Experimental Study of Few‐Layer Graphene: Optical Anisotropy and Pseudo‐Brewster Angle Shift in Vacuum Ultraviolet Spectral Range

Abstract

The optical properties of mono- and tri-layer graphene on SiO2/Si substrate were studied at hydrogen Lyman-alpha (121.6 nm) spectral line for the first time. We have experimentally demonstrated the optical anisotropy of graphene at this wavelength by retrieving the anisotropic ?effective? optical constants. The results confirm that the axis of symmetry is nearly perpendicular to the surface and coherently related to the π- orbitals structural orientation. Furthermore, we have observed that graphene strongly affects the performances of the substrate by inducing a pseudo-Brewster angle downshift, that depends on the number of graphene layers. This finding is in contrast with what happens in the visible spectral range, where the upshift of the pseudo-Brewster angle has been experienced in similar samples. This article is protected by copyright. All rights reserved.