拼接光栅技术是提高高功率激光器输出能量的一条可能途径，为保障高功率激光器光束时空光束质量，拼接光栅角度误差必须小于0.4 μrad，位移偏差小于20 nm。为了满足光栅拼接调整系统的高精度高稳定性要求，设计了光栅拼接旋转角度偏差检测方案用于测量两块相邻光栅之间的相对空间姿态。测量系统测量光束与压缩器主光束同轴，利用相移式干涉仪测量待测光，得到若干干涉图样，通过快速傅里叶变换还原波前得到相邻两块光栅相对空间角度偏差。通过实验验证了检测系统的理论可行性，目前在小口径光束下精度达到0.45 μrad。测量方案结合拼接光栅只需要测量波面倾斜误差的要求，简化了干涉测量光路及图像分析流程，有利于光栅拼接技术的工程化应用。

Tiled-grating technology is a possible approach to improve the high power laser output energy. For the protection of high-power laser beam temporal and spatial beam quality, stitching error of grating angle must be less than 0.4 μrad, and the piston deviation is less than 20 nm. A detecting system is designed to measure the error of rotation angle between tiled-gratings to meet the high accuracy and high stability of the tiled-grating assembly. A phase-shift interferometer is used to measure the detecting beam which is coaxial with the main laser beam, and some interference patterns are gotten and analyzed to reconstruct the wave front. The feasibility of the system has been verified by a series of experiments and the accuracy of the system is 0.45 μrad. Tiled-grating measurement program with only the requirements of wavefront tilt error, which simplifies the optical interferometry and image analysis process, will help grating tiling technology applied in engineering.