%D 2013 %L discovery1416553 %T Terahertz imaging of sub-wavelength particles with Zenneck surface waves %O © 2013 Author(s).. All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License. %V 103 %A M Navarro-Cia %A M Natrella %A F Dominec %A JC Delagnes %A P Kuzel %A P Mounaix %A C Graham %A CC Renaud %A AJ Seeds %A O Mitrofanov %X Impact of sub-wavelength-size dielectric particles on Zenneck surface waves on planar metallic antennas is investigated at terahertz (THz) frequencies with THz near-field probe microscopy. Perturbations of the surface waves show the particle presence, despite its sub-wavelength size. The experimental configuration, which utilizes excitation of surface waves at metallic edges, is suitable for THz imaging of dielectric sub-wavelength size objects. As a proof of concept, the effects of a small strontium titanate rectangular particle and a titanium dioxide sphere on the surface field of a bow-tie antenna are experimentally detected and verified using full-wave simulations. %N 22 %J APPLIED PHYSICS LETTERS