Design and characterization of metamaterial-based dual band absorber for infrared applications

This work discusses a metamaterial based dual band absorber operating at mid infrared regime. The design is composed of periodic resonant pattern that mainly utilizes U-shaped and cut wire resonators as a building block for the single unit cell. The simulated results are obtained using the full electromagnetic wave simulation package CST MWS. The absorber is designed to possess two distinct absorption bands centered at 9.57 and 4 mu m. The two bands are well separated with a first to second band ratio of 2.39. The sub-wavelength period size is measured to be 0.19 and 0.45 lambda with respect to the first and second bands respectively. High absorption is also observed for wide range of incident angles. Samples of this design were fabricated and tested. The measured response shows two absorption peaks with better than 80 % absorption for both peaks.