Gain type optical fiber surface plasmon sensor and detection sensing system thereof

The invention discloses a gain-type optical fiber surface plasmon sensor and a detection sensing system thereof, the gain-type optical fiber surface plasmon sensor comprises a multimode optical fiber with one end being an optical fiber end face, and the optical fiber end face sequentially comprises a precious metal layer, a plasmon active layer and a perfect absorber array outwards; wherein the noble metal layer is cured on the optical fiber end face of the multimode optical fiber; the plasmon active layer is cured on the upper surface of the noble metal layer; the perfect absorber array is solidified on the upper surface of the plasmon active layer and is composed of a plurality of cross-shaped nanogold units which are arranged regularly. According to the plasmon sensor, the MIM perfect absorber composed of metal, dielectric layer and metal can generate strong localized surface plasmon resonance at the absorption wavelength, and at the moment, incident light is effectively captured in the middle layer; incid