Terahertz generation from laser-driven ultrafast current propagation along a wire target.

Zhuo, H B; Zhang, S J; Li, X H; Zhou, H Y; Li, X Z; Zou, D B; Yu, M Y; Wu, H C et al. · Phys Rev E · 2017

basic_science · Level V

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Abstract

Generation of intense coherent THz radiation by obliquely incidenting an intense laser pulse on a wire target is studied using particle-in-cell simulation. The laser-accelerated fast electrons are confined and guided along the surface of the wire, which then acts like a current-carrying line antenna and under appropriate conditions can emit electromagnetic radiation in the THz regime. For a driving laser intensity ∼3×10^{18}W/cm^{2} and pulse duration ∼10 fs, a transient current above 10 KA is produced on the wire surface. The emission-cone angle of the resulting ∼0.15 mJ (∼58 GV/m peak electric field) THz radiation is ∼30^{∘}. The conversion efficiency of laser-to-THz energy is ∼0.75%. A simple analytical model that well reproduces the simulated result is presented.