Multiphonon Optical Spectrum of NaF

Abstract

The high-frequency exponential wing of the reststrahlen band of NaF is decomposed into a number of $N-\mathrm{phonon}$ absorption spectra ($N=2,3,4,5\mathrm{}$) by means of a temperature analysis. Overall agreement of the individual spectra with recent theoretical predictions is good, except for a fairly pronounced structure which indicates particularly strong contributions from certain frequencies of the TO and LO phonon branches.