检索结果-内蒙古大学图书馆

Chinese Optics Letters 2023年第12期21卷 87-91页

作者：丁婷婷唐永志孙雪芮黄义文江蓓刘瑾李志伟郑远林陈险峰 School of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghai 201620China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Shanghai Research Center for Quantum Sciences Shanghai 201315China Collaborative Innovation Center of Light Manipulation and Applications Shandong Normal UniversityJinan 250358China

optical frequency conversion based on the second-order nonlinearity(χ^((2))) only occurs in anisotropic media(or at interfaces) and thus is intrinsically polarization-dependent. But for practical applications, polarization-insensitive or independent operation is highly sought after. Here, by leveraging polarization coupling and second-order nonlinearity, we experimentally demonstrate a paradigm of TE/TM polarization-independent frequency upconversion, i.e., sum frequency generation, in the periodically poled lithium niobate-on-insulator ridge waveguide. The cascading of quasi-phase-matched polarization coupling and nonlinear frequency conversion is exploited. With a proper transverse electric field, TE and TM mode fundamental waves can be frequency-upconverted with an equal efficiency in the frequency converter. The proposed method may find ready application in all-optical wavelength conversion and upconversion detection technologies.

关键词： frequency upconversion polarization coupling lithium niobate on insulator ridge waveguide cascading process

Realizing a spatially correlated lattice interferometer

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Peng, Peng Mao, Dekai Liang, Yi Yin, Guoling Shui, Hongmian Song, Bo Zhou, Xiaoji State Key Laboratory of Advanced Optical Communication System and Network School of Electronics Peking University Beijing100871 China State Key Laboratory for Mesoscopic Physics Frontiers Science Center for Nano-Optoelectronics School of Physics Peking University Beijing100871 China Institute of Carbon-Based Thin Film Electronics Peking University Shanxi Taiyuan030012 China

Atom interferometers provide a powerful tool for measuring physical constants and testifying fundamental physics with unprecedented precision. Conventional atom interferometry focuses on the phase difference between two paths and utilizes matter waves with fixed coherence. Here, we report on realizing a Ramsey-Bordé interferometer of coherent matter waves dressed by a moving optical lattice in the gravity direction, and explore the resulting interference along multiple paths with tunable coherence. We investigate spatial correlations of atoms both within the lattice and between two arms by interferometry, and observe the emerging multiple interference peaks owing to the long-range coherence nature of the Bose-Einstein condensate. Our findings agree well with theoretical simulations, paving the way for high-precision interferometry with ultracold atoms. © 2024, CC BY.

关键词： Interferometers

Ultrahigh extinction ratio silicon micro-ring modulator by MDM resonance for high speed PAM modulation

学校读者我要写书评

暂无评论

Ultrahigh extinction ratio silicon micro-ring modulator by M...

optical Fiber communication (OFC) Conference

作者： Jiacheng Liu Jiangbing Du Weihong Shen Gangqiang Zhou Linjie Zhou Ke Xu Zuyuan He State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University Shanghai China Peng Cheng Laboratory Harbin Institute of Technology (Shenzhen) Shenzhen China

Silicon micro-ring modulator assisted by MDM resonance is experimentally demonstrated. Ultrahigh ER up to 55 dB was obtained for supporting 50 Gb/s PAM4 signaling with *** VπL, indicating promising performance for ad... 详细信息

ISBN: (纸本)9781557524669

关键词： Modulation optical resonators Extinction ratio Silicon optical fiber communication

High-Rate Point-to-Multipoint Quantum key Distribution using Coherent states

学校读者我要写书评

暂无评论

arXiv 2023年

作者： Bian, Yiming Zhang, Yichen Zhou, Chao Yu, Song Li, Zhengyu Guo, Hong State Key Laboratory of Information Photonics and Optical Communications School of Electronic Engineering 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 Huawei Technologies Co. Ltd. Shenzhen518129 China

Quantum key distribution (QKD) which enables information-theoretically security is now heading towards quantum secure networks. It requires high-performance and cost-effective protocols while increasing the number of users. Unfortunately, qubit-implemented protocols only allow one receiver to respond to the prepared signal at a time, thus cannot support multiple users natively and well satisfy the network demands. Here, we show a ‘protocol solution’ using continuous-variable quantum information. A coherent-state point-to-multipoint protocol is proposed to simultaneously support multiple independent QKD links between a single transmitter and massive receivers. Every prepared coherent state is measured by all receivers to generate raw keys, then processed with a secure and high-efficient key distillation method to remove the correlations between different QKD links. It can achieve remarkably high key rates even with a hundred of access points and shows the potential improvement of two orders of magnitude. This scheme is a promising step towards a high-rate multi-user solution in a scalable quantum secure network. Copyright © 2023, The Authors. All rights reserved.

关键词： Quantum cryptography

Tunable High Precision Signal Processing Based on the Simultaneous Photonic Filtering and Digitizing system

学校读者我要写书评

暂无评论

Tunable High Precision Signal Processing Based on the Simult...

Conference on Lasers and Electro-Optics Europe (CLEO EUROPE)

作者： Yiwei Sun Qinggui Tan Di Wang Dong Liang Sitong Wang Jingwen Gong Guiling Wu China Acaemy of Space Technology (Xi'an) Xi'an China Department of Electronic Engineering The state Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Institute for Advanced Communication and Data Science Shanghai Jiao Tong University Shanghai China Shanghai Huawei Technologies Company Ltd. Shanghai China

ISBN: (纸本)9798350345995

With the development of the communication and radar systems, the demand for precisely processing broadband signal has become urgent. The basic functions of filtering and digitizing are often needed together in many applications such as antialiasing and interference suppression in digital receivers. To break the bottleneck of the traditional methods, a recently-proposed simultaneous photonic filtering and digitizing system[1] can achieve analog pre-filtering and digitizing at the same time, and its equivalent system response can be tuned by shaping the optical sampling pulses. However, limited by the dilemma between the precision and duration of the shaped pulses, the bandwidth of the signal processing are constraint. The design rules to achieve precise signal procession are analysed. An optical shaping scheme based on the interference and frequency-to-time mapping is utilized in the system[2], as shown in Fig. 1(a). The response of the OF is $G(\omega)$ , and the tunable delay difference between interference arms is $\tau$ . The dispersive value of the SMF is $\Phi_{v}$ . The RF signals are processed and digitized in the IMDD link and EADC[2]. The equivalent system response $\mathrm{H}_{\mathrm{A}}(\omega)$ for signal processing is

关键词： Analog to digital converters Fourier transforms Interference Radar Signal processing systems design

Ultrahigh-coherence microcomb generation and low-noise amplification using integrated photonics

学校读者我要写书评

暂无评论

Ultrahigh-coherence microcomb generation and low-noise ampli...

IEEE Photonics Conference (IPC)

作者： Xuguang Zhang Zixuan Zhou Yijun Guo Minxue Zhuang Warren Jin Bitao Shen Yujun Chen Jiahui Huang Weiwei Hu Haowen Shu John E. Bowers Xingjun Wang Lin Chang State Key Laboratory of Advanced Optical Communications System and Networks School of Electronics Peking University Beijing China Department of Electrical and Computer Engineering University of California Santa Barbara Santa Barbara CA USA Frontiers Science Center for Nano-Optoelectronics Peking University Beijing China

ISBN: (数字)9798350361957

ISBN: (纸本)9798350361964

We demonstrate a high-coherence parallel integrated light source utilizing a self-injection locked microcomb and injection locking amplification. Our strategy exhibits a record high on-chip gain of 60 dB, nearly 0 dB noise factor, which enable more than 30 highly coherent channels in integrated photonics whose linewidths down to 10 Hz, power exceeding 20 dBm per line and a wall plug efficiency of 19%.

关键词： Injection-locked oscillators Noise system-on-chip Gain Photonics Plugs Light sources

Hybrid Near-Far Field Channel Estimation for Holographic MIMO communications

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Yue, Shaohua Zeng, Shuhao Liu, Liang Eldar, Yonina C. Di, Boya The State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China The Department of Electronic and Information Engineering The Hong Kong Polytechnic University Hong Kong The Faculty of Mathematics and Computer Science Weizmann Institute of Science Rehovot7610001 Israel

Holographic MIMO communications, enabled by large-scale antenna arrays with quasi-continuous apertures, is a potential technology for spectrum efficiency improvement. However, the increased antenna aperture size extends the range of the Fresnel region, leading to a hybrid near-far field communication mode. The users and scatterers randomly lie in near-field and far-field zones, and thus, conventional far-field-only and near-field-only channel estimation methods may not work. To tackle this challenge, we demonstrate the existence of the power diffusion (PD) effect, which leads to a mismatch between the hybrid-field channel and existing channel estimation methods. Specifically, in far-field and near-field transform domains, the power gain of one channel path may diffuse to other positions, thus generating fake paths. This renders the conventional techniques unable to detect those real paths. We propose a PD-aware orthogonal matching pursuit algorithm to eliminate the influence of the PD effect by identifying the PD range, within which paths diffuse to other positions. PD-OMP fits a general case without prior knowledge of near-field and far-field path numbers and the user’s location. The computational complexity of PD-OMP and the Cramér-Rao Lower Bound for the sparse-signal-recovery-based channel estimation are also derived. Simulation results show that PD-OMP outperforms state-of-the-art hybrid-field channel estimation methods. © 2024, CC BY-NC-ND.

关键词： Channel estimation

Up to 20 Mb/s Auxiliary Management and Control Channel Signal Transmission in 50 Gb/s PON system

学校读者我要写书评

暂无评论

Up to 20 Mb/s Auxiliary Management and Control Channel Signa...

optical Fiber communication (OFC) Conference

作者： Haipeng Guo Chuanchuan Yang Xin Qin Yunfeng Gao Ziyuan Zheng Hongbin Li State Key Laboratory of Advanced Optical Communication Systems and Networks Peking University Beijing China

Up to 20 Mb/s transmission of AMCC signal with different modulation formats over 50 Gb/s PAM4 PON is experimentally demonstrated. The results confirm power penalty for PON signal in AMCC superimposition is lower than ... 详细信息

ISBN: (纸本)9781943580866

关键词： optical fibers Modulation optical fiber communication

RIS-Assisted Secure Transmission Exploiting Statistical CSI of Eavesdropper

学校读者我要写书评

暂无评论

RIS-Assisted Secure Transmission Exploiting Statistical CSI ...

2021 IEEE Global communications Conference (GLOBECOM)

作者： Cen Liu Chang Tian Peixi Liu State Key Laboratory of Advanced Optical Communication Systems and Networks Peking University Beijing China

ISBN: (纸本)9781728181059

We investigate the reconfigurable intelligent surface (RIS) assisted downlink secure transmission where only the statistical channel of eavesdropper is available. To handle the stochastic ergodic secrecy rate (ESR) maximization problem, a deterministic lower bound of ESR (LESR) is derived. We aim to maximize the LESR by jointly designing the transmit beamforming at the access point (AP) and reflect beamforming by the phase shifts at the RIS. To solve the non-convex LESR maximization problem, we develop a novel penalty dual convex approximation (PDCA) algorithm based on the penalty dual decomposition (PDD) optimization framework, where the exacting constraints are penalized and dualized into the objective function as augmented Lagrangian components. The proposed PDCA algorithm performs double-loop iterations, i.e., the inner loop resorts to the block successive convex approximation (BSCA) to update the optimization variables; while the outer loop adjusts the Lagrange multipliers and penalty parameter of the augmented Lagrangian cost function. The convergence to a Karush-Kuhn-Tucker (KKT) solution is theoretically guaranteed with low computational complexity. Simulation results show that the proposed PDCA scheme is better than the commonly adopted alternating optimization (AO) scheme with the knowledge of statistical channel of eavesdropper.

关键词： Array signal processing Simulation Reconfigurable intelligent surfaces Approximation algorithms Linear programming Downlink Cost function

783-MHz fundamental repetition rate all-fiber ring laser mode-locked by carbon nanotubes

学校读者我要写书评

暂无评论

arXiv 2024年

作者： Dai, Maolin Liu, Bowen Ma, Yifan Shirahata, Takuma Yang, Ruoao Zhang, Zhigang Set, Sze Yun Yamashita, Shinji Department of Electrical Engineering and Information Systems The University of Tokyo Bunkyo-ku Tokyo113-8656 Japan Research Center for Advanced Science and Technology The University of Tokyo Meguro-ku Tokyo153-8904 Japan State Key Laboratory of Advanced Optical Communication Systems and Networks School of Electronics Peking University Beijing100871 China

We demonstrate a 783-MHz fundamental repetition rate mode-locked Er-doped all-fiber ring laser with a pulse width of 623 fs. By using carbon nanotubes (CNT) saturable absorber (SA), a relatively low self-starting pump threshold of 108 mW is achieved. The laser has a very compact footprint less than 10 cm × 10 cm, benefiting from the all-active-fiber cavity design. The robust mode-locking is confirmed by the low relative intensity noise (RIN) and a long-term stability test. We propose a new scheme for generating high repetition rate femtosecond optical pulses from a compact and stable all-active-fiber ring oscillator. © 2024, CC BY.

关键词： Carbon nanotubes