Optical Measurement of Photorecombination Time Delays

Measuring the photoionization time delay between electrons from different orbitals is one of the most important accomplishments of attosecond science. These measurements are typically done using attosecond pulses to photoionize a target inside a photoelectron spectrometer. In such experiments, the measured delay corresponds to the superposition of all possible paths to ionization and can include multiple sources of delay. These effects can be difficult to deconvolve. Here, we exploit the collision physics nature of recollision and show that, by perturbing recollision dynamics, photorecombination time delays due to electron dynamics and structure can be measured entirely optically and without obfuscation from molecular structure and propagation effects. While we concentrate on photorecombination delays in argon around the Cooper minimum our approach is general. Therefore, our work holds the potential to fundamentally change how attosecond measurement is performed and paves the way for the entirely optical measurement of ultrafast electron dynamics and photorecombination delays due to electronic structure, multielectron interaction, and strong-field driven dynamics in complex molecular systems and correlated solid-state systems.