The Extreme light pole groups twelve laboratories which develop and operate power lasers and the associated optics in order to study laser-matter interaction with very strong illumination, in all its aspects.

This activity, represented in the Triangle de la Physique by an exceptional concentration of means and skills, is already unquestionably and internationally recognized. The research work covers the whole of the interaction processes with a gas or solid target, ranging from non-linear optics of bound systems to ultra-relativistic optics of free electrons and ions in plasmas. The fundamental aspects form a consistent scope that is very rich in spectacular processes, which also has very strong potential for application.

Thus, the generation of Extreme UV and X radiation and the acceleration of charged particles, relatively under control in the non-linear and relativistic domains, are today used as sources with exceptional characteristics (ultra-short duration, peak luminosity, energy). These sources of light/particles open the perspective of dynamic studies at time scales of attoseconds, of studies of non-linear processes in the XUV and X domains, of building very compact performing accelerators. Ultra-relativistic optics, which is completely unexplored, encounters nuclear physics and high-energy physics.

The Extreme Light Infrastructure (ELI) laser project supported by the laboratories of the Triangle de la Physique now gives both a credible and a fascinating perspective on exploring this extreme domain.

The Extreme light centre sets three goals:

• Support development of a laser continuum, notably with power equal to or greater than 100 TW, in the perspective of ELI and up to its achievement;
• Promote application of the new sources of light and particles, in close partnership with the Fédération Lumière et Matière, which groups many users in the Triangle de la Physique, on the one hand, and the SOLEIL synchrotron and the Free Electron Laser project ARC-EN-CIEL on the other;
• Reinforce collaborative, experimental and theoretical studies of hot and dense plasmas, synergistically within the national framework of the Laser-Plasma Institute.