Low-threshold interband cascade lasers with power efficiency exceeding 9%

Midinfrared (3.6-3.8 mu m) interband cascade lasers based on InAs/GaInSb ty pe-II quantum wells have been demonstrated in the continuous-wave (cw) mode with low-threshold current densities (e.g., similar to 56 A/cm(2) at 80 K) and power efficiencies exceeding 9%. At a relatively low current of 0.4 A, we observed similar to 100 mW/facet of optical power out at 80 K (124 mW a t 60 K) from lasers mounted epilayer-side up with uncoated facets. These la sers were able to operate in the cw mode at temperatures up to 127 K. Also, in the pulsed mode, devices lased at temperatures up to 250 K and displaye d, at 80 K, a peak power efficiency exceeding 11%. (C) 2000 American Instit ute of Physics. [S0003-6951(00)02222-1].