Indirect stimulated emission at room temperature in the visible range.

Stimulated emission in indirect band-gap Al sub X Ga sub 1-X As is observed at room temperature. This indirect stimulated emission is based on alloy-disorder induced zero-phonon band-to-band transitions. A quadratic dependence of the threshold pump intensity on the erergy separation of the renormalized direct and indirect conduction bands is found. These threshold excitation intensities show a weak exponential increase with lattice temperature. The emmission wavelength and the emission intensity close to the crossover composition are strongly influenced by band-gap renormalization, which is treated in a multi-valley model. This model quantitatively explains the enhanced gap shrinkage in direct-gap AlGaAs close to the crossover composition.