Contains the lectures and seminars presented at the NATO ASI, which illustrated the basic aspects of the new, advanced laser sources as well as the rapidly developing technical applications. Among the specific topics: defining and measuring laser beam quality, quantum confined semiconductor lasers,

This text includes all the recent advances in the field of laser spectroscopy. Major results span from the control of matter by electromagnetic fields (trapping and coding) to high precision measurements on simple atomic systems and to quantum optics with single atoms. It includes a report of the Bose-Einstein condensation achieved by laser-cooling of rubidium atoms. Achievements in the technology of tunable sources, in particular of miniaturized solid state devices, are also reported. Most recent advances in molecular spectroscopy are illustrated with emphasis on "cooled" spectra, clusters...