Two-beam interferometric spectroscopy

Spectroscopy by two-beam interferometry is compared with conventional techniques and it is shown that considerable advantages may be expected in some measurements from the use of interferometers. The important advance in the last decade which allows this to be realized is the use of digital computers. Their use has also allowed the development of refractive index spectroscopy over wide spectral ranges using Michelson's interferometer. The duality of spectral and angular measurement is stressed and the potential of the spectroscopic analogue of the stellar intensity interferometer, which so far has not been developed, is analysed here.