光性能监测是实现可重配置波分复用光网络的一个关键技术。随着光通信速度从10 Gb/s提升到40 Gb/s甚至以上, 对光通道残余色散的容忍度下降到原来的1/16甚至以下, 需要对光通道的色散进行实时监测。利用非线性波导器件可进行全光域色散监测, 硅光波导具有较强的非线性特性, 其非线性折射率系数可达5×10-18 m2/W。当受光网络色散作用的信号光和探测光一起通过硅波导时, 将产生四波混频非线性效应, 光通道中不同色散值会产生不同程度的四波混频效应, 通过测量由四波混频效应产生的光谱变化结果, 可对波分复用光网络的色散进行监测。采用损耗系数为0.2 dB/cm, 长度为3 cm的硅波导, 模拟研究结果表明色散监测范围可达±40 ps/nm, 从而可以实现光网络色散的芯片级监测。

Optical performance monitoring (OPM) is one of the key techniques of the reconfigurable wavelength-division-multiplexing (WDM) optical networks. When the optical communication speed rises from 10 to 40 Gb/s and above, the residual chromatic dispersion (CD) tolerance of the optical channel is only 1/16 of the former 10 Gb/s system. So CD monitoring is the critical technique for WDM optical channels. Integration and all-optical domain can be achieved when using the nonlinear effects of optical waveguides to realize CD monitoring. Silicon optical waveguides have the relatively large nonlinearity with the nonlinear refractive index as 5×10-18 m2/W. After going through the WDM network with CD effects, the signal light wave has the four wave mixing (FWM) effect with the probe light in the silicon waveguide. This FWM effect induces changes in the output spectrum, and different dispersions of the optical channel lead to the varied effects of FWM. So, when detecting the different spectrum changes relates to FWM, the optical channel CD can be monitored. In this paper a 3 cm silicon optical waveguide is adopted with the loss index of 0.2 dB/cm. The monitoring dispersion range can be ±40 ps/nm. The results indicate that this OPM technique can be used to monitor the CD of the optical network on chip level.