Aberration measurements by a Talbot wavefront sensor in the presence of intensity variations

Abstract

Paper deals with the theoretical investigations of measurement accuracy of optical aberrations by Talbot wavefront sensor in the presence of random amplitude variations. Theoretical prediction of intensity distribution for gratings of any type based on their spatial spectrum is obtained, and it is shown that grating is fully restored in Talbot plane even for the high fraction of random amplitude. The possibilities of self-imaging phenomenon is investigated based on the simulation results. Simulation results show that pit displacement error increases when the correlation length decreases or when grating spatial spectrum increases. It is found that for defocus aberration intensity variations decrease measured defocus value and increment of aberrations of same order (oblique and vertical astigmatisms).