PROPAGATION AND TRANSFORMATION OF ELECTROMAGNETIC-WAVES IN ONE-DIMENSIONAL PERIODIC STRUCTURES

The different approximated analytical methods of calculation of the electromagnetic waves propagation in periodic dielectric structures are discussed. The analytical expressions for electromagnetic fields and refraction coefficients in the structures are obtained and discussed. Fields of application of the approximated analytical methods (theory of perturbation for the Born approximation and the Bragg condition, theory of coupled waves and modified theory of coupled waves and so on) are defined and discussed. It is shown that the modified theory of the coupled waves has the great field of application and its solutions are true almost at all periods and depths of modulation. The calculations of reflected coefficients as a function of frequency of electoromagnetic wave, different confinement media and thickness of structure. absorption and small nonlinearity and nonperiodity are given.