Perfect Dual-Band Absorber Based on Plasmonic Effect with the Cross-Hair/Nanorod Combination

Abstract

Plasmonic effect using a cross-hair can convey strongly localized surface plasmon modes among the separated composite nanostructures. Compared to its counterpart without the cross-hair, this characteristic has the remarkable merit of enhancing absorptance at resonance and can make the structure carry out a dual-band plasmonic perfect absorber (PPA). In this paper, we propose and design a novel dual-band PPA with a gathering of four metal-shell nanorods using a cross-hair operating at visible and near-infrared regions. Two absorptance peaks at 1050 nm and 750 nm with maximal absorptance of 99.59% and 99.89% for modes 1 and 2, respectively, are detected. High sensitivity of 1200 nm refractive unit (1/RIU), figure of merit of 26.67 and Q factor of 23.33 are acquired, which are very remarkable compared with the other PPAs. In addition, the absorptance in mode 1 is about nine times compared to its counterpart without the cross-hair. The proposed structure gives a novel inspiration for the design of a tunable dual-band PPA, which can be exploited for plasmonic sensor and other nanophotonic devices.

A Nanosensor Based on a Metal-Insulator-Metal Bus Waveguide with a Stub Coupled with a Racetrack Ring Resonator

“…Therefore, we adopted the Debye-Drude model: the dielectric constant of the medium is a parameter related to frequency. To express this frequency dependence of the medium, the most commonly used model is the Debye model [33][34][35]. Simulation is a good method to study and optimize SPP structures due to their size.…”

Ultrawide Bandgap and High Sensitivity of a Plasmonic Metal-Insulator-Metal Waveguide Filter with Cavity and Baffles

“…Recently, cavity resonance formed in MIM waveguides to obtain wavelength filtering and refractive index sensing functions has been investigated by theoretical estimations and experimental verifications [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 ]. Several resonance modes can be excited in the straight waveguide coupled with the resonance cavity under SPPs conditions, which are highly sensitive to the refractive index’s variation and the cavity’s shape [ 38 , 39 , 40 , 41 , 42 , 43 ].…”

Polarization-Insensitive Hybrid Plasmonic Waveguide Design for Evanescent Field Absorption Gas Sensor

“…Optical sensors have several applications in various fields, such as medicine, chemistry, biology, health, and safety requiring compact, reliable, and yet cost-effective optical devices [1][2][3][4]. Due to the high accuracy, the sensitivity of recognition, and detection of chemical products, optical gas sensors have been extensively investigated in the field of chemistry [5][6][7].…”