2-D LAU PATTERNS - IN-REGISTER INCOHERENT JOINT SUPERPOSITION OF MONTGOMERY PATTERNS

We describe an optical arrangement for obtaining simultaneously a 2-D Lau pattern in each plane parallel to a Montgomery-type screen. Each o ne of them appears as the in-register superposition of mutually incohe rent replicas of a different Fresnel diffraction pattern produced by t he object screen. The above joint superposition of Montgomery patterns is achieved by means of an encoded linear incoherent source that lies along the optical axis of the system. The radially symmetric version of the preceding expansion of the Lau phenomenon is applied to visuali ze, in an incoherent way, phase structures on a uniform background wit h good contrast.