Effect of ambient temperature on the measurement accuracy of Shack-Hartmann wavefront sensor

The centroid estimation, wavefront reconstruction and environment (typically temperature) are the main error sources of the Shack-Hartmann wavefront sensor (SHWS). In this paper, theoretical and experimental studies are conducted to analyze the effect of ambient temperature on the measurement accuracy of SHWS. The spot arrays corresponding to ambient temperature varied from 20.5 to 24 degrees are obtained by using the thermal analysis features in ZEMAX. The wavefronts are then reconstructed by home-made software from these spot arrays. By using the wavefront diffracted by a single mode optical fiber and the SHWS, the experiment setup is built to verify the results obtained by theoretical analysis. The results obtained by theoretical analysis and experiments are coincident well. The variation of the wavefronts measured by SHWS will be smaller than 0.06 nm RMS if the ambient temperature variation is controlled within 0.1 degree. The range of temperature within ±2 degrees, the max wavefront deviation is 2.12 nm. This research will be of guiding significance to ambient temperature control in high precision wavefront error metrology by using SHWS.