Contradirectional Coupling Between III–V Stacks and Silicon-On-Insulator Corrugated Waveguides for Laser Emission by Distributed Feedback Effect

We propose a distributed-feedback laser design that takes advantage of Bragg contradirectional coupling between a III-V stack and a silicon-on-insulator corrugated waveguide. This particular coupling scheme enables an equal share of the optical field between the III-V stack and the silicon waveguide, therefore providing an optimum tradeoff between modal gain and coupling efficiency. Numerical simulations indicate that a coupling constant of the order of 12 mm^-1 could be achieved for a 200-nm III-V stack-waveguide spacing, relaxing the constraints toward the integration technology.