Properties of double heterostructure injection lasers: Continuous room-temperature operation

Recently we prepared double heterostructure (DH) injection lasers that were the first junction lasers to operate continuously at and above 300°K. The lasers are multilayer structures of AlxGa1-xAs and GaAs that have the wider-gap material on both sides of a thin layer of the narrower-gap material and that, for CW room-temperature operation, were bonded onto diamond heat sinks. At 300°K the best DH Fabry-Perot lasers have lower threshold current densities A/cm²) than the best single heterostructure (SH) lasers (∼ 8000 A/cm²) or the best homostructure lasers ( kA/cm²). This results from improvement in optical and carrier confinement, and, in fact, passive guiding has been observed in active regions of the DH laser.