用时域有限差分算法(FDTD)分析了有限厚度金属狭缝对太赫兹(THz)脉冲进行时空整形的效应和特性.分析表明:这种基于衍射方法的准光学技术手段对横向磁场(TM)模式THz脉冲有很好的整形和滤波作用,而对横向电场(TE)模式THz脉冲几乎没有整形和滤波作用,并运用平面光波导理论对所获得的数据模拟结果进行了定性说明.这些分析结果可在相关实验中予以考虑和采用. The effects and characteristics of spatio-temporal shaping of THz pulses by a finite thickness metal slit are analyzed by FDTD method. The analysis shows that this method based on diffraction of a quasi-optical technique is effective for transverse magnetic field (TM) mode The THz pulse has good shaping and filtering effects, while almost no shaping and filtering of the transverse electric field (TE) mode THz pulse, and the qualitative simulation results of the obtained data are given by using the planar optical waveguide theory. In the relevant experiments to be considered and adopted.