Infrared scanning interferometry equipment and method employs a wide band infrared light source

摘要

The source (12) has a central wave length of more than approx. 1 mm. An interferometer (10) steers an infrared wave front (22) along a reference path and a second measurement front across the specimen surface (52). The reference and reflected measurement fronts are combined to provide an interference pattern. The optical difference between the two paths is varied over a range greater than the coherence length of the light source. The resultant data is analyzed to determine the surface profile