Effect of pinhole diameter on measurement accuracy of self-referencing interferometer wavefront sensor

Abstract

The diameter of pinhole is a critical element that affects the measurement accuracy of self-referencing interferometer wavefront sensor (SRIWFS), and its dimension is determined by the accuracy requirement of practical measurement and the intensity transmission. The effects of pinhole diameter on quality and intensity transmission of reference wave are analyzed on the basis of the Fourier optics theory, and then they are verified by numerical simulation and experiment. These results demonstrate that to obtain a good approximation to a reference wave, the pinhole diameter should equal half of the Airy-disk diameter produced by an unaberrated optic. In this way, the root-mean-square value of the reference wavefront is less than λ/100 for all aberrations with the peak-to-valley value of not smaller than one wavelength. These theoretical analyses and experimental results provide a valuable reference and illumination for determining the dimension of pinhole along with the analysis or design of SRIWFS for various testing tasks.