Beat wave excitation of plasma wave in a plasma channel

Summary form only given, as follows. Two collinear gaussian laser beams propagating through a preformed plasma channel exert a longitudinal ponderomotive force on the electrons at the difference frequency. The force drives a forward plasma wave propagating with the group velocity of the lasers. The radial inhomogeneity of the plasma channel strongly localizes the plasma wave with spheroidal wave functions. The evolution of the plasma wave with the distance of propagation is studied analytically. As the plasma wave acquires large amplitude it influences guiding and focusing of the pump lasers. Results indicate radial steering of the plasma channel and strong localization of the plasma wave.