Anisotropic ultrafast optical response of terahertz pumped graphene

Abstract

We have measured the ultrafast anisotropic optical response of highly doped graphene to an intense single cycle terahertz pulse. The time profile of the terahertz-induced anisotropy signal at 800 nm has minima and maxima repeating those of the pump terahertz electric field modulus. It grows with increasing carrier density and demonstrates a specific nonlinear dependence on the electric field strength. To describe the signal, we have developed a theoretical model that is based on the energy and momentum balance equations and takes into account optical phonons of graphene and substrate. According to the theory, the anisotropic response is caused by the displacement of the electronic momentum distribution from zero momentum induced by the pump electric field in combination with polarization dependence of the matrix elements of interband optical transitions.

5 pages, 4 figures

References in corpus (9)

• The electronic properties of graphene
• Making graphene visible
• Mid-infrared plasmons in scaled graphene nanostructures
• Rayleigh Imaging of Graphene and Graphene Layers
• Substrate limited electron dynamics in graphene
• Non-linear electromagnetic response of graphene
• Third harmonic generation in graphene and few-layer graphite films
• Mechanism for current saturation and energy dissipation in graphene transistors
• Second harmonic generation in graphene dressed by a strong terahertz field