用遗传算法搜索一维光子晶体带隙

利用遗传算法和传输矩阵法计算一维光子晶体能带结构,将一维光子晶体用像素填充法进行二进制编码模拟,结果找到全方位相对禁带宽度达42.54%的4层结构和43.75%的2层结构;给出了一维光子晶体4层最佳结构的能带图、20个原胞的反射率透射率频谱图.发现一维2层光子晶体的全方位禁带宽度对每层厚度的变化是不敏感的,但是随着两种介质折射率差的增大而增大.

Genetic algorithm searching of one-dimensional photonic crystal with broad band gap based on pixel-filled-in methods

A genetic algorithm(GA) approach and an eigen matrix method are used to search a one-dimensional(1D) photonic crystal of linear lattice with a maximal absolute band gap.The unit cell is devided equally into many thin films,and each filling pattern of films with two dielectric materials corresponds to a binary number.As a numerical example,the GA gives a 1D 4-thick-film structure with a relative width of the absolute band gap of about 42.54%,and 1D 2-thick-film structure about 43.75%.This paper gives the diagram of energy band,spectrograms of reflectivity and transmissivity in 20 cells.It is discovered that the absolute relative band gap of 2-thick-film cells is not sensitive to the thickness of each thick film,but that increases with the increase of the difference of two dielectric materials with different refractions.