Kastler, Alfred (1902-1984)

French physicist who worked on double-resonance techniques in spectroscopy, in which absorption of optical or radio-frequency radiation is used to study the energy levels in atoms. He was awarded the Nobel Prize for Physics in 1966 for his development of the technique known as ‘optical pumping’ in which light is used to excite (energize) an atom to a higher energy level. This work led to the invention of the maser and laser.

Kastler was born in Gebweiler (now Guebwiller), France, and educated at the University of Bordeaux. He became professor of physics at Bordeaux in 1938. He moved to the University of Paris in 1941 and remained there until he retired in 1972.