Intense multicycle THz pulses generated by laser-produced nanoplasmas

TL;DR

This paper introduces a new method to generate intense, narrowband terahertz pulses with GV/m-level fields using laser-produced nanoplasmas, achieving unprecedented field strength and spectral purity for advanced applications.

Contribution

The study demonstrates a novel laser-nanoplasma interaction scheme producing high-field, narrowband THz pulses with tunability and robustness, surpassing previous sources in field strength and spectral quality.

Findings

Generated THz pulses at ~30 THz beat frequency

Achieved peak field strength of 11.9 GV/m

Spectral width of approximately 5.3%

Abstract

We present a novel scheme to obtain robust, narrowband, and tunable THz emission by using a nano-dimensional overdense plasma target that is irradiated by two counter-propagating detuned laser pulses. So far, no narrowband THz sources with a field strength of GV/m-level have been reported from laser-solid interaction. We report intense THz pulses at beat-frequency ($\simeq$30THz) generated due to strong plasma current produced by the beat ponderomotive force in the colliding region, with an unprecedentedly high peak field strength of 11.9GV/m and spectral width $(\Delta f/f$$\simeq$$5.3\%)$ from 2D PIC simulations. Such an extremely bright narrowband THz source is suitable for various ambitious applications.