Stimulated Scattering of Waves by Particles

Abstract

Let us remind ourselves of the well known picture of the scattering of waves by individual particles when there is no plasma. One must distinguish between spontaneous and stimulated scattering. In the case of spontaneous scattering there is only a single wave which forces the particle to oscillate in its field; in the simplest case the oscillating particle, if it is charged, will emit dipole adiation with an intensity which is proportional to that of the incident wave. In the case of stimulated scattering there must be at least two waves present. The first wave forces the particle to oscillate and the second wave has a frequency and avenumber corresponding to the waves which are emitted by the oscillatin particle. The stimulated emission by the particle is the stimulated scattering which has an intensity proportional to the intensities of both incident waves. One must, of course, take into account also the process where the second wave causes the particle to oscillate and the first wave leads to the stimulated emission.