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

The fabrication of buried waveguides in InP-based quantum-well (QW) material through the use of implantation. Enhanced QW band edge blue-shifting is reported. First, the lateral selectivity of implantation-induced QW intermixing is investigated using a specially designed implantation mask and photoluminescence. The refractive index change of the intermixed material is measured near the band edge. In combination, the lateral resolution and the index difference have allowed for the fabrication of narrow buried waveguides in an InP-based laser structure. Detailed modeling of the mode excitation and beam propagation of these devices is performed, and results are compared with experimental near-field profiles. We demonstrate that the waveguides are single-mode for both TE and TM polarizations at wavelengths near the band edge. The potential applications of this waveguide structure include post-growth fabrication of buried waveguide lasers and other integrated components.