Production of Multiple Beam Fringes from Photographic Scatterers

Abstract

A method is described for the production of interference fringes equivalent to those produced by a series of linearly arranged pinholes without actually constructing such pinholes. Exposures of varying duration are recorded on a photographic plate which is successively displaced with respect to a laser speckle pattern. The Fourier transform of the pattern produced by these multiple exposures is then obtained optically by illuminating the plate with a converging spherical wave. The fringes observed are similar to those occurring in multiple beam hologram interferometry and to the lobes produced by one dimensional antenna arrays.