Analysis and optimization of the optical coupling between laser diodes and dielectric multimode waveguides

Optical interconnects integrated into electrical printed circuit boards have to be low cost and their manufacturing process has to comply with the established printed circuit board technology. Nearly all step index waveguides developed under these premises show rough surfaces between core and cladding leading to completely different power-loss characteristics of the propagating modes. In this paper we present a model for the coupling mechanism between a laser diode (VCSEL) and an integrated weak guiding dielectric multimode waveguide with rectangular cross section. The model is based on the mode matching method.