Stimulated emission and optical gain spectrum in highly excited CdSe

Abstract
The stimulated emission from CdSe at 80 °K under nitrogen or dye laser excitation has been studied. Its dependence on the pumping laser wavelength, on the excitation intensity, and on the excited length of the sample has been investigated. Optical gain spectrum measurements confirm the attribution of the light amplification process to two different radiative mechanisms involving, respectively, the exciton-exciton interaction and the electron-hole plasma recombination, for a photoinjected electron-hole density nc?1017 pairs/cm3.