▎ 摘　　要

A compact electro-absorption modulator based on graphene photonic crystal fiber is proposed. To enhance the graphene-light interaction efficiency, the innermost six air-holes of photonic crystal fiber are replaced by two large semicircular holes, and monolayer graphene is deposited on the two large semicircular holes. By optimizing the structure parameters, a strong graphene-light interaction is obtained. Moreover, the switch on-off point of the modulator is unchangeable, which is only related to the frequency of the incident light. The influence factors of this composite structure have been analyzed. The proposed modulator is compared with other graphene-based modulators, and the results show that it is filled without dielectric spacer. There are some excellent performances, such as an extinction ratio 7 dB of y-polarization mode, 3-dB modulation bandwidth of 70 GHz with small footprint of 205 mu m, and a consumption of energy per bit 59 pJ/bit.