Interference

Abstract

Basically, the reason for the study is to learn how interferometers operate and what quantities they are able to measure. There are two classes of interferometers: (i) those that study the properties of light itself, such as wavelength and spectral line width, and (ii) those that measure some quantity such as refractive index, displacement or surface topography. Some interferometers can perform both tasks. Historically, the Michelson interferometer is important because it established that the speed of light is independent of the Earth’s motion — a tenet vital for the general framework of the Special Theory of Relativity. More recently, it has been involved in a study of the tidal effects of the Moon on the Earth and continental drift.