涡旋光复用传输的相干解复用研究  

Coherent Demultiplexing of Vortex Beam Multiplexing Transmission

作　　者：杨尚君 李梦茹 柯程虎 丁德强 柯熙政[1,4] Yang Shangjun;Li Mengru;Ke Chenghu;Ding Deqiang;Ke Xizheng(School of Automation and Information Engineering,Xi′an University of Technology,Xi′an 710048,Shaanxi,China;School of Information Engineering,Xi′an University,Xi′an 710065,Shaanxi,China;School of Information Communication,National University of Defense Technology,Wuhan 430035,Hubei,China;Shaanxi Civil-Military Integration Key Laboratory of Intelligence Collaborative Networks,Xi′an 710048,Shaanxi,China)

机构地区：[1]西安理工大学自动化与信息工程学院,陕西西安710048 [2]西安文理学院信息工程学院,陕西西安710065 [3]国防科技大学信息通信学院,湖北武汉430035 [4]陕西省智能协同网络军民共建重点实验室,陕西西安710048

出　　处：《光学学报》2023年第20期56-66,共11页Acta Optica Sinica

基　　金：陕西省科研计划项目(18JK0341);陕西省重点产业创新项目(2017ZDCXL-GY-06-01);西安市科技计划项目(2020KJRC0083,22GXFW0115);国防科技大学自主创新科学基金项目(22-ZZCX-051)。

摘　　要：涡旋光相干检测通过改变本振光的拓扑荷数,在接收端实现涡旋光的相干解复用,也可以实现信息交换。本文分析了信号光斜程传输时拓扑荷数、海拔高度、传输距离对涡旋光复用通信系统性能的影响。结果表明:大气湍流造成的波前畸变会破坏不同拓扑荷数信号光与本振光波前之间的正交性;使用同一套自适应光学系统对上行和下行链路的信号光波前进行校正,比较分析了波前畸变预校正与后校正效果,发现下行链路的后校正效果要优于上行链路的预校正效果,为多路涡旋光复用传输奠定了理论基础。Objective Vortex beams,distinguished by their unique spiral wavefront structure,phase singularity,and orbital angular momentum,offer possibilities for enhancing system performance.Notably,vortex beams with different modes are spatially orthogonal,enabling their use in orbital angular momentum multiplexing for augmenting the channel capacity and spectral efficiency.Moreover,demultiplexing these beams at the receiving end provides an additional boost to system capabilities.This paper focuses on the application of coherent detection technology to a bi-directional slant path optical wireless communication system,employing orbital angular momentum multiplexing.This approach eliminates the need for image recognition steps,such as diffraction interference,thereby reducing errors introduced during the process.It analyzes the impact of the topological charge,altitude,and transmission distance on the performance of a vortex optical multiplex communication system.By incorporating an adaptive optics system for uplink and downlink correction,we can minimize crosstalk between modes,leading to improved detection sensitivity and channel capacity.Methods The architecture of the orbital angular momentum multiplexing coherent detection system for optical wireless communication using bi-directional slant transmission is illustrated in Fig.1.Fig.2 presents a schematic view of the system′s transmitting and receiving ends.At the transmitting end,the source signal laser is split into four beams using a 1×4 coupler.The signal for each channel undergoes external modulation after series-to-parallel conversion and is then transformed into a vortex beam,with topological charges of 1,2,3,and 4,through spiral phase plates.These channels are then combined with a 4×1 coupler for coaxial transmission.At the receiving end,a 1×4 coupler divides the beam into four channels,each mixed with local oscillator vortex beams with corresponding topological charges.Following balanced detection,the electric signal is recovered,demodulated,and then conver

关 键 词：涡旋光束 大气湍流 相干检测 相干增益 

分 类 号：TN929.12[电子电信—通信与信息系统]