▎ 摘　　要

The metallic tortuous hollow ring array in the metallic film is proposed to enhance the modulation efficiency of the graphene based terahertz (THz) amplitude modulation. In the tortuous ring configuration, multimode resonant is excited to enhance the interaction between the THz wave and the graphene. With the change of the chemical potential of the graphene layer, the resonant frequencies are shift and the transmission peaks are tuned. It is enhanced more than 9 times for the amplitude modulation depth of the THz transmission and a maximum modulation efficiency of 74 dB/eV is obtained in the tortuous ring array based modulator. The enhancement of the modulation efficiency will decrease of the applied modulation voltage and will help to the energy saving and device lifetime prolonging.