Switchable multifunctional terahertz metasurfaces employing vanadium dioxide

• Published in: Scientific reports Vol. 9; no. 1; p. 5454
• Main Authors: Li, Xike, Tang, Shiwei, Ding, Fei, Zhong, Shuomin, Yang, Yuanqing, Jiang, Tao, Zhou, Jun
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-04-2019; Nature Publishing Group
• Subjects: 639/624/399/1015; 639/624/400/561; Design; Humanities and Social Sciences; multidisciplinary; Polarization; Science; Science (multidisciplinary); Vanadium
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-019-41915-6

In this paper, we design a type of switchable metasurfaces by employing vanadium dioxide (VO
2
), which possess tunable and diversified functionalities in the terahertz (THz) frequencies. The properly designed homogeneous metasurface can be dynamically tuned from a broadband absorber to a reflecting surface due to the insulator-to-metal transition of VO
2
. When VO
2
is in its insulating state, the metasurface can efficiently absorb the normally incident THz wave in the frequency range of 0.535–1.3 THz with the average absorption of ~97.2%. Once the VO
2
is heated up and switched to its fully metallic state, the designed metasurface exhibits broadband and efficient reflection (>80%) in the frequency range from 0.5 to 1.3 THz. Capitalizing on such meta-atom design, we further extend the functionalities by introducing phase-gradients when VO
2
is in its fully metallic state and consequently achieve polarization-insensitive beam-steering and polarization-splitting, while maintaining broadband absorption when VO
2
is in insulating state.