Excitation of cyclic Sommerfeld waves and Wood's anomalies in plane wave scattering from a dielectric cylinder at oblique incidence

An analysis is presented of the scattering of a plane electromagnetic wave in the case of oblique incidence from a circular dielectric cylinder. Under certain conditions, this scattering process involves the excitation of cyclic surface Sommerfeld waves (SWs) capable of propagating over large distances along the cylinder. It is shown that the interaction of SWs of low azimuthal order with the cylinder continuous (radiation) modes gives rise to cyclic Sommerfeld resonances (SRs), analogous to well-known Wood's anomalies in a plane wave scattering from one-dimensional metallic diffraction gratings. Conditions necessary for the effective excitation of SWs and SRs are established and the SW and SR contributions to mode formation in microstructured optical fibers are discussed.