Frequency tuning of far-infrared radiation on hot excitons

Abstract

Generation of far-infrared radiation by hot excitons in semiconductors (CdS) has been recently obtained experimentally on a large amount of transitions. It is shown theoretically that selection of separate lines can be achieved, in particular, by lowering temperature to ≤4.2K (herewith many of lines those intensities depend on the exciton wave vector would disappear) and by the use of different induced lattices of exciton states inverse population. Tuning is achievable by pressure, applied magnetic field and changing excitation level.