CROSS-LINKED POLYMER MATERIALS FOR NONLINEAR OPTICS .1. UV-CURED ACRYLIC-MONOMERS BEARING AZOBENZENE DYES

In this paper results are presented on two different acrylic monomers 1 and 2 that have been converted by relatively fast UV curing (90 min) at modest temperatures (ca. 60-70 degrees C) into highly stable nonli near optic (NLO) materials in which loadings of NLO molecules up to 50 w/w % can be achieved. Although the azobenzene derivatives such as NL O chromophores 1 and 2 exhibit partial degradation during UV-initiated radical polymerization, the highly cross-linked formulations showed v ery stable second harmonic generation activities. Especially NLO chrom ophore 2 which has a resonantly enhanced d(33) of 13 pm/V is stable du ring more than a year at room temperature and shows no relaxation for a week at 80 degrees C.