Demonstration of Ultrafast THz Absorption Modulation in a Graphene-Based Thin Absorber

We present the experimental and theoretical study of an ultrafast, optically tunable graphene-based thin film absorption modulator for operation in the THz regime. An ultrafast near-IR pulse induces the generation of hot carriers in the graphene sheet, consequently, reducing its conductivity with a decay time of 2.79 ps. As a result, a modulation of 40% in the THz absorption at 2.17 THz is observed in the structure.