Rough surface interferometry at 106 μm

Abstract

An IR Twyman-Green interferometer is described. It uses a cw CO(2) laser as a light source operating at a 10.6-microm wavelength. Theoretical analysis and experimental measurements of the relationship between the contrast of the interference fringes and the rms roughness of test surfaces are discussed. Interferometric testing results and special alignment methods are shown for rough surface optics.