CONTINUOUS-WAVE OPERATION OF INAS/INASXSB1-X MIDINFRARED LASERS

Effective band gaps of type-II superlattices (SLs) can cover a wide infrared wavelength range, even beyond the narrowest band gap of any natural antimonide semiconductor alloys. This letter reports the first InAs/InAsxSb1-x type-II SL lasers with cw, optically pumped operation up to 95 K. The stimulated emission results from spatially indirect transitions of relatively extended electron states in the InAs/InAsxSb1-x SL conduction band to the hole states that are localized in the InAsx Sb1-x layers. The lasing wavelength is around 3.3-3.4 μm. Equivalent threshold current densities are estimated to be 3.3 and 56 A/cm2 at sample temperatures of 5 and 95 K, respectively. The characteristic temperature (T0) is approximately 32 K. These results demonstrate that the InAs/InAsxSb1-x type-II SL clad by AlAs0.16Sb0.84 ordered-alloy layers is a promising material system for midwave infrared semiconductor lasers. © 1995 American Institute of Physics.