Optical Absorption of Silver in Photochromic Glasses: Optically Induced Dichroism

Abstract

The absorption spectrum of silver halide‐based photochromic glasses darkened by uv light is shown to vary with glass composition and photochromic heat treatment. The nature of the absorption is explained in terms of the anisotropic geometry of the photolytically produced silver specks. A correlation is established between the uv‐induced spectrum and the dichroic behavior that can be induced by bleaching with polarized light. A specific model is proposed for the silver‐speck geometry and calculations show goad agreement with experimental data.