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Coherent optical OFDM scheme with inter-carrier interference self-cancellation and common phase error compensation

Chinese Optics Letters 2010年第7期8卷 634-638页

作者：吴毅凌李巨浩赵春旭赵玉萍张帆陈章渊 State Key Laboratory of Advanced Optical Communication Systems & Networks Peking University

Schemes integrating inter-carrier interference （ICI） self-cancellation and common phase error （CPE） com- pensation for coherent optical orthogonal frequency division multiplexing （CO-OFDM） systems are investi- gated. The purpose of our research is to counteract the impacts of laser phase noise and fiber nonlinearity. We propose two ICI self-cancellation-based CO-OFDM schemes, and adopt a pilot-aided decision feedback （DFB） loop for CPE compensation. The proposed schemes are compared with conventional CO-OFDM schemes at the same spectral efficiency. Simulations show that our schemes can not only enhance laser linewidth tolerance of the CO-OFDM system, but also present strong robustness against fiber nonlinearity.

关键词： Error compensation Frequency allocation Orthogonal functions Spectrum analyzers Telecommunication systems

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Bidirectional radio-over-fiber systems with SSB modulation and wavelength reuse based on injection-locked semiconductor lasers

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Chinese Optics Letters 2010年第11期8卷 1040-1042页

作者：洪成张诚段俊胡薇薇徐安士陈章渊 State Key Laboratory of Advanced Optical Communication Systems and Networks Peking University

A 60-GHz bidirectional radio-over-fiber （RoF） system using two-carrier-injected distributed feedback （DFB） laser is proposed and demonstrated to realize optical single sideband （SSB） modulation for *** injection-locked Fabry-P＇erot laser is also carried out to realize wavelength reuse in *** of 2.5 Gb/s on a 60-GHz carrier for downlink and 622-Mb/s baseband signal for uplink are both successfully demonstrated over 50-km single mode fiber without chromatic dispersion compensation.

关键词： Electromagnetic dispersion Feedback Lasers Single mode fibers

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LLM4WM: Adapting LLM for Wireless Multi-Tasking

arXiv

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arXiv 2025年

作者： Liu, Xuanyu Gao, Shijian Liu, Boxun Cheng, Xiang Yang, Liuqing State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China Guangzhou511400 China Guangzhou511400 China Department of Electronic and Computer Engineering The Department of Civil and Environmental Engineering The Hong Kong University of Science and Technology Hong Kong

The wireless channel is fundamental to communication, encompassing numerous tasks collectively referred to as channel-associated tasks. These tasks can leverage joint learning based on channel characteristics to share representations and enhance system design. To capitalize on this advantage, LLM4WM is proposed—a large language model (LLM) multi-task fine-tuning framework specifically tailored for channel-associated tasks. This framework utilizes a Mixture of Experts with Low-Rank Adaptation (MoE-LoRA) approach for multi-task fine-tuning, enabling the transfer of the pre-trained LLM’s general knowledge to these tasks. Given the unique characteristics of wireless channel data, preprocessing modules, adapter modules, and multi-task output layers are designed to align the channel data with the LLM’s semantic feature space. Experiments on a channel-associated multi-task dataset demonstrate that LLM4WM outperforms existing methodologies in both full-sample and few-shot evaluations, owing to its robust multi-task joint modeling and transfer learning capabilities. Copyright © 2025, The Authors. All rights reserved.

关键词： Semantics

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Probing multi-mobility edges in quasiperiodic mosaic lattices

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Science Bulletin 2025年第1期70卷 58-63页

作者： Jun Gao Ivan M.Khaymovich Xiao-Wei Wang Ze-Sheng Xu Adrian Iovan Govind Krishna Jiayidaer Jieensi Andrea Cataldo Alexander V.Balatsky Val Zwiller Ali W.Elshaari Department of Applied Physics KTH Royal Institute of TechnologyAlbanova University CentreStockholm SE-10691Sweden Nordita Stockholm University and KTH Royal Institute of TechnologyStockholm SE-10691Sweden Institute for Physics of Microstructures Russian Academy of SciencesNizhny Novgorod 603950Russia Center for Integrated Quantum Information Technologies(IQIT) School of Physics and Astronomy and State Key Laboratory of Advanced Optical Communication Systems and NetworksShanghai Jiao Tong UniversityShanghai 200240China Department of Physics University of ConnecticutStorrsConnecticut 06269USA

The mobility edge(ME)is a crucial concept in understanding localization physics,marking the critical transition between extended and localized states in the energy *** localization scaling theory predicts the absence of ME in lower dimensional ***,the search for exact MEs,particularly for single particles in lower dimensions,has recently garnered significant interest in both theoretical and experimental studies,resulting in notable ***,several open questions remain,including the possibility of a single system exhibiting multiple MEs and the continual existence of extended states,even within the strong disorder ***,we provide experimental evidence to address these questions by utilizing a quasiperiodic mosaic lattice with meticulously designed nanophotonic *** observations demonstrate the coexistence of both extended and localized states in lattices with broken duality symmetry and varying modulation *** single-site injection and scanning the disorder level,we could approximately probe the ME of the modulated *** results corroborate recent theoretical predictions,introduce a new avenue for investigating ME physics,and offer inspiration for further exploration of ME physics in the quantum regime using hybrid integrated photonic devices.

关键词： Mobility edge Localization physics Mosaic lattice Nanophotonics

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Semiconductor quantum dot-doped glass as spectral converter for photovoltaic application

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Chinese Science Bulletin 2014年第1期59卷 16-22页

作者： Lu Sun Chun Jiang State Key Laboratory of Advanced Optical Communication System and Networks Shanghai Jiao Tong University

In this article,we focus on using the multiexciton generation(MEG)effect of quantum dot(QD)to realize quantum cutting of high-energy photons which will give rise to a remarkable increase of total photon *** avoid the complicated solving of Schro¨dinger equation,we take approximations and develop a method for fast evaluating the quantum efficiency of MEG *** this basis,we calculate the detailed balance limit of efficiency of Si single-junction solar cell with Si QD-doped glass placed on top of it as a spectral converter *** shows that the efficiency will reach 36%which is 6%higher than that without the converter *** have also explored the influence of QD radius,QD-doping density,QD,and host material,device working temperature on the efficiency.

关键词：半导体量子点掺杂玻璃转换器光谱应用光伏太阳能电池量子剪裁

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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

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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

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Design of Raman-parametric fiber amplifier for wavelength division multiplex transmission system

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Chinese Optics Letters 2008年第5期6卷 327-330页

作者：江晓弘姜淳章晓鸣 State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University

We optimize the novel configuration of a hybrid fiber amplifier - Raman assisted-fiber-based optical parametric amplifier （R-FOPA）, in which the parametric gain and Raman gain profiles are combined to achieve a flat composite gain profile. The pump powers and the fiber length in the hybrid amplifier are effectively optimized by genetic algorithm （GA） scheme. The optimization results indicate that the RFOPA can achieve a 200-nm flat bandwidth spectrum with the gain of 20 dB and ripple of less than 4 dB.

关键词： Computer networks Electric power transmission Fiber amplifiers Fiber optics Genetic algorithms Light amplifiers Microwave amplifiers Multiplexing Optimization Parametric amplifiers Parametric devices

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Distribution of millimeter waves over a fiber link with high frequency stability(Invited Paper)

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Chinese Optics Letters 2016年第12期14卷 21-24页

作者：董毅刘张唯一王小成邓楠谢玮霖胡卫生 State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University

We present a theoretical analysis, systematic simulation, and experimental measurements for the phase noise,timing jitter, and frequency stability in the frequency distribution of millimeter waves over distant optical fiber links. The conception that the dissemination of a higher frequency reference instead of a lower one can achieve a better frequency stability is discussed and verified. We find that the system＇s noise floor, including thermal noise,shot noise, and any other noise from electronic components, is considered to be a fundamental limitation for a frequency reference transmission system. Benefiting from the high-precision time delay variation discrimination and accurate locking control operation, a highly stabilized reference is distributed to a remote end over a 60 km spooled fiber, achieving a frequency stability of 4 × 10^（-17） at an average time 1000 s, corresponding to 23 fs of RMS timing jitter（0.01 Hz^（–1） MHz）.

关键词： millimeter jitter dissemination discrimination links conception locking distant instead verified

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Joint optimizing of interleaving and LDPC decoding for burst errors in PON systems

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Science China(Information Sciences) 2020年第2期63卷 233-235页

作者： Lei ZHANG Chuanchuan YANG Fan ZHANG State Key Laboratory of Advanced Optical Communication Systems and Networks Peking University

Dear editor,Driven by the continuously increasing demand for large capacity data services, the upgrade for high speed passive optical network (PON) system is of great importance. To meet the stringent optical power bu... 详细信息

关键词： PON Joint optimizing of interleaving and LDPC decoding for burst errors in PON systems

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