Apparatus and methods for determining thickness and refractive index of
thin films and bulk materials are provided. Such apparatus may include a sample
support adapted to hold a sample in close contact with the base of a prism, a thermal
controller that regulates the temperature of the sample, a light source operable
to direct incident light at a variety of incident angles the base of the prism,
and a detector positioned to receive output light from the prism. The output light
has intensity variations as a function of incident angle. Sample thickness and
refractive index may be determined from the intensity variations.