METHOD AND APPARATUS FOR EVALUATING WAVEFRONT ABERRATION

摘要

PROBLEM TO BE SOLVED: To reduce the time required for the evaluation of wavefront aberrations in a method and an apparatus for evaluating wavefront aberrations. SOLUTION: The wavefront aberration evaluation method comprises a process (a) for forming interference fringes by superposing a first light on a second light of which at least either one contains wavefront aberrations of an optical system; a process (b) for changing the phase difference between the phase of the first light and the phase of the second light until the difference between a minimum phase difference and a maximum phase difference exceeds at least (2π/n)×(n+1) at prescribed phase intervals of 2π/n (wherein, n is an integer equal to 2 or greater); a process (c) for imaging interference fringe images at the prescribed phase intervals; a process (d) for producing a plurality of groups of images comprising a plurality of interference fringe images continuous at the prescribed phase intervals; a process (e) for determining wavefront aberrations on the basis of the plurality of images contained in the groups of images on each of the plurality of groups of images; and a process (f) for evaluating the wavefront aberrations of the optical system by averaging a plurality of wavefront aberrations determined on the plurality of groups of images. COPYRIGHT: (C)2006,JPO&NCIPI