We theoretically investigate the plasmon coupling in metallic nanorod dimers. A pronounced dip is found in the extinction spectrum due to plasmonic Fano resonance, which is induced by destructive interference between the bright dipole plasmon of a short nanorod and the dark quadrupole plasmon of a long nanorod. This Fano interference can also be explained as the coupling between the bright and dark modes both supported by the whole dimer. The Fano resonance can be tuned by adjusting the spatial or spectral separation between two nanorods in the dimer.
© 2011 Optical Society of America
Original Manuscript: January 31, 2011
Revised Manuscript: March 24, 2011
Manuscript Accepted: March 24, 2011
Published: April 20, 2011
Zhong-Jian Yang, Zong-Suo Zhang, Li-Hui Zhang, Qun-Qing Li, Zhong-Hua Hao, and Qu-Quan Wang, "Fano resonances in dipole-quadrupole plasmon coupling nanorod dimers," Opt. Lett. 36, 1542-1544 (2011)