Multiband selective absorbers made of 1D periodic Ag/SiO<sub>2</sub>/Ag core/shell coaxial cylinders horizontally lying on a planar substrate.In this paper, we present a one-dimensional periodic microstructure for multiband selective absorbers of thermal radiation.  Furthermore, the effects of a silver core radius, spacer shell thickness, a confocal elliptical core/shell cylinder on the property of multiband absorption, and the absorptivity of the structure with one core/four shells coaxial cylinders were explored.
THERM
The spectral-directional absorptivity of the proposed structure was numerically investigated with the finite element based Comsol Multiphysics software. 
Comsol Multiphysics