Tunable Plasmon-Induced-Transparency Effect in a Simple Planar Composite Structure

• Published in: Plasmonics (Norwell, Mass.) Vol. 16; no. 3; pp. 965 - 972
• Main Authors: Qi, Jianxia, Zhang, Yunguang, Wang, Yongkai, Cao, Zhanli, Han, Qingyan, Wang, Zhongyu, Wang, Boyang, Dong, Jun
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2021; Springer Nature B.V
• Subjects: Biochemistry; Biological and Medical Physics; Biophysics; Biotechnology; Chemistry; Chemistry and Materials Science; Composite structures; Coupling; Metamaterials; Multipoles; Nanorods; Nanotechnology; Plasmonics; Switches; Tunable filters; Plasmon-induced transparency; Plasmon resonance; Slow light
• ISSN: 1557-1955; 1557-1963
• DOI: 10.1007/s11468-020-01362-w

A planar metamaterial structure has been designed to obtain surface plasmon-induced-transparency (PIT) effect, which is composed of a nanodisk sandwiched between double rods. From theoretical perspective, the three-level plasmonic system has been utilized to analyze the near-field coupling mechanism. Besides, the simulation results show that PIT resonance can be tailored by structure parameters. Particularly, when the length of the rods is more than twice of the diameter of the disk, two PIT windows are generated simultaneously, based on the coupling between the bright mode of the nanodisk and two multipole dark modes of rods. Furthermore, a metamaterial structure, composed by a disk and two pairs of nanorods, is suggested to achieve the polarization-independent plasmon-induced-transparency effect. As a result, this work shows great application prospect in the area of compact optical devices, such as multiband tunable filters, plasmonic switches, and slow light devices.