FABRICATION OF CURVED MIRRORS FOR VISIBLE SEMICONDUCTOR-LASERS USING ELECTRON-BEAM LITHOGRAPHY AND CHEMICALLY ASSISTED ION-BEAM ETCHING

(Al)GaInP ridge-waveguide lasers with curved dry-etched mirrors have b een fabricated which operate in the visible-light regime at a waveleng th of 690 nm. High-resolution electron-beam lithography is used to def ine the mirror shapes in a 25 nm design grid while the rest of the fab rication technology is done conventionally by optical lithography. The mirror patterns are transferred into the underlying epitaxial layers by chemically assisted ion-beam etching. The properties of the laser d evices are comparable to devices with cleaved facets. Single-mode beha vior is observed up to cw output power levels of 30 mW. The horizontal far-field angle of the emitted light can be influenced by varying the curvature radius of the mirror facets.