High resolution central fringe identification

Abstract

A high resolution central fringe identification by using the heterodyne interferometry with a tunable laser-diode and a fixed wavelength laser is presented. It can be operated easily and can be used to judge which arm of the Michelson interferometer is longer. The feasibility is demonstrated and it has 0.2 nm resolution. (C) 1998 Elsevier Science B.V. All rights reserved.