Current status and application progress of CTFEL high average power THz source

The tunability, high power, high repetition rate and picoseconds-pulse time structure of terahertz (THz) radiation make the THz free-electron laser (FEL) a very attractive THz source of coherent radiation. China Academy of Engineering Physics terahertz free electron laser (CTFEL) is the first THz FEL user facility in China, which consists of a GaAs photocathode high-voltage DC gun, a superconducting RF linac, a planar undulator and a quasi-concentric optical resonator. The terahertz laser’s frequency is continuous adjustable from 0.7 THz to 4.2 THz. The average power is more than 10 W and the micro-pulse power is more than 0.3 MW. In addition, a super-radiation THz source based on CTFEL has also been built, with a frequency range of 0.1~0.7 THz. In the near future, by upgrading the electron energy, the frequency of facility will be extended to 0.1~125 THz, which will achieve full coverage of the THz band. The current status and future prospects of CTFEL THz radiation source are emphasized in this paper, and some important user experiments are introduced briefly.