HYBRID MODES IN ASYMMETRIC PERIODIC STRATIFIED DIELECTRIC WAVE-GUIDES

The conditions of occurrence of both hybrid surface modes and hybrid guided modes in a periodic stratified dielectric film in contact with a positive birefringent uniaxial material and a dielectric isotropic medium are studied by means of the 4 x 4 transfer matrix formalism. The dispersion relations of these hybrid modes are exactly calculated. The allowed values of the propagation constant of both surface modes and guided modes form a band structure. The same is true for the allowed values of the direction of propagation required for the existence of these modes. These band structures are explored with the help of numerical solutions of the eigenvalue equation. The lower cutoff thicknesses for various hybrid guided modes are obtained. The TE-dominant-TM-dominant guided-mode conversion effect is suggested.