Laser-Energy Transfer and Enhancement of Plasma Waves and Electron Beams by Interfering High-Intensity Laser Pulses

Authors

P. Zhang, University of Michigan, Ann Arbor
N. Saleh, University of Michigan, Ann Arbor
Shouyuan Chen, University of Michigan-Ann ArborFollow
Z.M. Sheng, Laboratory of Optical Physics, Institute of Physics, People's Republic of China
Donald P. Umstadter, University of Nebraska-LincolnFollow

Date of this Version

11-28-2003

Comments

Published by American Physical Society. Physical Review Letters, 91, 225001-1 (2003). http://prl.aps.org. Copyright © 2003 American Physical Society. Permission to use.

Abstract

The effects of interference due to crossed laser beams were studied experimentally in the high-intensity regime. Two ultrashort (400 fs), high-intensity (4×10¹⁷ and 1.6×10¹⁸ W/cm²) and1µm wavelength laser pulses were crossed in a plasma of density 4×10¹⁹ cm³. Energy was observed to be transferred from the higher-power to the lower-power pulse, increasing the amplitude of the plasma wave propagating in the direction of the latter. This results in increased electron self-trapping and plasma-wave acceleration gradient, which led to an increased number of hot electrons (by 300%) and hot-electron temperature (by 70%) and a decreased electron-beam divergence angle (by 45%), as compared with single-pulse illumination. Simulations reveal that increased stochastic heating of electrons may have also contributed to the electron-beam enhancement.