Degrees of freedom of an optical image in coherent illumination, in the presence of aberrations

Abstract

The problem of the degrees of freedom of an optical image in coherent light, in the presence of noise, is investigated in the case where the image is not perfectly aplanatic. In particular, we examine the case where the image of a unit (line) source at a distance x from the axis differs from the image of an axial source by a quadratic phase factor.