Metamaterial Electromagnetic Wave Absorbers (Adv. Mater. 23/2012)

The image shows a dual-band metamaterial perfect absorber. The structure, described on page OP98 by W. J. Padilla and co-workers, is made of a checkerboard pattern of two gold crosses on a ground plane separated by a dielectric. The crosses of different sizes resonate at two frequencies, causing an impedance match condition and hence unity absorption at those frequencies. In this rendering, the incoming light (white) and the reflected white (red) are seen where green and blue light have been absorbed.