US 12,149,041 B2
Terahertz radiator based on coherent SPR amplified by stimulation
Fang Liu, Beijing (CN); Yuechai Lin, Beijing (CN); Jinyu Li, Beijing (CN); Yidong Huang, Beijing (CN); Kaiyu Cui, Beijing (CN); Xue Feng, Beijing (CN); and Wei Zhang, Beijing (CN)
Assigned to Tsinghua University, Beijing (CN)
Filed by Tsinghua University, Beijing (CN)
Filed on Jun. 23, 2021, as Appl. No. 17/304,582.
Claims priority of application No. 202010591435.3 (CN), filed on Jun. 24, 2020.
Prior Publication US 2021/0408754 A1, Dec. 30, 2021
Int. Cl. H01S 3/0959 (2006.01); G01N 21/3581 (2014.01); H01S 5/12 (2021.01)
CPC H01S 3/0959 (2013.01) [G01N 21/3581 (2013.01); H01S 5/1234 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A terahertz radiator based on coherent Smith-Purcell radiation amplified by stimulation, comprising: an electron emission source, a pumping source, a primary resonant cavity structure, and a primary grating structure; wherein the primary grating structure is located inside the primary resonant cavity structure;
the electron emission source is located at an axial inlet position of the primary resonant cavity structure, and is configured to emit electron beams which are incident into the primary resonant cavity structure along an axial direction of the primary resonant cavity structure and then fly along a surface of the primary grating structure;
the pumping source is located at an inlet position on a side wall of the primary resonant cavity structure, and is configured to emit pumping signals which are incident into the primary resonant cavity structure and then interacts with the primary grating structure on the surface of the primary grating structure to generate a periodic electromagnetic field; the periodic electromagnetic field causes electrons flying along the surface of the primary grating structure to preliminarily bunch to obtain preliminarily bunched electrons; wherein the frequency of the pumping source is in a vertical resonance mode of the primary resonant cavity structure;
the preliminarily bunched electrons interact with the primary grating structure to generate coherent Smith-Purcell radiation;
the coherent Smith-Purcell radiation and the pumping signals vertically resonate in the primary resonant cavity structure, and together modulate the electron energy in the primary resonant cavity structure, causing an increase in the electron bunching density, thereby enhancing the coherent Smith-Purcell radiation;
in the primary resonant cavity structure, a positive feedback process is formed by an energy interaction between free electrons and the coherent Smith-Purcell radiation to obtain coherent Smith-Purcell radiation amplified by stimulation and periodic bunched electron bunches.