Assembly of optoelectronics for efficient chip-to-waveguide coupling

This paper presents two solutions to achieve efficient optical coupling between vertical cavity surface emitting lasers and planar optical waveguides, by minimizing the free space optical path length. One approach is based on embedding of optoelectronic chips in polymer layers, and the other approach on flip-chip assembly using micro-bumps. These micro-bumps are defined by laser-induced-forward-transfer (LIFT), a technique in which the bumping material can be transferred from a donor carrier to the waveguiding substrate. In both cases, out-of-plane bending of the light is accomplished by using a 45 degrees micro-mirror interface.