Longitudinal field acceleration of electrons by a tightly focused TMsub01/sub laser mode

摘要

Energetic electrons generation by longitudinal field acceleration from a laser pulse is demonstrated. The lon-gitudinal field is generated by focusing a radially polarized TM01 ultrashort laser pulse(1.8 microns, 550μj,15 fs) with a high numerical aperture parabola.The created longitudinal field is intense enough to ionize and accelectrons with a few tens of keV from a low density oxygen gas.We measured the generated electrons bunches characteristics:polarization dependance, number of charges per shot, energy and divergence.