The optical power flow around a plasmonic particle has been a topic of research interest over the years [see e.g., Am. J. Phys. 51, 323 (1983) ; Opt. Express 13, 8372 (2005) ]. Here we revisit this problem with an emphasis on higher-order resonances, and we present the theoretical results of our analysis for such power-flow distribution for plasmonic nanoparticles at their multipolar resonances. Results for the second and third orders of resonance show optical power-flow patterns that are significantly different from that of the first-order resonance inside and around plasmonic superdirective nanoparticles, with multicenter vortices, saddle points, and saddle lines and with an anomalous circulation of power resembling higher-order modes in a resonant cavity. A potential application of these optical flow patterns to trap or move a neighboring nanoparticle is also briefly suggested.
© 2007 Optical Society of America
Original Manuscript: March 19, 2007
Manuscript Accepted: May 15, 2007
Published: August 16, 2007
Andrea Alù and Nader Engheta, "Higher-order resonant power flow inside and around superdirective plasmonic nanoparticles," J. Opt. Soc. Am. B 24, A89-A97 (2007)