A THz Tuned Plasmonic Material Absorber in Visible Light Spectrum for Low Power Devices

In this paper, a tuned plasmonic material absorber consisting of a novel resonator structure is presented. The proposed unit cell ultra-thin 85 nm structure provides absorption of more than 90% in the entire visible light spectrum (450 – 750 THz). This plasmonic material absorbs electromagnetic (EM) waves due to electric and magnetic resonances achieved by the metal-insulator-metal layer. The proposed absorber is constituted on a SiO
2
dielectric substrate of 55 nm thickness and a metal (Chromium) of 15 nm thickness on top and bottom layers. The stronger energy concentration due to plasmonic resonance provides higher absorbing efficiency. By this, a THz unit-cell absorber in the visible light spectrum as an energy harvester for low-power devices is proposed.