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Updated: Jan 4, 2026

Design, Fabrication, and Experimental Characterization of Plasmonic Photoconductive Terahertz Emitters
Published on: July 8, 2013
Conductivity Induced by High-Field Terahertz Waves in Dielectric Material
B D O'Shea1,2, G Andonian1, S K Barber1,3
1UCLA Department of Physics and Astronomy, 405 Hilgard Avenue, Los Angeles, California 90095, USA.
Abstract:
An intense, subpicosecond, relativistic electron beam traversing a dielectric-lined waveguide generates very large amplitude electric fields at terahertz (THz) frequencies through the wakefield mechanism. In recent work employing this technique to accelerate charged particles, the generation of high-power, narrow-band THz radiation was demonstrated. The radiated waves contain fields with measured amplitude exceeding 2 GV/m, orders of magnitude greater than those available by other THz generation techniques at a narrow bandwidth. For fields approaching the GV/m level, a strong damping has been observed in SiO_{2}. This wave attenuation with an onset near 850 MV/m is consistent with changes to the conductivity of the dielectric lining and is characterized by a distinctive latching mechanism that is reversible on longer timescales. We describe the detailed measurements that serve to clarify the underlying physical mechanisms leading to strong field-induced damping of THz radiation (hω=1.59 meV, f=0.38 THz) in SiO_{2}, a bulk, wide band-gap (8.9 eV) dielectric.
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