Focal length switchable metalens based on vanadium dioxide.
Appl Opt
; 63(9): 2148-2155, 2024 Mar 20.
Article
in En
| MEDLINE
| ID: mdl-38568566
ABSTRACT
A metalens is a flat lens that can control the phase of light so that dispersed light can be reconcentrated. This study devised a tunable metalens with a switchable focal length based on the phase transition properties of vanadium dioxide (V O 2). The unit structure comprises three layers from bottom to top gold, polyimide, and two square resonant rings. The metalens can not only transform incident x-polarized waves into y-polarized waves but also achieve beam focusing simultaneously. The designed metalens achieves polarization conversion efficiency at an operating frequency of 0.8 THz. In the insulating state of V O 2, the beam focal point is at L=1914µm; in the metallic state, the wave converges at L=982µm, closely aligning with the predetermined focal length. By controlling external temperature, focal point switching can be achieved, making it highly versatile in practical applications.
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Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Appl Opt
Year:
2024
Document type:
Article
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