PURPOSE:To convert weak signal to an electric signal up to a high frequency in a broad wavelength region of infrared rays, by providing a tunnel barrier vertically with respect to an intermediate layer in an upper electrode, on which light is projected, confining optically excited quasi-particles, utilizing high sensitivity of a superconductive optical detector, and implementing a high speed characteristic. CONSTITUTION:A low superconductive electrode 2 is provided on a substrate 1. An intermediate layer 3 of an insulator or a semiconductor, which forms a tunnel barrier, is formed on the electrode 2. An upper electrode 5 of a superconductor, which includes a tunnel barrier in the film, is provided. The upper and lower electrodes of the superconductor are isolated by an insulating layer 6. Each layer of these four layers 2, 3, 5 and 6 can be manufactured by a thin film forming technology utilizing a vacuum evaporation method or a sputtering method using a suitable target and a pattern forming technology utilizing a lithography method.
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