Article
Engineering, Multidisciplinary
Mehtab Singh, Ahmad Atieh, Moustafa H. Aly, Somia A. Abd El-Mottaleb
Summary: This article introduces a novel 120 Gbps free space optics (FSO) transmission scheme that combines orbital angular momentum (OAM) multiplexed signals with spectral amplitude coded (SAC) optical code division multiplexing access (OCDMA) technique. By utilizing four OAM beams, each carrying three independent channels, the capacity of the FSO system is increased to 120 Gbps. Experimental results demonstrate that under different weather conditions, including clear air, varying levels of rain, haze, and fog, longer propagation distances can be achieved with a low bit error rate (BER).
ALEXANDRIA ENGINEERING JOURNAL
(2022)
Article
Engineering, Electrical & Electronic
Hang Yang, Shilie Zheng, Hongqi Zhang, Nan Li, Donghui Shen, Tong He, Zuomin Yang, Zhidong Lyu, Xianbin Yu
Summary: In this article, a THz-OAM wireless communication system operating at 100 GHz based on a transmissive metasurface is proposed for the first time. The system demonstrates the generation of two high mode purity OAM beams with excellent orthogonality, which are used as two independent communication channels to achieve a data rate of 10 Gbit/s. This work validates the feasibility of multiplexing metasurface and highlights the potential of THz-OAM wireless communication systems for future large capacity wireless services.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Optics
Zhibing Liu, Shecheng Gao, Zhaoyu Lai, Yuru Li, Zhaohuan Ao, Jinpei Li, Jiajing Tu, Yanxiong Wu, Weiping Liu, Zhaohui Li
Summary: By utilizing an optical diffraction neural network, a low-crosstalk OAM de/multiplexer operating in the full C+L band is developed. The device supports 16 OAM modes with low insertion loss and intermode crosstalk. This research has great application prospects for mode de/multiplexers and mode division multiplexing communication systems.
LASER & PHOTONICS REVIEWS
(2023)
Article
Engineering, Electrical & Electronic
Xinzhou Su, Hao Song, Huibin Zhou, Kaiheng Zou, Yuxiang Duan, Narek Karapetyan, Runzhou Zhang, Amir Minoofar, Haoqian Song, Kai Pang, Shlomo Zach, Andreas F. Molisch, Moshe Tur, Alan E. Willner
Summary: We demonstrate a THz integrated circuit that can generate and multiplex multiple data-carrying OAM beams using a pixel-array-based OAM mode converter. The device includes coupling spikes to couple THz signals to the circuit, mode expansion structures to match the OAM mode converter, and a pixel-array-based OAM mode converter to emit and multiplex OAM beams with different mode orders. The generated OAM order depends on the input port.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Nan Li, Shilie Zheng, Hang Yang, Tong He, Donghui Shen, Hongqi Zhang, Zuomin Yang, Zhidong Lyu, Lu Zhang, Xianbin Yu
Summary: In this article, a novel broadband dual-polarized reflective metasurface is proposed to enable the multiplexing of orbital angular momentum (OAM) and polarization in the terahertz (THz) region. The metasurface can generate two coaxially propagating OAM beams with distinct modes for each polarization. A THz wireless communication system was demonstrated using the metasurface, achieving an aggregate 48 Gbit/s data transmission with a low bit error rate (BER) below 3.8e-3. This work showcases the feasibility of using metasurfaces for multidimensional multiplexing in ultrahigh-speed THz communication systems.
IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES
(2023)
Editorial Material
Optics
Gianluca Ruffato
Summary: A recent publication suggests a solution to overcome the limitations of optical techniques and high-intensity beams by probing highly-intense vortex pulses with a structured reference beam.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Optics
Bubai Dutta, Bibhatsu Kuiri, Rinki Atta, Nilanjana Sarkar, Ardhendu Sekhar Patra
Summary: OAM mode multiplexing is used to enhance transmission capacity and spectral efficiency in a (2 x 8 x 112 Gbps) 1792 Gbps bi-directional FSO link. An optical frequency comb lines generator is employed as a broadband laser source. The system's efficiency is tested in different turbulence situations.
OPTICS COMMUNICATIONS
(2023)
Article
Engineering, Electrical & Electronic
Yingning Wang, Yuanpeng Liu, Wenqian Zhao, Jian Yang, Wenpu Geng, Yuxi Fang, Changjing Bao, Yongxiong Ren, Zhi Wang, Yan-ge Liu, Zhongqi Pan, Yang Yue
Summary: This paper designs and analyzes a multi-ring-air-core fiber supporting thousands of OAM modes, and investigates the tradeoffs between ring number/density and system performance parameters. Based on the analytical results, the fiber has high transmission rate and spectrum efficiency, and shows great potential for various applications in optical communication systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Nanoscience & Nanotechnology
Haoqian Song, Runzhou Zhang, Nanzhe Hu, Huibin Zhou, Xinzhou Su, Hao Song, Kaiheng Zou, Kai Pang, Cong Liu, Daeyoung Park, Brittany Lynn, Greg Gbur, Aristide Dogariu, Richard J. Watkins, Jerome K. Miller, Eric Johnson, Moshe Tur, Alan E. Willner
Summary: The study experimentally investigated the effects of dynamic aerosols, dynamic curvature, as well as their comprehensive impact on a single OAM beam. It was found that the power coupling ratio of the OAM beam increased under different factors, with dynamic air and water interface causing wavefront distortion, beam wandering, scattering, and absorption.
Review
Nanoscience & Nanotechnology
Jian Wang, Jun Liu, Shuhui Li, Yifan Zhao, Jing Du, Long Zhu
Summary: This paper provides an overview of the applications of orbital angular momentum (OAM) and other technologies in optical communications, covering topics such as the fundamentals of OAM, modulation, multiplexing, multicasting, communication in turbulence, structured light communications, as well as discussing the prospects and challenges for the future.
Article
Optics
Han Cao, Yize Liang, Lulu Wang, Zhengsen Ruan, Hongya Wang, Jinwei Zeng, Jian Wang
Summary: In this paper, a quasi-wavelet conformal mapping method is proposed and demonstrated for scalable and efficient dense OAM demultiplexing in optical communications. The method divides the OAM mode into concentric rings and maps them to tilted plane waves, reducing demultiplexing crosstalk. It is compared with other methods and shown to achieve efficient demultiplexing for 15 OAM modes with low crosstalk. The method is also applied to data-carrying OAM-MDM communications with favorable performance.
LASER & PHOTONICS REVIEWS
(2023)
Article
Engineering, Electrical & Electronic
Bubai Dutta, Bibhatsu Kuiri, Nilanjana Sarkar, Binoy Das, Manish Dev Sharma, Ardhendu Sekhar Patra
Summary: This article proposes a system for high-speed data transmission using OAM beams and validates its feasibility through simulations. The system achieves transmission of a large number of data channels through self-injection locked quantum dash-laser diodes and multiplexing technologies.
OPTICAL AND QUANTUM ELECTRONICS
(2022)
Article
Physics, Applied
Heng Wang, Shixing Yu, Na Kou, Zhao Ding, Zhengping Zhang
Summary: This Letter presents a cylindrical conformal holographic impedance metasurface for orbital angular momentum (OAM) generation. The conformal holographic metasurface is designed by establishing the element library and deducing the formula of holographic tensor impedance modulation. The feasibility of the scheme is verified by simulations and experiments, and the results are in good agreement with theoretical analysis. The efficient generation of OAM vortex wave energy by the cylindrical conformal impedance metasurface provides a reference for OAM communication and vortex radars with conformal devices.
APPLIED PHYSICS LETTERS
(2022)
Editorial Material
Nanoscience & Nanotechnology
Alan E. Willner, Cong Liu
Summary: Structured light is a promising technology for increasing communication capacity by transmitting multiple orthogonal beams simultaneously. Future challenges lie in utilizing multiple orbital angular momentum modes to enhance system performance.
Article
Optics
Yuhang Wu, Andong Wang, Long Zhu
Summary: This paper proposes a novel network architecture that integrates convolutional layers and residual structures to compensate for the adverse effects of atmospheric turbulence on OAM beam transmission. By harnessing the local feature learning capability of convolutional layers and the information-preserving function of residual structures, the proposed network can mitigate power fluctuations and reduce mode crosstalk. Experimental results show significant improvements in received optical power and reduction in mode crosstalk using the proposed network under varying turbulence conditions.
Article
Statistics & Probability
Ting Tian, Jingwen Zhang, Shiyun Lin, Yukang Jiang, Jianbin Tan, Zhongfei Li, Xueqin Wang
Summary: This study utilized interventions implemented in China and applied them to simulate the potential outcomes in South Korea, Italy, and the United States. The results showed that mild interventions in the early stage were effective in controlling the epidemic, while stricter measures were necessary for severe outbreaks.
JOURNAL OF APPLIED STATISTICS
(2023)
Article
Computer Science, Artificial Intelligence
Jiangxin Yang, Lingyu Wang, Lifei Ren, Yanpeng Cao, Yanlong Cao
Summary: This paper proposes an end-to-end light field angular super-resolution network by exploiting structure and scene information to mitigate the trade-off between angular and spatial resolution. It utilizes a Light Field ResBlock to extract epipolar plane image features and scene features, and employs 4D deconvolution to upsample the angular resolution based on these features. The refinement network further exploits LF structure and scene information to alleviate artifacts induced by too little angular information.
APPLIED INTELLIGENCE
(2023)
Article
Engineering, Electrical & Electronic
Sizhe Xing, Guoqiang Li, Aolong Sun, Jiang Chen, Zhixue He, Junwen Zhang, Nan Chi
Summary: This study demonstrates a rate-flexible coherent TDM-PON in burst-mode based on PS-QAMmodulations and LO power adjustment technology, achieving a 300G peak rate and ultra-wide dynamic range. A new metric, DRNRP, is introduced to indicate the overall performance of achievable capacity and flexibility.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Guoqiang Li, Sizhe Xing, Junlian Jia, Zhongya Li, Junwen Zhang, Nan Chi
Summary: Coherent technology is a promising solution for future 100-Gb/s and even
200-Gb/s single-wavelength time-division multiplexing passive optical network (TDM-PON) systems. One of the key issues for coherent TDM-PON is the upstream burst-mode amplification.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Jianyang Shi, Zhongya Li, Junlian Jia, Ziwei Li, Chao Shen, Junwen Zhang, Nan Chi
Summary: In this paper, a learning-based waveform-to-waveform automatic equalization framework is proposed to overcome the shortcomings of small bandwidths and high harmonic interference levels in a seamless fiber-terahertz integrated communication system. Experimental results show that with this method, a data rate of 80.78 Gbps can be achieved for discrete multitone modulation signals over 5 km of fiber and 1 m of 209-GHz terahertz signals. Compared to an approach without preprocessing, a receiver sensitivity gain exceeding 1.3 dB is successfully achieved at a data rate of 60 Gbps. This proposed method is a promising scheme for future seamless fiber-terahertz integrated communication systems that require high speed and low cost.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2023)
Article
Computer Science, Artificial Intelligence
Yanpeng Cao, Xi Tong, Fan Wang, Jiangxin Yang, Yanlong Cao, Sabin Tiberius Strat, Christel-Loic Tisse
Summary: This paper proposes a method for enhancing low-light visible images by utilizing complementary edge/texture features from thermal images. The proposed TGLLE-Net, which incorporates a CDC-MRF module and a TGCB module, effectively extracts and enhances features from both visible and thermal channels. Experimental results demonstrate that TGLLE-Net outperforms existing methods in terms of restoration accuracy, visual perception, and computational efficiency.
Article
Computer Science, Artificial Intelligence
Yanlong Cao, Lingyu Wang, Lifei Ren, Jiangxin Yang, Yanpeng Cao
Summary: This paper proposes a view position prior-supervised light field angular super-resolution network to improve the trade-off between angular and spatial resolution in light field imaging. The asymmetric feature extraction block and spatial-angular interaction module are introduced to enhance feature extraction and establish view correlations. Experimental results demonstrate the superiority of the proposed method in various datasets.
Article
Engineering, Electrical & Electronic
Junwen Zhang, Guoqiang Li, Sizhe Xing, Nan Chi
Summary: With the adoption of the single-wavelength 50G PON standard, research on the next-generation optical access network beyond 50G has begun. Coherent passive optical network (C-PON) based on multi-access coherent optics and DSP is a promising candidate for future high-speed PON, thanks to its superior sensitivity. This paper reviews recent studies and progress on flexible C-PON in terms of access speed, multiple-access architecture, and deployment scenarios.
OPTICAL FIBER TECHNOLOGY
(2023)
Article
Physics, Applied
Yingzhe Wang, Xuefeng Zheng, Tian Zhu, Shaozhong Yue, Ailing Pan, Shengrui Xu, Peixian Li, Xiaohua Ma, Jincheng Zhang, Lixin Guo, Yue Hao
Summary: Degradation and defect evolution in GaN-based UV LEDs under 3 MeV proton irradiation were investigated thoroughly in this study. An intrinsic C-N-related defect with an abnormally decreased concentration after irradiation was identified. A defect evolution model under proton irradiation was established: C atoms departed from the C-N-related defect aligned along the dislocation in the active region stimulated by the displacement damage effect, leaving behind a nitrogen vacancy (V-N) aligned along the dislocation, accompanied by the generation of a non-interacting carbon interstitial (C-i). The increase in V-N and C-i jointly contributed to the decrease in optical power and the increase in leakage current.
APPLIED PHYSICS LETTERS
(2023)
Article
Automation & Control Systems
Wenbin Zhu, Rui Liang, Jiangxin Yang, Yanlong Cao, Guizhong Fu, Yanpeng Cao
Summary: In recent years, diverse detection methods have been proposed to achieve highly accurate image segmentation. However, low contrast and background noise interference still pose challenges to defect detection. Existing deep learning-based methods for defect detection mostly learn rich features on the whole image.
ENGINEERING APPLICATIONS OF ARTIFICIAL INTELLIGENCE
(2023)
Article
Chemistry, Analytical
Wenkai Yue, Ruixuan Liu, Peixian Li, Xiaowei Zhou, Yang Liu, Bo Yang, Yingxiao Liu, Xiaowei Wang
Summary: This paper investigates the effect of high-temperature annealing on the X-ray diffraction full width at half the maximum (XRD FWHM) of a 3.5 mu m-thick hydride vapor phase epitaxy-aluminum nitride (HVPE-AlN) (002) face. Tensile strain in the HVPE-AlN samples is gradually released with increasing annealing temperature. An aluminum oxynitride (AlON) region is generated at the contact interface between HVPE-AlN and sapphire when the annealing temperature exceeds 1700 degrees C, and the AlON structure conforms to the characteristics of Al5O6N.
Proceedings Paper
Engineering, Electrical & Electronic
Guoqiang Li, An Yan, Sizhe Xing, Zhongya Li, Wangwei Shen, Jiaye Wang, Junwen Zhang, Nan Chi
Summary: To address burst-signal processing in downstream transmission when switching modulation formats, we propose and experimentally demonstrate a pilot-aided DSP scheme with continuous SOP tracking, carrier-phase recovery, and channel estimation in a 300G flexible CPON based on 4/16/64-QAMs.
2023 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION, OFC
(2023)
Proceedings Paper
Engineering, Electrical & Electronic
Zhongya Li, Changle Huang, Junlian Jia, Guoqiang Li, Wangwei Shen, Jianyang Shi, Ziwei Li, Chao Shen, Junwen Zhang, Nan Chi
Summary: In this paper, we proposed and experimentally demonstrated a bit-wise end-to-end deep learning-based autoencoder for a fiber-THz integrated DFT-S-OFDM communication system at 209 GHz. Compared with the traditional DFT-S-OFDM system at 50 Gbps, it achieved a sensitivity gain of more than 5.5 dB.
2023 OPTICAL FIBER COMMUNICATIONS CONFERENCE AND EXHIBITION, OFC
(2023)
Meeting Abstract
Gastroenterology & Hepatology
Zheng Zhang, Peng Li, Sheng Wang, Zhendong Jin, Yiqi Du, Aiming Yang, Yunlu Feng, Xiaoping Zou, Lei Wang, Xiaoyan Wang, Li Tian, Pinghong Zhou, Yiqun Zhang, Jun Liu, Zhen Ding, Junwen Zhang, Jian Yang, Siyu Sun, Shutian Zhang
JOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY
(2023)
Article
Engineering, Electrical & Electronic
Chupeng Yi, Yang Lu, Ziyue Zhao, Hengshuang Zhang, Bochao Zhao, Peixian Li, Xiaohua Ma, Yue Hao
Summary: This paper presents a design for a K-band high-efficiency power amplifier (PA) using modified resistive-reactive hybrid continuous modes (HCMs). The modified modes increase the real part of the fundamental impedance which helps reduce the impedance transformation ratio and make HCMs more practical. By combining this method with a compact output matching network (OMN), a high-performance and highly integrated PA can be achieved. Experimental results show that the designed PA has a saturation output power greater than 0.5 W and an average power-added efficiency (PAE) of 42%.
IEEE MICROWAVE AND WIRELESS TECHNOLOGY LETTERS
(2023)
