Terahertz radiation source and terahertz time-domain spectroscopy system and method

The invention relates to a terahertz radiation source and a terahertz time-domain spectroscopy system and method, the terahertz radiation source comprises a metal grating structure and a hyperbolic grating structure, the metal grating structure comprises a first grating, the hyperbolic grating structure comprises a second grating arranged on the first grating, and the second grating is arranged on the hyperbolic grating structure. The second grating comprises a first layer and a second layer which are alternately stacked, the first layer is formed by a material with plasma frequency covering the terahertz wave band, and the second layer is formed by a material with dielectric property in the terahertz wave band. The terahertz radiation source provided by the invention has a double-cycle structure of a metal grating structure and a hyperbolic grating structure, and can obviously enhance the electron-substance interaction by utilizing the coupling of in-plane Cerenkov radiation and Smith-Purcell radiation, so t