Infrared Plasmonic Refractive Index Sensor with Ultra-High Figure of Merit Based on the Optimized All-Metal Grating

Abstract

A perfect ultra-narrow band infrared metamaterial absorber based on the all-metal-grating structure is proposed. The absorber presents a perfect absorption efficiency of over 98% with an ultra-narrow bandwidth of 0.66 nm at normal incidence. This high efficient absorption is contributed to the surface plasmon resonance. Moreover, the surface plasmon resonance-induced strong surface electric field enhancement is favorable for application in biosensing system. When operated as a plasmonic refractive index sensor, the ultra-narrow band absorber has a wavelength sensitivity 2400 nm/RIU and an ultra-high figure of merit 3640, which are much better than those of most reported similar plasmonic sensors. Besides, we also comprehensively investigate the influences of structural parameters on the sensing properties. Due to the simplicity of its geometry structure and its easiness to be fabricated, the proposed high figure of merit and sensitivity sensor indicates a competitive candidate for applications in sensing or detecting fields.

Plasmonic Sensors Based on Funneling Light Through Nanophotonic Structures

“…Our objective is to couple incident light to SPR is aim to enhance both sensitivity and spectral resolution of plasmonic sensors and hence the FOM. In that sense, very narrow spectral resolutions are reported, being as low as 2.5 nm for thin metallic film nanostructures [15], and 0.66 nm for a metamaterial absorber based on an all-metal-grating structure [16]. When subwavelength high-aspect ratio slits are involved, light funnels through these narrow and deep apertures confining the electromagnetic wave within a restricted volume close to them [17][18][19].…”

Comprehension of peculiar local emission behavior of InGaAs quantum well by colocalized nanocharacterization combining cathodoluminescence and electron microscopy techniques

“…The spectrum is well fitted with a double Gaussian profile. 19 The highest and smallest energy peaks were attributed to free-exciton (FE) transition and to localized exciton (LE) transition, respectively, which exhibit a slightly lower energy due to potential modulation. A study of InGaAs/InAlAs single QW (Ref.…”

“…A study of InGaAs/InAlAs single QW (Ref. 19) has highlighted that a decrease in QW thickness induces FE and LE FWHM increases. This effect is due to a larger spread of carrier wave function, which leads to higher sensibility to interface and composition fluctuations.…”

Numerical Investigation on Multiple Resonant Modes of Double-Layer Plasmonic Grooves for Sensing Application

“…Currently, most research involving groove sensors has concentrated on the near-infrared region. However, very few studies have been achieved on the visible region [25][26][27][28]. In addition, the resonant mode of a single-layer groove sensor possesses a relatively wide full wave at half maximum (FWHM), resulting in a low figure of merit (FOM) in the sensing detection and limiting its sensing application to some extent [29][30][31][32][33][34][35][36].…”