Liquid Crystal Frequency Tunable Terahertz Metamaterial Absorber

Here, we theoretically and experimentally realize a terahertz (THz) perfect metamaterial absorber with an actively tunable frequency response. The structure is made of a complementary frequency selective surface (CFSS) and a metal backplane where the subwavelength space between them is filled with liquid crystal. By applying a voltage between CFSS and metal backplane a resonance frequency shifts about 4.5 GHz at 0.567 THz is obtained while the absorbance maintains at %90.