niobate waveguide. The photon pairs are separated in a beam splitter and transmitted via two fibers of 25 km. The wave packets are relatively delayed and recombined on a second beam splitter, forming a large Mach-Zehnder interferometer. Coincidence counts between the photons at the two output modes are registered. The main challenge consists in the trade-off between low count rates due to narrow filtering and length fluctuations of the 25-km-long arms during the measurement. For balanced paths a Hong-Ou-Mandel dip with a net visibility of 47.3% is observed, which is close to the maximal theoretical value of 50% developed here. This proves the practicability of a long-distance Bell-state measurement with two independent sources, as, e.g., required in an entanglement swapping configuration in the scale of tens of kilometers.
TL;DR: In this paper, an all-optical exclusive or gate by use of an integrated semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer sped up by an assistant light was proposed.
Abstract: We propose, for the first time to our knowledge, an all-optical exclusive or gate by use of an integrated semiconductor optical amplifier (SOA)-based Mach-Zehnder interferometer sped up by an assistant light. Through numerical simulations it is shown that, by use of a continuous-wave (cw) assistant light at the SOA transparency wavelength to increase the gain recovery rate of the SOA, the operating speed limit of the xor gate can be increased. The SOA parameters and the assistant light energy are discussed and designed to optimize the performance of the xor gate.
Patent•
15 Dec 2005
TL;DR: In this paper, an apparatus and method for using a counter-propagating signal method for locating events is described, and the method uses a Mach Zehnder interferometer through which counter propagating signals can be launched and the time difference between receipt of those signals is used to determine the location of the event.
Abstract: An apparatus and method for using a counter-propagating signal method for locating events is disclosed. The apparatus and method uses a Mach Zehnder interferometer through which counter-propagating signals can be launched. If the sensing zone of the Mach Zehnder interferometer is disturbed, modified counter-propagating signals are produced and the time difference between receipt of those signals is used to determine the location of the event. Polarisation controllers (43, 44) receive feedback signals so that the polarisation states of the counter-propagating signals can be controlled to match the amplitude and/or phase of the signals. Detectors are provided for detecting the modified signals.
TL;DR: In this paper, which-path information is erased not by modifying the interferometer apparatus, but instead by modifying information obtained from measurements performed on a second beam, whose polarization is correlated with that of the inter-ferometer beam.
Abstract: We have demonstrated the operation of a quantum eraser based on a polarization interferometer. Which-path information is erased not by modifying the interferometer apparatus, but instead by modifying the information obtained from measurements performed on a second beam, whose polarization is correlated with that of the interferometer beam. We compare the results obtained when the two beams are in an entangled state (quantum correlations) and in a mixed state (classical correlations). We find that classical correlations can mimic most, but not all, of the quantum-mechanical behavior.
TL;DR: This paper investigates the nonlinear distortion of Orthogonal Frequency-Division Multiplex (OFDM) signals caused by a Radio-over-Fiber stage in the transmission chain if a Mach-Zehnder electro-optical modulator is employed.
Abstract: Radio-over-Fiber (RoF) techniques enable transmission of microwave and millimeter-wave signals for long distances with small loss. Due to the limited signal handling capabilities of electrical/optical components, proper leveling is necessary in order to achieve the highest dynamic range while maintaining distortion at acceptable level. This paper investigates the nonlinear distortion of Orthogonal Frequency-Division Multiplex (OFDM) signals caused by a Radio-over-Fiber stage in the transmission chain if a Mach-Zehnder electro-optical modulator is employed.
TL;DR: Two active Mach-Zehnder interferometers are integrated in a monolithic InP/InGaAsP photonic integrated circuit, which forms a crucial component for optical signal processing: an optical memory element or set-reset flip-flop.
Abstract: Two active Mach-Zehnder interferometers are integrated in a monolithic InP/InGaAsP photonic integrated circuit. Together they form a crucial component for optical signal processing: an optical memory element or set-reset flip-flop. The switching time for this initial device is approximately 200 ps. The photonic integrated circuit contains active and passive optical components, including electro-optic phase shifters.
TL;DR: In this article, the authors investigated the full counting statistics of an electrical Mach-Zehnder interferometer penetrated by an Aharonov-Bohm flux, and in the presence of a classical fluctuating potential.
Abstract: We investigate the full counting statistics of an electrical Mach-Zehnder interferometer penetrated by an Aharonov-Bohm flux, and in the presence of a classical fluctuating potential. Of interest is the suppression of the Aharonov-Bohm oscillations in the distribution function of the transmitted charge. For a Gaussian fluctuating field we calculate the first three cumulants. The fluctuating potential causes a modulation of the conductance leading in the third cumulant to a term cubic in voltage and to a contribution correlating modulation of current and noise. In the high voltage regime we present an approximation of the generating function.
TL;DR: In this article, a Mach-Zehnder interferometer (MZI) optical switch based on a 1.5/spl mu/m InGaAs-AlGaInAs multiple-quantum-well structure is reported.
Abstract: A highly efficient monolithically integrated Mach-Zehnder interferometer (MZI) optical switch based on a 1.5-/spl mu/m InGaAs-AlGaInAs multiple-quantum-well structure is reported. The device was fabricated by integrating phase shifter sections with bandgap-shifted low-loss waveguides obtained by a single step sputtered SiO/sub 2/-annealing quantum-well intermixing technique. Evaluation of the refractive index change induced by current injection (plasma, band-filling, band-shrinkage effects) and applied electric field (quantum confined Stark effect) based on the MZI was investigated. A device with an active length of 400 /spl mu/m in one of the MZI arms had an extinction ratio /spl ges/20 dB with a half-wavelength current (I/sub /spl pi//) and half-wavelength voltage V/sub /spl pi// as low as 3.2 mA and 3.5 V (1.9 V in push-pull configuration), respectively.
Patent•
JDSU1
TL;DR: In this article, an optical external modulator with a first interferometer section and a second interferer section formed on an electro-optic substrate is described. And the optical time delay is used for at least partially compensating for a velocity mismatch between the light and the RF drive signal.
Abstract: An optical external modulator includes an optical waveguide having a first interferometer section and a second interferometer section formed on an electro-optic substrate. An electrode structure disposed on the substrate transmits an RF drive signal that is applied to the first and second interferometer sections in series. A reflector optically coupled to the substrate redirects light away from the first interferometer section to the second interferometer section and provides an optical fold region that introduces an optical time delay between the first and second interferometer sections. The optical time delay is used for at least partially compensating for a velocity mismatch between the light and the RF drive signal.
TL;DR: In this paper, the optical single sideband (SSB) modulations are analyzed under the assumption that SSB modulators are constructed using Mach-Zehnder (MZ) interferometers.
Abstract: Modulator output and fiber transmission characteristics of optical single sideband (SSB) modulations are analyzed under the assumption that SSB modulators are constructed using Mach-Zehnder (MZ) interferometers. The fiber input signal and the detected signal are derived theoretically for SSB modulation with and without an optical carrier. Optical SSB fiber transmission simulations show that the received signal waveform is degraded by harmonic components due to non-linear switching curve of MZ interferometer as a component of SSB modulators even if the Hilbert transformers is ideal for the definition. The optical SSB suppressed carrier is preferred to the SSB with an optical carrier from a viewpoint of waveform degradation.
TL;DR: Two generalized array configurations of ring-coupled MZI are presented and their characteristics in terms of the amplitude and phase response of the ring arrays as well as the transmission output of the MZIs are discussed.
Abstract: Ring resonators are waveguide realizations of Fabry-Perot resonators which can be readily integrated in array geometries to implement many useful functions Its nonlinear phase response can be readily incorporated into a Mach-Zehnder interferometer to produce specific intensity output function We present two generalized array configurations of ring-coupled MZI and discuss their characteristics in terms of the amplitude and phase response of the ring arrays as well as the transmission output of the MZIs The two types of array have distinct transfer functions and effective phase shifts, and can be tailored to phase-engineer a wide-range of MZI transmission functions
TL;DR: In this paper, an interferometer which is capable of measuring phase at a Heisenberg limit of 1/3 was proposed, which consumes three indistinguishable photons, consisting of two beam splitters with two-third reflectivity and two mirrors.
Abstract: We describe an interferometer which is capable of measuring phase at a Heisenberg limit of 1/3. The proposed interferometer, which consumes three indistinguishable photons, consists of two beam splitters with two-third reflectivity and two mirrors. It is shown that the oscillation period of the quantum interference is three times shorter than in the classical case and the interference visibility is 100%. A de Broglie wavelength given by {lambda}{sub 0}/3 can then be observed in this scheme, where {lambda}{sub 0} is the wavelength of a single photon. Compared with similar phase measurements [Mitchell et al., Nature (London) 429, 161 (2004); Walter et al., ibid. 429, 158 (2004)] by multiphoton maximally entangled states (MES), a three-photon MES is not generated in our proposal.