A novel approach to further decrease the thickness of ultrathin perfect metamaterial absorbers

This work presents a novel approach to further decrease the thickness of the ultra thin perfect metamaterial absorbers by adjusting the geometric dimensions of the resonators. Both simulational and experimental results with a typical metamaterial absorber structure show that the thickness of the absorber decreases from ~8 μm to ~4 μm by increasing the width of the cross-resonator from 10 μm to 40 μm. The results can be well explained with the interference theory which shows that the near-unity absorption is due to a destructive interference of the multiple reflections in the metamaterial absorber.