Demonstration of an optical mixing technique to drive Kinetic   Electrostatic Electron Nonlinear waves in laser produced plasmas
  A nitrogen gas Raman cell system has been constructed to shift a 70 J 527 nm laser beam to 600 nm with 20 J of energy. The 600 nm probe and a 200J, 527 nm pump beam were optically mixed in a laser produced (gas jet) plasma. The beating of the two laser beams formed a ponderomotive force that can drive Kinetic Electrostatic Electron Nonlinear (KEEN) waves discovered in Vlasov-Poisson simulations by Afeyan et al [1,2]. KEEN waves were detected in these experiments where traditional plasma theory would declare there to be a spectral gap (ie no linear waves possible). The detection was done using Thomson scattering with probe wavelengths of both 351 nm and 263.5 nm. 
J. L. Kline, B. Afeyan, W. A. Bertsche, N. A. Kurnit, D. S.   Montgomery, R. P. Johnson, and C. Niemann
physics.plasm-ph nlin.AO physics.optics