Vers l'intégration monolithique d'une micro-optique active en polymère sur VCELs

This thesis deals with the study and the development of novel polymer MOEMS (Micro Optical Electrical Mechanical Systems) for Vertical-Cavity Surface-Emitting Lasers (VCSELs) passive and active beam shaping. To improve the photonic integration of these compact laser sources in optical communication and detection systems (sensors, biomedical analysis), we have designed and fabricated a polymer-based microsystem suitable for a monolithic integration on VCSELs. It includes a refractive microlens deposited onto a suspended membrane that is moved vertically to modify dynamically the microlens-source distance. MOEMS design has been optimized by means of numerical modeling of Gaussian laser beam propagation as well as of membrane thermo-mechanical actuation. Technological steps for collective fabrication on VCSELs arrays have been developed. In particular, several methods for microlens optimal alignment relatively to the laser source have been investigated. SU-8 reliability resist has been also studied. Finally, fabricated MOEMS have been characterized. A vertical displacement of 8μm has been achieved under 3V applied, in good agreement with modeling results. This corresponds to a shift of lens focal plane of 20μm, thus demonstrating the interest of our approach.