POLED POLYMERIC NONLINEAR OPTICAL-MATERIALS - ENHANCED 2ND HARMONIC-GENERATION TEMPORAL STABILITY OF EPOXY-BASED MATRICES CONTAINING A DIFUNCTIONAL CHROMOPHORIC CO-MONOMER

The long-term orientational stabilization of nonlinear optical (NLO) chromophores which have been preferentially aligned within a polymeric medium by electric field poling represents a crucial test of the extent to which polymer relaxation/physical aging can be controlled chemically and is of paramount importance to the development of efficient polymer-based second-order NLO materials.1 We recently reported2 an effective approach to chromophore immobilization which utilizes electricfield-induced alignment of high-βvec chromophores dispersed within a two-component epoxy matrix3 which is concurrently subjected to thermal cross-linking.4 The chromophores are found to exhibit higher levels of orientational stability within the cross-linked matrix, as evidenced by significantly improved second harmonic generation (SHG) temporal stability. Nevertheless, the SHG efficiency of such guest-host systems is severely limited by the low chromophore number densities and still less than optimum chromophore immobilizations which are practicable.2, 5 We communicate here the synthesis and implementation of a second generation epoxy-based NLO chromophore system in which a reactive high-βvec chromophore serves as both the NLO-active component and as the diamine cross-linking agent of the matrix (Scheme I). We also demonstrate that the SHG temporal stability of such materials can be enhanced significantly by employing an oligomeric epoxide reagent. © 1992, American Chemical Society. All rights reserved.