Abstract

The spectrum of white light passing through a Michelson interferometer develops a sinusoidal modulation, the frequency of which is determined by the path difference between the interferometer arms. Dispersive white light interferometry is capable of measuring relatively large distances (hundreds of µm) with high precision, and without moving parts. However, as with all interferometric methods, it is very sensitive to phase noise arising from such factors as vibrations or air turbulence. The random phase jumps reduce the visibility of the white light fringes. This limitation imposes stringent conditions upon the stability of the interferometer, and its applicability to field measurements is thus restricted.

© 1998 IEEE