光纤Kerr非线性信号损伤的监测与管理机制研究

With the growth of various broadband data traffic, the bandwidth requirements for access network and metro-network are also increased, which makes the optical fiber transmission system be upgraded urgently. However, the nonlinear signal impairments originated from fiber Kerr nonlinearity, including the self-phase modulation (SPM), cross-phase modulation (XPM) and four-wave-mixing, will become the dominant factor to degrade the property of next-generation optical network characterized by dynamical reconfiguration, flexibility, high spectral-efficiency and ultra-large capacity. In this project, based on the previous research work, we focus on the research on the monitoring and management of nonlinear signal impairments due to fiber Kerr nonlinearity by applying the theoretical analysis, simulation and experimental validation based on the transfer function of volterra series. The research includes i) the measurement of nonlinear parameters of the dynamic fiber link, ii) quantization of various nonlinear signal impairments of the multi-channel system and iii) monitoring of the nonlinear signal impairments of superchannel transmission system. After the theory and experiment studies, it is supposed to achieve the aim of the exact measurement of nonlinearity parameter of dynamic fiber links, effect qualification of different nonlinear signal impairments of multi-channel system and online monitoring of nonlinear signal impairments of superchannel system. Then, it is further desired to offer the theory and technology supports to improve the efficiency of nonlinear compensation algorithm and the exactness of the parameters of inline optical performance monitoring in the next generation optical network.

随着各种宽带数据业务流量的增长，接入网和城域网的带宽需求不断增加，促使光纤传输系统急需升级，动态可重组、灵活高效、超大容量等将成为下一代光网络的主要特点。此时，因光纤Kerr效应引起的非线性信号损伤将成为影响系统性能的主要因素。本项目针对该问题提出采用基于volterra级数的传输函数法，深入研究：①动态传输链路的非线性参数测量；②不同非线性信号损伤的量化和③superchannel传输系统中的非线性信号损伤监测等内容。本项目拟在前期研究的基础上，采用理论分析、数值仿真结合实验验证的技术手段，解决光纤Kerr非线性信号损伤的监测和管理中存在的关键科学问题，达到实现动态传输链路的非线性参数的精确测量、多信道大容量系统的不同非线性信号损伤的有效量化及superchannel传输系统中的非线性信号损伤的在线监测等目标，为提高下一代光网络中非线性损伤补偿算法的效率及光性能监测参数的准确性奠定基础。

为了便于充分利用资助项目科研开展，在项目研究过程中，对项目研究计划内容做了一些调整。结合课题组前期研究优势，主要针对光频梳产生器、光信噪比监测、低成本相干接收机及相位估计、高级调制与解调技术等方面做了一些与本项目研究内容相关的研究工作。具体研究工作包括：提出了基于偏振调制器的单边带调制器及光频梳产生器；提出了基于偏振调制器的互补频移器及光频梳产生器；提出了基于三支波导干涉结构的单边带调制器及循环频移结构的光频梳产生器；基于低成本相干扫描接收机和参考谱技术的光信噪比监测研究；用于长距光接入网络的基于单端检测的低成本相干接收机研究；用于相干光OFDM传输系统的基于导频的盲相位估计方法及改进方案研究；用于短距离光互连系统的高级调制与解调技术研究等。这些研究工作充分拓展了项目的研究内容范围，丰富了项目的研究内容，取得了很多有意义的研究成果。.本项目在研究过程中，共发表标准项目资助科研学术论文13篇，其中SCI检索论文8篇，EI检索论文5篇，申请发明专利2项；同时，辅助培养硕士研究生4人。对比项目预期研究成果，本项目在执行时间里，已满足项目预期成果要求。