Wide-angle absorber with tunable intensity and bandwidth realized by a terahertz phase change material

A novel wideband absorber is proposed based on a square-shaped vanadium dioxide metamaterial at terahertz frequencies. Full-wave simulation shows that absorptance is greater than 90% in the range of 1.436-3.448 THz, and relative bandwidth ratio is 82.4% at the center frequency of 2.442 THz. With the increasing of the conductivity of VO2, absorption peak increases obviously enabling a large range of tunability from 3.4% to 100%. The thickness of the designed absorber is similar to lambda/7.9. Polarization independence and angular immunity of the designed absorber are systematically described by numerical results. Our design may find potential applications in switch and modulator.