Numerical simulations of density channel guiding and relattvistic optical guiding of laser pulses in a plasma

In the laser wakefield accelerator, a short (τL < 1 ps), high power (P > 10¹² W) laser pulse propagates in plasma to generate a large amplitude (E > 1 GV/m) wakefield. We present an axisymmetric nonlinear fluid model that allows simulation of laser pulse propagation through a plasma on the plasma time scale. We find that a laser pulse will propagate through a plasma for many vacuum diffraction lengths if either of two conditions are met: 1) an appropriately shaped plasma density channel can be obtained or 2) an ultra-high power tailored laser pulse can be created.