Abstract

There has been recent interest in studies of the influence of controlled spontaneous emission on the operating characteristics of lasers and light emitting diodes. Most cavity designs used in such work can be distinguished as either planar and of the Fabry-Perot type, or as possessing additional confinement in the lateral direction. For both cavity types the mirror design based on distributed Bragg reflectors (DBRs) plays an important role. Since the actual cavity length is set by light penetration into the mirrors, both the cavity length and the mirror reflectivity are set by the DBR design, which in turn sets the lateral mode profile for the planar cavity. In this talk we will present data characterizing the operation of a Fabry-Perot microcavity laser fabricated using high contrast DBRs of Al_xO_y/GaAs. The mirrors are formed by the selective conversion of AlAs into Al_xO_y using "wet oxidation" [1], resulting in the laser structure as illustrated in Fig.1. Four Al_xO_y/GaAs pairs are used on both the top and bottom (substrate) sides to form the laser cavity. In the actual laser cavity the oxidized mesa as illustrated in Fig.1 is 100μm in diameter while the lasing mode area is less than 10μm, so that the laser cavity is in fact planar. The resulting lasing characteristics of this cavity with high contrast DBRs are compared with those of a similar planar cavity design which uses the more typical AlAs/GaAs Bragg reflectors. For this second laser the upper reflector consists of sixteen pairs of AlAs/GaAs while the lower reflector (substrate side) consists of twenty-four pairs of AlAs/GaAs.

© 1995 Optical Society of America