Frequency-angular distribution for terahertz emission of single-color laser filament plasma under electrostatic field

TL;DR

This study experimentally investigates the frequency-angular distribution of terahertz emission from single-color laser filament plasma, revealing how electrostatic fields and laser pulse energy influence emission characteristics.

Contribution

First experimental analysis of THz frequency-angular distributions in laser filament plasma with and without electrostatic fields, highlighting the effects of electric fields and pulse energy.

Findings

Angular distribution varies significantly with spectral components.

Electric field increases maximal propagation angles.

Laser pulse energy affects low-frequency THz emission angles.

Abstract

Frequency-angular distributions for THz emission in the range of 0.1 - 3 THz generated in a single-color laser filament plasma situated both under and without electrostatic field are for the first time experimentally studied. The angular distribution for various spectral components of this THz emission is demonstrated to differ significantly. The maximal propagation angles for these components grow up under the electric field, the angular distribution for the low-frequency THz emission depending significantly on the laser pulse energy in contrast to the case of no electric field. An increase in the laser pulse energy leads to a decrease of the propagation angles for low-frequency THz emission and to disappearance of the local minimum in the angular distribution on the propagation axis.