All-optical diffraction and ultrafast switching in a terahertz-driven quantized graphene system

Abstract

Over the past few years, we have witnessed a substantial evolution in graphene optoelectronics. The tunability of the electronic structure of graphene has led to the next generation of carbon-based nano-photonic devices. Motivated by the unique optical properties of graphene, in the present work, we show that the landau-quantized graphene can be regarded as a platform for implementing a 2D laser-induced grating with high diffraction efficiency in the far-field regime. We consider a 2D doped graphene monolayer with a four-level system in Λ-configuration driven by a terahertz field. The electromagnetically induced Fraunhofer diffraction patterns are simulated for a weak probe field passing through the graphene nano-sheet. The optimum conditions for the maximum diffraction efficiency are investigated. Then, it is shown that the probe beam propagation can be coherently controlled via applying a terahertz field. The possibility of ultrafast all-optical switching of the probe beam is investigated. The proposed system may find applications in integrated nano-photonic devices for optical communications, infrared spectroscopy, astronomy, optical sensing, and also the realization of all-optical switching processes.