Nonlinear excitation of the second harmonic in a semiconductor superlattice placed into a magnetic field

The nonlinear interaction of waves in a periodic structure placed into a ma gnetic field is considered. The structure is comprised of alternate semicon ducting and insulating layers. The three-wave interaction technique is appl ied to studying the nonlinear processes. It is shown that nonlinear phenome na in media with translational symmetry and in homogeneous media differ. Co nditions for the resonant interaction between the first and second harmonic s are analyzed. It is found that the second harmonic is generated when the interacting first spatial harmonics both co- and counterpropagate, which is possible only in periodic structures. Resonance events improving the gener ation efficiency are discussed. (C) 2001 MAIK "Nauka/Interperiodica".