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

Optical poling is currently emerging as a powerful all-optical procedure fu r imparting non-centrosymmetry and moreover multipolar non-linear order to a functionalized polymer medium. Interference of mutually coherent fundamen tal and harmonic beams with adequate polarizations leads to permanent stati stical multipolar ordering of the medium breaking centrosymmetry. Selective angular hole-burning within an initially isotropic distribution of molecul es and subsequent molecular reorientation allow for a permanent imprint of the quadratic non-linear optical tensor associated to a controllable orient ational pattern. We provide evidence of this process, for the first time to our knowledge, i n a high-finesse microcavity configuration whereby all-optical dye orientat ion is achieved in the active layer of the microcavity. Microcavities embed ding optically poled films are shown to exhibit enhanced second harmonic ge neration (SHG) due to the longitudinal electric field modal resonance insid e the microcavity as compared to the significantly lower efficiency of plai n films in the absence of cavity. This demonstration opens a new route towa rds promising applications in the realm of polymer-based non-linear photoni cs. (C) 2000 Elsevier Science S.A. All rights reserved.