Thomas Elsaesser is a director emeritus at the Max-Born-Institute, Berlin, Germany, and a retired full professor for experimental physics at Humboldt University, Berlin. His research has focused on ultrafast phenomena in condensed matter, including (bio)molecular systems, inorganic solids, and nanostructures. Klaus Reimann was from 1999 to 2024 a scientist at the Max-Born-Institute, Berlin, Germany, in the field of ultrafast mid-infrared and THz spectroscopy. Before this he worked in the field of semiconductors under high pressures. Michael Woerner is a department head at the Max-Born-Institute, Berlin, Germany, and holds a lecturer qualification (Habilitation) in physics at Humboldt University, Berlin. His research focuses on ultrafast phenomena in solids and nanostructures.