Noise limitations of Michelson laser interferometers

Abstract

The noise limitations of two types of stabilised Michelson interferometers are analysed. These interferometers are suitable for the measurement of vibrational amplitudes in the picometre and femtometre range. Formulae are derived for the attainable signal-to-noise ratio, assuming that the shot noise of the photodiode sets the fundamental limitation. Measurements on several He-Ne lasers show that good agreement between theory and experiment is possible.