Invited paperFourier-transform heterodyne spectroscopy of liquid and solid surfaces

Abstract.

Fourier-transform heterodyne spectroscopy is a simple but powerful technique to study narrow line shapes and small frequency shifts. We review the technique and its application to the study of hydrodynamic fluctuations. We introduce a simple scheme for obtaining the full spectrum of light scattered from liquid and solid surfaces. Using this scheme we obtained a spectral resolution of 200 $\mu$Hz. Two applications of the technique, one involving the detection of counter-propagating capillary waves, the other measurement of the epitaxial crystal-growth speed of a crystalline silicon interface, are presented.