Room-temperature photopumped InGaN/GaN/AlGaN vertical-cavity surface-emitting laser

We report photopumped room-temperature surface-mode lasing at 401 nm in a I nGaAlN vertical-cavity surface-emitting laser grown on a sapphire substrate using metal-organic vapor-phase epitaxy. A 2 lambda cavity was formed by a quarter-wave Al0.15Ga0.85N/GaN distributed Bragg reflector on the one side of the active layer and a GaN-air interface on the other. A multilayer str ucture composed of 12-fold-stacked ultrathin InGaN insertions in a GaN matr ix served as an active layer providing ultrahigh material gain and making p ossible vertical lasing without use of the upper Bragg reflector. (C) 1999 American Institute of Physics. [S0003-6951(99)01535-1].