EFFICIENT POLING AND THERMAL CROSS-LINKING OF RANDOMLY BONDED MAIN-CHAIN POLYMERS FOR STABLE 2ND-ORDER NONLINEARITIES

We report our second-harmonic generation study of a new crosslinked ma in-chain polymer system for second-order nonlinear optics (NLO). In th is unique polymer system, the rigid second-order NLO chromophores are randomly bonded in the main chain with flexible links between the rigi d chromophores to allow electric poling at or above the glass transiti on temperature. A thermal crosslinker is added to crosslink the polyme r backbone during electric poling. The combination of the flexible cha in segments and crosslinking allows us to achieve a high degree of ali gnment ([cos3theta] almost-equal-to 0.34) and long-term ( > 2500 h) te mporal stability of the nonlinearities.