Spatially coherent control of infrared pulse propagation in a graphene monolayer system

In this paper, we have discussed the spatial dependence of linear and nonlinear optical properties of infrared laser pulse in a single-layer graphene system. We have proposed two scenarios for adjusting the linear and nonlinear optical properties of the medium. In the first assumption, the graphene system interacts by an elliptical polarized optical vortex light and we adjust the linear and nonlinear properties via ellipticity and vorticity parameters. We found that the enhanced nonlinear coefficient was obtained with reduced linear absorption. In the second assumption, we assumed that two composite optical vortex lights interact with graphene layer. In this case the linear and nonlinear optical properties can be controlled via orbital angular momentum (OAM) of the applied lights. Here, we have shown that by adjusting the azimuthal angle of the composite vortex light, the spatial control of linear and nonlinear properties is possible. We found that in some regions of space the probe absorption vanishes and enhanced the nonlinear coefficient accompanied with optical transparency. Our results may be useful applications in future in all-optical system devices in nanostructures.