Enhancing refractive index sensing capability with hybrid plasmonic–photonic absorbers

Abstract

A significantly enhanced refractive index sensor with a maximum figure of merit (FOM*) value of about 1337 has been demonstrated based on a hybrid plasmonic–photonic absorberviautilizing substantial absorption contrast between a perfect absorber (∼99% at normal incidence) and a non-perfect absorber when there are changes in the surrounding.

Improving Plasmon Sensing Performance by Exploiting the Spatially Confined Field

“…These sensing performance factors are also much larger than the conventional plasmonic sensing systems including the nanorods [27], nanoholes [36,37], and plasmonic-photonic crystalbased absorbers [22]. The PA-based sensor with ultra-high FOM* can present a potential for the application of ultrasensitive biosensing and particularly for the detection of weak signal in the complex surrounding [22,26,28]. Thereby, in comparison with the common sensor platform, the proposed sensing system provides a greatly improved performance for all the three factors (S, FOM, FOM*).…”

“…In addition, this sensing strategy offers great potential to maintain the performance of LSPR-based sensors even in nonlaboratory environments due to its simple and robust measurement scheme [26]. Based on this new strategy, several investigations have been demonstrated to improve the plasmon sensing performance by utilizing the metal-dielectricmetal (MDM) triple-layer PA systems [28,29] or the hybridized plasmonic-photonic crystals [22] to detect the molecular vibrational modes and RI environment. Although there are many applications for these PA-based sensors due to their advantages including the high FOM* resulted from the excellent relative spectral intensity changing before and after the detecting, the feasible way to further improve the sensing capability is still under study.…”

“…These binding nano-objects and the dielectric constant changing can be detected via the tracking of corresponding spectral shifts of the LSPR peak. Inspired by the possibilities that these plasmonic nanostructures offer to miniaturize and improve the sensitivity performance of the propagating surface plasmon resonancebased sensors [16], various conceptual refractometric LSPR sensing studies have been carried out by using nanorods [17], disks [18,19], or other nanoparticles [20][21][22] as the sensing platforms. These demonstrated sensors are with the ability to show high sensitivity (S=Δλ/RIU, Δλ is the wavelength shift and the RIU means the refractive index unit) due to the extremely enhanced local field around the metallic nanostructures.…”

Multi-Band High Refractive Index Susceptibility of Plasmonic Structures with Network-Type Metasurface

“…These remarkable features endow plasmonic structures an extreme sensitivity to the refractive index (RI) change of surrounding mediums with the penetration depth of the evanescent field [5,[8][9][10][11]. Based on the susceptibility to the change in RI of surrounding mediums due to the spectral shift caused by the excited surface plasmons [10][11][12], a promising technology has been developed for simple, label-free, cost-effective, and real-time optical sensing [8,[13][14][15]. So far, numerous sensors based on metallic nanostructures have been witnessed and widely employed for the detection of various analytes including cancer biomarkers, hazardous or toxic gases, DNA, and so on [15][16][17][18][19][20].…”

Plasmonic circular resonators for refractive index sensors and filters

“…This could lead to miniaturized photonic components with dimensions scale much smaller than those currently achieved [3,4], such as plasmonic waveguides [5][6][7][8] and plasmonic nanolasers [9,10]. Due to the susceptibility of SPs to surrounding dielectric, SPs and surface plasmon resonance (SPR) exhibit excellent properties for sensing applications [11][12][13]. In past decades, various plasmonic sensors based on SPs and SPR have been proposed and investigated [14][15][16][17][18][19][20][21][22][23][24], especially prism-coupled SPR sensors [14][15][16][17] and fiber-coupled SPR sensors [20][21][22][23][24].…”