利用空间非均匀场偏振门方案产生超短的X射线

Ultrashort attosecond X-ray source generation by using the spatial inhomogeneous polarization gating scheme

理论提出了一种利用空间非均匀场偏振门方案延伸高次谐波截止能量以及获得超短X射线光源的方法.计算结果表明,当适当调节两束圆偏振激光场的延迟时间以及空间非均匀参数时,不仅高次谐波谱的平台区域能得到很大的扩展,并且谐波谱上的干涉也明显减小,形成了一个由单一量子路径贡献而成的310 e V的超长平台区.谐波相位分析显示,平台区谐波相位呈线性分布.最后,通过适当的叠加谐波平台上的谐波,可获得一系列相位稳定的脉宽在50 as以下的超短X射线光源.

An efficient method to extend the harmonic cutoff energy and to obtain the ultrashort attosecond X-ray source has been theoretically investigated by using the spatial inhomogeneous polarization gating scheme.The results show that by properly choosing the delay time and the spatial inhomogeneous parameter of the two circularly polarized laser pulses,not only the harmonic cutoff energy is remarkably enhanced,but also the harmonic modulation is reduced,resulting in a 310 e V bandwidth with the single quantum path contribution.Moreover,harmonic phase analyses show that the phases of the harmonic plateau are almost the linear.Finally,by superposing a properly selected harmonics in the supercontinuum region,a series of phase-steady sub-50 as X-ray sources can be obtained.