Polarization dependence of graphene transient optical response: interplay between incident direction and anisotropic distribution of nonequilibrium carriers

The transient optical properties of graphene on a dielectric substrate rely on both the direction of light incidence and anisotropic distribution of excited carriers in graphene. Here, we experimentally and theoretically studied the polarization dependence of transient optical reflection and transmission caused by the interplay between the above two factors. The interplay between the two factors resulted in diverse polarization dependence characteristics and could shift the converting incident angle for inverse polarization dependence in transient optical response. For large angles of incidence, transient optical transmission exhibited a stronger polarization dependence and no sign reversal, compared with transient optical reflection. Our findings can be useful for designing high-speed photonic devices with controllable transient optical response of graphene.