Abstract
Using the electrostatic approximation, we analyze electromagnetic fields scattered by sharp conical metal tips, which are illuminated with light polarized along the tip axis. We establish scaling relations for the scattered field amplitude and phase, and verify the validity with numerical simulations. Analytic expressions for the wavelength at which the scattered field near the tip changes its direction and for the field decay near the tip extremity are obtained, relating these characteristics to the cone angle and metal permittivity. The results obtained have important implications for various tip-enhanced phenomena, ranging from Raman and scattering near-field imaging to photoemission spectroscopy and nano-optical trapping.
© 2014 Optical Society of America
Full Article | PDF ArticleMore Like This
Salvatore Tuccio, Luca Razzari, Alessandro Alabastri, Andrea Toma, Carlo Liberale, Francesco De Angelis, Patrizio Candeloro, Gobind Das, Andrea Giugni, Enzo Di Fabrizio, and Remo Proietti Zaccaria
Opt. Lett. 39(3) 571-573 (2014)
Izcoatl Saucedo-Orozco, Guadalupe López-Morales, and R. Espinosa-Luna
Opt. Lett. 39(18) 5341-5344 (2014)
Wei Bao, Matteo Staffaroni, Jeffrey Bokor, Miquel B. Salmeron, Eli Yablonovitch, Stefano Cabrini, Alexander Weber-Bargioni, and P. James Schuck
Opt. Express 21(7) 8166-8176 (2013)