Active control of narrowband total absorption based on terahertz hybrid Dirac semimetal-graphene metamaterials

A narrowband total absorber consists of a single layer of graphene, photoactive silicon and bulk Dirac semimetal and has been studied in three different ways for light absorption control without changing the geometry of the structure. Numerical simulation results show that the total absorption is achieved in the narrow spectral range by the critical coupling achieved by the guided resonance, and the results are in good agreement with the coupled mode theory. Interestingly, this device exhibits exceptional polarization insensitivity and excellent absorption stability over a range of incident angles. In addition, the extremely remarkable sensing performance is more conducive to the application of bio-chemical sensors. In this article, we propose that this work achieves a significant enhancement of the interaction of light and matter in single-layer graphene without graphene plasmon response. This simple and easily fabricated narrowband total absorption structure has outstanding potential applications in the design of modulators, filters and photodetectors.