Impact of truncation on absorption spectra in graphene-based random photonic crystal

Abstract

The present study investigates the influence of randomness on getting multi-mode broadband and narrowband absorption of graphene-embedded photonic structures. In the first proposed photonic configuration, with the change in randomness parameter, it is possible to get single, multi-mode broadband absorption up to 0.8. This value was further enhanced up to 0.99 by varying the Fermi-level to −0.9 eV. The position of absorption peaks can be tuned by varying thickness of the silicon carbide layer. Further, an investigation is carried out on the influence of adding a defective periodic PC to the first photonic configuration, which provided a multi-mode narrowband absorption with a value up to 0.99 and the strength and location of absorption peaks can be altered to the desired value by changing the graphene’s Fermi level and thickness of the silicon carbide layer. Finally, the authors also survey the influence of magnetic field B on the absorption behaviour of LCP and RCP waves. The results indicate that the FWHM of absorption peaks expanded with applying a positive magnetic field for LCP waves, whereas it shrinks for RCP waves. It has applications in the design of tunable broadband, narrowband absorbers, and sensors.