周期层数及入射角对一维光子晶体带隙的影响

一维光子晶体基本周期的介质折射率取n2=1.5和n3=2.5,采用传输矩阵法,通过For-tran编程进行数值计算,分别得到了不同周期层数(N)及不同入射角度(θ1)下的一维光子晶体透射谱;从光子带隙频宽、带隙中心位置及带隙中心的透射率值等方面,分析并讨论了周期层数及入射角对一维光子晶体带隙特性的影响。结果表明,随着N值的增加,带隙中心的透射率值迅速减小,当N增至16层时,一维光子晶体基本形成;此外,在0°～85°内,随着入射角度的增加,带隙低频值向左移动,高频值向右移动,带隙宽度呈增加的趋势,入射角不影响光子带隙的中心位置。

Effects of the Cycle Layer Number and Incident Angle on the Band Gap of One-Dimensional Photonic Crystal

The refractive indexes of the basic cycle for the one-dimensional photonic crystal were n2=1.5 and n3=2.5,and the transmittance spectra of the one-dimensional photonic crystal with different cycle layer numbers(N) and different angles(θ1) were obtained by the theoretical calculation with the characteristic matrix method and the Fortran program.The effects of the cycle layer numbers and incident angles on the band gap characteristic of the one-dimensional photonic crystal were analyzed and discussed from the aspects of the bandwidth,center location and transmittance of the band gap.The results show that the transmittance decreases rapidly with the increase of N value,and when it increases to 16 layers,the one-dimensional photonic crystal is formed.In addition,with the increase of the incident angle within 0°~85°,the low frequency is moved to the left,while the high frequency is moved to the right,and the width of the band gap demonstrates an increasing trend.The incident angle cannot affect the center position of the photonic band gap.