We investigate the light transmission properties of double-overlapped annular apertures in a silver film with the three-dimensional finite-difference time-domain method. It has been found that the transmission peaks are attributed to the localized surface plasmon resonance (LSPR) of nanocavities and the surface plasmon polaritons (SPPs) of the nanoparticles. The peaks of the LSPR are blueshifted when the overlapping distance is increased. Moreover, a Fano-type resonance appears in the transmitted spectral response with an appropriate overlapping distance, which is elucidated as the hybridization results of the SPPs of the nanoparticles. The number and position of the Fano resonance can be tuned through varying the overlapping distance and other geometric parameters.
© 2011 Optical Society of America
Diffraction and Gratings
Original Manuscript: July 20, 2010
Revised Manuscript: December 15, 2010
Manuscript Accepted: December 24, 2010
Published: January 28, 2011
Hailong Liu, Na Wang, Yonghong Liu, Yantao Zhao, and Xijun Wu, "Light transmission properties of double-overlapped annular apertures," Opt. Lett. 36, 385-387 (2011)