PHENOXYSILICON POLYMER WITH STABLE 2ND-ORDER OPTICAL NONLINEARITY

A new cross-linked second-order nonlinear optical material based on an alkoxysilane dye and a multifunctional phenoxyl molecule has been investigated. The design approach to this polymer system is also discussed. The nonlinear optical chromophore can be directly bound to an aryl-bridged network during the curing process. After cross-linking at 200-degrees-C for 30 min, the cross-linked polymeric material was found to be amorphous with a T(g) of 110-degrees-C and a degradation temperature of 278-degrees-C. The poled and cross-linked sample exhibits a second-order nonlinear optical coefficient, d33, of 77 pm/V. After being subjected to thermal treatment at 105-degrees-C for 24 h, a reduction of only 19% of d33 was observed for the poled and cured sample. This d33 value remained unchanged at 105-degrees-C for another 144 h, to which measurements were carried out. Detailed characteristics of the cross-linked material are discussed.