▎ 摘 要
After advent of graphene as a saturable absorber, it has been proved as a promising material to generate ultrafast laser pulses. Here, we have measured the properties of flake-graphene saturable absorber mirrors of various flake sizes, dependent on the fabrication technique. These mirrors enabled us to obtain the mode-locking bandwidth of 16 nm in an erbium-doped fiber laser. Mirrors with large flake size and multi-layered thickness induce strong pulse shaping and reflect wideband mode-locked pulse train.