▎ 摘　　要

We experimentally demonstrate a passively mode-locked Er:Yb doped double-clad fiber laser using a graphene nanocoated optical taper. Averaging 20 mu m of clad diameter with a length of 6mm, such a saturable absorber enables a strong light-graphene interaction owing to the evanescent field of the excited cladding mode. With the highest pump power of 5W, the 326th harmonic mode locking of soliton bunches with an average output power of 520 mW was obtained in a fiber ring cavity that has a fundamental frequency of 1.67 MHz. This is the highest average output power yet reported in graphene-based passively mode-locked fiber lasers. Published by AIP Publishing.