THz near-field nanoscopy of graphene layers

Far-field terahertz imaging is limited by diffraction to low resolutions in the 50 μm range. On the other hand, near-field optical nanoscopy is a recent technique that shows permittivity contrasts at the nanoscale. We present here images of graphene layers on SiO
₂
obtained by scattering scanning near-field nanoscopy at 2.5 THz that show high contrasts.