Propagation of high power, quasi-radially polarized TEM$_{01}$ modes in a plasma waveguide*

The longitudinal electric field of a tightly focused radially polarized laser pulse has been proposed and investigated as a compact means of accelerating femtosecond scale electron bunches. However, generation of high power, short pulse lasers with radial polarization has presented a significant technical challenge. We present a simple method of generating quasi-radial polarization by creating a pi-phase delay between two halves of a linearly polarized laser. When focused, the quasi-radially polarized pulse creates an approximately TEM$_{01}$ mode. We investigate guiding of the TEM$_{01}$ mode in a plasma waveguide over a range of intensities approaching $a_{0} =1$.