Cutoff characteristics of dielectric-filled circular holes embedded in dispersive plasmonic medium

The cutoff characteristics of dielectric-filled circular holes embedded in a dispersive plasmonic mediumare investigated.Since two distinctive operating modes,surface plasmon polariton and circular waveguidemodes,can exist in the slow and fast wave regions,respectively,the cutoff characteristics for each areseparately investigated for linear and radial polarizations of the guided fields.As a result,the cutoffwavelengths for the linear and radial polarizations with very small subwavelength hole radii are found tobe limited by the plasma resonance wavelength and plasma wavelength,which in turn are dependent andindependent,respectively,of the dielectric constant of the dielectric filler material.