Surface modes of a symmetric plane dielectric slab waveguide (a lossy medium)

A theoretical investigation shows that the surface HE-(H-) modes of a lossy symmetric dielectric slab waveguide do not have energy flux through the boundaries, i.e., are identical to guided modes. For surface EH(E-) modes in the case of weakly absorbing materials, the energy flux through the boundaries is a small; guided EH(H-) modes are quasi-surface waves. A numerical algorithm for solving these problems is proposed.