Wakefield amplification via coherent Resonant excitation with two copropagating laser pulses in homogeneous plasma

TL;DR

This study demonstrates that using two co-propagating laser pulses with optimal timing and duration in a homogeneous plasma can significantly amplify wakefields, reaching up to three times the amplitude of single-pulse excitation.

Contribution

The paper introduces a novel scheme for wakefield amplification using two synchronized laser pulses, supported by analytical and simulation results showing optimal conditions for maximum enhancement.

Findings

Maximum wakefield amplification occurs when pulse separation is about a quarter of the plasma wavelength.

Coherent resonant excitation can triple the wakefield amplitude compared to a single pulse.

Precise control of pulse timing and duration is crucial for efficient energy transfer.

Abstract

In the present study, wakefield amplification via coherent resonant excitation using two co propagating laser pulses in a homogeneous plasma is investigated. The proposed scheme is based on linearly polarized leading seed pulse followed by a trailing pulse with identical or controlled parameters, enabling phase synchronized energy transfer to the plasma wave. By systematically varying the temporal pulse widths and inter pulse separation, conditions for resonant enhancement of the wakefield are established. Analytical modelling, supported by particle in cell simulations, reveals that maximum amplification occurs when the pulse separation approaches a quarter of the plasma wavelength, ensuring constructive interference of the plasma oscillations driven by successive pulses. Under optimal conditions, the coherent resonant excitation leads to a significant enhancement of the wakefield amplitude, reaching up to three times of that produced by a single laser pulse. The results demonstrate that precise control of pulse spacing and duration enables efficient energy coupling into plasma waves, providing a robust pathway for enhanced wakefield generation in laser plasma interaction regimes.