| 摘要 |
PURPOSE:To provide the optical waveguide switching element which controls the reflection or transmission intensity of light by photoirradiation at a high speed by constituting the switching element of a photochromic compd. thin film or high-molecular thin film dispersed with a photochromic compd. and a prism. CONSTITUTION:Incident light I0 enters the prism and is partly transmitted and guided at the boundary of the prism and the thin film. The remaining light is reflected. The guided light is captured by another prism. The intensity thereof is designated as I. The ratio of the intensity I of the guided light and the intensity of the reflected light depends on the incident angle of the light. The incident angle at which the waveguide intensity I is maximized is selected when the photochromic compd. is an isomer A. The refractive index of the thin film changes and the waveguide intensity I decreases if the photochromic compd. is irradiated with control light P1 and an isomer B is formed therein by a photochromic reaction. The optimum waveguide condition is again satisfied and the waveguide intensity I increases if the isomer B is returned to the isomer A by changing the wavelength of the control light to P2. |
