Observation of Ultrahigh Gradient Electron Acceleration by a Self-Modulated Intense Short Laser Pulse

A laser pulse with a power of $\ensuremath{\sim}3$ TW and a duration of 1 ps has been focused onto a gas. Ultrahigh-gradient electron acceleration has been observed in the laser-produced plasma with a density of $\ensuremath{\sim}{10}^{19}$ c${\mathrm{m}}^{--3}$ when injecting 1 MeV $/c$ electrons. The simulation of the laser-plasma interaction revealed the existence of ultrahigh-gradient wake fields excited due to self-modulation of the laser pulse and its electron acceleration, consistent with the experimental results.