Hw. Oviatt et al., APPLICATIONS OF ORGANIC BRIDGED POLYSILSESQUIOXANE XEROGELS TO NONLINEAR-OPTICAL MATERIALS BY THE SOL-GEL METHOD, Chemistry of materials, 7(3), 1995, pp. 493-498
Sol-gel precursors of alpha,omega-bis(triethoxysilyl)-bridged polysils
esquioxanes containing a sidechain chromophore with known second-order
nonlinear optical properties were synthesized. Thin films were formed
from these precursors without the addition of other sol-gel forming c
omponents. The films were poled while curing at elevated temperatures.
Poled films derived from 4-nitroaniline or 2,4-dinitroaniline chromop
hores resulted in sol-gel based materials with d(33) coefficients of 3
5-37 and 9-10 pm/V, respectively. Electrooptic coefficients r(33) (1.3
mu m) extrapolated from d(33) were calculated to be 9-10 and 2-2.5 pm
/V, respectively.