Super-intense Single Attosecond Pulse Generation by Plasma Gating

A robust plasma gating to generate a single ultra-intense attosecond pulse is developed. It is a manifestation of the hole-boring effect that limits the strongest attosecond pulse emission within one laser cycle. The generated pulse is characterized by a stabilized harmonic phase $\psi \approx \pm\pi/2$ and a slowly decaying exponential spectrum bounded by $\gamma$-spike scaling and CSE scaling. The phase oscillations in low-frequency region and fluctuations in high-frequency region are discussed. We also show that the phase fluctuations in high-frequency region can be reduced by including radiation reaction force.