Attosecond Time-Resolved Imaging of Molecular Structure by Photoelectron Holography
ABSTRACT Dynamic imaging of the molecular structure of H2+ is investigated by attosecond photoelectron holography. The interference between direct (reference) and backward rescattered (signal) photoelectrons in attosecond photoelectron holography reveals the birth time of both channels and the spatial information of molecular structure. This is confirmed by simulations with a semiclassical model and numerical solutions of the corresponding time-dependent Schrödinger equation, suggesting an attosecond time-resolved way of imaging molecular structure obtained from laser induced rescattering of ionized electrons. It is shown that both short and long rescattered electron trajectories can be imaged from the momentum distribution.
SourceAvailable from: K. J. Yuan[Show abstract] [Hide abstract]
ABSTRACT: We present photoelectron angular distribution of the aligned molecular ion H-2(+) by intense ultrashort attosecond extreme ultraviolet laser pulses from numerical solutions of time-dependent Schrodinger equations. Photoionization from a superposition state of the ground 1s sigma(g) and the excited 2p sigma(u) states with pulses at photon energies above the ionization potential, (h) over bar omega>I-P, and intensity 10(14) W/cm(2), yields pulse duration dependent asymmetry of photoelectron angular distributions. We attribute the asymmetry to the periodical oscillation of the coherent electron wave packets, resulting from the interference of the two electronic states. For the processes with long pulse durations, such duration dependence is absent and symmetric angular distributions are obtained.Chinese journal of chemical physics 12/2014; 27(6):647-652. DOI:10.1063/1674-0068/27/06/647-652 · 0.72 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Photoelectrons ionized from atoms and molecules in a strong laser field are either emitted directly or rescattered by the nucleus, both of which can serve as efficiently useful tools for molecular orbital imaging. We measure the photoelectron angular distributions of molecules (N2, O2 and CO2) ionized by infrared laser pulses (1320 nm, 0.2 ~ 1 × 10(14) W/cm(2)) from multiphoton to tunneling regime and observe an enhancement of interference stripes in the tunneling regime. Using a semiclassical rescattering model with implementing the interference effect, we show that the enhancement arises from the sub-laser-cycle holographic interference of the contributions of the back-rescattering and the non-rescattering electron trajectory. It is shown that the low-energy backscattering photoelectron interference patterns have encoded the structural information of the molecular initial orbitals and attosecond time-resolved dynamics of photoelectron, opening new paths in high-resolution imaging of sub-Ångström and sub-femtosecond structural dynamics in molecules.Scientific Reports 02/2015; 5:8519. DOI:10.1038/srep08519 · 5.08 Impact Factor
Nature Physics 07/2014; 10(8):594-600. DOI:10.1038/nphys3010 · 20.60 Impact Factor