在高功率激光装置中，大口径电光开关晶体KDP在表面抛光过程中会引入大量的中高频调制，这种中高频段调制会对高功率激光驱动器性能产生影响。基于快速傅里叶变换理论和元件波前数据，对神光Ⅱ升级装置进行了计算模拟，研究中高频调制对光束近场均匀性和远场聚焦能力的影响，并且讨论了在光束传输放大过程中该频段调制对装置的可能危害。

The perturbation of middle and high spatial frequency caused by the polish process of the large aperture KDP crystal in high-power laser system has a certain impact on the performance of the facility. To study the effects of this kind of phase perturbation on the near-field uniformities and far-field focusing abilities, a calculation model which is based on fast Fourier transform (FFT) theory and optics wavefront data of SG-Ⅱ is established. The potential dangerousness which derives from the laser propagation to the facility is discussed.