  We experimentally demonstrate an infrared broadband absorber for TM polarized
light 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 nano-antennas 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. The present broadband
absorber works very well in a wide angular range.
