Single-cycle strong terahertz pulse generation from a vacuum-plasma interface driven by intense laser pulses

Area of Science:

• Plasma Physics
• Laser-Plasma Interactions
• Terahertz Science

Background:

• Terahertz (THz) pulse generation is crucial for various scientific and technological applications.
• Current methods for generating intense THz pulses often face limitations in power, tunability, or efficiency.
• Understanding laser-matter interactions in plasma is key to developing novel THz sources.

Purpose of the Study:

• To investigate the generation of single-cycle strong terahertz pulses from laser-irradiated plasma slabs.
• To develop a theoretical model predicting the THz emission characteristics based on laser and plasma parameters.
• To explore the potential of this method for creating tunable, high-power THz sources.

Main Methods:

• Irradiation of tenuous plasma slabs with ultrashort intense laser pulses.
• Theoretical modeling based on laser ponderomotive force-induced electron acceleration and current generation.
• Numerical simulations to validate the theoretical model and assess THz source performance.

Main Results:

• Terahertz pulses are generated via laser ponderomotive force acting on plasma electrons.
• The emission frequency is determined by the ratio of laser pulse duration (τL) to the plasma period (2π/ωp).
• Numerical simulations confirm the theoretical predictions, demonstrating megawatt power and MV/cm field strengths with broad frequency tunability.

Conclusions:

• Laser-plasma interaction provides a viable pathway for generating high-power, tunable single-cycle terahertz pulses.
• The developed theoretical model accurately predicts THz emission characteristics, offering a design tool for future sources.
• This approach holds promise for advancing THz technology across diverse applications.