Ultra-intense attosecond pulses emitted from laser wakefields in non-uniform plasmas

作者：Liu, Y.; Li, F. Y.; Zeng, M.; Chen, M.; Sheng, Z. M.^*

来源：Laser and Particle Beams, 2013, 31(2): 233-238.

DOI：10.1017/S0263034613000220

• Attosecond pulses
• Laser wakefields
• Non-uniform plasmas
• Residual transverse momentum

A scheme of generating ultra-intense attosecond pulses in ultra-relativistic laser interaction with under-dense plasmas is proposed. The attosecond pulse emission is caused by an oscillating transverse current sheet formed by an electron density spike composed of trapped electrons in the laser wakefield and the residual transverse momentum of electrons left behind the laser pulse when its front is strongly modulated. As soon as the attosecond pulse emerges, it tends to feed back to further enhance the transverse electron momentum and the transverse current. Consequently, the attosecond pulse is enhanced and developed into a few cycles later until the density spike is depleted out due to the pump laser depletion. To control the formation of the transverse current sheet, a non-uniform plasma slab with an up-ramp density profile in front of a uniform region is adopted, which enables one to obtain attosecond pulses with higher amplitudes than that in a uniform plasma slab.

• 出版日期2013-6
• 单位上海交通大学