Buried Heterostructure GaAs/GaAlAs Distributed Bragg Reflector Surface Emitting Laser with Very Low Threshold (5.2 mA) under Room Temperature CW Conditions

Abstract

We would like to report on the performance of buried heterostructure (BH) GaAs/Ga 0.65 Al 0.35 As surface emitting (SE) lasers with p-type Ga 0.9 Al 0.1 As/Ga 0.4 Al 0.6 As and SiO 2 /TiO 2 multilayer Bragg reflectors (MBR) under room temperature CW conditins. The buried heterostructure was formed by a selective LPE growth technique with a Ga 0.55 Al 0.45 As mask instead of the conventional SiO 2 mask. The GaAlAs mask was very useful for forming uniformly small active regions of about 5 µm in diameter. Under room temperature CW conditions, the threshold current was 5.2 mA. The external differential quantum efficiency was about 16% and more than 0.6 mW of output power was obtained. The lasing wavelength was about 897 nm.