Atomic and Molecular Oscillators: Masers

The idea of a device using quantum transitions induced in molecules by a radiation field to achieve microwave amplification by stimulated emission of radiation, now familiarly known by the acronym maser, was first described by Gordon, Zeiger, and Townes, of Columbia University (Gordon et al., 1954) and independently proposed by Basov and Prokhorov, of the Lebedev Institute for Physics, in 1954. Townes, Basov, and Prokhorov shared the 1964 Nobel Prize in physics, “for fundamental work in the field of quantum electronics, which has led to the construction of oscillators and amplifiers based on the maser-laser principle.”