使用大量的有限元法求解偏微分方程，计算一维光子晶体的透射特性和反射特性，分析了该信号的时域、频域、倒谱，循环谱等。- Using a large number of finite element method to solve partial differential equations, Calculated transmission characteristics and reflection characteristics of the one-dimensional photonic crystals, Analysis of the signal time domain, frequency domain,