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Submilliwatt, widely tunable coherent microcomb generation with feedback-free operation

Advanced Photonics 2023年第3期5卷 144-154页

作者： Haowen Shu Lin Chang Chenghao Lao Bitao Shen Weiqiang Xie Xuguang Zhang Ming Jin Yuansheng Tao Ruixuan Chen Zihan Tao Huajin Chang Shaohua Yu Qifan Yang Xingjun Wang John E.Bowers Peking University School of ElectronicsState Key Laboratory of Advanced Optical Communication Systems and NetworksBeijingChina University of California Santa BarbaraDepartment of Electrical and Computer EngineeringSanta BarbaraCaliforniaUnited States Peking University School of PhysicsState Key Laboratory for Artificial Microstructure and Mesoscopic PhysicsBeijingChina Peng Cheng Laboratory ShenzhenChina Peking University Frontiers Science Center for Nano-OptoelectronicsBeijingChina

Microcombs are revolutionizing optoelectronics by providing parallel, mutually coherent wavelengthchannels for time-frequency metrology and information processing. To implement this essential function inintegrated photonic systems, it is desirable to drive microcombs directly with an on-chip laser in a simpleand flexible way. However, two major difficulties have prevented this goal: (1) generating mode-lockedcomb states usually requires a significant amount of pump power and (2) the requirement to align laser andresonator frequency significantly complicates operation and limits the tunability of the comb lines. Here, weaddress these problems by using microresonators on an AlGaAs on-insulator platform to generate dark-pulsemicrocombs. This highly nonlinear platform dramatically relaxes fabrication requirements and leads to arecord-low pump power of <1 mW for coherent comb generation. Dark-pulse microcombs facilitated bythermally controlled avoided mode crossings are accessed by direct distributed feedback laser *** any feedback or control circuitries, the comb shows good coherence and stability. With around150 mW on-chip power, this approach also leads to an unprecedentedly wide tuning range of over one freespectral range (97.5 GHz). Our work provides a route to realize power-efficient, simple, and reconfigurablemicrocombs that can be seamlessly integrated with a wide range of photonic systems.

关键词： dark-pulse microcomb direct pumping scheme widely tunable source

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Joint Beam Management and Resource Allocation in a GEO and LEO Spectrum-Sharing System for Effective Interference Avoidance

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IEEE Transactions on Cognitive Communications and Networking 2024年

作者： Zhao, Di Song, Bin Du, Xiaojiang Xidian University State Key Laboratory Of Integrated Services Networks Xi'an710071 China Xidian University Hangzhou Institute Of Technology Hangzhou311231 China Stevens Institute Of Technology Department Of Electrical And Computer Engineering HobokenNJ07030 United States

The large-scale expansion of low Earth orbit (LEO) satellite constellations has ushered in a new era of space communications. However, the limitations of orbital and spectrum resources pose significant obstacles. With the aid of cognitive radio technology, spectrum sharing between LEO and geostationary Earth orbit (GEO) satellite communication systems provides a feasible solution to alleviate spectrum scarcity. Aiming at the scenario where LEO satellites pass through GEO satellite coverage areas, we seek to explore flexible and efficient spectrum sharing schemes to achieve co-linear interference avoidance. In this paper, we formulate a joint optimization problem for beam management and resource allocation, emphasizing the necessity of improving system throughput while ensuring quality of service for GEO satellite users. To address this issue, we first construct a space information model to describe the signal connections between satellites and users, as well as the overlapping coverage relationships among satellites. Then, we develop an adaptive approach that integrates both model-based and model-free deep reinforcement learning (DRL) methods. Guided by the space information graph, the model-based DRL employs a hybrid attention mechanism to mitigate beam-level interference through beam hopping and pointing optimization. Meanwhile, the model-free DRL optimizes channel allocation and power control to achieve user-level spectrum sharing, aiming to maximize resource utilization through continuous interaction. Simulation results demonstrate that the proposed algorithm significantly enhances the overall system throughput, showing its potential for effective interference coordination in the coexistence of LEO and GEO satellite communication systems. © 2015 IEEE.

关键词： Satellite communication systems

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All-optical data class-specific image encryption using diffractive neural networks

All-optical data class-specific image encryption using diffr...

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Frontiers in Optics + Laser Science 2023, FiO, LS 203: Part of Frontiers in Optics + Laser Science 2023

作者： Bai, Bijie Wei, Heming Yang, Xilin Gan, Tianyi Mengu, Deniz Jarrahi, Mona Ozcan, Aydogan Electrical and Computer Engineering Department University of California Los AngelesCA90095 United States Bioengineering Department University of California Los Angeles90095 United States 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 University of California Los AngelesCA United States

We present an all-optical data-class-specific transformation framework that encrypts image data using separate transformations uniquely assigned to each data class. The presented method was experimentally tested under... 详细信息

ISBN: (纸本)9781957171296

关键词： Image encryption Light diffraction Near infrared Neural networks Numerical simulation Optical computing

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Reinforced Multi-teacher Knowledge Distillation for Efficient General Image Forgery Detection and Localization 39

Reinforced Multi-teacher Knowledge Distillation for Efficien...

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39th Annual AAAI Conference on Artificial Intelligence, AAAI 2025

作者： Yu, Zeqin Ni, Jiangqun Zhang, Jian Deng, Haoyi Lin, Yuzhen School of Computer Science and Engineering Sun Yat-sen University China School of Cyber Science and Technology Sun Yat-sen University China Department of New Networks Peng Cheng Laboratory China Guangdong Key Laboratory of Intelligent Information Processing Shenzhen University China

ISBN: (纸本)157735897X

Image forgery detection and localization (IFDL) is of vital importance as forged images can spread misinformation that poses potential threats to our daily lives. However, previous methods still struggled to effectively handle forged images processed with diverse forgery operations in real-world scenarios. In this paper, we propose a novel Reinforced Multi-teacher Knowledge Distillation (Re-MTKD) framework for the IFDL task, structured around an encoder-decoder ConvNeXt-UperNet along with Edge-Aware Module, named Cue-Net. First, three Cue-Net models are separately trained for the three main types of image forgeries, i.e., copy-move, splicing, and inpainting, which then serve as the multi-teacher models to train the target student model with Cue-Net through self-knowledge distillation. A Reinforced Dynamic Teacher Selection (Re-DTS) strategy is developed to dynamically assign weights to the involved teacher models, which facilitates specific knowledge transfer and enables the student model to effectively learn both the common and specific natures of diverse tampering traces. Extensive experiments demonstrate that, compared with other state-of-the-art methods, the proposed method achieves superior performance on several recently emerged datasets comprised of various kinds of image forgeries. © 2025, Association for the Advancement of Artificial Intelligence (***). All rights reserved.

关键词： Knowledge transfer

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Fully integrated hybrid microwave photonic receiver

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Photonics Research 2022年第6期10卷 1472-1483页

作者： JIACHEN LI SIGANG YANG HONGWEI CHEN XINGJUN WANG MINGHUA CHEN WEIWEN ZOU Beijing National Research Center for Information Science and Technology(BNRist) Department of Electronic EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Advanced Optical Communications System and Networks Department of ElectronicsSchool of Electronics Engineering and Computer SciencePeking UniversityBeijing 100871China State Key Laboratory of Advanced Optical Communication Systems and Networks Intelligent Microwave Lightwave Integration Innovation Center(imLic)Department of Electronic EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Microwave photonic receivers are a promising candidate in breaking the bandwidth limitation of traditional radio-frequency(RF)*** further balance the performance superiority with the requirements regarding size,weight,and power consumption(SWa P),the implementation of integrated microwave photonic microsystems has been considered an upgrade ***,up to now,to the best of our knowledge,chip-scale fully integrated microwave photonic receivers have not been reported due to the limitation of material *** this paper,we report a fully integrated hybrid microwave photonic receiver(FIH-MWPR)obtained by comprising the indium phosphide(In P)laser chip and the monolithic silicon-on-insulator(SOI)photonic circuit into the same substrate based on the low-coupling-loss micro-optics *** from the integration of all optoelectronic components,the packaged FIH-MWPR exhibits a compact volume of 6 cmand low power consumption of 1.2 *** FIH-MWPR supports a wide operation bandwidth from 2 to 18 ***,its RF-link performance to down-convert the RF signals to the intermediate frequency is experimentally characterized by measuring the link gain,the noise figure,and the spurious-free dynamic range metrics across the whole operation frequency ***,we have utilized it as a de-chirp receiver to process the broadband linear frequencymodulated(LFM)radar echo signals at different frequency bands(S-,C-,X-,and Ku-bands)and successfully demonstrated its high-resolution-ranging *** the best of our knowledge,this is the first realization of a chip-scale broadband fully integrated microwave photonic receiver,which is expected to be an important step in demonstrating the feasibility of all-integrated microwave photonic microsystems oriented to miniaturized application scenarios.

关键词： method microwave bands

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Secure Wireless-Powered zeRIS Communications

arXiv

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arXiv 2025年

作者： Chen, Jingyu Cao, Kunrui Diamantoulakis, Panagiotis D. Lv, Lu Yang, Liang Chi, Haolian Ding, Haiyang School of Information and Communications National University of Defense Technology Wuhan430035 China Department of Electrical and Computer Engineering Aristotle University of Thessaloniki Thessaloniki54124 Greece State Key Laboratory of Integrated Services Networks Xidian University Xi’an710071 China College of Computer Science and Electronic Engineering Hunan University Changsha410082 China

This paper introduces the concept of wireless-powered zero-energy reconfigurable intelligent surface (zeRIS), and investigates a wireless-powered zeRIS aided communication system in terms of security, reliability and energy efficiency. In particular, we propose three new wireless-powered zeRIS modes: 1) in mode-I, N reconfigurable reflecting elements are adjusted to the optimal phase shift design of information user to maximize the reliability of the system;2) in mode-II, N reconfigurable reflecting elements are adjusted to the optimal phase shift design of cooperative jamming user to maximize the security of the system;3) in mode-III, N1 and N2 (N1+N2 = N) reconfigurable reflecting elements are respectively adjusted to the optimal phase shift designs of information user and cooperative jamming user to balance the reliability and security of the system. Then, we propose three new metrics, i.e., joint outage probability (JOP), joint intercept probability (JIP), and secrecy energy efficiency (SEE), and analyze their closed-form expressions in three modes, respectively. The results show that under high transmission power, all the diversity gains of three modes are 1, and the JOPs of mode-I, mode-II and mode-III are improved by increasing the number of zeRIS elements, which are related to N2, N, and N12, respectively. In addition, mode-I achieves the best JOP, while mode-II achieves the best JIP among three modes. We exploit two security-reliability trade-off (SRT) metrics, i.e., JOP versus JIP, and normalized joint intercept and outage probability (JIOP), to reveal the SRT performance of the proposed three modes. It is obtained that mode-II outperforms the other two modes in the JOP versus JIP, while mode-III and mode-II achieve the best performance of normalized JIOP at low and high transmission power, respectively. © 2025, CC BY.

关键词： Outages

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A 3D cluster-based channel model with time-space consistency (invited paper)

A 3D cluster-based channel model with time-space consistency...

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2021 IEEE/CIC International Conference on Communications in China, ICCC 2021

作者： Huang, Ziwei Cheng, Xiang School of Electronics Engineering and Computer Science Peking University State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronics Beijing100871 China

ISBN: (纸本)9781665443852

This paper proposes a novel three-dimensional (3D) cluster-based sixth-generation (6G) model for millimeter wave (mmWave) massive multiple-input multiple-output (MIMO) channels. In the proposed model, a novel method based on visibility region (VR) is developed, where the smooth and consistent birth and death of clusters in both the time domain and space domain are successfully captured. By using the developed method, the space-time non-stationarity and time-space consistency of channels can be modeled for the first time. Based on the proposed model, important channel statistical properties are derived and thoroughly investigated. Simulation results demonstrate that the smooth birth and death of clusters, time-space consistency, and space-time non-stationarity are modeled sufficiently. © 2021 IEEE.

关键词： Millimeter waves

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CHECKWHY: Causal Fact Verification via Argument Structure

arXiv

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arXiv 2024年

作者： Si, Jiasheng Zhao, Yibo Zhu, Yingjie Zhu, Haiyang Lu, Wenpeng Zhou, Deyu Key Laboratory of Computing Power Network and Information Security Ministry of Education Shandong Computer Science Center Qilu University of Technology Shandong Academy of Sciences China School of Computer Science and Engineering Southeast University China Key Laboratory of New Generation Artificial Intelligence Technology and Its Interdisciplinary Applications Southeast University Ministry of Education China Shandong Provincial Key Laboratory of Computer Networks Shandong Fundamental Research Center for Computer Science China

With the growing complexity of fact verification tasks, the concern with "thoughtful" reasoning capabilities is increasing. However, recent fact verification benchmarks mainly focus on checking a narrow scope of semantic factoids within claims and lack an explicit logical reasoning process. In this paper, we introduce CHECKWHY, a challenging dataset tailored to a novel causal fact verification task: checking the truthfulness of the causal relation within claims through rigorous reasoning steps. CHECKWHY consists of over 19K "why" claim-evidence-argument structure triplets with supports, refutes, and not enough info labels. Each argument structure is composed of connected evidence, representing the reasoning process that begins with foundational evidence and progresses toward claim establishment. Through extensive experiments on state-of-the-art models, we validate the importance of incorporating the argument structure for causal fact verification. Moreover, the automated and human evaluation of argument structure generation reveals the difficulty in producing satisfying argument structure by fine-tuned models or Chain-of-Thought prompted LLMs, leaving considerable room for future improvements1 Copyright © 2024, The Authors. All rights reserved.

关键词： Benchmarking

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A design method for high fabrication tolerance integrated optical mode multiplexer

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Science China(Information Sciences) 2020年第6期63卷 184-194页

作者： Bitao SHEN Haowen SHU Linjie ZHOU Xingjun WANG State Key Laboratory on Advanced Optical Communication Systems and Networks Department of ElectronicsSchool of Electronics Engineering and Computer Science Peking University State Key Laboratory of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Nano-optoelectronics Frontier Center of Ministry of Education Peking University

The tapered asymmetric directional coupler has the potential to realize high fabrication tolerance and high transmission efficiency on-chip mode multiplexer. However, the geometry parameter selection of tapered structure remains empirical. In this paper, we propose a design method for the tapered structure based on genetic algorithm. Combined with the adjusted coupling equations and interpolation method, lowtime-cost optimization can be realized. Three mode multiplexers(TE0&TE1, TE0&TE2 and TE0&TE5)are designed by our method. According to simulation results, the insertion loss of the designed devices is lower than 1.8 dB and the crosstalk is lower than-15 dB when the fabrication error is within required range(±10 nm for TE0&TE2 and TE0&TE5, and ±20 nm for TE0&TE1) in the bandwidth of 1.5–1.6 μm. In addition, the entire optimization process takes only 2 h for each device, which is around the time cost of a single 3 D simulation.

关键词： mode multiplexer directional coupler taper structure coupled-mode theory genetic algorithm

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Lattice-based group encryptions with only one trapdoor

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Science China(Information Sciences) 2022年第5期65卷 205-222页

作者： Jing PAN Jiang ZHANG Fangguo ZHANG Xiaofeng CHEN Willy SUSILO State Key Laboratory of Integrated Service Networks(ISN) Xidian University State Key Laboratory of Cryptology School of Computer Science and Engineering Sun Yat-sen University Guangdong Key Laboratory of Information Security Institute of Cybersecurity and Cryptology School of Computing and Information TechnologyUniversity of Wollongong

Group encryption(GE), the encryption analog of group signatures, is a fundamental primitive that offers a privacy-preserving service for a specific receiver concealed within a group of certified *** other cryptographic primitives, GE constructions are always considered relative to the potential danger of quantum computations. The only existing lattice-based variant appeared in the work of Libert et al.(Asiacrypt'16). Despite its non-trivial achievement, the construction suffers in terms of efficiency due to the extensive use of lattice trapdoors. In this paper, we develop an integrated zero-knowledge argument system that is friendly to both accumulated values and hidden matrices and supports efficient designs from *** on this system, we propose efficiency enhancing GE where only group users are required to possess the lattice trapdoors and the other parties are not. In particular, we utilize lattice-based cryptographic accumulators to confirm prospective group members and use the dual Regev encryption scheme to provide privacy for ciphertext recipients. These modifications significantly increase GE efficiency. In addition, under the intractability assumptions of the standard lattice problems, we prove the security of the proposed scheme in the standard model(assuming interaction during the proof phase), which retains the strongest level of security as the only currently available candidate.

关键词： lattice cryptography group encryptions lattice trapdoors accumulators zero-knowledge

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