Dynamically tunable excellent absorber based on plasmon-induced absorption in black phosphorus nanoribbon

Abstract

The realization of plasmon-induced absorption (PIA) via local plasmon resonance coupling on the surface of two-dimensional metamaterials based on nanostructures heavily depends on the well-designed patterned antenna. However, due to the limitation of nanostructures’ size and the difficulty of material formation, it is challenging to achieve the expected performance of such a device. We propose and numerically simulate PIA in response to mid-infrared using two black phosphorus (BP) layers that are composed of upper double BP ribbons and lower single BP ribbons to avoid BP chips patterning. The theoretical transmission spectrum of the structure calculated by the coupled mode theory is in good agreement with the simulated curve. The resonant intensity of the reflection window is affected by interlayer spacing, and the resonant wavelength of the reflection window can be realized by dynamically varying carrier density. The absorption performance of the system can be enhanced not only by the gold mirror that is totally reflected at the bottom of the structure but also by the polarization angle of the incident wave. The designed system could be expected on various optical devices, including plasmonic sensors, dual-frequency absorbers, and switch controllers.