Temporal Characterization of a Self-Modulated Laser Wakefield

Authors

S.P. Le Blanc, University of Michigan, Ann Arbor
M.C. Downer, University of Michigan, Ann Arbor
R. Wagner, University of Michigan, Ann Arbor
Shouyuan Chen, University of Michigan, Ann ArborFollow
Anatoly Maksimchuk, University of MichiganFollow
G. Mourou, University of Michigan, Ann Arbor
Donald P. Umstadter, University of Nebraska-LincolnFollow

Date of this Version

12-30-1996

Comments

Published by American Physical Society. Physical Review Letters 77, 5381 (1996). http://prl.aps.org. Copyright © 1996 American Physical Society. Permission to use.

Abstract

The temporal envelope of plasma density oscillations in the wake of an intense (l∼4×10¹⁸ W/cm², λ = 1 μm) laser pulse (400 fs) is measured using forward Thomson scattering from a copropagating, frequency-doubled probe pulse. The wakefield oscillations in a fully ionized helium plasma (n_e = 3×10¹⁹ cm^-3) are observed to reach maximum amplitude ( δn_e/n_e∼0.1) 300 fs after the pump pulse. The wakefield growth ( 3.5 ps^-1) and decay ( 1.9 ps^-1) rates are consistent with the forward Raman scattering instability and Landau damping, respectively.