Alfred Kastler

Alfred Kastler
(1902 - 1984)

French physicist who won the Nobel Prize for Physics in 1966 for his discovery and development of methods for observing Hertzian resonances within atoms.
In 1920 Kastler went to Paris to study at the Ecole Normale Superieure. After serving on the science faculties at Bordeaux and Clermont-Ferrand in France and Louvain in Belgium, he returned to the Ecole Normale Superieure to teach (1941-68). He was professor and codirector of the laboratory of physics there at the time of the Nobel award. During his long and fruitful teaching career he trained an entire generation of French physicists. From 1968 until his retirement in 1972, Kastler served as director of research at the National Centre of Scientific Research. He was active in peace movements and in groups opposed to nuclear proliferation.

Kastler's Nobel-Prize-winning research facilitated the study of atomic structures by means of the radiations that atoms emit under excitation by light and radio waves. His method of stimulating atoms in a particular substance so that they attain higher energy states was called "optical pumping." Since the light energy used to stimulate the atoms was reemitted, optical pumping marked an important step toward the development of the maser and the laser.