Intense laser matter interaction in atoms, finite systems and condensed media: recent experiments and theoretical advances

This special issue of the European Journal of Physics: Special Topics entitled “Intense Laser Matter Interaction in Atoms, Finite Systems and Condensed Media” published a set of 21 articles aiming to put in perspective this burgeoning area of science, application and technology. The invention of chirped pulse amplification by Strickland and Mourou, which led to their Nobel prizes in 2018, has ushered in a new era in photon–matter interaction where coherent intense light pulses in the optical and infrared domains play a central role. This development has not only called in creative experimental methods, but has demanded new theoretical approaches working in the non-perturbative and highly nonlinear regimes of light–matter interaction. Both for fundamental physics as well as key applications these have played an essential role. Key pillars of this subject, captured in this collection, are laser-induced nanometer-scale plasmas ignited in unsupported nanoparticles, laser-based particle acceleration taking advantage of unprecedented field gradients, the generation of high-order harmonics opening up attosecond science and ultrafast X-ray spectroscopy, and the generation of terahertz pulses for time-domain spectroscopy of new materials.