TE polarization broadband absorber based on stacked metal-dielectric grating structure

The broadband absorption effect of stacked metal-dielectric grating structures is studied. Two TE polarization broadband absorbers, which consisted of two or three pairs of vertically cascaded metal-dielectric grating structures, are designed and investigated. The absorbers exhibit near-unity absorbance at multiple adjacent wavelengths and high absorbance over a wide wavelength range. The electric field distributions at multiple adjacent resonant wavelengths are investigated, which can provide a qualitative understanding of such broadband absorption behavior. The mechanism of such broadband absorption effect is attributed to guided mode resonance in different dielectric spacer layers. It is believed that the results may provide useful guidance for the design of TE polarization broadband absorbers.