Excitation of longitudinal waves by conversion of transverse waves

The dynamics of three interacting waves in a magnetoactive plasma is discussed using the methods of non-linear optics. The frequencies of the transverse wave are assumed very large whereas the frequency of the longitudinal wave may be a frequency characteristic of the system. A general formula for the length of the total conversion is given in terms of the longitudinal electron permeability. Two examples of conversion are discussed in detail, i.e. excitation of Bernstein modes and of ion cyclotron waves. It is shown that for sufficiently large but attainable amplitudes of the transverse waves the length of conversion may be of practical interest.