对高功率激光系统中使用的衍射光学元件(DOE)在束匀滑时产生的表面反射光场进行了模拟计算。计算表明, 随着传输距离的增大, 反射光由于干涉叠加会产生一定数量的光强极值点, 有可能会对前端元件造成损伤。因此, 在高功率激光系统应用中, 有必要对元件进行一定角度的倾斜放置, 从而使反射光偏离前端元件。通过模拟计算分析了衍射元件放置时, 倾斜角度对各项束匀滑指标的影响, 发现匀滑性急剧变差, 并在实验上观察到了相应的定性结果。设计了相位补偿方法, 以保证倾斜放置下衍射光学元件的束匀滑能力, 并给出了相位补偿的数值模拟结果。

In high power laser system the light intensity distribution of surface reflection produced by diffractive optical element (DOE) used in beam smoothing was calculated. Calculation showed that with the increasing of transmission distance, the reflected light due to interference would produce a certain number of extreme points, which could be harm to the front element. As a result, in the high-power laser system, it is necessary to place DOE with a tilt angle, so that the reflection light can deviate from the front element. The impact on beam smoothing with changing angle was calculated, and the sharp deterioration of smoothing was found and the corresponding qualitative results were observed in experiment. Phase compensation method was presented, to maintain the ability of the beam smoothing with DOE tilted, and the numerical simulation of phase compensation was given.