Characterization of 700 μJ T rays generated during high-power laser solid interaction.

Area of Science:

• Plasma Physics
• Laser-Matter Interaction
• Terahertz Science

Background:

• Laser-produced plasmas serve as compact sources of electromagnetic radiation.
• Recent research indicates laser-driven ion accelerators can generate energetic broadband terahertz pulses (T-rays).

Purpose of the Study:

• To report the generation and characterization of record-breaking energetic terahertz pulses.
• To investigate the dependence of T-ray yield on laser energy and identify the generation mechanism.

Main Methods:

• Utilized laser-produced solid density plasmas and compact ion accelerators.
• Measured terahertz pulse energy and characterized the spectrum from 0.1-133 THz.
• Analyzed the dependence of T-ray yield on incident laser energy and emission pattern.

Main Results:

• Achieved record-breaking terahertz pulse energies of no less than 0.7 mJ.
• Observed a linear relationship between T-ray yield and incident laser energy, with no saturation.
• Identified noncollinear emission and high yield, suggesting generation via the transient field at the rear surface of the solid target.

Conclusions:

• Laser-driven compact ion accelerators are highly efficient sources of energetic terahertz pulses.
• The transient field at the rear surface of solid targets is the primary mechanism for high-yield T-ray generation.
• These findings pave the way for advanced applications of powerful terahertz sources.