Methods for attaining dispersion-free operation of a multiple-beam interferometer

Ways of simplifying practical construction of a dispersion-free Fabry — Perot interferometer are considered. The interferometer is intended for detection of small mechanical displacements. Instead of frequency tuning a light source, it is proposed to alter the temperature of the interferometer mirrors. Moreover, it is reported that the required tuning range can be narrowed by the use of mirrors with a large optical thickness.