Aleksandr Prokhorov | Biography

Aleksandr Mikhailovich Prokhorov was born in 1916, in Atherton, Australia. His parents Mikhail and Mariya, had fled from Siberia to Australia in 1911 because of Mikhail's involvement in revolutionary activities. The family returned to the Soviet Union in 1923, but Alekxandr's graduate studies were interrupted by World War II. He was eventually awarded a Ph.D. in physical and mathematical sciences for his research on the radiation produced by electrons in the high-energy orbits of the synchrotron, a circular particle accelerator that uses electrical and magnetic fields to propel the components of atoms to extremely high speeds.

Prokhorov and and Nikolai G. Basov became involved in the stimulated emission of radiation from gas molecules. Three decades earlier in 1917, Albert Einstein had studied the effects of radiation on atoms. Using quantum mechanics, Einstein confirmed earlier hypotheses that electrons in an atom tend to absorb small amounts of energy and jump to higher energy levels in the atom. They then re-emit the absorbed radiation and return to lower, less energetic orbitals. But Einstein also discovered that in some instances an electron in a higher energy level can, simply by virtue of being exposed to radiation, jump to a lower energy level and emit a photon of a wavelength identical to that of the external radiation. This process became known as stimulated emission.

Prokhorov and Basov saw in Einstein's analysis a way of using molecules to amplify the energy of a given beam of radiation. Radiation could be used to stimulate the emission of more photons of the same wavelength within an atom, creating a domino effect among other atoms, thus stimulating the emission of more photons. This cascade of energy emission could result in a mechanism for generating more and more intense beams of radiation with a very narrow range of wavelengths. Later researchers used these findings to develop masers (microwave amplification by stimulated emission of radiation) and lasers (light amplification by stimulated emissions of radiation).

By the time Prokhorov and Basov published their discovery of the molecular generator, American physicist Charles H. Townes had built a working maser and published his conclusions in Physical Review. In awarding the 1964 Nobel Prize in Physics, the Nobel committee recognized the contributions of all three physicists. The discovery of the molecular generator provided the theoretical basis for the development of both masers and lasers, on which Prokhorov has concentrated his research efforts since the mid-1950s.

In 1941 Prokhorov married Galina Alekseyevna Shelepina, with whom he had one son. He was appointed professor at Moscow State University in 1959 and eventually returned to the Lebedev Institute, where he was appointed deputy director in 1972. Prokhorov was awarded the Lenin Prize in 1959 and the Lomonosov Gold Medal of the Soviet Academy of Sciences in 1988.

Prokhorov died on January 8, 2002, at his home in Moscow.