Characteristics of modified surface plasmon polaritons on double-coated metal nanofilms

Abstract

The symmetrically and asymmetrically double-coated metal nanofilms are presented to transmit the modified surface plasmon polaritons. Compared with the short-range surface plasmon polaritons on single-coated metal nanofilms, the mode widths of the modified surface plasmon polaritons increase a little, but their propagation distances can increase three orders of magnitude, correspondingly their 1D figures of merit increase nearly three orders of magnitude. The long-range propagation together with the deep-subwavelength confinement of light energy makes the planar waveguides particularly useful in the fields of nanophotonics, integrated photonic circuits and nonlinear optics.