Superconducting fractal nanowire single-photon detector and preparation method thereof

The invention discloses a superconducting fractal nanowire single-photon detector and a preparation method thereof. The single-photon detector comprises a substrate, nanowires, a nano antenna, a hydrogen silsequioxane layer and a silver reflecting layer, wherein the nanowires are arranged in a fractal manner and are used for achieving insensitive absorption and polarization of the nanowires on light in two polarization states; and an array nano antenna is added on the basis of the nanowires. The preparation method comprises the following steps: sputtering a layer of superconducting material on the substrate by a magnetron sputtering method; preparing an electrode in a manner of combining photoetching and electronic beam evaporation; the fractal nanowire is prepared in a manner of matching electron beam exposure with reactive ion beam etching; and the nano antenna is prepared in a manner of combining the electron beam exposure with the electronic beam evaporation. According to the superconducting fractal nanowire single-photon detector, the polarization sensitivity of the superconducting nanowire single-photon detector is lowered; the polarization sensitivity is less than 0.02; the absorption efficiencies of two orthogonal polarization states reach 80%; the wideband absorption efficiency is higher than 70%; and the superconducting fractal nanowire single-photon detector is applicable to various superconducting materials.