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arXiv 2025年

作者： Cao, Mengyuan Zhang, Haobo Eldar, Yonina C. Zhang, Hongliang State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China School of Electronic and Computer Engineering Peking University Shenzhen Graduate School Shenzhen518055 China Department of Mathematics and Computer Science Weizmann Institute of Science Rehovot7610001 Israel

Due to its ability to precisely control wireless beams, holographic multiple-input multiple-output (HMIMO) is expected to be a promising solution to achieve high-accuracy localization. However, as the scale of HMIMO increases to improve beam control capability, the corresponding near-field (NF) region expands, indicating that users may exist in both NF and far-field (FF) regions with different electromagnetic transmission characteristics. As a result, existing methods for pure NF or FF localization are no longer applicable. We consider a hybrid NF and FF localization scenario in this paper, where a base station (BS) locates multiple users in both NF and FF regions with the aid of a reconfigurable intelligent surface (RIS), which is a low-cost implementation of HMIMO. In such a scenario, it is difficult to locate the users and optimize the RIS phase shifts because whether the location of the user is in the NF or FF region is unknown, and the channels of different users are coupled. To tackle this challenge, we propose a RIS-enabled localization method that searches the users in both NF and FF regions and tackles the coupling issue by jointly estimating all user locations. We derive the localization error bound by considering the channel coupling and propose an RIS phase shift optimization algorithm that minimizes the derived bound. Simulations show the effectiveness of the proposed method and demonstrate the performance gain compared to pure NF and FF techniques. Copyright © 2025, The Authors. All rights reserved.

关键词： communication channels (information theory)

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Velocity-comb modulation transfer spectroscopy

arXiv

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arXiv 2025年

作者： Guan, Xiaolei Xiao, Zheng Liu, Zijie Wang, Zhiyang Zhang, Jia Gao, Xun Chang, Pengyuan Shi, Tiantian Chen, Jingbiao State Key Laboratory of Advanced Optical Communication Systems and Networks Institute of Quantum Electronics School of Electronics Peking University Beijing100871 China Institute of Quantum Information and Technology Nanjing University of Posts and Telecommunications Nanjing210003 China National Key Laboratory of Advanced Micro and Nano Manufacture Technology School of Integrated Circuits Peking University Beijing100871 China Hefei National Laboratory Hefei230088 China

Sub-Doppler laser spectroscopy is a crucial technique for laser frequency stabilization, playing a significant role in atomic physics, precision measurement, and quantum communication. However, recent efforts to improve frequency stability appear to have reached a bottleneck, as they primarily focus on external technical approaches while neglecting the fundamental issue of low atomic utilization ( Copyright © 2025, The Authors. All rights reserved.

关键词： Frequency stability

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Overcoming user-rate limit of quantum network

arXiv

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arXiv 2025年

作者： Xu, Yuehan Zhang, Qijun Zhang, Junpeng Liao, Xiaojuan Shen, Ziyi Liu, Xu Zhang, Beibei Tan, Zicong Zhou, Zehao Dai, Jisheng Jiang, Xueqin Huang, Peng Wang, Tao Zeng, Guihua State Key Laboratory of Advanced Optical Communication Systems and Networks Center of Quantum Sensing and Information Processing Shanghai Jiao Tong University Shanghai200240 China College of Information Science and Technology Donghua University Shanghai201620 China Shanghai Research Center for Quantum Sciences Shanghai201315 China Hefei National Laboratory Hefei230088 China

Quantum networks revolutionize the way of information transmission and are an essential step in building a quantum internet. Generally, the information capacity per user-channel in a quantum network drastically decreases with the increase of network capacity, making it difficultly scale to large-user scenarios. To break this limit, we develop a quantum network architecture in which the information capacity per user-channel is independent of the network capacity (NCI-QN), and all previous quantum networks can be regarded as special examples. Three aspects are investigated. Firstly, a quantum network scheme formulated in a comprehensive multi-mode time-frequency representation is presented. Then, information characteristics of the proposed quantum network are delineated by expanding the well-known Pirandola-Laurenza-Ottaviani-Banchi (PLOB) bound and the Holevo bound from the linear combination of point-to-point links to a complex network architecture, demonstrating clear proofs of the network capacity independence. Finally, a practical NCI-QN with a network capacity of 19 is experimentally demonstrated using optical frequency comb in quantum key distribution network scenarios, in which the security under the asymptotic case, finite-size effect, composable security, and composable finite-size security are verified, with a secret key rate up to 8.75 Gbps. This achievement overcomes the user-rate limit of quantum network, which is the keystone for the development of the quantum internet. Copyright © 2025, The Authors. All rights reserved.

关键词： Quantum cryptography

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SPP-MIM Hybridization Meta-Films for High-Sensitivity and High-Stability Biosensing at optical Fiber End-Facets

SSRN

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SSRN 2025年

作者： He, Chenjia Sun, Xiaqing Zhong, Hao Meng, Qing-Feng Zhou, Xuetong Liu, Sihang Zheng, Li Kong, Xiangyang Chen, Shengfu Yang, Tian State Key Laboratory of Advanced Optical Communication Systems and Networks Key Laboratory for Thin Film and Microfabrication The Ministry of Education School of Electronic Information and Electrical Engineering Shanghai Jiao Tong University Shanghai200240 China School of Material Science and Engineering Shanghai Jiao Tong University Shanghai200240 China State Key Laboratory of Materials for Integrated Circuits Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences Shanghai200050 China Key Laboratory of Biomass Chemical Engineering College of Chemical and Biological Engineering Zhejiang University Hangzhou310027 China

The specific optical dispersion of metal-insulator-metal (MIM) waveguide allows the hybridization of surface plasmon polaritons (SPPs) and the waveguide, which is not possible with dielectric waveguides. SPP-MIM hybridization creates such a meta-film that integrates the previously incompatible respective merits of SPR and LSPR, including a flat biosensing interface, a high surface sensitivity and efficient coupling with spatially confined illumination. On the other hand, to achieve stable and reproducible performance is one of the greatest but unresolved challenges for nanophotonic biosensors. Yet the underlying mechanism of instability is not well understood. We conclude, from a literature survey, that the stability of biosensing performance is strongly correlated with the flatness of the physical sensing interface. A nanostructured interface, at least, would introduce surface gas nanobubbles to interfere with the interactions between analytes in the solution and ligands on the solid substrate. Hence, the SPP-MIM meta-film provides a capable solution for sealing photonic nanostructures under a flat and stable biosensing interface. We embed the meta-film with a plasmonic crystal cavity and integrate it on a single-mode fiber's end-facet to detect biomolecular interactions. This device demonstrates highly reproducible sensorgrams and convincing detection of biotinylated proteins at down to 30 fM, with the sensorgrams following the Langmuir model. Having both high sensitivity and high stability, our device proposal provides an unprecedentedly comprehensive solution for optical fiber-tip plasmonic devices. It has immediate application values for biomolecular interaction analysis and drug discovery. © 2025, The Authors. All rights reserved.

关键词： MIM devices

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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

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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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Light Localization in Slot Photonic Crystal Waveguide

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Chinese Physics Letters 2009年第1期26卷 126-129页

作者：武隽彭超李艳萍王子宇 State Key Laboratory on Advanced Optical Communication Systems and Networks Peking University Beijing 100871

A single-mode photonic crystal waveguide with a linear tapered slot is presented, which can localize light spatially by changing the slot width. Its effective bandwidth is 52nm, from 1500nm to 1552nm. Along the tapered structure, the slot width is reduced, and the corresponding band curve shifts. The group velocity of light becomes zero at the band edge. Therefore, different frequency components of the guided light are slowed down and finally localized at correspondingly different widths inside a tapered slot photonic crystal waveguide. Furthermore, this structure can confine light wave in a narrow slot waveguide, which may effectively enhance the interaction between light and the low-index wave-guiding materials filled in the slot.

关键词： field emission molybdenum dioxide enhancement factor

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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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All-optical amplitude-shift keying and differential phase-shift keying to differential phase amplitude-shift keying format combination in highly nonlinear fiber

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Chinese Optics Letters 2009年第7期7卷 564-567页

作者：吴琳张德朝张帆陈章渊徐安士 State Key Laboratory of Advanced Optical Communication Systems and Networks Electronics Department Peking University

We propose an all-optical modulation formats combination scheme that merges an amplitude-shift keying （ASK） signal and a differential phase-shift keying （DPSK） signal into a single differential phase amplitude- shift keying （DPASK） signal based on parametric amplification in a highly nonlinear fiber. By optimizing the power of the ASK channel, formats combination of ASK and DPSK to DPASK signal is successfully demonstrated by computational simulation. The demodulation process of the generated DPASK pulses is investigated and the relationship between optical signal-to-noise ratio （OSNR） penalty and the input ASK power is presented. The proposed scheme may be used for increasing spectral efficiency and all-optical logic device.

关键词： Amplification Light modulation Logic devices optical devices Phase shift Phase shift keying Signal to noise ratio Spectrum analyzers

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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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