convertible perfect absorber with single ring resonator: tunable single band/dual-band visible

This study proposes a single and dual-band tunable and convertible perfect absorber in the infrared band, consisting of a dielectric layer and a metallic bottom film. primarily a tunable single-frequency absorber in the infrared region had been introduced. subsequently, with the change in geometric structure, the proposed structure can be converted from infrared single-band to visible double-band frequency. the numerical simulation results indicate that the absorption spectrum of the single-band resonator is tuned from 337.4 thz to 210.2 thz, 227.3 thz, and 297.7 thz by changing effective parameters: ring width, ring height, and dielectric height. next, by the parametric study of the proposed absorber dimensions, the absorption rate is obtained 99% more at the designed frequencies; lastly, the dual-band absorption with an average performance of 99.98% in the visible spectrum. the proposed plasmonic absorber in this research has a variety of applications, including sensing, imaging, wavelength-selective thermal emission, photodetectors, and so on.