Relativistic Generation of Isolated Attosecond Pulses in aλ3Focal Volume

Lasers that provide an energy encompassed in a focal volume of a few cubic wavelengths (${\lambda }^3$) can create relativistic intensity with maximal gradients, using minimal energy. With particle-in-cell simulations we found, that single 200 attosecond pulses could be produced efficiently in a ${\lambda }^3$ laser pulse reflection, via deflection and compression from the relativistic plasma mirror created by the pulse itself. An analytical model of coherent radiation from a charged layer confirms the pulse compression and is in good agreement with simulations. The novel technique is efficient ($\sim 10\%$) and can produce single attosecond pulses from the millijoule to the joule level.