The tunable absorber films of grating structure of AlCuFe quasicrystal with high Q and refractive index sensitivity

Due to the continuous development of terahertz field and material science, terahertz absorbers have received extensive attention. The paper proposes a tunable absorber film of grating structure of AlCuFe quasicrystal. The absorber film composed of a AlCuFe quasicrystal grating structure and a gold substrate, making it easy to process. The absorber film has three perfect absorption bands in its working frequency band. When the polarization direction of the incident wave changes, it becomes perfect absorber film in a single band. Through the analysis of the relative impedance of the absorber film, the relative impedance of the absorber film in the absorption band is close to the impedance of the free space, which conforms to the classical theory. By analyzing its electric field, the absorber film absorbs the electromagnetic wave mainly by the guided film resonance and LSPR effect, and the absorber film has excellent tuning, high Q value and sensitivity of the absorber film. Among them, the highest Q value of the mode is 242, the refractive index sensitivity of each mode is more than 2700 and the highest reaches 4032. In general, the absorber film has great application prospects in fields such as biomedicine and communication science.