Probing Molecular Frame Wigner Time Delay and Electron Wavepacket Phase Structure of CO Molecule

The time delay of photoelectron emission serves as a fundamental building block to understand the ultrafast electron emission dynamics in strong-field physics.Here,we study the photoelectron angular streaking of CO molecules by using two-color(400+800nm)corotating circularly polarized fields.By coincidently measuring photoelectrons with the dissociative ions,we present molecular frame photoelectron angular distributions with respect to the instantaneous driving electric field signatures.We develop a semiclassical nonadiabatic molecular quantum-trajectory Monte Carlo(MO-QTMC)model that fully captures the experimental observations and further ab initio simulations.We disentangle the orientation-resolved contribution of the anisotropic ionic potential and the molecular orbital structure on the measured photoelectron angular distributions.Furthermore,by analyzing the photoelectron interference patterns,we extract the sub-Coulomb-barrier phase distribution of the photoelectron wavepacket and reconstruct the orientation-and energy-resolved Wigner time delay in the molecular frame.Holographic angular streaking with bicircular fields can be used for probing polyatomic molecules in the future.