Stimulated emission by optical excitation is investigated in CdZnTe/Cd
MnTe quantum well heterostructures. Laser action is achieved at 4.2 K
and at 77 K with relatively low threshold values of the excitation int
ensity. Photoluminescence excitation spectra of the stimulated emissio
n are obtained indicating that the optical gain involves exciton-excit
on inelastic scattering.