The effective index method is applied to simplify an awg structure from 3d to 2d . two simulation methods are presented in detail based on the gaussian beam propagation formula and the finite difference beam propagation method 文中采用等效折射率方法把三维结构简化为二维结构,然后分别基于高斯光束的传播和有限差分光束传播方法( fd - bpm ) ,给出了两种对整个awg进行全局模拟的具体方法。