Surface roughness measurement in the submicrometer range using laser scattering

A technique for measuring surface roughness in the submicrometer range is d eveloped. The principle of the method is based on laser scattering from a r ough surface. A telecentric optical setup that uses a laser diode as a ligh t source is used to record the light field scattered from the surface of a rough object. The light intensity distribution of the scattered band, which is correlated to the surface roughness, is recorded by a linear photodiode array and analyzed using a single-chip microcomputer. Several sets of test surfaces prepared by different machining processes are measured and a meth od for the evaluation of surface roughness is proposed. (C) 2000 Society of Photo-Optical instrumentation Engineers. [S0091-3286(00)00406-2].