▎ 摘　　要

The optical properties of graphene coated D-shaped single mode fiber and photonic crystal fiber are numerically analyzed. Enhancement of the graphene-light interaction is found in graphene coated D-shaped photonic crystal fiber, which introduces a tunable polarization of the D-shaped fiber by changing the chemical potential of the coated graphene. An optimal polarizer model is demonstrated with the extinction ratio of 66.26 dB/mm and the insertion loss of 9.4 dB/mm The modulator extinction ratios of the TE mode and TM mode are 11.5 dB and 5 dB, respectively, with a device length of 100 mu m. This paper provides a theoretical reference for the optical property research of the graphene fiber.