基于时域有限差分(FDTD)法，对金属线栅结构的太赫兹(THz)偏振特性进行了仿真分析，研究了占空比和金属层厚度对偏振特性的影响，发现随着厚度的增加，0.1~10 THz范围内出现了周期性高透射现象。基于飞秒激光微加工技术制备了周期性金属线栅太赫兹偏振片，利用时域太赫兹光谱系统进行了实验测试，实验结果与仿真结果相吻合，偏振片的消光比在40 dB~45 dB范围内，偏振度为1，显示了良好的偏振特性。

Based on the finite-difference time-domain (FDTD) method, the terahertz (THz) polarization characteristics of a metal wire grid structure are simulated and analyzed. The influences of duty ratio and metal layer thickness on the polarization characteristics are investigated. It is found that the periodic high transmission phenomenon in the range of 0.1-10 THz occurs with the increase of the metal layer thickness. The metal wire grid THz polarizer is fabricated by the femtosecond laser micro-machining technique, which is tested by the time-domain terahertz spectroscopy system. The experimental results are consistent with the simulation ones. The extinction ratio of the polarizer is in the range of 40 dB-45 dB and the polarization degree is 1, which indicates that the polarizer possesses a good polarization characteristic.