Plasmonic wideband and tunable absorber based on semi etalon nano structure in the visible region

Abstract

In this study, a plasmonic meta-surface absorber by semi-etalon structure is introduced due to the importance of wideband absorbers in the visible region as solar absorber. For this purpose, soft nanolithography method was adopted to construct semi-etalon absorber based on poly-dimethyl-siloxane flexible membrane and gold grating structure onto its top and down side. In parallel, the structure was simulated by the aid of finite difference time domain method, and obtained good agreement between the measured and simulated results. The results indicated the etalon-based absorber achieved light absorption from 500 to 700 nm compared to one face gold grating which works in the wavelength range 500 to 600 nm with half of absorbed power. In addition, color production was evaluated via the proposed structure, and tunable colors were produced by changing the polarization and incidence angle. Thus, the proposed structure as a good wide-band absorber, and can be used for producing tunable colors under different polarization and incidence angles. The absorber can offer new insight in larger area solar absorber based on soft nano-lithography method because of the low cost and flexibility.