Intense laser beam guiding in self-induced electron cavitation channel in underdense plasmas

In underdense plasmas, the transverse ponderomotive force of anintense laser beam with Gaussian transverse profile expels electronsradially, and it can lead to an electron cavitation. An improvedcavitation model with charge conservation constraint is applied tothe determination of the width of the electron cavity. The envelopeequation for laser spot size derived by using source-dependentexpansion method is extended to including the electron cavity. Thecondition for self-guiding is given and illuminated by an effectivepotential for the laser spot size. The effects of the laser power,plasma density and energy dissipation on the self-guiding conditionare discussed.