| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide an optical coupling device by a surface plasmon, the device making surface plasmon excitation efficiency higher and conducting high-efficiency optical coupling. <P>SOLUTION: A metallic thin film is formed into a belt state with a prescribed width W on the surface of an optical waveguide substrate 12, which has a core 1 and a clad 2 covering the core 1 for making the film a metallic waveguide 3, and an overclad layer 4 whose refractive index is adjusted to be a prescribed value is provided on the metallic waveguide 3. The path of the metallic waveguide 3 is superimposed on a light transmission route (core 1) in an optical waveguide. A surface plasmon resonance phenomenon is generated to the metallic waveguide 3, due to excitation by an evanescent wave due to the light of the metallic waveguide 3, and a surface plasmon polariton is transmitted. The clad 2 and the overclad layer 4 (conductive body) have their common direct connecting part, and accordingly, high light energy can be supplied to an interface. At a resonance point, stronger combination occurs to enhance the excitation efficiency; and at a point other than the resonance point, absorption and loss are reduced, since the width of the metallic waveguide 3 is narrow. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
