Crosslinkable, nonlinear optical copolymers: Processing, corona poling, and second harmonic generation studies

摘要

AbstractPolymethacrylate copolymers, containing nonlinear optically active 4′‐dialkylamino‐4‐nitroazobenzene side groups and crosslinkable 2‐butenyl side groups were synthesized and characterized. Films of these copolymers can be thermally crosslinked at elevated temperatures and photochemically crosslinked by exposure with UV light. Both methods allow the control of the crosslinking density. A precrosslinking step, prior to the corona‐poling step, can be applied to optimize alignment and relaxation of the chromophores. During corona‐poling, the temperature dependence of the second harmonic generation (SHG) of an Nd‐YAG laser (1.064 μm) was studied for films with different degrees of precrosslinking. Depending on the conditions of precrosslinking, the SHG signal intensity and the alignment stability can be maximized. © 1993 Joh