Performance analysis of a Shack-Hartman wavefront sensor with variable subaperture pixels

The major error source of Shack-Hartmann wavefront sensor consists of the photon noise, the readout noise, and the sampling error. In this paper, the measurement error of Shack-Hartmann wavefront sensor with variable subaperture pixels is analyzed under the consideration of various threshold values and detecting dynamic ranges. A generalized expression, which is used for fitting the sampling error of Shack-Hartmann wavefront sensor with variable subaperture pixels, is presented. The computational results and the experimental results of the measurement error of Shack-Hartmann wavefront sensor with different pixels per subaperture are also given.