▎ 摘　　要

In this paper, the nonlinear absorption and optical isolation properties of graphene on a ZnSe substrate were studied at 10.6 mu m. The relationships between graphene saturable absorption parameters, the damage threshold and number of layers were studied by experiment. The results show that single-layer graphene on a ZnSe substrate has a higher damage threshold and lower nonsaturable loss coefficient than multilayer graphene and is more suitable for high-power MOPA-CO2 laser systems. The simulation results show that 90% of the small-signal noise light can be suppressed by 50 passes through single-layer graphene, and the ratio of the noise to the main pulse can be reduced from 1% to 0.15%.