Sensing and switching capabilities of a tunable GST-based perfect absorber in near-infrared region

Abstract

In this paper a GST-based perfect absorber is investigated for sensing applications. The simulation results show the high sensitivity and figure of merit of 900 nm per refractive index unit (RIU) and 15 RIU−1, respectively. The sensing parameters are also studied for different biomedical applications such as detection of glucose in water, malaria infection, bacillus bacteria, and cancer cells. The phase change material GST makes the structure tunable and switchable by changing the phase through different annealing temperatures. By changing temperature, the optical characteristics of GST are altered and so the perfect absorption can be tuned at different near-infrared wavelengths. Moreover, the sweep between the amorphous and crystalline states of GST results in switching capability with the high extinction ratio of 13.97 dB at λ = 1724 nm. Therefore, the perfect tunable absorber supports our new idea of multi-application plasmonic devices with two capabilities of sensing and switching, simultaneously. Also, the E-field distributions and analytical method of equivalent circuit model are utilized to verify the simulation results and demonstrate a better insight of the proposed structure performance. The polarization independency of the proposed structure, tunability, good sensing and switching performances are some other benefits of our proposed structure, which can pave the way for development of new investigations about the phase change material applications in plasmonic studies.

Optically Reconfigurable Spherical Ge‐Sb‐Te Nanoparticles with Reversible Switching

“…[20] Only several works reported on an optically induced reversible switching of the GST-based structures. [21,22] In most of the experimental papers, GST alloys were employed as dielectric layers. [23,24] Recently, a metasurface of crystalline nanorods or NPs in an amorphous GST layer was published, [25,26,27] however to the best of our knowledge the reversible optical tuning of GST NPs in air has not been reported so far.…”

Electrically Tunable Perfect Terahertz Absorber Using Embedded Combline Graphene Layer

“…Working on the metamaterial regime due to exotic features with an exceptional conductivity leads to the creation of great high-tech achievements [1,2]. With the advent of the Surface Plasmon Resonance(SPR) phenomenon, the fabrication procedure of equipment based on terahertz technology is also revolutionized, especially manufacturing detectors and perfect absorbers [3,4]. The various wide range of absorbers as polarization insensitive/dependent absorbers [5,6], broad/narrowband absorbers [7][8][9], hyperbolic absorbers [10], plasmonic absorber [11,12], and van der Waals (vdW) absorbers [13,14] have been engineered from microwave [15], through terahertz [16], infrared [17], and also into the visible range [18].…”

Perfect Absorption and Refractive-Index Sensing by Metasurfaces Composed of Cross-Shaped Hole Arrays in Metal Substrate

“…Recently, there is increasing interesting in studying the perfect absorption of electromagnetic waves for refractive-index sensing by employing metasurfaces , metallic nanostructures , and graphene nanostructures [62][63][64][65][66][67][68][69][70][71], in violet [62], visible [1][2][3][4][5][33][34][35][36][37][38][39][40][41][42][43]63,64], infrared [6][7][8][9][10][11][12][13][14][15][16][17][44][45][46][47][48][49][50][51][52]…”

“…Recently, there is increasing interesting in studying the perfect absorption of electromagnetic waves for refractive-index sensing by employing metasurfaces [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 ], metallic nanostructures [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , …”

“…For metal nanostructures, the well-known surface plasmon resonances or the other resonance modes are able to result into the huge electromagnetic field enhancement, which can be also utilized for the perfect absorption and refractive-index sensing [ 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 ]. For example, Shi et al theoretically studied a multi-band perfect absorber for sensing application in visible and near-infrared regions, which is based on the excitations of localized surface plasmons, delocalized surface plasmon polaritons, and lattice plasmon resonances, in the periodic arrays of gold nanodisks with a prismatic hole standing on silica/gold bilayer films [ 36 ].…”