Ultrathin Bi‐Switchable Vanadium Dioxide‐Based Multifunctional Metamaterial for Terahertz Polarization Modulation

Abstract

A broadband multi‐functional bi‐switchable ultrathin optical metamaterial design is investigated, which can achieve a high polarization conversion efficiency over a wide band of frequencies in the terahertz (THz) regime. The proposed design switches from a linear and circular polarization converter (LPC/CPC) to an efficient absorber by using the phase change property of a functional material, vanadium dioxide (VO2). The proposed design shows switching from an absorber to a reflector using the mechanical configuration of the functional material, and therefore the design can be used as a bi‐switchable device. The first type of switching is accomplished by changing the conductivity of the functional material, while the second type of switching is achieved with the help of the mechanical configuration of the functional material. Moreover, the structure is responsive to wide incident angles. The proposed switchable design has the potential to contribute to the development of tunable polarization rotating devices and on/off switching LPC devices, which have wide applications in detection, sensing, and communications.

Ultra-broadband and thin switchable multifunctional metamaterial for terahertz wave

“…Switchable metamaterials based on phase transition materials have garnered significant interest from the scientific community due to their ability to give a programmable degree of freedom in light-matter interaction and information processing [12]. Up to this point, there has been significant utilization of phase change materials such as VO 2 [13][14][15], GST [16][17][18], and GeTe [19,20] in the pursuit of achieving bi-functional and multi-functional switchable metamaterials [21][22][23][24][25][26][27][28][29]. Among these materials, VO 2 exhibits thermal tunability and possesses an optical response spanning from the THz to visible spectrum regimes, which has been widely utilized as a switching component.…”