INDUCED RADIATIVE PROCESSES IN QUANTUM AND CLASSICAL THEORIES
Igor I Sobel'man, Igor Viktorovich Tyutin
It is pointed out that induced radiation effects cannot be purely quantum in nature and that they must be present in the classical theory of radiation processes. The classical theory is usually built on the example of the harmonic oscillator. Several effects arising from the interaction of the oscillators with the field disappear when harmonic oscillators are considered. This is particularly true when one is concerned with radiation processes induced by the field. In addition, the interaction between the field and the radiation of nonlinear oscillators (their frequencies depend on the energy) was not previously considered from the standpoint of the classical theory. Because of these reasons and because of the interest in the problem of quantum generators the question of the role of induced radiation in classicai theory was examined. The theory is described, and some specific properties of the classical system are contrasted with those of the quantum system. The description includes a discussion of spontaneous radiation processes and both harmonic and anharmonic oscillators are considered. The limiting transition from quantum to classical theory is discussed, and a detailed comparison of the two more » theories is made. An ensemble of oscillators distributed in energy is discussed in the classical theory. It is shown, for certaln determined conditions, that classical systems do not absorb but rather enhance incident radiation. (TTT) « less
Soviet Physics Uspekhi•Feb 28, 1963•5 citations