Diffusion-model interpretation of the darkening and fading of photochromic glasses

Abstract

It has been verified that in photochromic glasses containing copper‐cadmium halides the fading depends on darkening conditions. The diffusion model described is consistent with observed darkening and fading kinetics, intensity dependence of equilibrium darkening, darkening time dependence of the initial fading rate, and depth dependence of equilibrium darkening.