Evaluation of photoinduced change in refractive index of a polymer film doped with an azobenzene liquid crystal by means of a prism-coupling method

Abstract

The photoinduced change in refractive index of poly(methyl methacrylate) films doped with an azobenzene liquid crystal was measured by the prism-coupling method. Upon irradiation of the film with a high-pressure mercury lamp at 366nm, the coupling angles shifted and then recovered to the initial position by turning off the light. The change in refractive index was found to be 2×10−3, which is attributed to the reversible photoisomerization of the azobenzene moieties.