从实验上研究了光电导天线电极之间激光光斑大小对太赫兹波产生的影响。另外,理论模拟了激光功率密度与太赫兹波辐射强度之间的关系,与实验结果非常吻合。泵浦光激光功率密度的增加能够显著的提高太赫兹波辐射强度,但是当超过一定值后会趋于饱和,此时若继续减小光斑尺寸,激光功率密度的增加不会使太赫兹产生继续增强。但是,太赫兹波却会随着光斑尺寸的减小而变弱。 The influence of laser spot size on the generation of terahertz wave is studied experimentally. In addition, the relationship between laser power density and terahertz radiation intensity is simulated theoretically, which is in good agreement with the experimental results. The increase of pump laser power density can significantly increase the intensity of terahertz radiation, but it will become saturated when a certain value is exceeded. If the spot size continues to be reduced at this time, the increase of laser power density will not cause the generation of terahertz Enhanced. However, the terahertz wave becomes weaker as the spot size decreases.