中文摘要：

采用电子束蒸发制备了1064nm高反膜样品，并通过激光预处理系统对样品表面的部分区域进行了光栅式扫描，形成等离子体烧蚀区域。搭建了光束质量测试系统，记录在样品表面有无等离子体烧蚀两种情况下的反射光束的空间强度分布。采用经典周期图法，分别计算了各自的强度分布的功率谱密度。结果表明，等离子体烧蚀导致的传输光束峰值强度对应于功率谱密度曲线中心峰值强度，而周期性起伏则体现在相应频率下的峰值。因此功率谱密度曲线可以作为表征光学元件对传输光束调制的手段。

英文摘要：

The 1064 nm high reflectors are prepared by e-beam deposition, and via laser conditioning with raster scanning on certain areas, plasma scalds are formed on the surface. The beam quality testing system is built. The spatial intensity distribution of laser beam reflected by the samples with or without plasma scalds is recorded. The power spectral density of laser beam is calculated with periodogram method. The results indicate that the peak of the power spectral density corresponds to the peak intensity of the transmitted beam which is modulated by plasma scalds. Therefore the modulation of transmitted laser beam can be analyzed and characterized using the power spectral density calculated from the distribution of the laser beam.