传统的光束漂移测量及校正系统结构复杂、实时性低。针对这一问题，提出了一种基于散焦光栅成像装置的光束对准系统，该系统利用±1级衍射光斑的位置变化来计算光束的平漂量和角漂量，并控制2块倾斜镜分别实现光束平漂和角漂的校正。衍射光斑的形态变化和相机的采样能力是影响系统漂移量测量及校正能力的重要因素。实验结果表明：系统能实现静态和准静态光束漂移量的稳定闭环，光束校正后的离轴残差为0.1 mm，倾斜残差约12″。最后指出系统的改进方向。

A new beam alignment system based on the imaging system of defocus gratings is proposed. Conventional beam measurement and correction systems are always complex and non-real-time. The proposed system uses the location change of the ±1 order diffraction spots to compute the displacement and angle drift and controlls two quick tilt mirrors to eliminate the drift. The measurement and correction capabilities of the system are restricted by the shape of the diffraction spot and the sampling capability of the camera. Results show that the system can collimate the beam disturbed by static drift or quasi-static drift. The remained displacement drift is equal to 0.1 mm, and the remained angle drift is 12″. In the end, methods of improving the capability of the system are analyzed.