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FeynmanPAQS: A graphical interface program for photonic analog quantum computing

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arXiv 2018年

作者： Tang, Hao Zhu, Yan-Yan Gao, Jun Lee, Marcus Lai, Peng-Cheng Jin, Xian-Min State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China Institute of Natural Sciences Shanghai Jiao Tong University Shanghai200240 China Synergetic Innovation Center of Quantum Information and Quantum Physics University of Science and Technology of China Hefei Anhui230026 China School of Physical Science University of Chinese Academy of Science Beijing100049 China Deparment of Physics Cambridge University CambridgeCB3 0HE United Kingdom

We present a user-friendly software for photonic analog quantum computing with an installable MATlab package and the graphical user interface (GUI) that allows for convenient operation without requiring programming skills. Arbitrary Hamiltonians can be set by either importing the waveguide position files or manually plotting the configuration on the interactive board of the GUI. Our software provides a powerful approach to theoretical studies of two-dimensional quantum walks, quantum stochastic walks, multi-particle quantum walks and boson sampling, which may all be feasibly implemented in the physical experimental system on photonic chips, and would inspire a rich diversity of applications for photonic quantum computing and quantum simulation. We have also improved algorithms to ensure the calculation efficiency of the software, and provided various panels and exporting formats to facilitate users for comprehensive analysis of their research issues with abundant theoretical results. Copyright © 2018, The Authors. All rights reserved.

关键词： Graphical user interfaces

Simultaneous Transmission of ASK, OCS-ASK and FSK Signals in A Radio over Fiber system Using A Single-drive Mach-Zehnder Modulator

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Journal of Physics: Conference Series 2011年第1期276卷

作者： Liang Zhang Yanzhi Wu Tong Ye Junbo Xu Xiaofeng Hu Yikai Su State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Road Dongchuan 800# Shanghai 200240 China Fiberhome Technologies Wuhan 430074 China

We propose a bidirectional radio over fiber (RoF) system for simultaneous generation and transmission of amplitude shift keying (ASK), optical carrier suppressed amplitude shift keying (OCS-ASK) and frequency shift keying (FSK) signals based on one single-drive Mach-Zehnder modulator (MZM). The feasibility of the proposal is verified by experiments and error-free performances are achieved for all the data.

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Multi-scale GCN-assisted two-stage network for joint segmentation of retinal layers and disc in peripapillary OCT images

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arXiv 2021年

作者： Li, Jiaxuan Jin, Peiyao Zhu, Jianfeng Zou, Haidong Xu, Xun Tang, Min Zhou, Minwen Gan, Yu He, Jiangnan Ling, Yuye Su, Yikai John Hopcroft Center for Computer Science Shanghai Jiao Tong University Shanghai200240 China Department of Preventative Ophthalmology Shanghai Eye Disease Prevention and Treatment Center Shanghai Eye Hospital Shanghai200040 China Department of Ophthalmology Shanghai General Hospital Shanghai Jiao Tong University Shanghai200080 China Department of Electrical and Computer Engineering The University of Alabama AL35487 United States State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Shanghai200240 China

An accurate and automated tissue segmentation algorithm for retinal optical coherence tomography (OCT) images is crucial for the diagnosis of glaucoma. However, due to the presence of the optic disc, the anatomical structure of the peripapillary region of the retina is complicated and is challenging for segmentation. To address this issue, we developed a novel graph convolutional network (GCN)-assisted two-stage framework to simultaneously label the nine retinal layers and the optic disc. Specifically, a multi-scale global reasoning module is inserted between the encoder and decoder of a U-shape neural network to exploit anatomical prior knowledge and perform spatial reasoning. We conducted experiments on human peripapillary retinal OCT images. The Dice score of the proposed segmentation network is 0.820 ± 0.001 and the pixel accuracy is 0.830 ± 0.002, both of which outperform those from other state-of-the-art techniques. Copyright © 2021, The Authors. All rights reserved.

关键词： optical tomography

Propagation effects of seeded collective emission by two-photon excited oxygen atoms

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Physical Review Research 2023年第4期5卷 043293-043293页

作者： Xin Wang Yu-Hung Kuan Jun Jie Cui Yu Kun Yang Fan Xing Wen-Te Liao Luqi Yuan Yongjun Cheng Zeyang Liao Zheng Li Song Bin Zhang School of Physics and Information Technology Shaanxi Normal University Xi'an 710119 China School of Physics Sun Yat-Sen University Guangzhou 510275 China Department of Physics National Central University Taoyuan City 32001 Taiwan Republic of China School of Physics Henan Normal University Xinxiang 453007 China Physics Division National Center for Theoretical Sciences Taipei 10617 Taiwan Republic of China Quantum Technology Center National Central University Taoyuan City 32001 Taiwan Republic of China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and Astronomy Shanghai Jiao Tong University Shanghai 200240 China State Key Laboratory for Mesoscopic Physics and Collaborative Innovation Center of Quantum Matter School of Physics Peking University Beijing 100871 China Collaborative Innovation Center of Extreme Optics Shanxi University Taiyuan Shanxi 030006 China Peking University Yangtze Delta Institute of Optoelectronics Nantong Jiangsu 226010 China

A strong ultraviolet pumping laser propagating through the atmosphere could activate the medium and produce the forward and backward coherent air lasing. In this work, we present the theoretical analyses of forward and backward lasing dynamics in the long gain medium consisting of oxygen atoms. By numerically solving the semiclassical Maxwell-Bloch equations, we demonstrate that the atom density, the gain medium length, and the collisional decoherence rate substantially regulate the forward and backward air laser radiation at 845 nm. Especially, our study points out that lower atom density and moderate collisional decoherence rate are favorable for the backward radiation amplification in a long medium, since such conditions balance the competing processes of forward and backward radiation fields. The simulation shows that long medium backward air lasing becomes challenging in the oxygen atom system via double-photon pump, because the amplification can only occur around z=0, and the amplified backward radiation does not carry the spectral information of atoms throughout the medium. On the other hand, certain mechanisms such as variation of backward-seeding delay could possibly alleviate the suppression of backward amplification.

关键词： Air lasing Collective effects in quantum optics Quantum optics Ultrafast optics

Beyond Fourier transform: Break the axial resolution limit in optical coherence tomography

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arXiv 2020年

作者： Ling, Yuye Wang, Mengyuan Gan, Yu Yao, Xinwen Schmetterer, Leopold Zhou, Chuanqing Su, Yikai John Hopcroft Center for Computer Science Shanghai Jiao Tong University Shanghai China Department of Electrical and Computer Engineering University of Alabama AL United States Singapore Institute for Health Technologies Nanyang Technological University Singapore Singapore Eye Research Institute Singapore National Eye Centre Singapore School of Chemical and Biomedical Engineering Nanyang Technological University Singapore Institute of Biomedical Engineering Shenzhen Bay Lab Shenzhen China School of Biomedical Engineering Shanghai Jiao Tong University Shanghai China State Key Lab of Advanced Optical Communication Systems and Networks Department of Electronic Engineering Shanghai Jiao Tong University Shanghai China

optical coherence tomography (OCT) is a volumetric imaging modality that empowers clinicians and scientists to noninvasively visualize and examine the microscopic cross-sectional architectures of biological samples. By taking advantage of the coherence gating, OCT could achieve micrometer-level axial sectioning with high sensitivity. In the past decade, substantial efforts have been made to push the axial resolution of Fourier-domain OCT (FD-OCT) further into the sub-micron regime by physically extending the system's spectral bandwidth. Here, we offer a new perspective on this problem with the help of a new theoretical framework. We identified a key limitation on the reconstruction's axial resolution, which is induced by the Fourier transform-based reconstruction algorithm. To break this limit, we presented a novel optimization-based algorithm to recover the super-resolution image from ordinary FD-OCT measurements with proper physical assumptions. To prove the concept, we retrieved images at a resolution higher than the theoretical prediction in both phantoms and biological samples. Copyright © 2020, The Authors. All rights reserved.

关键词： optical tomography

Photon retention in coherently excited nitrogen ions

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arXiv 2020年

作者： Yao, Jinping Wang, Luojia Chen, Jinming Wan, Yuexin Zhang, Zhihao Zhang, Fangbo Qiao, Lingling Yu, Shupeng Fu, Botao Zhao, Zengxiu Wu, Chengyin Yakovlev, Vladislav V. Yuan, Luqi Chen, Xianfeng Cheng, Ya Shanghai201800 China State Key Laboratory of Advanced Optical Communication Systems and Networks School of Physics and Astronomy Shanghai Jiao Tong University Shanghai200240 China University of Chinese Academy of Sciences Beijing100049 China School of Physical Science and Technology ShanghaiTech University Shanghai200031 China Department of Physics National University of Defense Technology Changsha410073 China State Key Laboratory for Mesoscopic Physics School of Physics Peking University Beijing100871 China Texas A&M University College StationTX77843 United States Shanghai Research Center for Quantum Sciences Shanghai201315 China Jinan Institute of Quantum Technology Jinan250101 China Collaborative Innovation Center of Light Manipulations and Applications Shandong Normal University Jinan250358 China Collaborative Innovation Center of Extreme Optics Shanxi University Shanxi Taiyuan030006 China

Quantum coherence in quantum optics is an essential part of optical information processing and light manipulation. Alkali metal vapors, despite the numerous shortcomings, are traditionally used in quantum optics as a working medium due to convenient near-infrared excitation, strong dipole transitions and long-lived coherence. Here, we proposed and experimentally demonstrated photon retention and subsequent re-emittance with the quantum coherence in a system of coherently excited molecular nitrogen ions (N+2) which are produced using a strong 800 nm femtosecond laser pulse. Such photon retention, facilitated by quantum coherence, keeps releasing directly-unmeasurable coherent photons for tens of picoseconds, but is able to be read-out by a time-delayed femtosecond pulse centered at 1580 nm via two-photon resonant absorption, resulting in a strong radiation at 329.3 nm. We reveal a pivotal role of the excited-state population to transmit such extremely weak re-emitted photons in this system. This new finding unveils the nature of the coherent quantum control in N+2 for the potential platform for optical information storage in the remote atmosphere, and facilitates further exploration of fundamental interactions in the quantum optical platform with strong-field ionized molecules. Copyright © 2020, The Authors. All rights reserved.

关键词： Photons

A Shifted Double‐Diamond Titania Scaffold

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Angewandte Chemie 2016年第3期129卷

作者： Hong Li Ye Liu Xin Cao Lu Han Chun Jiang Shunai Che School of Chemistry and Chemical Engineering State Key Laboratory of Metal Matrix Composites Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 P.R. China School of Electronic Information and Electrical Engineering State Key Laboratory of Advanced Optical Communication Systems and Networks Shanghai Jiao Tong University 800 Dongchuan Road Shanghai 200240 P.R. China

Photonic crystals are expected to be metamaterials because of their potential to control the propagation of light in the linear and nonlinear regimes. Biological single‐network, triply periodic constant mean curvature surface structures are considered excellent candidates owing to their large complete band gap. However, the chemical construction of these relevant structures is rare and developing new structures from thermodynamically stable double‐network self‐organizing systems is challenging. Herein, we reveal that the shifted double‐diamond titania scaffold can achieve a complete band gap. The largest (7.71 %) band gap is theoretically obtained by shifting 0.332 c with the dielectric contrast of titania (6.25). A titania scaffold with similar shifted double‐diamond structure was fabricated using a reverse core–shell microphase‐templating system with an amphiphilic diblock copolymer and a titania source in a mixture of tetrahydrofuran and water, which could result in a 2.05–3.78 % gap.

关键词： Blockcopolymere Diamantstrukturen Selbstorganisation Titandioxid Vollständige Bandlücke

Waveguide-integrated twisted bilayer graphene photodetectors (vol 15, 3688, 2024)

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NATURE communicationS 2024年第1期15卷 3688页

作者： Wu, Qinci Qian, Jun Wang, Yuechen Xing, Luwen Wei, Ziyi Gao, Xin Li, Yurui Liu, Zhongfan Liu, Hongtao Shu, Haowen Yin, Jianbo Wang, Xingjun Peng, Hailin Peking University Center for Nanochemistry Beijing Science and Engineering Center for Nanocarbons Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Beijing Graphene Institute Beijing P. R. China (GRID:grid.510905.8) Peking University Center for Nanochemistry Beijing Science and Engineering Center for Nanocarbons Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Beijing Graphene Institute Beijing P. R. China (GRID:grid.510905.8) Peking University Academy for Advanced Interdisciplinary Studies Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Peking University State Key Laboratory of Advanced Optical Communications System and Networks School of Electronics Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Peking University School of Engineering Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Peking University State Key Laboratory of Advanced Optical Communications System and Networks School of Electronics Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Beijing Graphene Institute Beijing P. R. China (GRID:grid.510905.8) Peking University Academy for Advanced Interdisciplinary Studies Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Peking University Center for Nanochemistry Beijing Science and Engineering Center for Nanocarbons Beijing National Laboratory for Molecular Sciences College of Chemistry and Molecular Engineering Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Beijing Graphene Institute Beijing P. R. China (GRID:grid.510905.8) Peking University Academy for Advanced Interdisciplinary Studies Beijing P. R. China (GRID:grid.11135.37) (ISNI:0000 0001 2256 9319) Peking University State Key Laboratory of Advanced Optical Com

Graphene photodetectors have exhibited high bandwidth and capability of being integrated with silicon photonics (SiPh), holding promise for future optical communication devices. However, they usually suffer from a low photoresponsivity due to weak optical absorption. In this work, we have implemented SiPh-integrated twisted bilayer graphene (tBLG) detectors and reported a responsivity of 0.65 A W–1 for telecom wavelength 1,550 nm. The high responsivity enables a 3-dB bandwidth of >65 GHz and a high data stream rate of 50 Gbit s–1. Such high responsivity is attributed to the enhanced optical absorption, which is facilitated by van Hove singularities in the band structure of high-mobility tBLG with 4.1o twist angle. The uniform performance of the fabricated photodetector arrays demonstrates a fascinating prospect of large-area tBLG as a material candidate for heterogeneous integration with ***-integrated graphene photodetectors exhibit promising bandwidths at telecom wavelengths, but their responsivity is usually limited. Here, the authors report the wafer-scale fabrication of waveguide-integrated detectors based on twisted bilayer graphene, showing responsivities up to 0.65 A/W and 3-dB bandwidths >65 GHz.

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Reconfigurable Intelligent Surface Assisted High-Speed Train communications: Coverage Performance Analysis and Placement Optimization

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arXiv 2023年

作者： Liu, Changzhu He, Ruisi Niu, Yong Han, Zhu Ai, Bo Gao, Meilin Ma, Zhangfeng Wang, Gongpu Zhong, Zhangdui The State Key Laboratory of Advanced Rail Autonomous Operation The School of Electronics and Information Engineering The Frontiers Science Center for Smart High-speed Railway System The Beijing Engineering Research Center of High-Speed Railway Broadband Mobile Communications Beijing Jiaotong University Beijing100044 China The State Key Laboratory of Advanced Rail Autonomous Operation Beijing Jiaotong University Beijing100044 China The National Mobile Communications Research Laboratory Southeast University Nanjing211189 China The Department of Electrical and Computer Engineering The University of Houston HoustonTX77004 United States The Department of Computer Science and Engineering Kyung Hee University Seoul446-701 Korea Republic of Henan Joint International Research Laboratory of Intelligent Networking and Data Analysis Zhengzhou University Zhengzhou450001 China Research Center of Networks and Communications Peng Cheng Laboratory Shenzhen China The Tsinghua Space Center the Beijing National Research Center for Information Science and Technology Tsinghua University Beijing100091 China The College of Information Engineering Shaoyang University Shaoyang422000 China The Beijing Key Lab of Transportation Data Analysis and Mining School of Computer and Information Technology Beijing Jiaotong University Beijing100044 China

Reconfigurable intelligent surface (RIS) emerges as maximization problem is formulated to facilitate RIS discrete an efficient and promising technology for the next wireless phase design and RIS placement optimization, which is subject generation networks and has attracted a lot of attention owing to coverage probability constraint. Simulation results validate to the capability of extending wireless coverage by reflecting that better coverage performance and higher travel distance signals toward targeted receivers. In this paper, we consider can be achieved with deployment of RIS. The impacts of some a RIS-assisted high-speed train (HST) communication system key system parameters including transmission power, signal-to-to enhance wireless coverage and improve coverage probability. noise ratio threshold, number of RIS elements, number of RIS First, coverage performance of the downlink single-input-single- quantization bits, horizontal distance between base station and output system is investigated, and the closed-form expression RIS, and speed of HST on system performance are investigated. of coverage probability is derived. Moreover, travel distance In addition, it is found that RIS can well improve coverage probability with limited power consumption for HST communications. Copyright © 2023, The Authors. All rights reserved.

关键词： Railroads