Resonant optical tunnel effect through dielectric structures of subwavelength cross sections

We show that optical tunnel effects through elongated structures of subwave length cross sections can be enhanced by the appropriate structuration of t he local dielectric function. Even under total internal reflection, transfe r channels can be excited to perform spatially confined photonic transfer b etween transparent media linked by such subwavelength structures. The optic al properties of such systems are analyzed using field susceptibilities, al so known as electromagnetic Green's dyadics, which determine both the local density of photon states and the optical transmittance of the system. Gree n's dyadics obtained by solving numerically a set of dyadic Dyson equations are applied to study the optical properties of subwavelength structures co nnecting two semi-infinite materials. [S1063-651X(99)12005-1].