Fundamental and specific steps in Shack-Hartmann wavefront sensor design

Abstract

Shack-Hartmann sensors are widely used to measure wavefront aberrations. We present the fundamental and specific engineering steps in the design of Shack-Hartmann wavefront sensors. Typical performance requirements such as sensor dynamic range, sensitivity and accuracy are defined and discussed. We investigate the trade-offs between these performance metrics and the factors affecting the trade-offs. A first order approach for selecting the optimal parameters of the sensor central piece, the lenslet array, is presented. We also propose a quick tolerance analysis method that can predict the wavefront measurement error due to misalignments, using only the ray-tracing software.