Asymptotic method for the Bragg reflection from media with nonperiodic perturbation of gyrotropy

The consideration of electromagnetic wave propagation in inhomogeneous media usually assumes either smooth variation of medium parameters, or their rigorously periodical perturbation. Combination of smooth and oscillated parameter perturbations leads to additional peculiarities of Bragg reflection. Presence of gyrotropy of permittivity or permeability causes coupling of waves with different polarizations. In the present paper using the complex form of asymptotic method of Krylov, Bogoliubov and Mitropolsky (KBM), mutual transformation of direct and indirect waves with two polarizations is considered in the case of oblique incidence of plane wave on medium section with small magnetic gyrotropy and/or anisotropy and weak longitudinal inhomogeneity