An important problem in integrated optoelectronics is the efficient coupling of a diode laser source to a passive waveguide. For optoelectronic integrated circuits, the monolithic integration of the source and the waveguide is essential.
One approach is to epitaxially grow the source, a diode laser, above the waveguide and use a combination folding mirror and intermediate layer to couple the radiation into the underlying passive waveguide. This thesis models such a configuration. A 45$\sp\circ$ folding mirror, or etched facet angle, directs the laser perpendicular to a dielectric stack mirror. The purpose of the dielectric stack mirror is to provide 30% reflectivity as optical feedback to the laser. A second etch angle directs the energy transmitted through the dielectric stack mirror towards a coupling layer of lower refractive index creating total reflection at the interface. The laser is then coupled by means of an evanescent wave into the passive waveguide located below the coupling layer.
By manipulating the material parameters and the etch angles, the maximum coupling efficiency was determined to be 18% with the corresponding etch angle of 39.4$\sp\circ$. The tolerance of this angle is large, with minimal decrease in efficiency.
