Refractive Index Changes of Doped Polymer Films Induced by the Photoelimination of Meso-Ionic Heterocyclic Compounds with and without a Sulfur Atom

Abstract

We measured refractive index changes of doped polymer films induced by photoelimination of meso-ionic heterocyclic compounds. A poly(methyl methacrylate) (PMMA) film containing 30 wt% 3-phenyl-1,2,3,4-oxatriazole-5-thione (3POTT) showed a large refractive index change of -0.02 during photoirradiation, at a wavelength far from the resonant region. PMMA films containing meso-ionic compounds with a sulfur atom in the meso-ionic ring showed large refractive index changes during photoirradiation, while PMMA films containing 3-phenyl-1,2,3,4-oxatriazole-5-one, which possess no sulfur atoms in the meso-ionic ring, showed relatively small changes in refractive index. This difference may be due to the existence of a sulfur atom in the meso-ionic ring. We estimated the specific refractions of the eliminating groups, and we found that both the existence of a sulfur atom and the position of the sulfur atom in the meso-ionic group affect the specific refractions.