On the Transformation of Light into Heat in Solids. II

Abstract

The results arrived at in a preceding paper are generalized for diatomic crystals (§§1, 2, 3). A direct determination of the probability of light absorption in a linear lattice leads to the establishment of a selection rule amounting to the law of the conservation of momentum for the light quanta and the "excitation quanta." This rule enables one to explain the linear structure of the spectra of solid bodies at low temperatures (§4). The preceding results are generalized and applied to a new description of the process of light scattering in crystals (§5) and the theory improved by introducing the width of the excitation lines and allowing for the damping of the exciting light waves.