Experimental analysis and modeling of buried waveguides fabricated by quantum-well intermixing

The fabrication of buried waveguides in InP-based quantum-well (QW) materia l through the use of implantation-enhanced QW band edge blue-shifting is re ported. First, the lateral selectivity of implantation-induced QW intermixi ng is investigated using a specially designed implantation mask and photolu minescence. The refractive index change of the intermixed material is measu red near the band edge. In combination, the lateral resolution and the inde x difference have allowed for the fabrication of narrow buried waveguides i n an InP-based laser structure. Detailed modeling of the mode excitation an d beam propagation of these devices is performed, and results are compared with experimental near-field profiles. We demonstrate that the waveguides a re single-mode for both TE and TM polarizations at wavelengths near the ban d edge. The potential applications of this waveguide structure include post -growth fabrication of buried waveguide lasers and other integrated compone nts.