利用微扰理论给出“等效矩形波导法”，分析了费米型截面硅基聚合物阵列波导光栅的传输特性.模拟表明，波导的费米型截面将使阵列波导光栅的传输光谱产生漂移、并使串扰增大.为了消除光谱漂移、减小串扰、实现正常的解复用功能，对阵列波导光栅的结构参量进行了重新优化.结果表明，重新设计的费米型截面聚合物阵列波导光栅的光谱响应和串扰恢复到初始设计的聚合物矩形截面阵列波导光栅的水平.

By employing the perturbation theory,a method called “equivalent rectangular technique” was proposed for analysing the transmission characteristics of the silica-based polymeric AWG with Fermi-like core cross-sections.Simulation results show that the Fermi-like core cross-sections lead to the shift of the transmission spectrum,and result in the increase of the crosstalk.In order to eliminate the shift of the transmission spectrum,reduce the crosstalk,and further realize the normal demultiplexing,the optimum redesign of the AWG was carried out.The result shows that the spectral response and the crosstalk of the redesigned AWG with the Fermi-like cross-sections are very close to those of the original designed AWG with the rectangular core cross-sections.