The substructure method was introduced to set up mathematical model of finite periodic composite structure,to solve its wave equation,and to derive its time-average power flows.

In order to obtain high conversion efficiency for optical parametric process in a one-dimensional photonic crystal(PC),the one-dimensional transfer matrix method was used to investigate the linear properties of compounding period photonic crystal(CPPC).

We present a photonic crystal, in which each period is made of a few different parts, called photonic crystal with a complicated periodic structure in this paper.