Plasmonic Nanosensor Based on Independently Tunable Multiple Fano Resonances

Abstract

A novel refractive index nanosensor with compound structures is proposed in this paper. It consists of three different kinds of resonators and two stubs which are side-coupled to a metal-dielectric-metal (MDM) waveguide. By utilizing numerical investigation with the finite element method (FEM), the simulation results show that the transmission spectrum of the nanosensor has as much as five sharp peaks of Fano resonance. Due to their different resonance mechanisms, each peak of resonances can be independently tuned by adjusting the corresponding parameters of the structure. In addition, the sensitivity of the nanosensor is up to , and it also has an excellent performance with a high group refractive index of . For the sake of different functions to practical applications, a legitimate combination of various different components, such as T-shaped, ring, and split-ring cavities, has been proposed to make the nanosensor dramatically reduce its dimensions without sacrificing performance. These designing concepts pave a new way to construct such compact on-chip plasmonic structures, and it can be widely applied to nanosensors, optical splitters, filters, optical switches, nonlinear photonic and slow-light devices.

Study of Fano resonance and its application in MIM waveguide using a k-shaped resonator

“…Because the sharp change between the transmission dip and peak of the spectra line of the proposed waveguide is most likely to produce an abrupt phase shift, which will lead to a change in the group index and a certain time delay. The group index is usually used to describe the slow light effect, which is de ned as follows [45] n…”

“…SPPs are able to break through the conventional optical diffraction limit and achieve local eld enhancement in the subwavelength range, resulting in miniaturization and high integration of optical devices [3][4]. Therefore, waveguide devices based on SPPs have attracted more extensive and in-depth research, for example, refractive index sensors [5][6][7], lters [8][9], optical logic devices [10], optical switches [11][12], Surface Plasmon Bragg Gratings [13], modulators [14], etc.…”

Plasmonic Demultiplexer With Tunable Output Power Ratio Based on Metal-Dielectric-Metal Structure and E7 Liquid Crystal Arrays

“…The resonance wavelength of the structure can be controlled at around 1310 nm, which is a convenient and traditional optical window. The dependence between the resonance wavelength and the size of the bar can be derived from Equations (9,10), and the details of which have been discussed in our previous work [30]. The distance between adjacent bars in the array is fixed at D = 100 nm, avoiding the adjacent bar interference while maintaining a compact size for integration.…”

Employment of Resonators for Resolution Enhancement in Plasmonic Refractive Index Sensors

“…The attractive feature of surface plasmon polarites (SPP), ie the restriction of light in nano-dimensions, has caused this phenomenon to be widely studied and this feature can be used to build many plasmonic structures such as filters [1], multiple optical instruments [2], absorbers [3], splitters [4] and sensors [5][6][7][8][9][10][11][12][13]. Also metal-insulated-metal plasmonic waveguide (MIM) due to its ability to limit light in a small area and its compatibility with electronic operating systems is widely used in the design of many plasmonic devices.…”