Bleaching of excitonic absorption in II–VI laser diodes under lasing conditions

The lasing mechanism for II–VI laser diodes is studied with a novel pump-and-probe scheme that allows for probing the absorption spectrum under actual lasing conditions. For high quality samples containing a 10 nm Zn1−xCdx Se single quantum well, the exciton is bleached for carrier densities in the gain/lasing range in accordance with numerical solutions of the semiconductor Bloch equations. Furthermore, emission spectra are obtained for a sample within a cavity resonator, and the results are in qualitative agreement with results obtained from a non-equilibrium Green's functions theory for the coupled carriers and photons system.