Raman spectra and effects of electrical field and stress in DQW AlGaAs lasers

Abstract

Optical phonon Raman lines (TO-GaAs-like and TO,LO-AIAs-Iike) are shifted to lower energies and are asymmetrically broadened in electrical field compared with that of AlGaAs without field. Simultaneously are increased the intensities of all (optical and acoustical) Raman lines in electrical field. These increasings are different for different "components' of the optical phonons lines. The most significant amplification of intensities (about 3-times) is observed for the lines which correspond to the layers with Al-concentration x=O.3. These experimental results on intensity increasing in electrical field can be describe by phonon Cherencov-effect for optical and acoustical phonons.We discuss also the low frequency tail intensity increasing and stress effects and the nature of the second temperature maximum (not at the centre of the emitter).