Arthur Leonard Schawlow (born 5.05. 1921) - American physicist, member of the National Academy of Sciences (1970). Born in Mount Vernon. Graduated from the University of Toronto (1942). In 1949-51 he worked at Columbia University, in 1951—61 at the Bell Telephone Laboratories. From 1961 professor at Stanford University.
His work was in microwave and optical spectroscopy, quantum electronics and laser spectroscopy. In 1958, together with C. Townes, he proposed the principle of operation of the laser and, independently of A. M. Prokhorov and R. Dicke, the idea of using the Fabry — Perot interferometer as the resonator in infrared and visible-range lasers. In 1959 he put forward the idea of using a crystal of artificial ruby as the working substance of a laser. His work on laser crystals (1960 — 61) began laser spectroscopy.
From the 1970s the main direction of Schawlow's research became high-resolution nonlinear laser spectroscopy. In 1974, independently of N. Bloembergen, he was the first to observe narrow two-photon resonances experimentally, which led to the development of two-photon Doppler-free spectroscopy. In 1975 he considered the possibility of radiative cooling of particles to ultralow temperatures. He proposed a number of methods of ultra-high-resolution laser spectroscopy, in particular intra-Doppler two-photon optogalvanic spectroscopy (1979), the polarisation-intermodulation method (1981) and others. For his contribution to the development of laser spectroscopy he was awarded the Nobel Prize in 1981.
President of the American Physical Society (1981). The T. Young Medal and others.