Probing time delay of strong-field resonant above-threshold ionization*

Abstract

The high-resolution three-dimensional photoelectron momentum distributions via above-threshold ionization (ATI) of Xe atoms are measured in an intense near circularly polarized laser field using velocity map imaging and tomography reconstruction. Compared to the linearly polarized laser field, the employed near circularly polarized laser field imposes a more strict selection rule for the transition via resonant excitation, and therefore we can selectively enhance the resonant ATI through certain atomic Rydberg states. Our results show the self-reference ionization delay, which is determined from the difference between the measured streaking angles for nonadiabatic ATI via the 4f and 5f Rydberg states, is 45.6 as. Our method provides an accessible route to highlight the role of resonant transition between selected states, which will pave the way for fully understanding the ionization dynamics toward manipulating electron motion as well as reaction in an ultrafast time scale.

Strong-field response time and its implications on attosecond measurement

“…These phenomena have been further applied to ultrafast measurements of electron dynamics in atoms and molecules, [20,21] with achieving unprecedented time resolution of attosecond. For example, scientists have developed attoclock technology for studying tunneling time, [22][23][24][25][26] high-order harmonic spectroscopy technology for monitoring the trajectories of scattered electrons, [27] and attosecond streaking technology for probing Wigner time delay of electrons. [28,29] Although attosecond measurement has made impressive discoveries and achievements, it is still in the primary stage of development.…”

Taking snapshots of a moving electron wave packet in molecules using photoelectron holography in strong-field tunneling ionization*

“…In the past decades, the rapidly developing attosecond techniques open up the way to access the electron motion on their intrinsic time scales, [6][7][8] inspiring widespread interests on monitoring the ultrafast electronic dynamics. [9] Previously proposed techniques for observing coherent electronic dynamics include high-order harmonic spectroscopy, [10][11][12][13][14] attosecond transient absorption, [15,16] ultrafast streaking [17] and electron wave packet (EWP) interferometric technique, [18][19][20] etc. Moreover, both x-ray scattering [21] and attosecond electron scattering [22] are also proposed as promising methods to monitor instantaneous electronic density distribution.…”