Propagation of short intense laser pulses in gas-filled capillaries.

ABSTRACT

The guided laser pulse propagation and wake-field generation are studied in a wide (in comparison with the laser spot size) gas-filled capillary with an on-axis gas density depletion, which can be produced by a rapid spin of the capillary around its axis or by radially propagating shock waves generated in a piezoceramic tube. A single equation for the wake-field potential, which describes the fully relativistic plasma response in the presence of optical field ionization (OFI) of a gas, is derived and used to demonstrate a guided propagation of a short intense laser pulse over many Rayleigh lengths in a leaky plasma channel produced by the pulse due to OFI in the capillary filled with a radially inhomogeneous gas. The efficient generation of a regular wake field over long distances suitable for the laser wake-field accelerators is shown.