VCSEL beam control with collective and self-aligned polymer technologies

We present recent results on the integration of polymer microlenses on single mode Vertical-Cavity Surface-Emitting Lasers (VCSELs) to achieve output beam control. We describe in particular low cost and collective fabrication methods developed to allow for a self-alignment of the lens with the laser source. These approaches are based either on surface tension effects or on a self-writing process using novel Near Infra-Red (NIR) photopolymers. Results on beam collimation at 850nm are presented and compared to a fully vectorial and three-dimensional optical model that takes into account the complete geometry of laser resonator is used. Results on short distance focusing using self-aligned microtips are presented. Considerations to achieve an active beam control by means of polymer-based MEMS (Micro-electro-mechanical System) are also discussed. Potential applications may concern the improvement of VCSEL insertion in optical interconnects or sensing systems, as well as the fabrication of optical micro-probes for near-field microscopy.