MEMS switchable infrared metamaterial absorber

Abstract

We experimentally demonstrate a switchable metamaterial absorber for infrared spectral region using MEMS technology. In order to achieve active tunability; air gap is introduced as the part of dielectric spacer layer and is electrostatically actuated. As the air gap is decreased, the peak absorption wavelength will blue shift accordingly. The tuning range is approximately 700 nm for 300 nm air gap change. Complementary cross is used as the metamaterial unit cell pattern. Owing to the π/2 rotational symmetry of the metamaterial unit cell geometry and out of plane actuation direction of the metamaterial layer, the resultant absorption retains the polarization insensitive characteristics at different actuation states. Additionally high temperature stable materials such as, molybdenum and silicon-di-oxide are used as structural materials for potential use in rugged applications.