Design of triple-band metamaterial absorbers with refractive index sensitivity at infrared frequencies

Abstract

A triple-band perfect plasmonic metamaterial absorber based on a metal/insulator/metal (MIM) structure is designed. A new freedom through tuning the thicknesses of each ring structures is introduced to realize a quasi-three-dimensional perfect absorber at three extinction wavelengths by using the finite difference time domain method. The physical machine is explained by the time domain field analyses and the coupled mode theory. The characteristics of the absorber make our proposed strategy applicable for the design of more general multiband and broadband perfect absorbers. In addition, these perfect absorbing metamaterials are found to exhibit excellent performance in refractive index sensing.

Ultra-High Refractive Index Sensing Structure Based on a Metal-Insulator-Metal Waveguide-Coupled T-Shape Cavity with Metal Nanorod Defects

“…When RI and temperature increase from 1.0 to 1.1 and 0 °C to 20 °C, respectively, the maximum values of sensitivity can reach as high as 8028 nm/RIU and 3.30 nm/0 °C, respectively. To the best of our knowledge, the RI sensitivity of the proposed plasmonic MIM waveguide sensors is much higher compared with previously reported SPPs’ waveguide sensors [22,24,37,40,41,48,59,60,61,62,63,64].…”

“…Here, the plasmon resonance condition is corresponding to the T-shape cavity that is associated with the varied photonic density of states in the T-shape cavity, and hence changed the irradiative damping rate in the proposed structure [59,60]. It is worth noting that a higher transmittance dip ( T = 42.58%) at λ res = 2528 nm for mode 1 (see the dashed line in Figure 6) is reached when the diameter of the silver nanorod is equal to the width of the wider rectangular cavity, i.e., w 1 = 2 r 1 = 50 nm.…”

Metal-Insulator-Metal-Based Plasmonic Metamaterial Absorbers at Visible and Infrared Wavelengths: A Review

“…The strategies of multi-band and broadband absorption are classified into three groups: asymmetrically-shaped [ 47 , 52 , 85 , 86 , 87 , 88 , 89 ] or multi-size [ 42 , 65 , 66 , 90 , 91 , 92 , 93 , 94 ] micropatches, multi-layers of MIM structure [ 95 , 96 , 97 , 98 , 99 , 100 ], and embedded in dielectric materials [ 57 , 101 , 102 ]. The first two are based on multi-resonance that produces multi-mode absorption.…”

A wide-angle and TE/TM polarization-insensitive terahertz metamaterial near-perfect absorber based on a multi-layer plasmonic structure

“…Several methods have been proposed to achieve satisfactory absorption at multiple frequencies or broadband absorption in recent years, and common methods can be roughly grouped into three categories: (a) Use two or more metal resonators of different sizes or structures in the same plane [22][23][24][25] . (b) Use resonant structures made of different types of metals in the same plane 26 .…”