Topical Review: Extracting molecular frame photoionization dynamics from experimental data

Abstract

Methods for experimental reconstruction of molecular frame (MF) photoionization dynamics, and related properties—specifically MF photoelectron angular distributions (PADs) and continuum density matrices—are outlined and discussed. General concepts are introduced for the non-expert reader, and experimental and theoretical techniques are further outlined in some depth. Particular focus is placed on a detailed example of numerical reconstruction techniques for matrix-element retrieval from time-domain experimental measurements making use of rotational-wavepackets (i.e. aligned frame measurements)—the ‘bootstrapping to the MF’ methodology—and a matrix-inversion technique for direct MF-PAD recovery. Ongoing resources for interested researchers are also introduced, including sample data, reconstruction codes (the Photoelectron Metrology Toolkit, written in python, and associated Quantum Metrology with Photoelectrons platform/ecosystem), and literature via online repositories; it is hoped these resources will be of ongoing use to the community.