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Synesthesia of Machines (SoM)-Enhanced ISAC Precoding for Vehicular networks with Double Dynamics

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IEEE Transactions on communications 2025年

作者： Yang, Zonghui Gao, Shijian Cheng, Xiang Yang, Liuqing Peking University State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Beijing100871 China Internet of Things Thrust Guangzhou511400 China Hong Kong University of Science and Technology Department of Electronic and Computer Engineering Hong Kong

Integrated sensing and communication (ISAC) technology is vital for vehicular networks, yet the time-varying communication channels and rapid movement of targets present significant challenges for real-time precoding design. Traditional optimization-based methods are computationally complex and strongly depend on perfect prior information, which is often unavailable in double-dynamic scenarios. In this paper, we propose a synesthesia of machine (SoM)-enhanced precoding paradigm that leverages modalities such as positioning and initial channel information to adapt to these dynamics. Utilizing a deep reinforcement learning (DRL) framework, our approach pushes ISAC performance boundaries. We also introduce a parameter-shared actor-critic architecture to accelerate training in complex state and action spaces. Extensive experiments validate the superiority of our method over existing approaches. © 1972-2012 IEEE.

关键词： Deep reinforcement learning

Arbitrary control of the flow of light using pseudomagnetic fields in photonic crystals at telecommunication wavelengths

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arXiv 2025年

作者： Hu, Pan Sun, Lu Chen, Ce Li, Jingchi Ni, Xiong He, Xintao Dong, Jianwen Su, Yikai State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Shanghai200240 China State Key Laboratory of Optoelectronic Materials and Technologies School of Physics Sun Yat-Sen University Guangzhou510275 China

In photonics, the idea of controlling light in a similar way that magnetic fields control electrons has always been attractive. It can be realized by synthesizing pseudomagnetic fields (PMFs) in photonic crystals (PhCs). Previous works mainly focus on the Landau levels and the robust transport of the chiral states. More versatile control over light using complex nonuniform PMFs such as the flexible splitting and routing of light has been elusive, which hinders their application in practical photonic integrated circuits. Here we propose an universal and systematic methodology to design nonuniform PMFs and arbitrarily control the flow of light in silicon PhCs at telecommunication wavelengths. As proofs of concept, a low-loss S-bend and a highly efficient 50:50 power splitter based on PMFs are experimentally demonstrated. A high-speed data transmission experiment is performed on these devices to prove their applicability in real communication systems. The proposed method offers a new paradigm for the exploration of fundamental physics and the development of novel nanophotonic devices. Copyright © 2025, The Authors. All rights reserved.

关键词： Photonic integrated circuits

Long distance local local oscillator continuous variable quantum key distribution with digital signal processing

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arXiv 2025年

作者： Qi, Dengke Wang, Xiangyu Ma, Jiayu Li, Zhenghua Chen, Ziyang Lu, Yueming Yu, Song State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications Beijing100876 China School of Cyberspace Security Beijing University of Posts and Telecommunications Beijing100876 China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Center for Quantum Information Technology Peking University Beijing100871 China

Quantum key distribution relying on the principles of quantum mechanics enables two parties to produce a shared random secret key, thereby ensuring the security of data transmission. Continuous variable quantum key distribution (CV-QKD) is widely applied because it can be well combined with standard telecommunication technology. Compared to CV-QKD with a transmitting local oscillator, the proposal of CV-QKD with a local local oscillator overcomes the limitation that local oscillator will attenuate as transmission distance increases, providing new possibilities in long-distance transmission. However, challenges still persist in practical long-distance transmission, including data sampling and recovery under low signal-to-noise ratio conditions. In order to better recover data and reduce the additional excess noise, we propose the least squares fitting algorithm to get more accurate sampling data and complete more accurate phase compensation. Herein, we demonstrate the long-distance local local oscillator CV-QKD experiment which have considered the effect of finite-size block over 120 km of standard optical fiber with high efficient real-time post-processing. The results not only verify the good performance of the system over long distance, but also paves the way for large-scale quantum secure communications in the future. Copyright © 2025, The Authors. All rights reserved.

关键词： Quantum cryptography

Compact 780-nm Rb optical Clock

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arXiv 2025年

作者： Chen, Zhendong Liu, Tianyu Yang, Qiaohui Wang, Ya Miao, Jie Chen, Jingming Pan, Duo Yang, Ruoao Wu, Jianjun Zhang, Zhigang Chen, Jingbiao Cao, Shiying State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China Division of Time and Frequency Metrology National Institute of Metrology Beijing100013 China Hefei National Laboratory Hefei230088 China

We demonstrated a compact 780 nm rubidium optical clock, which includes an optical frequency standard and an optical frequency comb, with an optical volume of 11. 6 liters. Unlike the 778 nm rubidium atomic clocks based on two-photon transition, here, the laser frequency is stabilized to the hyperfine transitions of the 87Rb 5S1/2 F=2→5P3/2 F’=3, using modulation transfer spectroscopy (MTS). This approach effectively eliminates Doppler background and provides a high signal to noise ratio and high sensitivity. A nearly 300 MHz microwave signal, whose phase exactly tracks that of the optical frequency standard, is generated via the optical frequency comb, yielding a frequency instability of 1.91 E-13 @1 s and 5.29 E-14 @1000 s in the electronic domain. To the best of our knowledge, this is the most precise frequency stabilization result for the first-excited-state transition of alkali metal atoms to date and represents the first optical clock based on this transition. These results offer a promising approach for the development of portable optical *** Codes 14J60 Copyright © 2025, The Authors. All rights reserved.

关键词： Two photon processes

Divided GHz burst mode amplification to mJ burst energy and kHz burst rate

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Chinese Optics Letters 2025年第1期 77-80页

作者：吴云峰杨伯威林哲杨若傲陈星宋晏蓉张志刚 School of Physics and Optoelectronic Engineering Beijing University of Technology State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University State Key Laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

We demonstrated a divided pulse amplification of burst pulse trains. The intraburst rate is 1 GHz, and the burst rate ranges from 1.5 k Hz to 15 MHz. Under the pump power of 100 W, the burst pulse energy is adjustable from 2.2 μJ to 22 mJ. The pulse width of combined and compressed pulses is 275 fs with beam quality M2of 1.2.

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Joint frequency offset estimation and adaptive equalization for a coherent passive optical network

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Chinese Optics Letters 2025年第4期23卷 040602-040602页

作者： Feng, Yiyang Li, Zhengxuan Liu, Chenyu Cao, Bingyao Yi, Lilin Song, Yingxiong Key Laboratory of Specialty Fiber Optics and Optical Access Networks Joint International Research Laboratory of Specialty Fiber Optics and Advanced Communication Shanghai University Shanghai200444 China State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University Shanghai200240 China

Coherent optics are emerging as promising solutions for future passive optical networks. However, upstream burst-mode coherent detection faces challenges due to the need for fast digital signal processing and its susceptibility to laser wavelength drift. To address these issues, we propose an algorithm capable of rapid channel equalization and frequency offset estimation (FOE). The feasibility of the proposed scheme is experimentally verified through 128-Gbit/s 16QAM signal transmission systems. Consequently, integrating a fine FOE tap into the adaptive equalization allows for rapid convergence and accurate frequency offset estimates within ∼±0.5 times the symbol rate while maintaining low complexity. © 2025 Chinese Optics Letters.

关键词： Passive optical networks

Progress in silicon-based reconfigurable and programmable all-optical signal processing chips

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Frontiers of Optoelectronics 2025年第1期18卷 10-10页

作者： Xu, Jing Dong, Wenchan Huang, Qingzhong Zhang, Yujia Yin, Yuchen Zhao, Zhenyu Zeng, Desheng Gao, Xiaoyan Gu, Wentao Yang, Zihao Li, Hanghang Han, Xinjie Geng, Yong Zhai, Kunpeng Chen, Bei Fu, Xin Lei, Lei Wu, Xiaojun Dong, Jianji Su, Yikai Li, Ming Liu, Jianguo Zhu, Ninghua Guo, Xuhan Zhou, Heng Wen, Huashun Qiu, Kun Zhang, Xinliang Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information Huazhong University of Science and Technology Wuhan430074 China Optics Valley Laboratory Wuhan430074 China State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Shanghai200240 China Key Lab of Optical Fiber Sensing and Communication Networks University of Electronic Science and Technology of China Chengdu611731 China Institute of Intelligent Photonics Nankai University Tianjin300071 China Key Laboratory of Optoelectronic Materials and Devices Institute of Semiconductors Chinese Academy of Sciences Beijing100083 China College of Physics and Optoelectronic Engineering Shenzhen University Shenzhen518060 China School of Electronic and Information Engineering Beihang University Beijing100191 China

Taking the advantage of ultrafast optical linear and nonlinear effects, all-optical signal processing (AOSP) enables manipulation, regeneration, and computing of information directly in optical domain without resorting to electronics. As a promising photonic integration platform, silicon-on-insulator (SOI) has the advantage of complementary metal oxide semiconductor (CMOS) compatibility, low-loss, compact size as well as large optical nonlinearities. In this paper, we review the recent progress in the project granted to develop silicon-based reconfigurable AOSP chips, which aims to combine the merits of AOSP and silicon photonics to solve the unsustainable cost and energy challenges in future communication and big data applications. Three key challenges are identified in this project: (1) how to finely manipulate and reconfigure optical fields, (2) how to achieve ultra-low loss integrated silicon waveguides and significant enhancement of nonlinear effects, (3) how to mitigate crosstalk between optical, electrical and thermal components. By focusing on these key issues, the following major achievements are realized during the project. First, ultra-low loss silicon-based waveguides as well as ultra-high quality microresonators are developed by advancing key fabrication technologies as well as device structures. Integrated photonic filters with bandwidth and free spectral range reconfigurable in a wide range were realized to finely manipulate and select input light fields with a high degree of freedom. Second, several mechanisms and new designs that aim at nonlinear enhancement have been proposed, including optical ridge waveguides with reverse biased PIN junction, slot waveguides, multimode waveguides and parity-time symmetry coupled microresonators. advanced AOSP operations are verified with these novel designs. Logical computations at 100 Gbit/s were demonstrated with self-developed, monolithic integrated programmable optical logic array. High-dimensional multi-valu

关键词： Four wave mixing

Generation of Multi-Channel Co-axial Quasi-Perfect Vortex Electromagnetic Waves with Equal Divergence Radii Based on Aperture-Shared Metasurface

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IEEE Transactions on Antennas and Propagation 2025年

作者： Deng, Li Yang, Kaiqiao Yin, Kaiyue Chen, Jiawei Qu, Meijun Feng, Botao Beijing University of Posts and Telecommunications Beijing Laboratory of Advanced Information Networks Beijing Key Laboratory of Network System Architecture and Convergence Beijing100876 China Southeast University Institute of Electromagnetic Space State Key Laboratory of Millimeter Wave Nanjing211189 China Communication University of China School of Information and Communication Engineering Beijing Beijing100024 China Shenzhen University College of Electronics and Information Engineering Shenzhen518060 China

Vortex electromagnetic (EM) waves hold significant promise for next-generation wireless communication applications. However, their practical deployment is hindered by varying divergence characteristics across vortex modes with different mode numbers. To overcome this challenge and enable true spatial multiplexing of orbital angular momentum (OAM) waves, a dual-polarized shared-aperture metasurface is proposed. By leveraging both polarization and OAM multiplexing, quasi-perfect vortex (QPV) EM waves with co-axial beams and equal divergence radii are successfully generated at microwave frequencies. Initially, the properties of quasi-perfect vortex waves in the microwave band are analyzed, followed by the design of a dual-polarized metasurface unit. This unit integrates parasitic damping-coupled patches based on the traditional Jerusalem cross structure, providing polarization-independent control and approximately 360° phase-tuning capability. Furthermore, simulations validate the effectiveness of the dual-polarized single-mode metasurface design. Based on this, the concept is extended to a 4-channel multiplexing metasurface, operating at 15 GHz and capable of generating QPV waves. Finally, experimental results from the fabricated metasurface demonstrate the generation of QPV waves with OAM mode numbers 0, +2, +1, and -1, achieving simulated and measured OAM mode purities of 0.835 and 0.70, respectively. The experimental data closely aligns with simulations, confirming the effectiveness of the design. This study offers new insights into generating and applying perfect vortex EM waves, paving the way for high-capacity near-field wireless communication systems and advanced control of novel EM physical dimensions. © 1963-2012 IEEE.

关键词： Near field communication

Scattering Environment Aware Joint Multi-user Channel Estimation and Localization with Spatially Reused Pilots

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arXiv 2025年

作者： Tian, Kaiyuan Chi, Yani Zhou, Yufan Liu, An The State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China The China Academy of Information and Communications Technology Beijing100191 China The College of Information Science and Electronic Engineering Zhejiang University Hangzhou310027 China

The increasing number of users leads to an increase in pilot overhead, and the limited pilot resources make it challenging to support all users using orthogonal pilots. By fully capturing the inherent physical characteristics of the multi-user (MU) environment, it is possible to reduce pilot costs and improve the channel estimation performance. In reality, users nearby may share the same scatterer, while users further apart tend to have orthogonal channels. This paper proposes a two-timescale approach for joint MU uplink channel estimation and localization in MIMO-OFDM systems, which fully captures the spatial characteristics of MUs. To accurately represent the structure of the MU channel, the channel is modeled in the 3-D location domain. In the long-timescale phase, the time-space-time multiple signal classification (TST-MUSIC) algorithm initially offers a rough approximation of scatterer positions for each user, which is subsequently refined through the scatterer association algorithm based on density-based spatial clustering of applications with noise (DBSCAN) algorithm. The BS then utilizes this prior information to apply a graph-coloring-based user grouping algorithm, enabling spatial division multiplexing of pilots and reducing pilot overhead. In the short timescale phase, a low-complexity scattering environment aware location-domain turbo channel estimation (SEA-LD-TurboCE) algorithm is introduced to merge the overlapping scatterer information from MUs, facilitating high-precision joint MU channel estimation and localization under spatially reused pilots. Simulation results verify the superior channel estimation and localization performance of our proposed scheme over the baselines. Copyright © 2025, The Authors. All rights reserved.

关键词： Channel estimation