Embedded-mirror semiconductor laser

Abstract

Data are presented demonstrating the operation of a current-injection laser diode with embedded reflectors instead of etched or cleaved facets. The laser structure, grown by molecular beam epitaxy, uses AlAs-GaAs superlattices SL’s in place of conventional AlxGa1−xAs cladding layers. The sample is patterned, etched, and Zn diffused to selectively disorder the SL cladding layers producing a ∼200×∼100 μm rectangular laser cavity embedded in the surrounding AlxGa1−xAs. Following Si3N4 deposition and metallization, the diodes are cut (not cleaved) with intentionally damaged edges. These devices operate as lasers (77 K, pulsed operation) with a mode spacing corresponding to either the ∼100-μm or the ∼200-μm cavity length formed by the selective interdiffusion of the SL cladding layer. This embedded-mirror laser structure may be useful in the development of optical integrated circuits by allowing semiconductor lasers to be monolithically integrated with other optical devices.