Design and analysis of nanostructured subwavelength metamaterial absorber operating in the UV and visible spectral range

The design of broadband metamaterial perfect absorber (MPA) is proposed that operates in the ultraviolet and the visible regions of the electromagnetic spectrum. The MPA structure is of nanoscale in size and comprised of three layers – the U-shaped resonators (made of gold) of subwavelength size are embedded over a nanolayer of dielectric medium (silica glass), which is backed by a copper nanolayer surface. It is found that the proposed structure yields absorption peaks with the absorptivity over 99% in the aforesaid spectral range corresponding to both the transverse electric and the transverse magnetic polarizations of the incident electromagnetic wave. Furthermore, the angular dependence (of the incident light) of absorption characteristics is also analyzed along with the behavior of the absorber under varying thickness of nanosized resonators. It is expected that the proposed kind of perfect absorber would be highly useful in integrated heat-absorbing mediums that would include sensors, integrated photodetectors, thermal imaging, solar cells, etc.