Advances in mid-IR antimonide type-II W lasers

High-power, high-brightness mid-infrared (mid-IR, 3-5 /spl mu/m) lasers operating at ambient or thermoelectric cooler temperatures are needed for such applications as longrange chemical sensing to monitor pollutants, industrial process control, medical diagnostics, and IR countermeasures. A particularly promising approach is based on the four-constituent "W" type-II antimonide quantum-well laser. W structures have demonstrated the ability to strongly suppress Auger non-radiative recombination and also to limit the internal optical loss. We discuss recent advances in the performance of mid-IR antimonide type-II quantum well lasers.