We demonstrate theoretically an analog of electromagnetically induced transparency (EIT) in the plasmonic metamaterial with the unit cell consisting of three parallel metallic rods. The electromagnetic mechanism for the EIT-like transmission is discussed based on our investigation of the localized surface plasmon resonances in three trirod configurations. We find that the transmission minima surrounding the transparency window on both sides correspond to two detuned magnetic resonances, which arise respectively from the antiphase plasmon couplings between a long rod and a short rod and between two short rods. A decrease of more than 10 times in the group velocity can be achieved for the trirod structure at the transparency window in the optical regime, and the EIT-like response can be well described by the theoretical model of two harmonic oscillators. This work not only reveals the EIT-like transmission in plasmonic metamaterial consisting of detuned magnetic “atoms,” but also provides further insight into the plasmons’ interactions, especially for metallic nanostructures comprising multiple metallic elements.
© 2012 Optical Society of America
Original Manuscript: October 10, 2011
Revised Manuscript: December 26, 2011
Manuscript Accepted: December 30, 2011
Published: April 11, 2012
Pei Ding, Chunzhen Fan, Yongguang Cheng, Erjun Liang, and Qianzhong Xue, "Plasmon-induced transparency by detuned magnetic atoms in trirod metamaterials," Appl. Opt. 51, 1879-1885 (2012)