| 摘要 |
PROBLEM TO BE SOLVED: To provide a surface plasmon resonance sensor with a change in an output increased as compared with a change in the refractive index of a substance to be measured to enhance its sensitivity. SOLUTION: On a surface of an optical wave-guide substrate 12 comprising a core 1 and a clad 2 covering the core 1, a metallic thin film 3 causing surface plasmon resonance to occur with respect to a prescribed wavelength of light is formed to cause a surface plasmon resonance phenomenon to occur as to the substance 10 to be measured touching the thin film 3. The thin film 3 is formed into the shape of a strip of a prescribed width W, and disposed so as to overlap with a propagation route (core 1) of light propagating through the wave-guide substrate 12. The width W of the thin film 3 is made equal to or smaller than a mode field diameter. Since the clad 2 and the substance 10 comprise portions at which they directly touch each other, constituents of the propagating light passing through the outside of a side edge of the thin film 3 are kept from being absorbed into or lost in the thin film 3, allowing light energy to be more supplied to an interface as against a conventional whole-area structure. COPYRIGHT: (C)2008,JPO&INPIT
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