Ultra-broadband and thin switchable multifunctional metamaterial for terahertz wave

Abstract

An ultra-broadband thin multi-functional and switchable optical metamaterial is examined in the terahertz (THz) regime. The proposed design achieved high polarization conversion efficiency and can be switched from a polarization converter to an absorber using the phase change transitioning of vanadium dioxide (VO2). The linear polarization conversion is achieved from 6.0 THz to 15.0 THz, achieving a bandwidth of 9.0 THz, and the absorption is realized from 5.0 THz to 16.0 THz with a bandwidth of 11.0 THz. These broadband characteristics were achieved by a simple metamaterial design incorporating a few layers. The relative bandwidth was 85% for the polarization conversion and 105% for the absorption. Moreover, the angular stability of the designed structure is impressive for various incident angles from 00 to 450. The proposed switchable design has the potential to contribute to the development of tunable polarization rotating devices, on/off switching LPC devices, which have wide application potentials in THz detection, sensing, and communications.