Related Experiment Video
Updated: Jun 2, 2026
06:16
Femtosecond Laser Filaments for Use in Sub-Diffraction-Limited Imaging and Remote Sensing
Published on: April 25, 2019
Terahertz radiation from a laser plasma filament
H-C Wu1, J Meyer-Ter-Vehn, H Ruhl
1Max-Planck-Institut für Quantenoptik, D-85748 Garching, Germany. hcwu@lanl.gov
Summary
This study reveals how intense laser pulses generate terahertz (THz) radiation in plasma filaments. Nonuniform plasma density creates a radiating current, forming a forward-propagating, radially polarized THz pulse.
Area of Science:
- Plasma Physics
- Laser-Plasma Interactions
- Terahertz (THz) Science
Background:
- Intense femtosecond laser pulses interacting with plasma can generate broadband electromagnetic radiation.
- Understanding the mechanisms behind terahertz (THz) radiation generation is crucial for various applications.
Purpose of the Study:
- To elucidate the underlying physics of terahertz (THz) radiation generation from plasma filaments formed by intense femtosecond laser pulses.
- To identify the key factors contributing to the characteristics of the generated THz radiation.
Main Methods:
- Utilized two-dimensional particle-in-cell (PIC) simulations.
- Analyzed the interaction dynamics between a femtosecond laser pulse and a plasma filament.
Main Results:
- Identified nonuniform plasma density within the filament as the source of a net radiating current for THz emission.
- Localized the primary radiating current to the laser pulse and the initial wakefield cycle.
- Observed the constructive forward buildup of a single-cycle, radially polarized THz pulse.
- Attributed the single-cycle waveform to the radiation damping effect.
Conclusions:
- The study clarifies the THz radiation mechanism in laser-induced plasma filaments.
- Nonuniform plasma density and radiation damping are critical for generating single-cycle, radially polarized THz pulses.
