title: Observation of relativistic cross-phase modulation in high-intensity laser-plasma interactions.
abstract: A nonlinear optical phenomenon, relativistic cross-phase modulation, is reported. A relativistically intense light beam (I = 1.3 x 10(18) W cm(-2), lambda = 1.05 microm) is experimentally observed to cause phase modulation of a lower intensity, copropagating light beam in a plasma. The latter beam is generated when the former undergoes the stimulated Raman forward scattering instability. The bandwidth of the Raman satellite is found to be broadened from 3.8-100 nm when the pump laser power is increased from 0.45-2.4 TW. A signature of relativistic cross-phase modulation, namely, asymmetric spectral broadening of the Raman signal, is observed at a pump power of 2.4 TW. The experimental cross-phase modulated spectra compared well with theoretical calculations. Applications to generation of high-power single-cycle pulses are also discussed.
authors.affiliation: Department of Physics and Astronomy, University of Nebraska, Lincoln, Nebraska 68588, USA. schen6@unl.edu
authors.forename: S
authors.initials: S
authors.lastname: Chen
authors.forename: M
authors.initials: M
authors.lastname: Rever
authors.forename: P
authors.initials: P
authors.lastname: Zhang
authors.forename: W
authors.initials: W
authors.lastname: Theobald
authors.forename: D
authors.initials: D
authors.lastname: Umstadter