▎ 摘　　要

We propose and numerically investigate a dielectric-thickness-adjusting method to manipulate the graphene surface plasmon polariton (SPP). The dispersion relationships of graphene SPP at different dielectric thickness are derived by solving the analytic equations. In addition, the SPP effective index at cutoff dielectric thickness is obtained according to different dielectric permittivity and working frequencies. As a typical application, a plasmonic Bragg reflector is designed by alternately depositing dielectric gratings along the transverse direction of the SPP propagation. The performance of the Bragg reflector is analyzed at different grating thickness, and the effective index at cutoff thickness is verified by numerical simulation. The proposed method will have important potential prospects in designing graphene-based wave trapping and slow wave devices in future.