COMPARATIVE ANALYSIS OF CIRCULAR AND TRIANGULAR GOLD NANODISKS FOR FIELD ENHANCEMENT APPLICATIONS
Keywords:Plasmonics, metal nanoparticles, optical scattering,, near and far field analysis
In this paper, we present a quantitative comparison of circular and triangular gold nanodisks with the same length and thickness. The method of moments is used to solve numerically the scattering problem. With this model, we investigate the spatial near field distribution, spectral response, far field diagrams, and bandwidth wavelength of these particles. Our results show that the resonant wavelength and the near field enhancement and confinement of the triangular particle are larger than those for the circular particle, but the resonance bandwidth and scattering cross section of the triangular particle are smaller.
D. W. Pohl, "Near field optics as an antenna problem,`` Near Field: Principles and Applications, The second Asia- Pacific Workshop on Near Field Optics, Beijing, China, pp. 9-21, Oct. 1999.
T. H. Taminiau, et. al., "Near-Fields driving of a optical monopole antenna,`` J. Opt. A: Pure Appl. Opt., vol. 9, pp. S315-S321, 2007.
B. Hecht, et. al., "Prospects of resonant optical antennas for nano-analysis,`` Chimia, vol. 60(11), pp. 765-769, 2006.
H. Fischer, and O. J. F. Martin, "Engineering the optical response of plasmonic nanoantennas,`` Opt. Express, vol. 16(12), pp. 9144-9154, 2008.
R. Kappeler, et. al., "Field computation of optical antennas,`` J. Comput. Theor. Nanosci., vol. 4(3), pp. 686-691, 2007.
O. Sqalli, I. Utke, P. Hoffmann, and F. M. Weible, "Gold elliptical nanoantennas as probes for near field optical microscopy,`` J. Appl. Phy., vol. 92(2), pp. 1078-1083, Jul. 2003.
W. Rechberger, et al., "Optical properties of two interacting gold nanoparticles,`` Opt. Commu., vol. 220, pp. 137-141, 2003.
J. Nelayah, et. al., "Mapping surface plasmons on a single metallic nanoparticle,`` Nat. Phy., vol. 3, pp. 248-353, May 2007.
V. Myroshnychenko, et. Al, "Modelling the optical response of gold nanoparticles,`` Chem. Soc. Rev., vol. 37, pp. 1792- 1805, 2008.
D. E. Livesay, and K. M. Chen, "Electromagnetic fields induced inside arbitrary shaped biological bodies,`` IEEE Trans. Micro. Theo. Thec., vol. 22(12), pp. 1273-1280, Dec. 1974.
C. A. Balanis, Antenna Theory: Analysis and Design, 3rd ed., New Jersey: John Wiley, 2005.
J. A. Stratton, Electromagnetic Theory, New York: McGraw-Hill, 1941.
K. Q. da Costa, and V. Dmitriev, "Resonances of modified bowtie nanoparticles with higher field enhancements``, to be published in the ITS 2010 - International Telecommunications Symposium.
J. Aizpurua, G. W. Bryant, L. J. Richter, and F. J. G. Abajo, "Optical properties of coupled metallic nanorods for fieldenhanced spectroscopy,`` Phys. Review B, vol. 71, 2005.