利用符号计算推导光学三阶微环滤波器传输函数，代入参数计算光谱响应，并对关键参数做扫描，绘制4通道微环滤波器响应谱。-Utilizing symbolic computation to derive the third-order optical micro-ring filter transfer function, substitutes the parameters to calculate the optical response. The key parameters are swept and the optical response of a four-channel micro-ring filter is drawn.