Single-band to multi-band perfect absorption in monolayer-graphene-based dielectric metasurfaces

Perfect absorption in graphene-based nanostructures has attracted much attention due to its potential applications in novel photodectors and light modulators with high integrability. Based on critical coupling theory, we propose a graphene-based dielectric metasurface, demonstrating graphene-assisted single-band to multi-band perfect absorption with independent band selectivity in the near-infrared range. The proposed graphene-metasurface absorber can support a delocalized guided mode resonance and a series of localized cavity modes with different order, which can be selectively excited at will by simply tuning the geometry of the system, thus realizing an independent control of single-band to multi-band perfect absorption at critical coupling condition. The proposed hybrid structure possesses simple structural configuration and is easily accessible by standard nano-fabrication technique. Our results may find potential applications in the design of novel photoelectronic devices such as graphene-based photodectors or light modulators with flexible multi-band selectivity for desired wavelength.