Applied Physics B

, Volume 84, Issue 1, pp 3–9

Plasmonic effects in near-field optical transmission enhancement through a single bowtie-shaped aperture


DOI: 10.1007/s00340-006-2237-7

Cite this article as:
Jin, E. & Xu, X. Appl. Phys. B (2006) 84: 3. doi:10.1007/s00340-006-2237-7


In this paper, the enhanced optical transmission through a special type of aperture of a bowtie shape is investigated through near-field imaging and finite-difference numerical analysis. Under linear polarizations in two orthogonal directions, the optical near fields of the bowtie aperture and comparable square and rectangular apertures made in gold and chromium thin films are measured and compared. The bowtie aperture is able to provide a nanometer-sized optical spot when the incident light is polarized across the bowtie gap and delivers a considerable amount of light. Localized surface plasmons are clearly observed in the near-field images for both bowtie and rectangular apertures in gold, but invisible in chromium. Finite-difference time-domain calculations reveal that, depending on the polarization of the incident light, the unique optical properties of the bowtie aperture are a result of either the optical waveguide and the coupled surface plasmon polariton modes existing in the bowtie gap or the coupling between the two open arms of the bowtie aperture.

Copyright information

© Springer-Verlag 2006

Authors and Affiliations

  1. 1.School of Mechanical EngineeringPurdue UniversityWest LafayetteUSA