▎ 摘　　要

Amplification of terahertz radiation is achieved by combining optically pumped graphene with a dielectric resonant cavity through numerical simulation. Graphene is attached to a one-dimensional grating and sandwiched between two distributed Bragg reflectors. The whole cavity enhances the interaction of graphene with the terahertz wave while being transparent to the pump light. When the femtosecond pulse pump light at 1.5 mu m with the peak intensity of 8.7 W/mm(2) is considered, graphene is driven to a pin medium. Due to the enhancement of the cavity and the proper complex conductivity of graphene, the amplitude of the transmitted beam is amplified 172 times at 3.82 THz at room temperature, showing great potential in the development of terahertz amplifiers and even lasers. (C) 2021 Optica Publishing Group