Experimental verification of the nonadiabatic effect in strong-field ionization with elliptical polarization

作者：Min Li, Mingming Liu, Ji-Wei Geng, Meng Han, Xufei Sun, Yun Shao, Yongkai Deng, Chengyin Wu, Liang-You Peng, Qihuang Gong, Yunquan Liu · 发表于：Physical Review A · 年份：2017 · DOI：10.1103/physreva.95.053425 · 被引用次数：60 · 研究领域：Laser-Matter Interactions and Applications、Advanced Fiber Laser Technologies、Atomic and Molecular Physics

We perform high-resolution measurement of ellipticity-resolved momentum distributions from tunneling ionization of atoms along the major and minor axes in strong elliptically polarized fields, respectively. With developing a subcycle nonadiabatic strong-field tunneling theory for arbitrary laser polarization, we show that the electron initial conditions for positions and momenta after the tunneling are nonadiabatically intertwined with the instantaneous laser field. We extract the transverse and longitudinal momentum distributions at the tunnel exit with respect to the field ellipticity. We calibrate the laser intensity with ab initio calculation by solving the time-dependent Schr\"odinger equation. The nonadiabatic effects are confirmed experimentally and theoretically. Disentangling the effect of the long-range Coulomb potential from the laser field, we have further demonstrated that the momentum-time structure of the tunneling wave packet in strong laser fields can be approximatively imaged when treating the Coulomb effect perturbatively.