Macroscopic Description of Laser-Type Matter.

The relationship between the formalism developed previously for the macroscopic description of laser-type matter macroscopic quantum mechanics and several forms of semiclassical radiation theory are examined. It is shown that macroscopic quantum mechanics may be regarded as a generalization of conventional semiclassical radiation theory. The development of macroscopic quantum mechanics is carried further by extending its applicability to situations in which the atomic cooperation is less than maximum, and introducing a physically meaningful quantitative measure of the atomic cooperation for a given state. The theory is applied to a four-level laser for which atomic cooperation exists not only in the lasing process but also in the pumping and relaxation processes. It is shown that under these conditions the laser exhibits properties similar to those of a parametric-amplifier with two idler frequencies. Author