A polarization-independent wide-angle dual directional absorption metamaterial absorber

In this paper, a polarization-independent wide-angle planar metamaterial absorber exhibiting dual directional absorption is proposed. Measurement results indicate that the planar metamaterial absorber achieves absorptivities of 86.87% and 91.48% to the normally incident electromagnetic waves propagating in forward (+z) and backward (-z) directions, respectively. Due to geometry's fourfold rotational symmetry, the absorber is polarization-independent. Additionally, the absorber works well for a wide range of incident angles for both transverse electric and transverse magnetic polarizations. Besides its impressing performance, this planar metamaterial absorber is also extremely thin that it's thickness is approximately 1/32 of the working wavelength.