Abstract
A new class of crosslinked polymer network based on organosoluble polyimides for second-order nonlinear optics has been developed. The T g 's of these aromatic polyimides can be tailored to suit subsequent processing and reaction. Sol-gel reaction of a nonlinear optically active alkoxysilane dye (ASD) is utilized to grow a network in polyimide matrices or create a interpolymer network among polyimide chains. Second harmonic coefficients, d 33 of 15 to 38 pm/V have been obtained for the poled/cured polyimide/ASD samples. Excellent long-term stability of the effective second harmonic coefficients (d eff ) at 120°C is observed. A nonlinear optical (NLO) interpenetrating polymer network (IPN) system consisting of PI/ASD and a crosslinkable NLO-active polymer is also reported.