Developments in ultrafast spectroscopy

The power of attosecond to picosecond laser pulses for deciphering ultrafast dynamics of charge carriers, atoms and molecules in gas and condensed phases is illustrated by the abundant literature dedicated to this field. As evidenced by its dissemination in various fields, ultrafast spectroscopy is essential in the interpretation and prediction of a variety of functions at the physics–chemistry–biology–materials frontiers. By exploring the detail of matter, ultrafast spectroscopy not only provides detailed structural understanding but also in-depth knowledge of the processes that control primary events and/or generate transient species, either at the atomic and molecular scale or in a specific environment.

Recent experimental developments in various spectroscopy methods allow the decrypting and probing of microscopic and ultrafast structural and electronic motion. The interpretation of these advanced experiments calls for accurate theories going beyond the Born–Oppenheimer approximation.

The attractiveness of the field addressed in this themed issue lies within its diversity in terms of molecular objects, challenging open questions, available methods and current theoretical developments. These ingredients pave the way to exceptional collaborative projects, not only among theoreticians to develop more accurate and affordable methods, but also with experimentalists to interpret optical signals or to help molecular design.

We welcome each and every one of the exciting papers contained in this issue which gathers a collection of more than 35 articles, among them 10 “hot” contributions, reporting recent developments and challenging applications in the field of ultrafast spectroscopy.

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