Demonstrating optical-path compensation in a Michelson interferometer

Abstract

In this paper we present a simple experiment using a fully compensated Michelson interferometer and a white-light source to demonstrate the importance and the effects of the optical-path compensation. Polyester sheets are introduced in one of the arms of the interferometer to partially decompensate the system. The change in mirror position required to see the fringes in these two cases is related to the refractive index and the thickness of the polyester sheets, and the degradation in the contrast of the white-light fringes due to the partial compensation can easily be demonstrated.