| 摘要 |
<p>An acoustooptic filter ensuring wide light transmission characteristics without shortening the interaction length, i.e. with a low power. An optical waveguide (3) is formed on the upper surface (2a) of an acoustooptic substrate (2), an interdigital electrode (4) for exciting a surface wave is formed on the acoustooptic substrate (2), the waveguide of a surface wave excited by the interdigital electrode (4) is extended in the direction substantially matching the optical waveguide, and an optical mode guided by the optical waveguide (3) is converted by the surface wave. In such an acoustooptic filter, the optical waveguide (3) is provided with a thin film ridge (5) as a means for varying the phase matching conditions in the interaction region of a light being guided by the waveguide (3) and surface acoustic wave by 0.235% or more from phase matching state.</p> |
