SYNTHESES OF 2ND-ORDER NONLINEAR-OPTICAL POLYURETHANES FOR ELECTROOPTIC ETALONS

Four polyurethanes containing high-beta NLO chromophores side-chain un its have been synthesized and characterized. These polymers have a ver y high chromophore density and large solubility in normal organic solv ents. We have been able to build transmission mode Fabry-Perot etalons using three of the NLO polyurethanes. Etalons using disperse red 19 ( DR 19) polymers (polymer 1 and 2) as the optoelectronic spacer layer w ith a thickness of about 1 mu m show a large modulation efficiency whi ch is comparable to the highest value so far reported for a reflection etalon device with a 4 mu m NLO polymer film. Polymer 3 (DCV-IPDI pol yurethane) has been repeatedly poled under a dc electric field as high as 210 V/mu m. Polymer 4, an ionic polymer, experiences dielectric br eakdown during parallel plate poling due to the high mobility of the s mall counterion, BF4-.