基于密度矩阵理论的偏振损伤联合补偿方案  

Joint Compensation Scheme for Polarization Impairment Based on Density Matrix Formalism

作　　者：郭瑶 张霞[1] 杜秋萍 杨震山 张晓光[3] GUO Yao;ZHANG Xia;DU Qiuping;YANG Zhenshan;ZHANG Xiaoguang(School of Physics Science and Information Engineering,Liaocheng University,Liaocheng 252000,China;Shandong Provincial key Laboratory of Optical Communications Science and Technology,Liaocheng 252000,China;State Key Laboratory of Information Photonics and Optical Communications,Beijing University of Posts and Tele-communications,Beijing 100876,China)

机构地区：[1]聊城大学物理科学与信息工程学院,聊城252000 [2]山东省光通信科学与技术重点实验室,聊城252000 [3]北京邮电大学信息光子学与光通信国家重点实验室,北京100876

出　　处：《光子学报》2023年第8期64-71,共8页Acta Photonica Sinica

基　　金：山东省自然科学基金(Nos.ZR2022MF284,ZR2018MA044);国家自然科学基金(No.61501214)。

摘　　要：利用密度矩阵理论构建的损伤模型结构简单,无需任何辅助矩阵,因此分析复杂度较低,在对光通信系统中光信号的损伤进行分析与补偿时凸显出巨大优势。将该理论初步应用至模式数目为2的偏分复用系统中,建立偏振模色散与偏振态旋转并存时的损伤模型,搭建了28 GBaud偏分复用正交相移键控相干光通信仿真传输系统,实现了30~170 ps大范围差分群时延与300 krad/s~2 Mrad/s快速偏振态旋转的联合补偿,验证了基于密度矩阵理论的损伤模型以及联合补偿方案在光通信系统中的有效性。该研究为下一步推广至N维模分复用系统中光信号的损伤分析与补偿提供了有效的途径。While effectively enhancing the transmission capacity of current commercial single-mode optical fiber communication systems,Polarization Division Multiplexing(PDM) technology also faces serious challenges from Polarization Mode Dispersion(PMD) and Rotation of State of Polarization(RSOP).PMD causes the broadening of optical pulses,resulting in crosstalk and distortion of the signals,which may significantly increase the Bit Error Rate(BER) of the system.Also,RSOP might cause rapid change in the polarization state of optical signals up to several hundred krad/s,preventing the two polarization signals from being correctly separated at the receiver.In practical optical fiber links,PMD and RSOP usually coexist and impose significant impairments on the system performance.The main work of this paper is to build an impairment model of PMD and RSOP and to conduct a joint compensation of the polarizationrelevant impairments.Traditionally,the Stokes formalism is employed to analyze the PMD and RSOP in commercial singlemode fibers that actually support two orthogonal polarization modes.The corresponding Stokes vector is a3-dimensional real vector with clear physical meaning,and can be intuitively represented in the geometrical Poincare sphere.However,the Stokes formalism requires 3 auxiliary 2 × 2 Pauli matrices,and when extended to the treatment of Modal Dispersion(MD) and Mode Coupling(MC) in an N-mode optical fiber(i.e.,a modal space of dimension N),a number of N~2-1 auxiliary N X N Gell-Mann matrices are required,which can drastically complicate the analysis of MD and MC effects as N increases.Recently,borrowing methodology from quantum mechanics,we proposed and developed the Density Matrix(DM)formalism for the MD and MC in a modal space of arbitrary dimension N≥2.Without requiring any auxiliary matrices,the DM formalism is simple and straightforward in formulation and application,and is thus particularly suitable for the study of modal properties and signal compensations in the optical communication system.In this pap

关 键 词：相干光通信 密度矩阵理论 偏振模色散 偏振态旋转 信号损伤补偿 

分 类 号：TN913.7[电子电信—通信与信息系统]