We investigate the response of multi-layer epitaxial graphene and chemical vapor deposition (CVD)-grown single-layer graphene to strong terahertz (THz) fields. Contrary to theoretical predictions of strong nonlinear response, the transmitted fields exhibit no harmonic generation, indicating that the nonlinear response is limited by fast electron thermalization due to carrier-carrier scattering....
We demonstrate time-resolved terahertz transmission ellipsometry of vertically aligned multi-walled carbon nanotubes. The angle-resolved transmission measurements reveal anisotropic characteristics of the terahertz electrodynamics in multi-walled carbon nanotubes. The anisotropy is, however, unexpectedly weak: the ratio of the tube-axis conductivity to the transverse conductivity, sigma[subscript z]/sigma[subscript xy] [similar or equal to]...
We investigate electron transport properties in large-area, single-layer graphene embedded in dielectric media, using free-space terahertz (THz) imaging and time-domain spectroscopy. Sandwiched between a thin polymethyl methacrylate (PMMA) layer and a Si substrate, graphene layers of different growth recipes exhibit distinctive spatial inhomogeneity of sheet conductivity. The non-contacting, non-destructive THz...
We demonstrate terahertz (THz) imaging and spectroscopy of single-layer graphene deposited on an intrinsic Si substrate using THz time-domain spectroscopy. A single-cycle THz pulse undergoes multiple internal reflections within the Si substrate, and the THz absorption by the graphene layer accumulates through the multiple interactions with the graphene/Si interface. We...