Ultranarrow Band Absorbers Based on Surface Lattice Resonances in Nanostructured Metal Surfaces

Abstract

Nanostructured metals have received a significant amount of attention in recent years due to their exciting plasmonic and photonic properties enabling strong field localization, light concentration, and strong absorption and scattering at their resonance frequencies. Resonant plasmonic and metamaterial absorbers are of particular interest for applications in a wide variety of technologies including photothermal therapy, thermophotovoltaics, heat-assisted magnetic recording, hot-electron collection, and biosensing. However, it is rather challenging to realize ultranarrow absorption bands using plasmonic materials due to large optical losses in metals that decrease the quality factor of optical resonators. Here, we theoretically and experimentally demonstrate an ultranarrow band absorber based on the surface lattice resonances (SLRs) in periodic nanowire and nanoring arrays on optically thick, reflecting metallic films. In experiments, we observed ultranarrow band resonant absorption peaks with a bandwidth of 12 nm and absorption amplitude exceeding 90% at visible frequencies. We demonstrate that the resonance absorption wavelength, amplitude of the absorption peak, and the bandwidth can be controlled by tuning the periodicity and the thickness of nanoring and nanowire arrays. Unlike conventional plasmonic absorbers utilizing common metal–insulator–metal stacks, our narrow band absorber consists solely of metals, facilitating stronger optical interaction between the SLR of periodic nanostructures and the highly reflective film. Moreover, by introducing asymmetry to the nanoring/nanowire hybrid system, we observe the spectral evolution of resonance splitting enabled by strong coupling between two individual SLRs arising from nanoring and nanowire arrays. Designing such all-metallic nanostructure arrays is a promising route for achieving ultranarrow band absorbers which can be used as absorption filters, narrow band thermal emitters in thermophotovoltaics, and plasmonic biosensors.

Large-Area, Lithography-Free Super Absorbers and Color Filters at Visible Frequencies Using Ultrathin Metallic Films

“…[13] More recently, several studies demonstrated strong resonant/absorptive characteristics from double-layer thin-film coatings [14,15] or metalinsulator-metal triple-layer [16,17] or multilayer [18,19] coatings in microwave, infrared (IR) spectrum and beyond. Particularly, in a recent work [14] [2,4,[20][21][22] spectral characteristics.…”

Color display and encryption with a plasmonic polarizing metamirror

“…As a result, such PSG color filter possesses a conspicuous spectral sensitivity to changes in the ambient environment [6,37,38]. We demonstrated this by fabricating three PSGs with the same period of 300 nm and coating these samples with different dielectric layers with a thickness of 35 nm as shown in Figure 5A.…”

“…The collective oscillation of free electrons and photons at the interfaces of metal and dielectric materials are called surface plasmons [1,2], which have attracted tremendous attention and provided a platform to investigate a great deal of novel physical properties such as perfect absorption [3][4][5][6], subdiffraction focusing [7][8][9][10], and negative refraction [11][12][13]. Among the plentiful research subjects in the big family of plasmonic metamaterials, one of the intensively investigated topics in recent decades is the design of color filters [14][15][16][17][18][19][20][21][22][23][24][25], where a specific color is observed if the scattered light of a particular wavelength range comes into our eyes when an object is illuminated with white light.…”

Quantification of Multiple Molecular Fingerprints by Dual‐Resonant Perfect Absorber

“…[1][2][3][4][5][6][7] Their performance relies on an impedance matching, i.e., they support both electric and magnetic resonances, which are tuned to match their impedance ( / Z μ ε = ) to that of the surrounding medium. [1][2][3][4][5][6][7] Their performance relies on an impedance matching, i.e., they support both electric and magnetic resonances, which are tuned to match their impedance ( / Z μ ε = ) to that of the surrounding medium.…”