2020/09/27 by Xuli Shen, A. Pukhov, Shen, X. F. +3
Engineering · Physics and Astronomy · #FOS: Physical sciences #Laser-Matter Interactions and Applications #Laser-Plasma Interactions and Diagnostics #Laser-induced spectroscopy and plasma #Plasma Physics (physics.plasm-ph)
paper · pdf · doi:10.48550/arxiv.2009.12918
openalex publication_date 2020/09/27 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We propose and demonstrate that relativistic harmonics with a slowly decaying power law are generated from a femtosecond lase pulse incident parallel to a micro-scale overdense plasma. It is shown that due to the excitation of a strong surface wave, dense electron nanobunches are continuously accelerated forward while oscillating in the transverse laser field. Even around the stationary phase point, relativistic gamma factors of the nanobunches increase considerably, leading to a much stronger attosecond burst, compared to the case with constant gamma. Our two-dimensional particle-in-cell simulations and analytical theory show that this synergistic function promises a power-law harmonic spectrum In/I0 = n-1. This is much flatter than the other well-known radiation mechanisms and paves the way to unprecedentedly large energy attosecond pulses.