Diffraction Anomaly of Various Types of Extended Source –By Polarizing Microscope with Crossed Nicols–

Abstract

Diffraction images by polarizing microscope with the crossed Nicols were extensively studied by Kubota and Saito. Their work is mainly on the diffraction image of a point source through this system. In this paper, the study is furthered to diffraction images of various types of extended coherent, incoherent or partially coherent secondary sources (object apertures) such as slit, circular, rectangular and triangular types. These images are of unusual patterns different from the Airy-type ones formed by an ordinary optical system, and the patterns are strongly dependent upon the illumination conditions of the source. Diffraction patterns are theoretically calculated on an electronic computer and shown in contour lines of intensity. Photographs taken with a ruby optical maser are shown for comparison. The relationships between the diffraction images and the size of the various extended sources or the illumination conditions are discussed.