Light Beam Deflection in Polymer Films by Dielectric Loss Heating

Light beam deflection caused by local refractive index change in polymer optical waveguide films was investigated experimentally and theoretically. The local refractive index change was induced by dielectric loss heating with an RF electric voltage applied to the electrodes deposited on the optical waveguide films. The incident light was deflected by the induced refractive index gradient in the film plane. The deflection angle depends on the guide thickness and the film thermal conductivity. The angle was approximately 5 degrees for a 190 µm thick polymethylmethacrylate film. Deflection speed was 150–200 msec. An application to a new 1×3 switch was also proposed and demonstrated.