Interference pattern of the Fizeau interferometer

Abstract

We analyze the structure and properties of the fringe pattern formed by a high-reflectivity Fizeau interferometer. Our analysis is based on the plane-wave representation of the wave field that is generated when an incident wave interacts with two planar mirrors that form a slight wedge. In particular, we show that within the parabolic approximation the field behind the wedge is self-imaging; it is periodic both in the direction of the incoming beam and in the perpendicular direction. Our approach lends itself to a unified and comprehensive treatment of the fringe transformation properties that occur when the system parameters are varied. The differences between the paraxial-optics and actual fringe patterns are discussed, and three-dimensional intensity plots are used to illustrate the main characteristics of the complex interference structures. Optimal detector locations are evaluated, and some concepts in Fizeau interferometry are clarified.