Dynamics of gain and stimulated emission in II-VI laser diodes

The dynamics of gain and stimulated emission of II-VI laser diodes is investigated after picosecond optical pumping. For this purpose we use time-resolved variable stripe-length measurements to study the gain dynamics after pulse excitation in waveguide geometry. Features of carrier heating and pronounced kinetic hole burning are observed in the transients of stimulated emission and gain. At high excitation densities spectral hole burning effects are additionally observed. The spectral hole recovers on a time scale of some picoseconds. We give an explanation in terms of a microscopic laser theory which is based oil the non-equilibrium Green's function technique.