We study the influence of dissipation in a semiconducting material with the semiconductor-dielectric periodic layered structure on the passband boundaries for eigenwaves. It is shown that allowance for losses in the superconductor leads to appearance of a bend in dispersion curves for the electromagnetic waves propagating in such a structure. In this case, the minimum value of the phase velocity of the wave is limited. It is found that if the collision rate is high, then one of the band boundaries in the region of cyclotron waves degenerates, i.e., the band “destruction” takes place.

We study the harmonic interaction in the nonlinear guiding layer located between two periodic layered structures. Analytical relations for the first-and second-harmonic amplitudes are obtained. It is shown that the nonlinear interaction coefficients become maximum at points where the Bragg resonance conditions are fulfilled for all structure layers of the studied waveguide including the guiding layer. The appreciable enhancement of the nonlinear interaction within the forbidden band described in experimental paper [1] is explained.