Additional waves and Fabry‐Perot interference of photoexcitons (polaritons) in thin II–VI crystals

Abstract

Abstract Within the frame work of Pekar's model for a spatially dispersive, bounded medium, optical spectra of thin crystals, reported by us recently, are analyzed, showing a structure due to the interference of additional waves and the Fabry‐Perot structure deviating markedly from the one expected in the classical case in the neighbourhood of exciton resonances. A comparison of the experimental reflectivity with that obtained numerically provides values for all physical parameters defining dispersion and damping of the photoexcitons. Some additional experimental results for excitons in thin crystals are reported: evidence for the induced surface wave, an effect of the forbidden exciton, etc.