The Experts below are selected from a list of 64782 Experts worldwide ranked by ideXlab platform
Takashi Saida - One of the best experts on this subject based on the ideXlab platform.
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Temperature insensitive and ultra wideband silica-based dual polarization Optical Hybrid for coherent receiver with highly symmetrical interferometer design.
Optics express, 2011Co-Authors: Yusuke Nasu, Takayuki Mizuno, Ryoichi Kasahara, Takashi SaidaAbstract:To extend the operation wavelength range of dual-polarization Optical Hybrids (DPOH), we propose a highly symmetrical interferometer design for a polarization beam splitter and an Optical Hybrid to reduce temperature and wavelength dependence. The design successfully decreases this dependence, and a fabricated DPOH with silica-based planar lightwave circuits provides temperature-insensitive performance with a polarization extinction ratio of over 25 dB and phase errors of less than 3 degrees over the entire C- and L-bands.
Yusuke Nasu - One of the best experts on this subject based on the ideXlab platform.
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Temperature insensitive and ultra wideband silica-based dual polarization Optical Hybrid for coherent receiver with highly symmetrical interferometer design.
Optics express, 2011Co-Authors: Yusuke Nasu, Takayuki Mizuno, Ryoichi Kasahara, Takashi SaidaAbstract:To extend the operation wavelength range of dual-polarization Optical Hybrids (DPOH), we propose a highly symmetrical interferometer design for a polarization beam splitter and an Optical Hybrid to reduce temperature and wavelength dependence. The design successfully decreases this dependence, and a fabricated DPOH with silica-based planar lightwave circuits provides temperature-insensitive performance with a polarization extinction ratio of over 25 dB and phase errors of less than 3 degrees over the entire C- and L-bands.
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Heterogeneous integration of high-speed InP PDs on silica-based planar lightwave circuit platform
37th European Conference and Exposition on Optical Communications, 2011Co-Authors: Yu Kurata, Yusuke Nasu, Munehisa Tamura, Haruki Yokoyama, Yoshifumi MuramotoAbstract:We demonstrate the first heterogeneous integration of high-speed InP PDs on a silica-based PLC platform. 28 Gbaud QPSK signal detection is realized using a coherent detector integrated with four PDs and a 90° Optical Hybrid.
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Dual polarisation Optical Hybrid using silica-based planar lightwave circuit technology for digital coherent receiver
Electronics Letters, 2010Co-Authors: Y. Sakamaki, Takashi Goh, T. Hashimoto, Kyota Hattori, Yusuke Nasu, Takayuki Mizuno, Hiroki Takahashi, Hiroshi Yamazaki, Sayaka Kamei, Takehiko KobayashiAbstract:Described is a compact dual polarisation Optical Hybrid (DPOH) that has been achieved by integrating polarisation beam splitters and 90°-Hybrids fabricated with silica-based planar lightwave circuit technology. The fabricated DPOH worked completely passively without any adjustments and its Optical characteristics were sufficient for the coherent detection of 111°Gbit/s DPQPSK signals.
Josep Prat - One of the best experts on this subject based on the ideXlab platform.
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Homodyne receiver prototype with time-switching phase diversity and feedforward analog processing
Optics letters, 2007Co-Authors: Josep M. Fabrega, Josep PratAbstract:A differential phase shift keying homodyne Optical receiver is experimentally demonstrated based on time-switching phase diversity, without the need for a 90° Optical Hybrid. It achieves high tolerance to phase noise and feasible implementation with off-the-shelf electrical and Optical components.
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Homodyne Receiver Implementation with Diversity Switching and Analogue Processing
2006 European Conference on Optical Communications, 2006Co-Authors: Josep M. Fabrega, Josep PratAbstract:A PSK homodyne Optical receiver is experimentally demonstrated based on time-diversity switching, without Optical Hybrid. It achieves high tolerance to phase noise and feasible implementation with off-the-shelf electrical and Optical components.
Moshe Zukerman - One of the best experts on this subject based on the ideXlab platform.
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An Optical Hybrid Switch With Circuit Queueing for Burst Clearing
Journal of Lightwave Technology, 2008Co-Authors: Eric Wong, Moshe ZukermanAbstract:We consider an Optical Hybrid switch that can function as an Optical burst switch and/or Optical circuit switch. We propose and describe in detail a new implementation whereby circuits have nonpreemptive priority over bursts. To achieve nonpreemptive priority, during circuit setup time, if there exist bursts that use wavelength channels (also called links) required by the circuit, the circuit is allowed to queue for a relatively short period of time until these bursts are cleared. We present an analysis based on a 3-D Markov chain that provides exact results for the blocking probabilities of bursts and circuits, the proportion of circuits that are delayed and the mean delay of the circuits that are delayed. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally scalable and accurate approximations based on reducing the 3-D state space into a single dimension. These scalable approximations that can produce performance results in few seconds can readily enable switch dimensioning. Extensive numerical results are presented to demonstrate the accuracy and the use of the new approximations.
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Performance evaluation of an Optical Hybrid switch with circuit queued reservations and circuit priority preemption
Optics express, 2006Co-Authors: Eric Wong, Moshe ZukermanAbstract:We provide here a new loss model for an Optical Hybrid switch that can function as an Optical burst switch and/or Optical circuit switch. Our model is general as it considers an implementation whereby some of the circuits have preemptive priority over bursts and others are allowed to queue their reservations. We first present an analysis based on a 3-dimension state-space Markov chain that provides exact results for the blocking probabilities of bursts and circuits, the proportion of circuits that are delayed and the mean delay of the circuits that are delayed. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally a scalable and accurate approximations based on reducing the 3-dimension state space into a single dimension. These scalable approximations that can produce performance results in a fraction of a second can readily enable switch dimensioning. Extensive numerical results are presented to demonstrate the accuracy and the use of the new approximations.
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Performance evaluation for an Optical Hybrid switch with circuit queued reservations.
Optics express, 2005Co-Authors: Eric Wong, Moshe ZukermanAbstract:We provide here a new loss model for an Optical Hybrid switch that can function as an Optical burst switch or Optical circuit switch or both simultaneously. We introduce the feature of circuit queued reservation. That is, if a circuit request arrives and cannot find a free wavelength, and if there are not too many requests queued for reservations, it may join a queue and wait until such wavelength becomes available. We first present an analysis based on a 3-dimension state-space Markov chain that provides exact results for the blocking probabilities of bursts and circuits. We also provide results for the proportion of circuits that are delayed and the mean delay of the circuits that are delay. Because it is difficult to exactly compute the blocking probability in realistic scenarios with a large number of wavelengths, we derive computationally scalable and accurate approximations which are based on reducing the 3-dimension state space into a single dimension. These scalable approximations that can produce performance results in a fraction of a second can readily enable switch dimensioning.
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ICOIN - Optical Hybrid Switching – Combined Optical Burst Switching and Optical Circuit Switching
Lecture Notes in Computer Science, 2004Co-Authors: Gyu Myoung Lee, Jun Kyun Choi, B. Wydrowski, Moshe Zukerman, Chul-hee KangAbstract:In this paper, we propose a new Optical Hybrid switching technique which combined Optical Burst Switching (OBS) and Optical Circuit Switching (OCS) using flow classification. In particular, this switching technique classifies incoming IP traffic flows into short-lived and long-lived flows for Quality of Service (QoS) provisioning according to traffic characteristics. The aim is to maximize network utilization while satisfying user’s QoS requirements. We model the system as a single server queue in a Markovian environment. The burst generation process is assumed to follow a two-state Markov Modulated Poisson Process (MMPP), and the service rate fluctuates based on the number of concurrent OCS sessions. Results for the delay and OBS burst assembly time are derived.
Ryoichi Kasahara - One of the best experts on this subject based on the ideXlab platform.
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Continuous and long-term stabilization of degenerate Optical parametric oscillators for large-scale Optical Hybrid computers.
Optics express, 2020Co-Authors: Takuya Ikuta, Ryoichi Kasahara, Takahiro Inagaki, Kensuke Inaba, Toshimori Honjo, Takushi Kazama, Koji Enbutsu, Takahiro Kashiwazaki, Takeshi Umeki, Hiroki TakesueAbstract:The minimum requirements for an Optical reservoir computer, a recent paradigm for computation using simple algorithms, are nonlinearity and internal interactions. A promising Optical system satisfying these requirements is a platform based on coupled degenerate Optical parametric oscillators (DOPOs) in a fiber ring cavity. We can expect advantages using DOPOs for reservoir computing with respect to scalability and reduction of excess noise; however, the continuous stabilization required for reservoir computing has not yet been demonstrated. Here, we report the continuous and long-term stabilization of an Optical system by introducing periodical phase modulation patterns for DOPOs and a local oscillator. We observed that the Allan variance of the Optical phase up to 100 ms was suppressed and that the homodyne measurement signal had a relative standard deviation of 1.4% over 62,500 round trips. The proposed methods represent important technical bases for realizing stable computation on large-scale Optical Hybrid computers.
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Temperature insensitive and ultra wideband silica-based dual polarization Optical Hybrid for coherent receiver with highly symmetrical interferometer design.
Optics express, 2011Co-Authors: Yusuke Nasu, Takayuki Mizuno, Ryoichi Kasahara, Takashi SaidaAbstract:To extend the operation wavelength range of dual-polarization Optical Hybrids (DPOH), we propose a highly symmetrical interferometer design for a polarization beam splitter and an Optical Hybrid to reduce temperature and wavelength dependence. The design successfully decreases this dependence, and a fabricated DPOH with silica-based planar lightwave circuits provides temperature-insensitive performance with a polarization extinction ratio of over 25 dB and phase errors of less than 3 degrees over the entire C- and L-bands.