Ultrashort pulses and free-electron lasers applications

This topical issue of the Central European Journal of Physics (CEJP) highlights the emerging field of ultrashort pulses and free-electron lasers applications. The systematic application of lasers in physics, chemistry, biology and medicine has been one the most important scientific revolutions of the past century. Their intensity, coherence and, more recently, short pulse duration has made it possible to go beyond traditional single-photon transitions, revealing novel aspects of atomic and molecular structure and dynamics. Current developments of coherent light sources in the x-ray regime promise to revolutionize even more these fields.