色散监测是实现高速光通信的一项关键技术,利用光波导器件的非线性效应进行色散监测可以实现集成化。硅光波导具有强烈的非线性特性,其非线性折射率系数约为5×10-18 m2/W。当信号光和抽运光耦合后通过硅光波导,会产生自相位调制(SPM),交叉相位调制(XPM)等非线性效应,这些效应都能引起光谱的变化。光通信链路中存在的不同色散值会使得信号波形发生变化,波形变化的信号会在硅光波导中产生不同程度的SPM,XPM效应。通过合理设置滤波器的中心频率和带宽,同时测量由SPM,XPM效应产生的光谱变化结果,可实现对链路中残余色散的监测。研究表明色散监测范围可达±40 ps/nm。

Dispersion monitoring is a key technique of realizing high-speed optical communication. The structure can be integrated on a chip when using the nonlinear effects of optical waveguides to monitor dispersion. Silicon optical waveguides have notable nonlinearity with the nonlinear refractive index as 5×10-18 m2/W. When the signal and the pump light go through the silicon optical waveguide after being coupled,high nonlinear effects,such as self-phase modulation (SPM) and cross-phase modulation (XPM) will occur. These effects will induce changes in the spectrum of the optical signal. The different dispersions of the link lead to different extent effects of SPM and XPM. By effectively setting the central frequency and bandwidth of the filters,the different spectrum changes related to SPM and XPM can be detected simultaneously,so to monitor the link dispersion can be realized. The monitoring dispersion range reaches ±40 ps/nm.