Ultra-broadband metamaterial absorber from visible to long-wave infrared

Abstract

Metallic resonators separated by dielectric films with vertically stacked configurations is a common way to achieve broadband absorption. Here, we theoretically propose an ultra-broadband metamaterial absorber, which consists of an array of nanowire coated with multiple layers of alternating Ti and ZnS nanorings. The average absorption is calculated to be 98.8% in the spectral range of 0.4 to 17 μm. The performance of the proposed absorber is robust against a large change of both the incident and polarization angles. The proposed absorber may find potential applications in photovoltaics, photodetectors and manipulation of mechanical resonances.