▎ 摘　　要

Two kinds of graphene-coated fiber systems are proposed and studied for optical trapping. Their plasmonic modes in uniform environment and close to the substrate are studied in the finite element method. The optical forces exerted on dielectric nanoparticle by these systems are calculated by standalone waveguide approximation. It is found that for the dielectric particle with diameter of 1 nm, the maximal optical forces generated by certain modes are more than 10(7) fN/W whereas their force ranges are only one to several nanometers. These results may have important applications in strong and high-precision optical tweezers.