Carrier-envelope phase effects in plasma-based electron acceleration with few-cycle laser pulses

Area of Science:

• Plasma physics
• Nonlinear optics
• Laser-matter interaction

Background:

• Relativistically intense laser pulses interacting with plasma can form electron cavities, known as bubbles.
• The carrier-envelope phase (CEP) of few-cycle laser pulses is crucial in nonlinear optical phenomena.

Purpose of the Study:

• To investigate the influence of carrier-envelope phase (CEP) on the dynamics of electron bubbles formed by few-cycle laser pulses in plasma.
• To develop an analytical model that describes CEP-dependent effects beyond the ponderomotive approximation.

Main Methods:

• Derivation of an analytical model extending beyond the ponderomotive approximation.
• Particle-in-cell (PIC) simulations to verify theoretical predictions.
• Calculation of plasma cavity asymmetry as a function of laser-plasma parameters.

Main Results:

• The electron cavity (bubble) shape becomes asymmetric and strongly dependent on the CEP for few-cycle laser pulses.
• CEP variations during laser pulse propagation in plasma induce transverse oscillations of the cavity.
• The trapped electron beam exhibits modulation in the polarization plane due to CEP effects.

Conclusions:

• CEP is a critical parameter controlling the symmetry and dynamics of electron bubbles in laser-plasma interactions.
• The developed analytical model accurately describes CEP-induced asymmetries and electron beam modulation.
• These findings are essential for controlling particle acceleration and radiation generation in laser-plasma systems.