Towards non-linear photonics in all-optically poled polymer microcavities

Optical poling is currently emerging as a powerful all-optical procedure fur imparting non-centrosymmetry and moreover multipolar non-linear order to a functionalized polymer medium. Interference of mutually coherent fundamental and harmonic beams with adequate polarizations leads to permanent statistical multipolar ordering of the medium breaking centrosymmetry. Selective angular hole-burning within an initially isotropic distribution of molecules and subsequent molecular reorientation allow for a permanent imprint of the quadratic non-linear optical tensor associated to a controllable orientational pattern. We provide evidence of this process, for the first time to our knowledge, in a high-finesse microcavity configuration whereby all-optical dye orientation is achieved in the active layer of the microcavity. Microcavities embedding optically poled films are shown to exhibit enhanced second harmonic generation (SHG) due to the longitudinal electric field modal resonance inside the microcavity as compared to the significantly lower efficiency of plain films in the absence of cavity. This demonstration opens a new route towards promising applications in the realm of polymer-based non-linear photonics. (C) 2000 Elsevier Science S.A. All rights reserved.