A Polarization Insensitive Broadband Absorbing Metasurface Based on Phase Change Material

We present in this paper the design and simulation of a broadband terahertz (THz) metasurface (MS) absorber utilizing the phase changing feature of vanadium dioxide (VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>). The proposed design achieves a 2.41 THz absorption bandwidth, providing over 90% absorption efficiency in the range of 4.27 THz to 6.68 THz under the metallic state of VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>. On the contrary, VO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf> reverts to its insulating state under thermal control which leads to near complete reflection of the incoming wave. Owing to the balanced design, the absorber offers polarization insensitive absorption. The device under both transverse electric (TE) and transverse magnetic (TM) polarization shows consistent performance with oblique incidence angles up to 40°. The proposed absorber has potential application in various fields such as terahertz switching, modulating and many other futuristic 6G applications.