Selective-mode optical nanofilters based on plasmonic complementary split-ring resonators

Abstract

A nanoplasmonic optical filtering technique based on a complementary split-ring resonator structure is proposed. The basic and modal properties of the square-nanoring are studied using the group theory. Degeneracy and non-degeneracy of the possible TM odd- and even-modes are characterized based on the symmetry elements of the ring structure. Distinctively, the proposed technique allows selecting and exciting the proper plasmonic modes of the nanoring in the side-coupled arrangement. It is found that the non-integer modes can be excited due to the presence of a metallic nano-wall. These modes are highly sensitive to the nano-wall dimensions, in contrast to the regular integer modes. Moreover, the transmission-line theory is used to derive the resonance condition of the modes. The results show the optical transmission spectrum of the investigated filter can be efficiently modified and tuned either by manipulation of the position or by variation of the width of the employed nano-wall inside the ring. The numerical results support the theoretical analysis.

Plasmon-induced transparency effect in a single circular split-ring core ring resonator side-coupled to a metal-isolator-metal waveguide

“…Till now, some circuit models have been successfully proposed to describe the resonance behavior of split-ring resonator (SRR), 34-36 the dark eigenmodes in terahertz metamaterials were studied by Chowdhury et al 37 Also, based on microwave concepts, transmission line models have been successfully used to describe the resonance behavior of MIM structures. 30,38,39 Here, in this section, considering the symmetry properties of the CSRCRR, a circuit model is adopted. But before that it is quite important to discuss why the two resonant modes, TM 2 and TM 2.5 , exist in the CSRCRR first.…”

Dynamically Tunable by Kerr Effect Multichannel Filter Based on Plasmon Induced Transparencies at Optical Communication Range

“…Among various SPPs structures, the metal-dielectric-metal (MDM) configuration has attracted great interest because the devices have a small footprint and are a benefit for chip-integrated. Many nanoscale SPP-based photonic devices such as band-pass [3][4][5][6][7][8][9][10] and band-stop [11][12][13][14][15] filters, (de)multiplexers [16], MachZehnder interferometers [17], switchings [18], sensors [19], and logic grates [20] have been investigated both numerically and experimentally. As one of the most prevalent devices in optical circuits, plasmonic filters based on plasmon-induced transparencies (PITs) which are strong destructive interferences coupling between wideband bright modes and narrowband dark modes have been studied widely [8,21].…”

Nanoscale devices based on plasmonic coaxial waveguide resonators

“…Despite the inherent ohmic loss associated with plasmonic waveguides, there is a great interest in this area, because the degree of achievable compactness in plasmonic-based nano-circuits is superior when compared to other technologies, such as silicon-based miniaturized circuits 3,4 . Two-dimensional (2-D) plasmonic metal-dielectric-metal (MDM) waveguides have been demonstrated both theoretically 5 and experimentally, and different optical components such as bends, splitters 6 , Y-combiners 7 , optical interferometers 8 , couplers 9 , and ring resonators 10 have been designed based on the MDM configuration. However, for practical purposes, realistic three-dimensional (3-D) structures have to be considered.…”