A new nanostructure for enhancing transmission and local field intensity in thin metal films is presented. The novel double-hole array design was numerically modelled using a finite-difference time-domain technique. Simulations were performed for different array periodicities and hole spacing to optimize the structure for maximum enhancement capabilities. An optimum double-hole array was able to produce simultaneous increase in transmission and near-field intensity. The local field enhancement was found to be 4 orders of magnitude greater than the incident field and strongly localized to a nanoscale area which is promising for a variety of applications. Arrays of the double-hole design were fabricated using a focussed-ion beam on a thin gold film. Linear measurements through the milled arrays showed the predicted enhancement in transmission for the optimum double-hole configuration. Finite-difference time-domain calculations were also done to study an isolated rectangular aperture to show the dependence of transmission on polarization of the incident beam and width of the aperture. Fabry-Perot resonances were shown to exist for different film thicknesses and the phase of reflection was calculated from the transmission results. A microfluidic device with an embedded surface plasmon sensor was developed and its sensitivity to changes in refractive index was shown.
| Identifer | oai:union.ndltd.org:uvic.ca/oai:dspace.library.uvic.ca:1828/2159 |
| Date | 04 February 2010 |
| Creators | Kumar, L. Kiran Swaroop |
| Contributors | Gordon, Reuven |
| Source Sets | University of Victoria |
| Language | English, English |
| Detected Language | English |
| Type | Thesis |
| Rights | Available to the World Wide Web |
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