Kastler, Alfred (1902-1984), a French scientist, was awarded the Nobel Prize for physics in 1966 for developing techniques to investigate the energy levels of atoms. Kastler developed, in collaboration with Jean Brossel, the double resonance method of investigating atoms. Each kind of atom has resonance, natural frequency of emitting light or radio waves. Between 1949 and 1951, Kastler used the double resonance method, combined with a technique called optical pumping, to study the mercury atom in its excited state (having one or more electrons raised to a higher energy level). This technique made it possible to study the fundamental states of atoms using optical methods for studying microwave radio resonances.
Alfred Kastler was born in Guebwiller in Alsace (now Alsace-Lorraine in France). From 1921 until 1926, he studied at the Ecole Normale Superieure, in Paris. He received his Ds. C. in physics from the University of Bordeaux in 1936. He taught at the universities of Bordeaux, Clermont-Ferrand, and the Ecole Normale Superieure.
