A thin film broadband absorber based on multi-sized nanoantennas

We experimentally demonstrate an infrared broadband absorber based on an array of nanostrip antennas of several different sizes. The broadband property is due to the collective effect of magnetic responses excited by these nanoantennas at distinct wavelengths. By manipulating the differences of the nanostrip widths, the measured spectra clearly validate our design for the purpose of broadening the absorption band. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3672002]