Optimal Design Study of Optical Cavity for Compact Terahertz Free-Electron Laser Oscillator

Presently a conceptual design for a compact Terahertz Free electron laser oscillator system is being undertaken at the Huazhong University of Science and Technology. Optical cavity are used to form an This paper presents the issue of optical cavity design which providing coherent radiation in the spectral range from 100 μm to 300 μm. The parameters of the optical cavity are calculated and optimized to obtain high FEL gains. Then, the performance of optical resonator is evaluated by numerical calculating of THz radiation intensity and pulse profile. It shows that the start-up time of the concept machine is less than 4us, and the pulse power outputs reach 1MW order with the optimal designed parameters.