Wide-range tunable, dual-band, background refractive index insensitive terahertz absorber based on graphene and Dirac semimetal

In this study, we propose a dual-band wide-range tunable terahertz absorber based on graphene and bulk Dirac semimetal (BDS), which consists of a patterned BDS array, dielectric material, continuous graphene layer, and gold mirror. Simulation results show that the absorption at 3.97 and 7.94 THz achieve almost 100%. By changing the Fermi energy of graphene and BDS, the resonance frequency can be tuned between 3.97 and 9.28 THz. In addition, we found that when the background refractive index changes, the absorption is almost the same. This feature will broaden its applications. Finally, the influence of structural parameters and incident angles on device performance is discussed. The proposed absorber may have potential applications in photoelectric sensors and other optoelectronic devices. (C) 2021 Society of Photo-Optical Instrumentation Engineers (SPIE)

Automated summary

In this study, a dual-band wide-range tunable terahertz absorber based on graphene and bulk Dirac semimetal (BDS) is proposed, achieving high absorption rates at 3.97 and 7.94 THz. The resonance frequency can be tuned by changing the Fermi energy of graphene and BDS, and the absorption is insensitive to changes in background refractive index, showing potential applications in various optoelectronic devices.