Multiphonon difference band absorption in diamond

摘要

The longwave absorption coefficient of diamond is composed of the two-phonon red wing and multiphonon difference (hot) bands. As temperature increases the difference bands rapidly grow in strength and dominate the absorption. A variation on a multiphonon sum band model is developed for difference bands and applied to a temperature dependent data set on CVD polycrystalline diamond that are 1.54 mm thick. The model can also be used to estimate multiphonon difference band contribution to the refractive index