On the eve of the laser's fiftieth anniversary, we cannot but marvel at the astounding progress accomplished since the first laser shot rang in the Hughes Research Laboratory in May 1960. The range of the laser applications is stupefying. At one extreme, it can be used to slow down the atoms to almost a complete stop in order to investigate its structure with meticulousness or make, ultra accurate clocks. At the other extreme, laser light can provide enormous electric fields capable of accelerating electrons from rest to close to the speed of light over only a fraction of a micrometer in a femtosecond, leading to extremely compact laser accelerator for material science, medical and environment applications. In the near future, the laser will produce pulses with peak power in the exawatt regime or hundred thousand times the world grid power during few femtoseconds. This laser called ELI for Extreme Light Infrastructure, is being designed and constructed in Europe. It will produce bursts of high energy particles and radiations in the attosecond and zeptosecond range and will be the gateway of a new laser-matter interaction regime: the ultra relativistic regime where not only electrons but ions are thrust to relativistic velocity. Finally, its intensity will be so large that il will be able to break down the vacuum into its fundamental elements and hence offering a new paradigm to analyze the texture of vacuum.

Gérard Mourou is Professor at the Ecole Polytechnique and Director of the Institut de la Lumière Extrême at ENSTA. He is also the A. D. Moore Distinguished University Emeritus Professor of the University of Michigan, Professor Mourou has made numerous important contributions in the field of ultrafast lasers, high-speed electronics as well as in medicine where he introduced the field femtosecond ophthalmology. However his most important one is certainly the invention of the laser amplification technique universally used today and known as Chirped Pulse Amplification (CPA) at the university of Rochester. CPA revolutionized the field of optics because it made possible the generation of extremely high laser intensities that opened a new branch of optics: relativistic optics, where laser-matter interaction is dominated by the relativistic character of the electrons. In this regime it is possible to make compact particle accelerators, or sources of coherent high energy radiation beams. Note also other applications such as in thermonuclear fusion where the short and intense pulse is used as a fast igniter. The field of relativistic optics is one of the most active fields of physics today. Gérard Mourou, proposed to the ESFRI (the European Strategy Forum on Research Infrastructures) with twelve European partners a new infrastructure called ELI (Extreme Light Infrastructure). ELI, will host the most intense laser in the world. ELI, is now on the road map of the large European Infrastructure facilities. Let's note that Gérard Mourou has also many other interests. In particular, he pioneered the field of femtosecond ophthalmology at the university of Michigan. In this application, the femtosecond laser is used to perform precise cut for myopia correction or corneal transplant. Today more than one million patients have received the femtosecond procedure.