Optically-controlled metamaterial absorber based on hybrid structure

Abstract

An optically-controlled metamaterial absorber based on a hybrid structure was investigated. Our hybrid absorber structure is a rectangular bar array with a period of 180μm, fabricated on a 25μm thick polyimide flexible substrate adhered to the surface of a high resistance silicon/polymer wafer. We varied the metamaterial structure and found that the length of the rectangular unit can modulate the resonant frequency, which was verified by experiments. The experimental results also show that the terahertz amplitude transmission spectra through the rectangular bar array decreased with increased laser power. As laser intensity surpassed 1.6W/cm2, the frequency-selected absorber changed to become a broad band absorber. These results indicate that alternative terahertz absorbers can be created using an optically-controlled metamaterial hybrid structure.