基于像素法用模拟退火-遗传算法搜索一维宽带隙光子晶体

将一维光子晶体用像素填充法进行二进制编码,把模拟退火、遗传算法、模拟退火-遗传混合算法与传输矩阵法结合,搜索、计算了一维光子晶体结构和能带,找到了全方位相对禁带宽度高达43.53%的四层结构和43.76%的两层结构,并给出了一维四层结构光子晶体的能带图及其4个原胞的反射率和透射率的频谱图；发现一维两层结构光子晶体的全方位禁带宽度对每层厚度的变化不敏感,但随着两种介质折射率差的增加而增大.

One-dimensional Photonic Crystal with Large Band Gaps Designed by Annealing-Genetic Algorithm

An annealing algorithm,a genetic algorithm,and a hybrid algorithm of Annealing algorithm and genetic algorithm are used to design a one-dimensional photonic crystal with the maximal band gap(difined as the gap to midgap ratio).The unit cell is divided equally into many pixels,and each filling pattern of pixels with two dielectric materials corresponds to a chromosome consisting of binary digits 0 and 1.Starting from randomly generated photonic crystal,the evolutionary algorithms yielded a photonic crystal with maximal band gap.Two structures are found with large band gaps,one is a structure of unit cell of two layers with band gap 43.76% ,the other is a structure of unit cell of four layers with band gap 43.53%.It is discovered that the band gap is not sensitive to the thickness of each layer of unit cell,but increases with the increase of the index difference of two dielectrics.