On The Changes in Optical Interferometry Induced by The Relativistic Motion of An Optical Medium

TL;DR

This paper explores how relativistic motion of optical media affects interference, reflection, transmission, and spectroscope performance, deriving new equations and demonstrating the impact on optical measurements.

Contribution

It introduces a modified framework for understanding optical interference and spectroscope resolution when the medium moves at relativistic speeds, linking special relativity with optics.

Findings

Derived conditions for interference with moving media

Formulated new reflection and transmission equations for relativistic media

Calculated the altered resolving power of a Fabry-Perot spectroscope with moving etalon

Abstract

We investigate the effects of the relativistic movement of an optical medium on the conditions of constructive and destructive interference, reflection and transmission pattern, and performance of spectroscopes. First, we consider the case of two beams reflected from a relativistically moving thin film and derive the conditions of constructive and destructive interference. Then we broaden the idea to multiple beam interference and formulate a new modified equation of reflection and transmission pattern of light from a relativistically moving plane parallel dielectric film. Finally, we determine the new effective resolving power of a Fabry-Perot spectroscope, which has a moving dielectric medium in its etalon. Here, we consider the case where the optical media move parallel to the plane of incidence of light. Throughout this paper, we use basic Lorentz transformation of space and time co-ordinates and electromagnetic fields to conduct these investigations. This paper can strongly motivate undergraduate physics students to associate the concepts of special relativity and optical interference.