With the development of nano-optic technology, the optical nano-antenna has been widely used in the fields of novel light sources, high-sensitive biological sensors, nanometer lithography, and nano-optical imaging. The relationship between the structural parameters of the antenna and the Purcell factor is very important for engineering applications. The electric near field profile of the antenna was calculated and analyzed by using the finite-difference time-domain (FDTD) method, and the influence of the structural parameters on the Purcell factor and the electric field was thoroughly investigated. A careful comparison of bowtie antenna radiation characteristics with different structural parameters was carried out. The results show that the thickness, the length and the curvature radius have great effects on the Purcell factor and the optical antenna's electric near field. These findings are promising for improving the performance of the optical bowtie nano-antenna.
2. Raether, H., "Surface Plasmons on Smooth Surfaces," Springer, 1988.
3. Ritchie, R., "Plasma losses by fast electrons in thin films," Physical Review, Vol. 106, No. 5, 874-881, 1957.
4. Economou, E., "Surface plasmons in thin films," Physical Review, Vol. 182, No. 2, 539-554, 1969.
5. Sweatlock, L., S. Maier, H. Atwater, J. Penninkhof, and A. Polman, "Highly confined electromagnetic fields in arrays of strongly coupled Ag nanoparticles," Physical Review B, Vol. 71, No. 23, 235408, 2005.
6. Ozbay, E., "Plasmonics: Merging photonics and electronics at nanoscale dimensions," Science, Vol. 311, No. 5758, 189-193, 2006.
7. Okamoto, K., I. Niki, A. Shvartser, G. Maltezos, Y. Narukawa, T. Mukai, Y. Kawakami, and A. Scherer, "Surface plasmon enhanced bright light emission from InGaN/GaN," Physica Status Solidi (A), Vol. 204, No. 6, 2103-2107, 2007.
8. Pillai, S., K. Catchpole, T. Trupke, and M. Green, "Surface plasmon enhanced silicon solar cells," Journal of Applied Physics, Vol. 101, 093105, 2007.
9. Yadipour, R., K. Abbasian, A. Rostami, and Z. D. Koozeh Kanani, "A novel proposal for ultra-high resolution and compact optical displacement sensor based on electromagnetically induced transparency in ring resonator ," Progress In Electromagnetics Research, Vol. 77, 149-170, 2007.
10. Mortazavi, D., A. Z. Kouzani, and K. C. Vernon, "A resonance tunable and durable LSPR nanoparticle sensor: Al2O3 capped silver nano-disks," Progress In Electromagnetics Research, Vol. 130, 429-446, 2012.
11. Shao, D. and S. Chen, "Direct patterning of three-dimensional periodic nanostructures by surface-plasmon-assisted nanolithography," Nano Letters, Vol. 6, No. 10, 2279-2283, 2006.
12. Fang, N., H. Lee, C. Sun, and X. Zhang, "Sub-diffraction-limited optical imaging with a silver superlens," Science, Vol. 308, No. 5721, 534-537, 2005.
13. Weeber, J.-C., E. Bourillot, A. Dereux, J.-P. Goudonnet, Y. Chen, and C. Girard, "Observation of light confinement effects with a near-field optical microscope," Physical Review Letters, Vol. 77, No. 27, 5332-5335, 1996.
14. Park, Q.-H., "Optical antennas and plasmonics," Contemporary Physics, Vol. 50, No. 2, 407-423, 2009.
15. Jiang, S.-F., F.-M. Kong, K. Li, and H. Gao, "Study of far-field directivity of optical dipole antenna," Acta Physica Sinica, Vol. 60, No. 4, 045203, 2011.
16. Degiron, A. and T. Ebbesen, "The role of localized surface plasmon modes in the enhanced transmission of periodic subwavelength apertures," Journal of Optics A: Pure and Applied Optics, Vol. 7, No. 2, S90, 2005.
17. MÄuhlschlegel, P., H.-J. Eisler, O. Martin, B. Hecht, and D. Pohl, "Resonant optical antennas," Science, Vol. 308, No. 5728, 1607-1609, 2005.
18. Taminiau, T. H., R. J. Moerland, F. B. Segerink, L. Kuipers, and N. F. van Hulst, , "λ/4 resonance of an optical monopole antenna probed by single molecule fluorescence," Nano Letters, Vol. 17, No. 1, 28-33, 2007.