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Generation of orbital angular momentum hologram using a modified U-net

Chinese Physics B 2024年第3期33卷 401-407页

作者：郑志刚韩菲菲王乐赵生妹 Institute of Signal Processing and Transmission Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology (Ministry of Education) Nanjing University of Posts and TelecommunicationsNanjing 210003China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China

Orbital angular momentum(OAM)holography has become a promising technique in information encryption,data storage and opto-electronic computing,owing to the infinite topological charge of one single OAM mode and the orthogonality of different OAM *** this paper,we propose a novel OAM hologram generation method based on a densely connected U-net(DCU),where the densely connected convolution blocks(DCB)replace the convolution blocks of the ***,the reconstruction process of the OAM hologram is integrated into DCU as its output layer,so as to eliminate the requirement to prepare training data for the OAM hologram,which is required by conventional neural networks through an iterative *** experimental and simulation results show that the OAM hologram can rapidly be generated with the well-trained DCU,and the reconstructed image's quality from the generated OAM hologram is significantly improved in comparison with those from the Gerchberg-Saxton generation method,the Gerchberg-Saxton based generation method and the U-net *** addition,a 10-bit OAM multiplexing hologram scheme is numerically demonstrated to have a high capacity with OAM hologram.

关键词： orbital angular momentum(OAM) holography OAM holography deep learning

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Efficient separating orbital angular momentum mode with radial varying phase

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Photonics Research 2017年第4期5卷 267-270页

作者： CHENG LI SHENGMEI ZHAO Institute of Signal Processing and Transmission Nanjing University of Posts and Telecommunications Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education

It is shown that orbital angular momentum(OAM) is a promising new resource in future classical and quantum communications. However, the separation of OAM modes is still a big challenge. In this paper, we propose a simple and efficient separation method with a radial varying phase. In the method, specific radial varying phases are designed and modulated for different OAM modes. The resultant beam is focused to the spots with different horizontal and vertical positions after a convex lens, when the coordinate transformation, including two optical elements with coordinate transformation phase and correct phase, operates on the received *** horizontal position of the spot is determined by the vortex phases, and the vertical position of the spot is dependent on the radial varying phases. The simulation and experimental results show that the proposed method is feasible both for separation of two OAM modes and separation of three OAM modes. The proposed separation method is available in principle for any neighboring OAM modes because the radial varying phase is controlled. Additionally, no extra instruments are introduced, and there is no diffraction and narrowing process limitation for the separation.

关键词： OAM Efficient separating orbital angular momentum mode with radial varying phase mode

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Quantum-enhanced interferometry with asymmetric beam splitters

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Science China(Physics,Mechanics & Astronomy) 2020年第6期63卷 22-32页

作者： Wei Zhong Fan Wang Lan Zhou Peng Xu YuBo Sheng Institute of Quantum Information and Technology Nanjing University of Posts and TelecommunicationsNanjing 210003China National Laboratory of Solid State Microstructures Nanjing UniversityNanjing 210093China School of Science Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China

In this paper,we investigate the phase sensitivities in two-path optical interferometry with asymmetric beam ***,we present the optimal conditions for the transmission ratio and the phase of the beam splitter to gain the highest sensitivities for a general class of non-classical states with parity ***,we address the controversial question of whether the scheme with a combination of coherent state and photon-added or photon-subtracted squeezed vacuum state is better or worse than the most celebrated one using a combination of coherent state and squeezed vacuum state.

关键词： quantum metrology quantum Fisher information Heisenberg limit optical interferometry

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A quantum search based signal detection for MIMO-OFDM systems

A quantum search based signal detection for MIMO-OFDM system...

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2011 18th International Conference on Telecommunications, ICT 2011

作者： Li, Fei Zhou, Lizhi Liu, Li Li, Haibo Key Lab of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunication Ministry of Education Nanjing China Department of Applied Physics and Electronics Umeå University Umeå Sweden

ISBN: (纸本)9781457700248

Multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) is considered as candidates for future broadband wireless services. In this paper a novel signal detection scheme based on Grover's quantum search algorithm is proposed for MIMO-OFDM systems. Grover's quantum search algorithm is based on the concept and principles of quantum computing, such as quantum bit, quantum register and quantum parallelism. An analysis is given to the theoretical basis of Grover's algorithm and the performance of Grover's algorithm is evaluated. A novel signal detector based on Grover's algorithm (GD) for MIMO-OFDM system is proposed. The simulation results show that the proposed detector has more powerful properties in bit error rate than MMSE detector and VBLAST-MMSE detector. The performance of the proposed GD detector is close to optimal when the failure probability is 0.001. When the failure probability is 0.00001, the performance of GD detector declines. In this case, our proposed improved Grover's algorithm based detector is still close to the optimal ML detector. The complexity of GD and IGD is O(√N). It's much better than classical ML detector which complexity is O(N). © 2011 IEEE.

关键词： Orthogonal frequency division multiplexing

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Fog node selection for low latency communication and anomaly detection in fog networks

Fog node selection for low latency communication and anomaly...

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2019 International Conference on communications, Information System, and Computer Engineering, CISCE 2019

作者： Li, Yuxiao Zhang, Yazhong Liu, Yuxiang Meng, Qingmin Tian, Feng Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Nanjing University of Posts and Telecommunications Ministry of Education College of Telecommunications and Information Engineering Nanjing210003 China

ISBN: (纸本)9781728136813

The application of 5G in IOT (Internet of things) puts forward strict requirements for network latency. In view of the fog network scenario with large-scale IOT devices, this paper proposes a procedure of unsupervised learning to efficiently realize the requirement of low-latency communication. We propose an integrated K-means clustering and PCA fog computing design, which facilitates a new service of fog, anomaly detection. Computer simulation shows that, in the presence of large-scale path loss, shadow and small-scale fading channel, the system design with low latency needs to consider the deployment of dense fog nodes and adopt more frequency or power resources at the same time. The proposed procedure and machine learning design not only facilitates the selection of fog nodes, but also presents a new example of anomaly detection using fog nodes. © 2019 IEEE.

关键词： Fog

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Cognitive radio spectrum sharing using improved Quantum Genetic Algorithm

Cognitive radio spectrum sharing using improved Quantum Gene...

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2011 International Conference on wireless communications and Signal Processing, WCSP 2011

作者： Li, Fei Zhu, Dongpo Tian, Feng Li, Haibo Key Lab of Broadband Wireless Communication and Sensor Network Technology Ministry of Education Nanjing University of Posts and Telecommunications Nanjing China Department of Applied Physics and Electronics Umeå University Umeå Sweden

ISBN: (纸本)9781457710100

A key challenge in cognitive radios (CR) network is how to adaptively and efficiently allocate transmission powers and spectrum among CR users according to the surrounding environment. In this paper, we propose a novel spectrum sharing based on our improved Quantum Genetic Algorithm (QGA) in a non-cooperative game for CR network. We improved the original QGA by quantum crossover operator, in order to overcome the shortcoming of the original QGA easily falling into a local extremum when used to optimize the continuous functions with many extrema. We used our improved QGA as a competitive strategy and conducted several simulations in two-user system and multi-user system. From simulation results, it is evident that the proposed improved QGA based spectrum sharing scheme has better convergence rate and higher sum capacity than GA based scheme even in multi-user CR system, namely up to 2bit/s/Hz increase in capacity. The simulation results also show that the population size of QGA affect sum capacity of cognitive radio system. The results demonstrated the effectiveness and the applicability of QGA in spectrum sharing in multi-user cognitive radio system. © 2011 IEEE.

关键词： Cognitive radio

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AN IDENTITY-BASED key AGREEMENT SCHEME FOR LARGE SCALE sensor networkS

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Journal of Electronics(China) 2013年第6期30卷 574-586页

作者： Yang Lijun Wu Meng Ding Chao College of Computer Science & Technology Nanjing University of Posts and Telecommunications College of Telecommunication & Information Engineering Nanjing University of Posts and Telecommunications Key Laboratory of Broadband Wireless Communication and Sensor Network Technology of Ministry of Education

To solve the problems of high memory occupation, low connectivity and poor resiliency against node capture, which existing in the random key pre-distribution techniques while applying to the large scale wireless sensor networks （WSNs）, an Identity-Based key Agreement Scheme （IBKAS） is proposed based on identity-based encryption and Elliptic Curve Diffie-Hellman （ECDH）. IBKAS can resist man-in-the-middle attacks and node-capture attacks through encrypting the key agreement parameters using identity-based encryption. Theoretical analysis indicates that comparing to the random key pre-distribution techniques, IBKAS achieves significant improvement in key connectivity, communication overhead, memory occupation, and security strength, and also enables efficient secure rekcying and network expansion. Furthermore, we implement IBKAS for TinyOS-2.1.2 based on the MICA2 motes, and the experiment results demonstrate that IBKAS is feasible for infrequent key distribution and rekeying for large scale sensor networks.

关键词： Large scale wireless sensor networks （WSNs） network security key agreement Iden-tity-based cryptography

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Perovskite light-emitting/detecting bifunctional fibres for wearable LiFi communication

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Light(Science & Applications) 2020年第1期9卷 441-449页

作者： Qingsong Shan Changting Wei Yan Jiang Jizhong Song Yousheng Zou Leimeng Xu Tao Fang Tiantian Wang Yuhui Dong Jiaxin Liu Boning Han Fengjuan Zhang Jiawei Chen Yongjin Wang Haibo Zeng MIIT Key Laboratory of Advanced Display Materials and Devices Institute of Optoelectronics&NanomaterialsSchool of Materials Science and EngineeringNanjing University of Science and TechnologyNanjing 210094China Peter Grünberg Research Center Laboratory of Broadband Wireless Communication and Sensor Network TechnologyMinistry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China

Light fidelity(LiFi),which is emerging as a compelling technology paradigm shifting the common means of highcapacity wireless communication technologies,requires wearable and full-duplex compact design because of its great significance in smart wearables as well as the‘Internet of Things’.However,the construction of the key component of wearable full-duplex LiFi,light-emitting/detecting bifunctional fibres,is still challenging because of the conflicting process between carrier separation and recombination,as well as the highly dynamic film-forming ***,we demonstrate light-emitting/detecting bifunctional fibres enabled by perovskite QDs with hybrid *** hybrid perovskite inks endow fibres with super-smooth QD ***,combined with the small exciton binding energy and high carrier mobility of perovskite QDs,enables successful integration of electroluminescence and photodetection into *** bifunctional fibres possess the narrowest electroluminescence full width at half maximum of ~19 nm and,more importantly,the capability for simultaneously transmitting and receiving *** successful fabrication of narrow emission full-duplex LiFi fibres paves the way for the fabrication and integration of low crosstalk interoperable smart wearables.

关键词： process perovskite functional

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Practical decoy-state BB84 quantum key distribution with quantum memory

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Chinese Physics B 2021年第6期30卷 133-136页

作者： Xian-Ke Li Xiao-Qian Song Qi-Wei Guo Xing-Yu Zhou Qin Wang Institute of Quantum Information and Technology Nanjing University of Posts and TelecommunicationsNanjing 210003China Broadband Wireless Communication and Sensor Network Technology Key Laboratory of Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China Telecommunication and Networks National Engineering Research Center Nanjing University of Posts and TelecommunicationsNanjing 210003China

We generalize BB84 quantum key distribution(QKD) to the scenario where the receiver adopts a heralded quantum memory(QM). With the heralded QM, the valid dark count rate of the receiver's single photon detectors can be mitigated obviously, which will lower the quantum bit error rate, and thus improve the performance of decoy-state BB84 QKD systems in long distance range. Simulation results show that, with practical experimental system parameters, decoy-state BB84 QKD with QM can exhibit performance comparable to that of without QM in short distance range, and exhibit performance better than that without QM in long distance range.

关键词： quantum key distribution quantum communication quantum memory decoy state

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Complete hyperentangled Greenberger–Horne–Zeilinger state analysis for polarization and time-bin hyperentanglement

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Chinese Physics B 2023年第6期32卷 122-126页

作者：曾志 Institute of Signal Processing and Transmission Nanjing University of Posts and TelecommunicationsNanjing 210003China Key Laboratory of Broadband Wireless Communication and Sensor Network Technology Ministry of EducationNanjing University of Posts and TelecommunicationsNanjing 210003China School of Physics and Astronomy Shanghai Jiao Tong UniversityShanghai 200240China

We present an efficient scheme for the complete analysis of hyperentangled Greenberger–Horne–Zeilinger(GHZ)state in polarization and time-bin degrees of freedom with two steps. Firstly, the polarization GHZ state is distinguished completely and nondestructively, resorting to the controlled phase flip(CPF) gate constructed by the cavity-assisted interaction. Subsequently, the time-bin GHZ state is analyzed by using the preserved polarization entanglement. With the help of CPF gate and self-assisted mechanism, our scheme can be directly generalized to the complete N-photon hyperentangled GHZ state analysis, and it may have potential applications in the hyperentanglement-based quantum communication.

关键词： hyperentangled state analysis polarization-time-bin hyperentanglement controlled phase flip(CPF)gate

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