Electron Beam Driven Generation of Frequency-Tunable Isolated Relativistic Subcycle Pulses

Area of Science:

• Physics
• Quantum Optics
• Plasma Physics

Background:

• Generating ultrashort electromagnetic pulses is crucial for various scientific applications.
• Existing methods for producing subcycle pulses face limitations in tunability and energy.

Purpose of the Study:

• To propose and validate a novel scheme for frequency-tunable subcycle electromagnetic pulse generation.
• To achieve amplification and frequency upshifting of electromagnetic pulses using an electron beam.

Main Methods:

• A pump electron beam is injected into a reflected electromagnetic seed pulse.
• 1D and 2D particle-in-cell simulations are used to demonstrate the amplification process.
• A fluid theory model is developed for process explanation and optimization.

Main Results:

• The electron beam amplifies the seed pulse's field.
• The central frequency of the seed pulse is upshifted, and its cycle count is reduced.
• Simulations confirm the feasibility of the proposed scheme.

Conclusions:

• The proposed scheme offers a novel pathway for generating tunable subcycle electromagnetic pulses.
• The method is capable of producing millijoule-strong mid-infrared subcycle pulses with current technology.
• The developed fluid model aids in understanding and optimizing this pulse generation technique.