Abstract

We reported all-MBE grown vertical resonator diodes with an active layer made of GaAs bulk and of GaAs/AlGaAs quantum wells. Vertical current injection through two semiconductor mirrors was made possible by a novel reflector structure on the p-side of the diode. This so-called hybrid-Bragg reflector makes use of constructive interference between a distributed Bragg reflector and a metal layer for enhanced reflectivity. Because of enhanced reflectivity of this combination, fewer pairs and lower index difference are required for the Bragg reflector which allows sufficiently high electrical conductance. Low current threshold laser emission from the etched hole in the substrate was observed in these devices. For example, threshold currents as low as 12 and 22 mA were achieved, respectively, for 10- and 15-µm diam devices with a 0.25-µm active bulk GaAs layer. Pulsed emission power exceeding 10 mW and an external slope efficiency of ~20-25% were observed. The short active layer thickness indicates the high degree of mirror reflectivity (R₁R₂ > 96%).

© 1989 Optical Society of America