Self-channelling of intense laser pulses in underdense plasma and stability analysis

Self-channelling of intense laser pulses have been studied in underdense plasma using three-dimensional particle-in-cell simulations, for different laser powers and plasma densities as well as analytical theory. It is found that single channel solution occurs for laser powers above the threshold power ( ∼ 1.1 P c r) and for plasma densities n 33 P c r, ring structure, an evacuated ring enclosed by electron filament, was observed in the simulations as predicted by analytical model. The stability of ring structure against symmetric and asymmetric azimuthal perturbations have been discussed.