Detection error of Shack-Hartmann wavefront sensors

The detecting error of Shack-Hartmann (S-H) sensor is one of the main error sources in adaptive pptical systems. In this paper the main sources of S-H sensor for both of the systematic error and random noise are analyzed. These factors are readout noise and background level of CCD camera, number of detecting pixels, and photon shot noise. Setting a threshold level in processing centroid of Hartmann spots is benefit for improving detecting accuracy. The theoretical analysis and experimental results are presented in this paper.