10.6 μm saturable absorption and optical isolation of graphene

Abstract

In this paper, the nonlinear absorption and optical isolation properties of graphene on a ZnSe substrate were studied at 10.6 μm. 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%.