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A 2 by 2 wavelength tunable Fabry-Perot filter by using an electro-optic polymer film

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Chinese Optics Letters 2004年第11期2卷 624-626页

作者：李新碗叶爱伦陈建平吴龟灵 State Key lab on Local Fiber Optical communication networks and Advanced Optical communication Systems

A tunable Fabry-Perot (F-P) filter by using electro-optic polymer film is proposed. The electro-optic polymer is alkoxysilane dye (ASD)/SiO2-TiO2 hybrid material, whose electro-optic coefficient 733 is about 5 pm/V, The wavelength tuning range of 3.8 nm under 400-V DC voltage and the nonlinear characteristic with the electric field have been obtained via electro-optical properties of polymer. Both of polymer film fabrication and F-P filter design have been introduced. The tunable F-P filter is designed for the application of two-input/two-output port wavelength-selective optical switch. Also, some problems have been discussed in this letter.

关键词： Dyes Electrooptical materials Optical communication equipment Optical films Optical switches Organic polymers

Wavelength dimensioning for wavelength-routed WDM satellite network

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Chinese Journal of Aeronautics 2016年第3期29卷 763-771页

作者： Liu Zhe Guo Wei Deng Changlin Hu Weisheng State Key lab of Advanced Optical communication Systems and networks Shanghai Jiao Tong University

Internet and broadband applications driven by data traffic demand have become key dri- vers for satellite constellations. The key technology to satisfy the high capacity requirements between satellites is optical satellite networks by means of wavelength division multiplexing inter- satellite links （ISLs） with wavelength routing （WDM-OSN）. Due to the limited optical amplifier bandwidth onboard the satellite, it is important to minimize the wavelength requirements to provi- sion requests. However, ISLs should be dynamically established and deleted for each satellite according to its visible satellites. Furthermore, different link assignments will result in different topologies, hence yielding different routings and wavelength assignments. Thus, a perfect match model-based link assignment scheme （LAS-PMM） is proposed to design an appropriate topology such that shorter path could be routed and less wavelengths could be assigned for each ISL along the path. Finally, simulation results show that in comparison to the regular Manhattan street net- work （MSN） topology, wavelength requirements and average end-to-end delay based on the topol- ogy generated by LAS-PMM could be reduced by 24.8% and 12.4%, respectively.

关键词： LAS LAS-PMM Routing Wavelength assignment Wavelength dimensioning WDM-OSN

Automatic mode-locking fiber lasers: progress and perspectives

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Science China(Information Sciences) 2020年第6期63卷 119-142页

作者： Guoqing PU Li ZHANG Weisheng HU Lilin YI State Key lab of Advanced communication Systems and networks Shanghai Institute for Advanced Communication and Data Science Shanghai Jiao Tong University

Polarization control in nonlinear polarization rotation based mode-locked fiber lasers is a longterm challenge. Suffering from the polarization drifts induced by environmental disturbances, nonlinear polarization rotation based mode-locked fiber lasers is difficult in continuously operating under the desired pulsation regime thereby substantially hindering their utilizations. The appearance of automatic modelocking techniques brings the light in addressing this challenge. Combining with various algorithms and electrical polarization control, automatic mode-locking techniques resolve the dilemma of nonlinear polarization rotation based mode-locked fiber lasers. We review the research progress of automatic mode-locking techniques in detail. Furthermore, we comment on the perspectives and potential applications of automatic mode-locking techniques.

关键词： nonlinear polarization rotation ultrashort pulses automatic mode-locking electrical polarization control optimization algorithms machine learning time stretch

Reliable routing mechanism based on neighbor stability for MANET

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The Journal of China Universities of Posts and Telecommunications 2009年第3期16卷 33-39页

作者： WU Da-peng WU Mu-qing ZHEN Yan Broadband communication networks lab Beijing University of Posts and Telecommunications Beijing 100876 China

One critical issue for routing in mobile Ad-hoc networks （MANETs） is how to select a reliable path that can last longer because mobility may cause frequent breakdown in radio links. A novel routing mechanism based on link lifetime estimation is proposed in this article. In this mechanism, the node＇s received signal strength is obtained continuously by using Newton interpolation polynomial, and by method of middle value and interception, the reference points are selected to estimate the link lifetime. With the constraint of link lifetime and hop counts, the source nodes set up the route hop by hop. The simulations show that link lifetime can be predicted regardless of mobility pattern. Moreover, the route discovery times and packet drop ratio can be reduced by the proposed mechanism, and thus improving the performance of MANETs.

关键词： Ad-hoc networks routing protocol link lifetime received signal strength interpolation polynomial

On the stability of multicast flow aggregation in IP over optical network for IPTV delivery

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Chinese Optics Letters 2008年第8期6卷 553-557页

作者：罗萱金耀辉曾庆济孙卫强郭薇胡卫生 State Key lab of Advanced Optical communication Systems and networks Shanghai Jiao Tong University

The stable multicast flow aggregation （MFA） problem in internet protocol （IP） over optical network under the dynamical scenario is studied. Given an optical network topology, there is a set of head ends and access touters attached to the optical network, in which each head end can provide a set of programs （IP multicasting flows） and each access router requests a set of programs, we find a set of stable light-trees to accommodate the optimally aggregated multicast IP flows if the requests of access touters changed dynamically. We introduce a program correlation matrix to describe the preference of end users＇ requests. As the original MFA problem is NP-complete, a heuristic approach, named most correlated program first （MCPF）, is presented and compared with the extended least tree first （ELTF） algorithm which is topology- aware. Simulation results show that MCPF can achieve better performance than ELTF in terms of stability with negligible increment of network resource usage.

关键词： Agglomeration Electric network topology Fiber optic networks Heuristic algorithms Heuristic programming Internet Mobile telecommunication systems Multicasting Nuclear propulsion Optical data processing Optical materials Routers Topology Trees (mathematics)

Multi-carrier Tb/s silicon photonic coherent receiver

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Science China(Information Sciences) 2024年第1期67卷 284-291页

作者： Zhen WANG Xingfeng LI Jingchi LI Jian SHEN Yong ZHANG Yikai SU State Key lab of Advanced Optical communication Systems and networks Department of Electronic EngineeringShanghai Jiao Tong University

We propose a silicon polarization-diversity coherent receiver for wavelength-multiplexing transmission without using the large-footprint arrayed waveguide grating(AWG).We have integrated our proposed coherent receiver on the silicon-on-insulator(SOI) platform for high-capacity *** the proposed coherent receiver,high-frequency photocurrent signals from other wavelengths are suppressed by electrical low-pass ***,the signal-signal beat interference(SSBI) generated from each wavelength is eliminated by the balanced *** two features lend to the proposed coherent receiver being free of the mm-scale *** have demonstrated our proposed coherent receiver to detect a 1.12-Tb/s wavelength-division-multiplexed and polarization-division-multiplexed 16-ary quadrature amplitude modulation(PDM-16-QAM) *** compact footprint of the silicon chip promises small-form-factor receivers for future ultra-high-capacity coherent communication systems that require a high integration level and low fabrication cost.

关键词： silicon photonics optical receivers coherent communication wavelength-division-multiplexing(WDM) polarization-division-multiplexing(PDM)

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Bend effect of the electrode for travelling wave integrated electro-optic modulators

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Chinese Optics Letters 2003年第7期1卷 401-403页

作者：张阜文陈福深邱昆 State Key lab of Broadband Optic Fiber Transmission and communication networks UESTC Chengdu 610054

In this paper, we have studied electrode bend effects on electrical characteristics of the modulator in the three aspects, which are arc length, characteristic impedance, and loss, applying the model in Ref. [1] and the finite element method (FEM). The results have shown that the effect only caused by the characteristic impedance is necessarily considered while its deviation is large, but others are negligible as we design a practical device. Finally, some transmission characteristics of coplanar line with different arc length of the bend have been tested, and the measured results are in good agreement with the theoretical analyses.

关键词： Finite element method Modulators Wave transmission Waveguides

An Isotropic Electric-Field Sensing System Using Optical Probe

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Chinese Physics Letters 2007年第4期24卷 965-967页

作者：杨拥军陈福深孙豹 Key lab of Broadband Optical Fiber Transmission and communication networks University of Electronic Science and Technology of China Chengdu 610054

We design an isotropic electric-field sensing system using an optical probe. The optical probe consists of three electric-field sensors based on a Mach-Zehnder interferometer with the structure of segmented electrodes, which are perpendicular to each other. The measured results show that the ±5 dB baseband can reach 3 GHz, the linear dynamics range is 70dB, and the minimum detectable electric field is lower than 90 dBμ V/m （the spectrum analyser resolution is 100 Hz）. The directional characteristics are almost isotropic within deviations of ±1.5 dB. Therefore this sensing system can be used in the electromagnetic compatibility measurements.

关键词： MACH-ZEHNDER INTERFEROMETER MODULATOR SENSOR

Smart Care: Energy-Efficient Long-Term Physical Activity Tracking Using Smartphones

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Tsinghua Science and Technology 2015年第4期20卷 348-363页

作者： Hui Liu Rui Li Sicong Liu Shibian Tian Junzhao Du School of Software and Institute of Software Engineering Xidian Universityand Science and Technology on Infomation Transmission and Dissemination in Communication Networks Lab.

Lack of physical activity is becoming a killer of our healthy life. As a solution for this negative impact, we propose SmartCare to help users to set up a healthy physical activity habit. SmartCare can monitor a user＇s activities over a long time, and then provide activity quality assessment and suggestion. SmartCare consists of three parts, activity recognition, energy saving, and health feedback. Activity recognition can recognize nine kinds of daily activities. A hybrid classifier that uses less power and memory with satisfactory accuracy was designed and implemented by utilizing the periodicity of target activity. In addition, a learning-based energy saver was introduced to reduce energy consumption by adjusting sampling rates and the set of features adaptively. Based on the type and duration of the activity recorded, health feedback in terms of the calorie burned was given. The system could provide quantitative activity quality assessment and recommend future physical activity plans. Through extensive real-life testing, the system is shown to achieve an average recognition accuracy of 98.0% with a minimized energy expenditure.

关键词： physical activity tracking hybrid classifier health feedback