Polarization-Induced Tunability of Plasmonic Light Absorption in Arrays of Sub-Wavelength Elliptical Disks

Abstract

Polarization-independent plasmonic light absorbers have been widely investigated in the past decades. Nevertheless, the feasibility for artificial manipulation of the optical properties by controlling the polarization state is desirable for numerous applications including the coloring, displaying, filtering, etc. Here, we present a straightforward method to achieve tunable multiple narrowband light absorption by using the polarization-dependent plasmonic cavity resonances in a common metal-dielectric-metal structure consisting of an elliptical disk array. Multiple light absorption bands with the maximal absorption of 98 % are achieved. Moreover, by controlling the illumination polarization state, artificial spectral modulation depth of these light absorption bands can be up to 90 % based on this structure platform. In addition, since this multispectral polarization-manipulated absorber is realized in such a common sub-wavelength plasmonic structure, it will open up a simple and universal approach for multispectral nanophotonic devices including the high-compact polychromatic color filtering, imaging, and detecting.