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Preemptive and non-preemptive scheduling of optical switches with configuration delay

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Science in China(Series F) 2006年第5期49卷 653-664页

作者： ZHANG Zhizhong CHENG Fang LUO Jiangtao MAO Qijian WANG Jun QIU Shaofeng Department of Communication Engineering Chongqing University of Posts and Telecommunications Chongqing 400065 China

Utilizing optical technologies for the design of packet switches and routers offers several advantages in terms of scalability, high bandwidth, power consumption, and cost. However, the configuration delays of optical crossbars are much longer than that of the electronic counterpart, which makes the conventional slot-by-slot scheduling methods no longer the feasible solution. Therefore, some tradeoff must be found between the empty time slots and configuration overhead. This paper classifies such scheduling problems into preemptive and non-preemptive scenarios, each has its own advantages and disadvantages. Although non-preemptive scheduling is inherently not good at achieving the above-mentioned tradeoff, it is shown, however, that the proposed maximum weight matching （MWM） based greedy algorithm is guaranteed to achieve an approximation 2 for arbitrary configuration delay, and with a relatively low time complexity O（N^2）. For preemptive scheduling, a novel 2-approximation heuristic is presented. Each time in finding a switch configuration, the 2-approximation heuristic guarantees the covering cost of the remaining traffic matrix to have 2-approximation. Simulation results demonstrate that 2-approximation heuristic （1） performs close to the optimal scheduling, and （2） outperforms ADJUST and DOUBLE in terms of traffic transmission delay and time complexity.

关键词： optical switches scheduling configuration delay.

optical Performance of 4×4 MEMS optical switches

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Optical Performance of 4×4 MEMS Optical Switches

Model GC1343S Integrated Modules with 3× 3 optical switches

Asia-pacific optical Communications 2004

作者： Qiaoyan Hu Yuzhou Zhao Xubin Lin Jing Li Baojun Li State Key Laboratory of Optoelectronic Materials and Technologies Sun Yat-Sen University Guangzhou China 510275 Email: qiaoyanhu@***

optical switches made with Micro-electro-mechanical Systems (MEMS) technology bear advantages of both MEMS and traditional optics. It is of very importance to control position misalignments and angula

关键词： optical communications optical switches MEMS

来源： cnki会议评论

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cnki会议

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Semiconductor Photonics and Technology 2000年第4期 206-206页

Free-space 1×2 wavelength-selective switches for wavelength-division multiplexing optical networks

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Chinese Optics Letters 2009年第7期7卷 553-555页

作者：李小奇梁静秋孙德贵李伟梁中翥 State Key Laboratory of Applied Optics Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Graduate University of Chinese Academy of Sciences

A free-space 1 ×2 wavelength-selective switch （WSS） based on thin-film filter technology is proposed. The 1 × 2 WSS is fabricated with an electromagnetic actuator, a reflecton prism, a narrow-band thin-film filter, and three fiber collimators. The working principle and the configuration of WSS are illuminated. The experimental results indicate a fiber-to-fiber insertion loss ranging from 1.109 to 1.249 dB with 2-V voltage input, which satisfies the application of optical fiber communication.

关键词： Microelectromechanical devices optical communication optical fiber fabrication optical fibers optical materials optical switches Thin film devices

Research on application of MOOC in optical packet switching

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Chinese Optics Letters 2010年第1期8卷 11-13页

作者：侯奋飞孙小菡 School of Electronic Science and Engineering Southeast University School of Physics and Technology Nanjing Normal University

An experiment on receiving and identifying multiple optical orthogonal codes （MOOC） sequence-based optical labels in an optical packet switching （OPS） network is reported. Two groups of MOOC with a code length of 23 and a code weight of 3 are used to identify the optical labels. The scheme and principle of OPS networks based on MOOC sequence-based optical labels are presented. Because optical labels contain OPS and routing information, the importance of optical label processing with multiple inconsecutive, random, and burst optical labels in an OPS network is pointed out. Considering the MOOC-based optical labels, we design a circuit consisting of a broadened network and a cascaded amplifier to receive multiple groups of low-power narrow pulses （optical labels in the MOOC-OPS network） with a period of 2 ns. The successful experimental results demonstrate that the designed scheme is feasible.

关键词： optical switches Packet switching Switching networks

Non-linear polarization orthogonality loss in a semiconductor optical amplifier

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Chinese Optics Letters 2016年第9期14卷 6-9页

作者：章威李政勇王海洋詹翔空宋中波吴重庆 Key Laboratory of Education Ministry on Luminescence and optical Information Technology Beijing Jiaotong University Institute of optical Information School of ScienceBeijing Jiaotong University

Polarization-based optical communications are attracting more attention recently, where the crucial points are polarization features and their measurements. Based on the Müller matrix method, we obtain measurable expressions for the polarization-dependent gain（PDG） and the loss of polarization orthogonality（LPO）, while give the boundary of the LPO for any PDG devices. We experimentally demonstrate that non-linear LPO can be created in a semiconductor optical amplifier and find that the LPO will slightly skim over the boundary near the threshold of the injected current. Furthermore, an empirical formula is achieved to gauge the LPO-induced power penalty, which is proven to be valid in differential polarization shift-keying transmission by executing a bit error rate measurement. Our conclusions are applicable to non-orthogonal polarization cases and valuable to polarization-related communications, even orbital angular momentum multiplexing.

关键词： Bit error rate Light amplifiers optical communication optical switches Phase shift keying Polarization Semiconductor insulator boundaries

Improved optical packet switching structure with recirculation buffer and feedback tunable wavelength converter

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Chinese Optics Letters 2009年第5期7卷 384-386页

作者：武程肖石林 State Key Laboratory of Advanced optical Communication Systems and Networks Shanghai Jiao Tong University

The performance of an optical switching network is mainly determined by its core node structure. An improved optical packet switching （OPS） node structure based on recirculation optical fiber delay line （FDL） and feedback tunable wavelength converter （TWC）, and a specific scheduling algorithm for the node structure are presented. This switching structure supports both point-to-point and point-to-multi- points broadcasting transmission with superior capacity expansion performance. Its superiority in packet loss probability is proved by simulation.

关键词： Feedback optical fibers optical switches Packet switching Switching systems

Finite element beam propagation method for analysis of plasmonic waveguide

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Chinese Optics Letters 2008年第8期6卷 572-574页

作者：陈建军李兆峰樊中朝杨富华 Research Center of Semiconductor Integration Institute of SemiconductorsChinese Academy of Sciences State Key Laboratory for Superlattices and Microstructures Institute of SemiconductorsChinese Academy of Sciences

The basic idea of the finite element beam propagation method （FE-BPM） is described. It is applied to calculate the fundamental mode of a channel plasmonic polariton （CPP） waveguide to confirm its validity. Both the field distribution and the effective index of the fundamental mode are given by the method. The convergence speed shows the advantage and stability of this method. Then a plasmonic waveguide with a dielectric strip deposited on a metal substrate is investigated, and the group velocity is negative for the fundamental mode of this kind of waveguide. The numerical result shows that the power flow direction is reverse to that of phase velocity.

关键词： Convergence of numerical methods optical switches Strip metal Waveguides

High Speed 2×2 optical Switch in Silicon-on-Insulator Based on Plasma Dispersion Effect

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Chinese Physics Letters 2005年第12期22卷 3097-3099页

作者：孙飞余金中陈少武 National Key Laboratory on Integrated Optoelectronics Institute of Semiconductors Chinese Academy of Sciences Beijing 100083

Based on free carrier plasma dispersion effect, a 2 × 2 optical switch is fabricated in a silicon-on-insulator substrate by inductively coupled-plasma technology and ion implantation. The device has a Mach-Zehnder interferometer structure, in which two directional couplers serve as the power splitter and combiner. The switch presents an insertion loss of 3.04 dB and a response time of 496ns.

关键词： optical switches