采用含掺杂半导体光子晶体的太赫兹梳状滤波器

用a 介质（n 型掺杂GaAs）和b 介质（TiO2）组成一含缺陷层的光子晶体。数值计算表明:此光子晶体在3.0~4.5 THz 范围内出现了5 个透射率为1 的缺陷模，这些缺陷模有如下特征:当n型掺杂GaAs 的掺杂浓度n由1017/cm3 增加到1019/cm3 时，缺陷模的中心、半峰全宽度和透射率均保持不变，但若n增至1020/cm3，则缺陷模的透射率开始下降。入射角增加，缺陷模的透射率保持不变，但其中心发生蓝移，移动率为变量，且半峰全宽度变窄。a、b 两介质或缺陷层c 的几何厚度分别增加时，缺陷模的透射率和半峰全宽度分别保持不变，中心位置红移。这些现象为此类光子晶体实现太赫兹频段的梳状滤波提供了理论指导。

Comb filtering in terahertz frequency based on photonic crystal containing doped semiconductor

A photonic crystal containing defect layer was composed of a medium (n-type doped GaAs) and b medium (TiO2). Numerical calculations indicate that there are 5 defect mode of 1 transmittance within 3.0-4.5 THz for the photonic crystal. These defect mode have following characteristics: when the doping concentration n of GaAs increases within 1017/cm3 to 1019/cm3, the center, the full width at half maximum (FWHM) and the transmittance of the defect mode remain unchanged, However, if n increased to 1020/cm3, the transmittance of the defect mode began to decline. With increasing angle of incidence, the transmittance of the defect mode remain unchanged, but their center blue-shift, the mobile rate are variable, and FWHM narrows. The central position of the defect mode occurs red shift with increasing the thickness of the media layer a, b or the defect layer c respectively, while both the transmittance and FWHM remain constant. These phenomena provide theoretical guidance for this type of photonic crystal to realize the comb filtering in terahertz frequency range.