Induced superradiation for a collection of three-level atoms

N three-level atoms interact simultaneously with classical and quantum fiel ds, which are in quasiresonance with various atomic transitions. The classi cal and quantum fields exchange photons by means of the atoms. It is shown that under certain conditions this process is collective. The number of pho tons in a quantized mode oscillates, and the amplitude of these oscillation s is proportional to N-2. The frequency of the oscillations is determined b y the frequencies of the classical and external fields. (C) 2000 MAIK "Nauk a/Interperiodica".