Nanoblocks embedded in L-shaped nanocavity of a plasmonic sensor for best sensor performance

Abstract

In this work, we proposed a highly sensitive design of a plasmonic sensor which is formed by embedding a periodic array of nanoblocks in L-shaped cavity formed by the metal–insulator–metal waveguide. The nanoblocks are placed in the strong electric field confinement region to further enhance its strength by confining it to a small area. To validate the study, the spectral characteristics of the proposed sensor design is compared to the spectral characteristics of a standard design having the same geometric parameters excluding nanoblocks in the cavity. The study shows that the incorporation of 5 nanoblocks of length 25 nm in the cavity can provide best performance indicators in the form of sensitivity, figure of merit and Q-factor. The sensitivity, figure of merit and Q-factor of the proposed sensor design is 1065 nm/RIU, 251.17 and 343.4 which is significantly higher than the standard L-shape resonator design. The sensor design can be developed with a single fabrication step. Due to the ease of fabrication and the highly responsive nature of the design, it can be used in biomedical applications.

Metal-Insulator-Metal Waveguide-Based Racetrack Integrated Circular Cavity for Refractive Index Sensing Application

“…There are two kinds of wavelength shifts known as redshift and blueshift which can be observed depending on the change (positive or negative) in the RI of the surrounding medium. From other studies [15,27], we learned that by narrowing down the path of the SPP wave by embedding the nano-blocks or nano-walls, the intensity of the SPP wave can be intensified. This leads to the higher light-matter interaction, eventually leading to a higher sensitivity.…”

“…Recently, two upto-date review papers on MIM WG-based plasmonic devices have been published and may be consulted for more detailed information (see [25,26]). The researchers anticipated highly attractive sensor designs with unique cavity designs [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42][43]. The FOM presented in some reports is very high.…”

Metal-Insulator-Metal Waveguide-Based Racetrack Integrated Circular Cavity for Refractive Index Sensing Application

“…There are two kinds of wavelength shifts known as redshift and blueshift which can be observed depending on the change (positive or negative) in the RI of the surrounding medium. From [27,15], we have learnt that by narrowing down the path of the SPP wave by embedding the nano-blocks or nano-walls, the intensity of the SPP wave can be intensified. This leads to the higher light-matter interaction, eventually leading to a higher sensitivity.…”

A Numerical Investigation of a Plasmonic Sensor Based on a Metal-Insulator-Metal Waveguide for Simultaneous Detection of Biological Analytes and Ambient Temperature

“…Such waveguides are plasmonic structures of a simple design, with two metal claddings surrounding an insulator, able to confine SPP mode at the subwavelength level. So far, numerous optical devices developed with this waveguide configuration have been widely investigated, for applica-tions such as biosensensing [6][7][8], temperature sensing [9,10], optical signal switching [11], demultiplexing [12], splitting [5], and filtering [13].…”

“…Nanomaterials 2021, 11, x FOR PEER REVIEW 2 of 15 with this waveguide configuration have been widely investigated, for applications such as biosensensing [6][7][8], temperature sensing [9,10], optical signal switching [11], demultiplexing [12], splitting [5], and filtering [13]. Plasmonic sensors are extremely attractive and in great demand owing to their small footprint and high sensing capabilities as compared with sensors based on other platforms such as silicon photonics or optical fiber [1,14].…”