New crosslinked polymer systems with high and stable optical nonlinearity

Thermo-crosslinkable copolymers (PGMAA and PGMAS) of glycidyl methacrylate containing azobenzene chromophores (20 mol%) and stilbene chromophores (19 mol%) respectively were synthesized and characterized. In order to obtain crosslinked polymers with high and stable second-order nonlinear optical (NLO) property, PGMAA and PGMAS were doped with a reactive nonlinear optical (NLO) dye, 4-nitro-4′-aminobiphenyl (20 mol% of the glydidyl group). In the poled state, these doped polymers systems (PGMAD and PGMSD) can be thermo-crosslinked to yield materials with high second-order (NLO) coefficient (d₃₃) of 4.33×10^?7 esu and 4.74×10^?7 esu respectively. The investigation of SHG decay at room temperature and 100°C showed that the polymer networks much improved the SHG stability.