Triple-band metamaterial perfect absorber for refractive index sensing in THz frequency

Abstract

A triple-band metamaterial perfect absorber (MPA) is founded of monolayer graphene in THz region which is adjustable and polarization-independent is presented. The first layer of the structure from top contains of a graphene ring at the center of structure with four graphene wheel-shaped around it and four graphene triangles in the corner. This proposed structure has caused us to achieve 98.64%, 99.97% and 99.98% perfect absorptions peaks at 8.17 THz, 9.74 THz and 11.95 THz, respectively. We can vary the absorption peak frequencies to our desirable frequencies by changing the Fermi level of graphene. By tunining the incident angle waves up to 60 degrees, the frequency peaks and the value of absorption change slightly. Moreover, very significant matter about suggested absorber structure design is that it is polarization independent so by tuning the polarization angle, the frequency peaks and the value of absorption remain unchanged. These aspects make the suggested absorber proper for applications such as imaging, detecting, filtering and sensing. We have investigated the application of the MPA in the sensing of refractive index. The refractive index of the unknown material can be measured through shifts of frequency peaks. Based on the obtained results, it seems that the metamaterial perfect absorber is a good candidate for biosensors application.

A Review: Active Tunable Terahertz Metamaterials

“…The absorber produces two wide‐band absorptions for different graphene Fermi levels: 0.1–3.1 THz and 6.25–8.55 THz. In 2023, Bahareh et al designed a tunable polarimetric independent triband absorber [ 114 ] consisting of patterned graphene in the first layer of the unit structure, containing a graphene ring in the center of the frame surrounded by four graphene wheels and four triangular graphene in the corners. The absorber achieves 98.64%, 99.97%, and 99.98% perfect absorption peaks at 8.17, 9.74 and 11.95 THz, respectively, as shown in Figure 20i.…”

“…Absorber cell structure designed by Bahareh et al Reproduced with permission. [ 114 ] Copyright 2023, Nature Springer.…”

A Polarization-Insensitive, Vanadium Dioxide-Based Dynamically Tunable Multiband Terahertz Metamaterial Absorber

“…Recent research has explored the integration of phase change materials (PCMs) [22,23], such as liquid crystal [24,25], graphene [26][27][28][29], and vanadium dioxide (VO 2 ), with MMAs to exploit their active tunability [30][31][32][33][34]. VO 2 holds significant prominence as a widely used PCM due to its unique properties.…”