Abstract
With the growing interest in the investigation of the optical properties of semiconductors, thin- films and ionic crystals, it has become imperative to measure accurately the micro-reflectance of such miniature materials. Tubbs (1966), Esposito et al (1967), Collins (1966) and Peisner et al (1974) have reported different techniques for measuring the reflectance near normal incidence of very small areas of crystals. As in usual practise, the reflectivity of the micro-sample is determined irr comparison to the absolute reflectivity of the reference sample. Most of the authors have not met all of the following conditions required for precise measurement of absolute reflectivity.