Prokhorov, Alexander Mikhailovich (1916-2002) was a Russian physicist who developed masers, a forerunner of lasers, with Russian physicist Nikolai Gennadievich Basov. For their work, Prokhorov and Basov shared the 1964 Nobel Prize in physics with the American physicist Charles Hard Townes.

Prokhorov was born on July 11, 1916, in Atherton, Australia, the son of Mikhail Ivanovich Prokhorov and Mariya Ivanovna Mikhailovna Prokhorov. The Prokhorovs had earlier fled to Australia after Mikhail Ivanovich escaped from Siberian exile. As Communist sympathizers, they were able to return to the Soviet Union in 1923 after the Russian Revolution.

Prokhorov graduated in physics from Leningrad State University in 1939. He became a research physicist at the Lebedev Institute of Physics in Moscow in 1946.

In 1953, Prokhorov and Basov stated principles for using the energy of molecules to amplify microwaves, which are short radio waves. They developed a device that came to be called a maser to amplify microwaves. The word maser stands for microwave amplification by stimulated emission of radiation. The essential part of a maser is a substance in an excited (higher energy) state. The atoms of the excited substance radiate energy of a particular frequency when stimulated (triggered) by a microwave of the same frequency. The energy released by the atoms adds to the stimulating wave, thereby amplifying it.

In 1955, Prokhorov and Basov proposed their method for producing a maser. Ten months earlier, Townes had independently reached similar conclusions at Columbia University in New York City. Masers have been mainly used for long-distance radar and for the amplification of weak microwave signals from distant stars.

Prokhorov established a laboratory at Moscow State University, where he became a professor in 1957. In 1969, he was appointed editor-in-chief of the Great Soviet Encyclopedia, the Soviet Union's major reference work. In 1973, he became head of the Institute of General Physics of the Academy of Sciences in Moscow.