微透镜阵列到CCD的距离是影响Hartmann-Shack波前探测器精度的主要装配误差之一。对该平移装配误差的修正, 能够有效减小波前探测误差。理论求解了球面波前通过微透镜引起的子孔径光斑质心移动量与波前探测器结构参数之间的关系, 借助该关系能够求出微透镜到CCD之间的实际距离, 以其改进波前斜率的计算。实验验证了理论推导的合理性, 并对实际装配参数进行标定, 得实际距离为24.2 mm。利用标定后的参数重建波前, 其相对误差减小20.4%。实验表明该标定方法能够有效提高波前传感器测量准确性。

The distance between the charge couple-device (CCD) and the micro lens array is one of the assembling errors which affects the accuracy of Hartmann-Shack wavefront detector. The correction of this motion assembly parameter can effectively reduce the wavefront detector error. The relationship between the subaperture spot centroid shift amount,caused by the spherical wavefront passing through the micro lens, and the structural parameters of wavefront sensor was derived theoretically. By utilizing the relationship, it is able to work out the actual distance from the CCD to the micro lens array and improve the calculation of the slope of wavefront. Experiments verified the rationality of theoretical derivation, and the actual assembly parameter calibrated is 24.2 mm. The wavefront was reconstructed by the calibrated parameter, the relative error can reduce by 20.4%. Experiment results show that the calibration method can effectively improve the measurement accuracy of wavefront sensor.