Ultrabroadband polarization-insensitive far-infrared metameterial absorber by gold nanowire array

In this paper, an ultra-broadband polarization-insensitive far-infrared metamterial absorber with gold nanowire is proposed. Unlike some traditional metamaterial absorbers consisting of multilayer structure, our design is made up of gold nanowire array which is much simpler. Height and permittivity constant gradient both contribute to the broadband absorption. Each single gold nanowire acts as a nano-resonator, an array of nanowires with different height and dielectric together realize ultrabroadband absorption. In addition, our design could be extended to any other frequency regimes, which indicates potential applications in infrared detection, imaging and so on.