Dynamics of photon number quantum fluctuations in multiphoton processes

The principles of reduction of quantum noise in optical radiation are discussed. The dynamics of photon number fluctuations in direct and cascade two-photon processes is investigated. The cases of absorption and emission for the fields originally prepared to coherent and thermal states are considered. It is shown that photon antibunching and bunching should occur for the passed radiation. The photon antibunching effect is only in definite time intervals of field interaction with resonance absorbing or emitting systems. The possible cases of accumulation of photon antibunching effects are considered. (author)