Open AccessActive terahertz spin Hall effect in vanadium dioxide metasurfaces
Author(s) -
Lei Kang,
Yuhao Wu,
Douglas H. Werner
Publication year - 2021
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.421283
Subject(s) - terahertz radiation , microwave , polarization (electrochemistry) , materials science , optoelectronics , resonator , optics , electromagnetic radiation , wavelength , physics , chemistry , quantum mechanics
Insulator-to-metal transition induces large material property variations in vanadium dioxide (VO 2 ) over a broad frequency band. VO 2 , therefore, has been introduced into metallic resonating structures to realize reconfigurable metadevices from microwave to optical wavelengths. Beyond enabling metal/VO 2 hybrid meta-atoms, in the THz regime metallic-phase VO 2 micro-structures can support strong electromagnetic resonances, offering great potential in active manipulation of THz radiation. In this paper, we show that VO 2 dipole antennas can be used to realize geometric phase coded metasurfaces for wave-front shaping and polarization rotation of THz waves. Moreover, we demonstrate that the corresponding efficiency of the THz spin Hall effect is closely related to VO 2 's THz electrical conductivity. In light of the dispersionless nature of the geometric phase, our study indicates that metasurfaces constructed by VO 2 subwavelength resonators are good candidates for active control of broadband THz radiation.