Accentuate of moiré in an interference pattern by defocusing

Abstract

The article considers a mathematical model of an incoherent optical system, into which defocusing is introduced as an aberration. When modeling, it is assumed that if non-coherent lighting is used to illuminate an object, then the transforming optical system should be considered as linear with respect to the intensity of the light. An analysis of the optical system of a general form was carried out, and relations were obtained for a system with a circular pupil, who allowed obtaining defocused images at the output of the optical system, and the defocusing value was rather simply adjustable. The proposed model can be used either as a low-pass filter for preprocessing of interferograms, or as a method for extracting informative image fragments, using which it is possible to synthesize the original image.