Long-wavelength stimulated emission in HgCdTe quantum well waveguide heterostructures

We report on stimulated emission (SE) at wavelengths up to 10.2 μm from waveguide HgCdTe structures with several quantum wells (QWs) inside the waveguide core. The onset of the SE takes place under optical pumping with intensity as low as 0.12 kW/cm
²
at 18K and 1 kW/cm
²
at 80K. The carrier recombination studies via pump-probe measurements in a very narrow gap HgCdTe QWs show that furthering the SE wavelength up to 50 μm is feasible. Aside from SE via interband transitions in QWs, we have also observed SE due to the transitions involving the deep center states. The position of both SE lines can be tuned by changing the temperature and at a certain pumping intensity “two-color” SE can be obtained.