Surface plasmon polaritons on metal cylinders with dielectric core

Metal cladded dielectric cylinders with submicron diameters may serve to model coated tips used in near-field scanning optical microscopy. The signal measured may be greatly influenced by resonance effects due to eigenmodes of the probe. Especially, using a photon scanning tunneling microscope setup, gold coated tips have been found to detect a signal proportional to the magnetic field distributions [E.Devaux et al., Phys. Rev. B 62, 10504 (2000)]. This effect is attributed to cylindrical surface plasmons. We present here fully retarded calculations of the dispersion and field patterns of the non-radiative plasmon modes in cylindrical geometry. We study the effect of varying the cylinder radius on the surface plasmon dispersion, thus justifying that the cylinder is a useful model for near field probes in spite of their slightly conical shape. 73.20.Mf,41.20.-q,78.20.-e,78.20.Bh Typeset using REVTEX 1 ha l-0 04 73 02 4, v er si on 1 13 A pr 2 01 0 Author manuscript, published in "Physical Review B 64, 12 (2001) 125420"