SURFACE ROUGHNESS STUDIES WITH DALLAS-DETECTOR ARRAY FOR LASER LIGHT ANGULAR SCATTERING.

Abstract

An instrument has been developed to study surface roughness by measuring the angular distributions of scattered light. A beam from a He-Ne laser illuminates the surface at an angle of incidence which may be varied. The scattered light distribution is detected by an array of 87 fiber optic sensors positioned in a semicircular yoke which can be rotated about its axis so that the scattered radiation may be sampled over an entire hemisphere. The output fom the detector array is digitized, stored, and analyzed in a laboratory computer. Results are analyzed by comparing the angular scattering data with theoretical angular scattering distributions computed from digitized roughness profiles measured by a stylus instrument.