Known and developed over the past twenty five years, lasers have been experimented in a variety of processes with an uneven success. Apart from fundamental physics experiments in which the various aspects of coherence are systematically exploited, applications in the field of Materials Science have been scattered recently over so many situations that it is apparently difficult today to conceive a comprehensive interpretation of all physical processes encountered. In some domains of research like photochemistry, development has been fast and rather self-supporting. In others, like solid-state processing, progress has been either very specific or deviated towards marginal applications, or else emerged as a joint-venture between physicists and chemists. This yielded a number of professional meetings, where day-to-day research activities are presented. In 1982, the Cargese ASI on "Cohesive properties of semiconductors under laser irradiation" was one of such meetings at which a prospective of the field was discussed at length in ebullient round-table sessions. Quoted from the proceedings, "the Institute helped to discern clearly the limits of existing theoretical approaches and the directions along which work is urgently needed within the next few years." Four years have passed and the field has literally explo ded. It must be mentioned that some of the most striking developments over the past two years were accurately predicted at the Institute in Cargese."

Among the many intense light sources, excimer lasers have a unique set of properties that place them at the forefront of tooling for material processing. Their extreme versatility means that they can be used in many areas of materials science and medicine. But three conditions need to be fulfilled in order that their versatility be truly appreciated and exploited: the characteristics and limitations of the sources must be known; the basic excimer laser processes should become reasonably widely known; and problems in search of a solution should be clearly identified. Excimer Lasers covers all three of these points in an instructive and logical way. Probably for the first time, both instrumental and fundamental aspects of excimer laser interaction with matter are presented side-by-side, with examples drawn from the widest range of materials. The articles gathered here are tutorial in their nature, thus making them suitable for a wide readership, from recent graduates and postgraduate students to those established scientists entering the field, all of whom could not find a better, nor more authoritative work with which to start their reading.

The impact of Materials Science in our environment has probably never been as massive and decisive as it is today. In every aspect of our lives, progress has never been so dependent on the techniques involved in producing ever more sophisticated materials in ever larger quantities, nor so demanding for technologists to imagine novel processes and circumvent difficulties, or take up new challenges. Every technique is based on a physical process which is put into practice and optimized. The better we know that process, the better the optimization, and more powerful the technique. Laser processing of materials is inscribed in that context. As soon as powerful coherent light sources were made available, it was realized that such intense sources of energy could be used to "heat, melt and crystallize" materials, i.e., to promote phase transitions in atomic systems. As early as 1964, attempts in that direction were made but received very little (if any) attention. Reasons for this lack of interest were several. For one thing, laser technology was not fully developed, so that the process offered poor reliability and no versatility. Also, improving the existing techniques was believed to be sufficient to meet the needs of the time, and there was no real motivation to explore new ways. Finally, and more important, the fundamentals of the physics behind the scenes were, and continue to be, way out of the runni g stream.

Among the many intense light sources, excimer lasers have a unique set of properties that place them at the forefront of tooling for material processing. Their extreme versatility means that they can be used in many areas of materials science and medicine. But three conditions need to be fulfilled in order that their versatility be truly appreciated and exploited: the characteristics and limitations of the sources must be known; the basic excimer laser processes should become reasonably widely known; and problems in search of a solution should be clearly identified. Excimer Lasers covers all three of these points in an instructive and logical way. Probably for the first time, both instrumental and fundamental aspects of excimer laser interaction with matter are presented side-by-side, with examples drawn from the widest range of materials. The articles gathered here are tutorial in their nature, thus making them suitable for a wide readership, from recent graduates and postgraduate students to those established scientists entering the field, all of whom could not find a better, nor more authoritative work with which to start their reading.

Known and developed over the past twenty five years, lasers have been experimented in a variety of processes with an uneven success. Apart from fundamental physics experiments in which the various aspects of coherence are systematically exploited, applications in the field of Materials Science have been scattered recently over so many situations that it is apparently difficult today to conceive a comprehensive interpretation of all physical processes encountered. In some domains of research like photochemistry, development has been fast and rather self-supporting. In others, like solid-state processing, progress has been either very specific or deviated towards marginal applications, or else emerged as a joint-venture between physicists and chemists. This yielded a number of professional meetings, where day-to-day research activities are presented. In 1982, the Cargese ASI on "Cohesive properties of semiconductors under laser irradiation" was one of such meetings at which a prospective of the field was discussed at length in ebullient round-table sessions. Quoted from the proceedings, "the Institute helped to discern clearly the limits of existing theoretical approaches and the directions along which work is urgently needed within the next few years." Four years have passed and the field has literally explo ded. It must be mentioned that some of the most striking developments over the past two years were accurately predicted at the Institute in Cargese."