A comprehensive study of tunable properties of broadband terahertz absorber based on graphene-embedded random photonic crystals

In the current study, we have explored the broadband absorption characteristics of graphene-layered random photonic crystals by the 4 x 4 characteristic matrix method. The findings confirm that under the influence of magnetic field B, optimal semi-random photonic crystals are capable of providing broadband absorption with a value greater than 84% in the wavelength range of 74.8-85.57 mu m. The absorption band is tuned to desired frequencies by appropriate selection of the thickness of the silicon carbide layer. An absorption and FWHM enhancement with respect to the number of layers in each elementary unit, Fermi-level, and period number are numarically revealed. The application of a positive magnetic field minimises fluctuations and enhances the FWHM value in the desired absorption band for LCP waves, whereas the converse is true for RCP waves. The proposed absorber has applications in polarization selective absorbers, sensors and terahertz imaging.

Automated summary

This study investigates the broadband absorption characteristics of graphene-layered random photonic crystals using the 4 x 4 characteristic matrix method. The results show that under the influence of a magnetic field, optimal semi-random photonic crystals can achieve broadband absorption greater than 84% in the wavelength range of 74.8-85.57 μm. The absorption band can be tuned by selecting the thickness of the silicon carbide layer. Numerical analysis demonstrates the enhancement of absorption and FWHM with the number of layers, Fermi level, and period number. The proposed absorber has potential applications in polarization selective absorbers, sensors, and terahertz imaging.