Extraction of phonon density of states from optical spectra

Abstract
A new method for inversion of optical luminescence spectra to obtain electron-phonon spectral densities is described. The method has been devised to invert error- and noise-contaminated experimental spectra. Although direct inversion is an ill-posed problem, our method succeeds by exponential attenuation of the spectral region distant from the zero-phonon line, especially the spectral tails. The method is illustrated by application to model data, and it is successfully applied to pulsed-laser data for ZnTe:O taken at 10 K. The resultant phonon density of states reveals dominant coupling to TA- and LO-phonon modes.