设计刻槽深度渐变的金属光栅，利用截止频率控制太赫兹表面波的传播距离.金属光栅刻槽深度在60 μm时的截止频率为0.6 THz，120 μm时的截止频率为1.1THz.同时根据半导体材料InSb在太赫兹波段的色散特性、载流子浓度和迁移率的经验公式、光栅结构的等效介质理论设计了温控的半导体光栅.在270～300 K温度范围内，半导体光栅中表面波的传播距离和温度成正比， 300 K时传播距离为270 K时的2～3倍.

With the cutoff frequency of the surface wave in terahertz, the gradient depth of the metal grating was designed, and find that the cutoff frequency is 0.6THz when the depth of the grating is 60 μm and 1.1 THz is nearly corresponding to the 120 μm. At the same time, the temperature controller semiconductor grating was designed. According to the dispersion characteristic of the semiconductor material (InSb) in terahertz region, the experience formula of the carrier concentration and mobility; equivalent medium theory of grating structure， it is shown that the propagation distance is proportion to the temperature in 270～300 K, which the propagation distance in 300 K is 2～3 times than the 270 K.