▎ 摘　　要

NOVELTY - The detector has a graphene quantum dot arranged on a side or bottom surface of a needle tip-shaped structure i.e. prism-shaped needlepoint structure or circular truncated cone-shaped needlepoint structure, where distance between the graphene quantum dot and the bottom surface of the needle tip-shaped structure is less than or equal to preset distance. Two graphene electrodes are respectively connected with two sides of the graphene quantum dot. Two metal electrodes are respectively connected with the graphene electrodes far away from a side of the graphene quantum dot. The graphene electrodes are respectively arranged on a first vertical surface and a second vertical surface. USE - Far infrared detector for a near-field microscope (claimed). ADVANTAGE - The detector can utilize the graphene quantum dot as a detecting element, so that the graphene quantum dot has wide frequency spectrum light absorption, high electric conductivity and low electron-phonon coupling, and efficiently detects a terahertz signal. The detector can place the graphene quantum dot on the side or bottom surface of the needle tip-shaped structure, so that detection efficiency of the graphene quantum dot can be greatly improved, thus detecting weak terahertz signal to realize detection of terahertz signal photon. The detector can fix the needle tip-shaped structure during utilization process, which simplifies detection process of the terahertz signal. DESCRIPTION OF DRAWING(S) - The drawing shows a perspective view of a far infrared detector.