Switchable and Tunable Terahertz Metamaterial Absorber with Ultra-Broadband and Multi-Band Response for Cancer Detection
Yadgar I. Abdulkarim
Abstract
This paper proposes a switchable and tunable terahertz metamaterial absorber utilizing a graphene-VO2 layered structure. The design employs reconfigurable seven-layer architecture from top to bottom as (topaz/VO2/topaz/Si/graphene/topaz/Au). CST software 2018 was used to simulate the absorption properties of terahertz waves (0–14 THz). The proposed metamaterial exhibits dual functionalities depending on the VO2 phase state. In the insulating state, the design achieves a tri-band response with distinct peaks at 3.12 THz, 5.65 THz, and 7.24 THz. Conversely, the VO2’s conducting state enables ultra-broadband absorption from 2.52 THz to 11.62 THz. Extensive simulations were conducted to demonstrate the tunability of absorption: Simulated absorption spectra were obtained for broadband and multi-band states. Electric field distributions were analyzed at resonance frequencies for both conducting and insulating states. The impact was studied of VO2 conductivity, loss tangent, and graphene’s chemical potential on absorption. The influence was investigated of topaz layer thickness on the absorption spectrum. Absorption behavior was examined of VO2 under different states and layer configurations. Variations were analyzed of absorption spectra with frequency, polarization angle, and incident angle. The proposed design used for the detection of cervical and breast cancer detection and the sensitivity is about is 0.2489 THz/RIU. The proposed design holds significant promise for real-world applications due to its reconfigurability. This tunability allows for tailoring absorption properties across a broad terahertz range, making it suitable for advanced devices like filters, modulators, and perfect absorbers.