Chen Zi-Yu, Li Xiao-Ya, Li Bo-Yuan, Chen Min, Liu Feng
Opt Express. 2018 Feb 19;26(4):4572-4580. doi: 10.1364/OE.26.004572.
The production of intense isolated attosecond pulse is a major goal in ultrafast research. Recent advances in high harmonic generation from relativistic plasma mirrors under oblique incidence interactions gave rise to photon-rich attosecond pulses with circular or elliptical polarization. However, to achieve an isolated elliptical attosecond pulse via polarization gating using currently available long driving pulses remains a challenge, because polarization gating of high harmonics from relativistic plasmas is assumed only possible at normal or near-normal incidence. Here we numerically demonstrate a scheme around this problem. We show that via control of plasma dynamics by managing laser polarization, it is possible to gate an intense single attosecond pulse with high ellipticity extending to the soft X-ray regime at oblique incidence. This approach thus paves the way towards a powerful tool enabling high-time-resolution probe of dynamics of chiral systems and magnetic materials with current laser technology.
产生高强度孤立阿秒脉冲是超快研究的一个主要目标。相对论性等离子体镜在斜入射相互作用下产生高次谐波的最新进展，产生了具有圆偏振或椭圆偏振的富含光子的阿秒脉冲。然而，利用目前可用的长驱动脉冲通过偏振选通来实现孤立椭圆阿秒脉冲仍然是一个挑战，因为相对论性等离子体产生的高次谐波的偏振选通被认为仅在正入射或近正入射时才有可能。在此，我们通过数值方法演示了一种解决该问题的方案。我们表明，通过控制激光偏振来控制等离子体动力学，有可能在斜入射时选通一个高强度、高椭圆率且延伸至软X射线波段的单个阿秒脉冲。因此，这种方法为利用现有激光技术实现手性系统和磁性材料动力学的高时间分辨率探测这一强大工具铺平了道路。
