Phase Measurement of a Fano Resonance Using Tunable Attosecond Pulses

摘要

We study photoionization of argon atoms close to the 3s23p6 → 3s13p64p Fano resonance using an attosecond pulse train and a weak infrared probe field. An interferometric technique combined with tunable attosecond pulses allows us to determine the phase of the photoionization amplitude as a function of photon energy. We interpret the experimental results using an analytical two-photon model based on the Fano formalism and obtain quantitative agreement