Sergei Ivanovich Vavilov (March 12 (24), 1891, Moscow — January 25, 1951, Moscow) — Soviet physicist, founder of the scientific school of physical optics in the USSR, full member (1932) and president of the USSR Academy of Sciences (1945-1951), public figure and science popularizer. Winner of four Stalin prizes (1943, 1946, 1951; 1952 posthumously). Chairman of the board of All-Union Znanie society (1947-1951).

Sergei Vavilov was born on March 12 (24), 1891 in Moscow in the family of Ivan Ilyich Vavilov (1863-1928), a rich shoe manufacturer, a glasnost of the Moscow City Duma. He studied at a commercial school in Ostozhenka, then, since 1909, at the physics and mathematics faculty of Moscow University, from which he graduated in 1914. During World War I S. I. Vavilov served in various engineering units. In 1914 he joined the 25th engineer battalion of the Moscow Military District as a volunteer. At the front Sergei Vavilov completed an experimental and theoretical work entitled «Frequencies of Vibrations of a Loaded Antenna.»

In 1918 — 1932 he taught physics at the Moscow Higher Technical School (MVTU, assistant professor), at the Moscow Higher Zootechnical Institute (MVZI, professor) and at Moscow State University (MSU, professor, head of the department). In parallel at the same time he headed the department of physical optics in the Institute of Physics and Biophysics of People’s Commissariat of Health of the RSFSR.

In 1931 he was elected a corresponding member, in 1932 a full member, in 1945 he was elected the president of the Academy of Sciences of the USSR. S.I. Vavilov initiated the creation of the All-Union Society «Znanie» and was its first chairman (1947-1951).

In September 1932 Vavilov was appointed scientific director of the State Optical Institute and remained its head until he was elected president of the Academy of Sciences of the USSR in 1945. He made a great contribution to the scientific activity of the Institute, organized and headed the laboratory of luminescence analysis, which he headed until his last days. He actively participated in the development of opto-mechanical industry of the country and GOI as a branch scientific center. He was an advocate of the necessity of close connection of science and industry, against division of science into «big» and «small» ones.

During the Great Patriotic War, Sergey Vavilov was in evacuation to Yoshkar-Ola. In June 1943 he was appointed by the commissioner of GKO of the USSR for the development and coordination of scientific work in the field of infrared technology. On the occasion of 300th anniversary of Isaac Newton’s birth, celebrated in January 1943, S.I. Vavilov wrote his scientific biography and study «Ether, light and matter in Newtonian physics», and translated from Latin «Lectures on optics».

On July 17, 1945 he was elected president of the Academy of Sciences of the USSR, replacing V.L. Komarov. On March 6, 1947 he became a member of the first membership of the Scientific Council of the Department of Physics and Technology of Moscow State University (later MIPT).

The main direction in science for S. I. Vavilov was the research in the field of physical optics, in particular, the phenomena of luminescence. In 1925, in cooperation with V. L. Levshin, he conducted a number of experiments, in the course of which the decrease of the absorption index of uranium glass at high intensities of light was discovered. The observed effect formed the basis of nonlinear optics.

He introduced the concept of quantum yield of luminescence and investigated the dependence of this parameter on the wavelength of the excitation light (Vavilov’s law). He studied the phenomenon of polarization of luminescence, became the founder of a new trend — microoptics, and did a lot for the development of nonlinear optics.

Together with his postgraduate student P. A. Cherenkov, he discovered the Vavilov-Cherenkov effect (Vavilov-Cherenkov radiation) in 1934; for this discovery Cherenkov was awarded the Nobel Prize in 1958, after Vavilov died. Vavilov himself was nominated for the Nobel Prize twice (in 1957 and 1958).

In the 1920s, on the initiative of S. I. Vavilov, the research aimed at the creation of new sources of light for that time — fluorescent lamps — began. Then, under his leadership, the work continued simultaneously in three scientific organizations — P.N. Lebedev PhIAN, GOI, and V.I. Lenin All-Russian Electrotechnical Institute.

Shortly before the beginning of the war, on May 30, 1941, at the general meeting of the AS USSR S.I.Vavilov made a report «Luminescent light sources», accompanying it with a demonstration of the first samples of luminescent lamps. Later, in the postwar years, with the most active participation of S. I. Vavilov their wide industrial production began.

Editor-in-chief of the Complete Works of M.V. Lomonosov in ten volumes (1950-1957; volume 11 was published in 1983).

Editor-in-chief of the second edition of the Great Soviet Encyclopedia (volumes 1-7; 1949-1951).

Deputy of the Supreme Soviet of the RSFSR (1938-1947). Deputy of the USSR Supreme Soviet from the Lenin district of Moscow (1946-1951).