Monolithic integration in III-V semiconductors via a universal damage enhanced quantum well intermixing technique

A novel technique for quantum well intermixing is demonstrated which has proven to be a reliable means for obtaining post-growth shifts in the band edge of a wide range of m-V material systems. The technique relies upon the generation of point defects via plasma induced damage during the deposition of sputtered silica, and provides a simple and reliable process for the fabrication of both wavelength tuned lasers and monolithically integrated devices. Wavelength tuned broad area oxide stripe lasers are demonstrated in InGaAs-InAlGaAs, InGaAs-InGaAsP, and GaInP-AlGaInP quantum well systems, and it is shown that low absorption losses are obtained after intermixing. Oxide stripe lasers with integrated slab waveguides have also enabled the production of a narrow single lobed far field (3 degrees) pattern in both InGaAs-mAlGaAs, and GaInP-AlGaInP devices. Extended cavity ridge waveguide lasers operating at 1.5 mu m are demonstrated with low loss (alpha=4.4 cm(-1)) waveguides, and it is shown that this loss is limited only by free carrier absorption in the waveguide cladding layers. In addition, the operation of intermixed multi-mode interference coupler lasers is demonstrated, where four GaAs-AlGaAs laser amplifiers are monolithically integrated to produce high output powers of 180 mW in a single fundamental mode. The results illustrate that the technique can routinely be used to fabricate low loss optical interconnects and offers a very promising route toward photonic integration.