Absolute Optical Absorption from Diffuse Reflectance

Abstract

An equation relating the diffuse reflectance of crystalline powders to particle size, index of refraction, and absolute optical absorption coefficient is derived. Absorption spectra calculated by means of this equation from diffuse reflectance of KCl:Tl, KBr:Tl, and didymium glass are shown to be in satisfactory agreement with absolute absorption measurements on clear crystals of the same materials.