Abstract

Radial shear interferometry is one of several methods used for measuring wavefronts. It is particularly attractive for testing aspheric optics because the fringe density can be controlled by varying the amount of shear. To be useful, however, it is necessary to be able to determine the wavefront given the measured interference pattern produced by the radial shear interferometer. The relationship between the wavefront and the measured interference pattern has, in the past, been expressed using sets of nonorthogonal polynomials. The purpose of this paper is to derive this relationship in terms of the orthogonal set of Zernike polynomials. This is attractive because the Zernike coefficients are directly related to the classical aberrations. The derived relationship is a closed-form solution that can easily be implemented on a computer. Applications and numerical examples are discussed.

© 1986 Optical Society of America