MODAL CHARACTERISTIC EQUATION AND DISPERSION CHARACTERISTICS FOR AN ELLIPTICAL BRAGG WAVEGUIDE WITH A SMALL NUMBER OF CLADDINGS

摘要

This article presents a rigorous analytical treatment of electromagnetic wave propagation in a new type of Bragg waveguide having elliptical core cross-section surrounded by Bragg cladding layers. Using Maxwell's equations in elliptical coordinates, the field components are obtained that specially incorporate Mathieu (q > 0) and the modified Mathieu functions (q < 0). Using this equation the modal dispersion curves for even guided modes are obtained and plotted for different cladding eccentricity e. It is found that the dispersion curves are discontinuous and modes can exist only in particular wavelength bands. Finally, the modal birefringence in the said waveguide is also estimated.