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Broadband and efficient terahertz helicity inversion by a reconfigurable reflective metasurface based on vanadium dioxide.
Broadband and efficient terahertz helicity inversion by a reconfigurable reflective metasurface based on vanadium dioxide.
- Source :
-
Applied Physics Letters . 8/19/2024, Vol. 125 Issue 8, p1-6. 6p. - Publication Year :
- 2024
-
Abstract
- We experimentally demonstrate the broadband and highly efficient inversion of the rotation direction of the terahertz circular polarization achieved by a dynamic metasurface with vanadium dioxide ( VO 2 ). This metasurface converts linear polarization into circular polarization. The rotational direction of the output circular polarization can be reversed based on the VO 2 phase transition. The VO 2 state can be dynamically switched by injecting direct current into an on-chip circuit. To improve the terahertz-wave utilization efficiency, the metasurface is operated at an incident angle of 45°, thereby eliminating the beam splitter typically used to separate the outgoing wave from the incident wave at normal incidence. To achieve broadband operation, we employ a dispersion-cancelation strategy that cancels the dispersive phase responses between orthogonal linear polarizations. This strategy was previously developed for static metasurfaces; we have applied it to the design of dynamic metasurfaces. At a center frequency of 0.99 THz, the experimental evaluation demonstrated helicity switching with conversion efficiencies of 92% and 87% for the insulating and metallic states of VO 2 , respectively. Dispersion cancelation is simultaneously achieved for the insulating and metallic states of VO 2 , resulting in a relative bandwidth of 0.26, which is 3.2 times broader than that of a previously developed efficient dynamic metasurface. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00036951
- Volume :
- 125
- Issue :
- 8
- Database :
- Academic Search Index
- Journal :
- Applied Physics Letters
- Publication Type :
- Academic Journal
- Accession number :
- 179242047
- Full Text :
- https://doi.org/10.1063/5.0220688