Active multiband varifocal metalenses based on orbital angular momentum division multiplexing

Metalenses as miniature flat lenses exhibit a substantial potential in replacing traditional optical component. Although the metalenses have been intensively explored, their functions are limited by poor active ability, narrow operating band and small depth of field (DOF). Here, we show a dielectric...

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Bibliographic Details
Published in:Nature communications 2022-07, Vol.13 (1), p.4292-4292, Article 4292
Main Authors: Zheng, Ruixuan, Pan, Ruhao, Geng, Guangzhou, Jiang, Qiang, Du, Shuo, Huang, Lingling, Gu, Changzhi, Li, Junjie
Format: Article
Language:English
Subjects:
142/126
639/624/399/1015
639/624/400/1021
Angular momentum
Arrays
Aspect ratio
Depth of field
Electron beams
Humanities and Social Sciences
Laboratories
multidisciplinary
Multiplexing
Optical components
Optical properties
Optics
Phase assignment
Physical properties
Physics
Science
Science (multidisciplinary)
Titanium dioxide
Vortices
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Summary:Metalenses as miniature flat lenses exhibit a substantial potential in replacing traditional optical component. Although the metalenses have been intensively explored, their functions are limited by poor active ability, narrow operating band and small depth of field (DOF). Here, we show a dielectric metalens consisting of TiO 2 nanofins array with ultrahigh aspect ratio to realize active multiband varifocal function. Regulating the orbital angular momentum (OAM) by the phase assignment covering the 2π range, its focal lengths can be switched from 5 mm to 35 mm. This active optical multiplexing uses the physical properties of OAM channels to selectively address and decode the vortex beams. The multiband capability and large DOFs with conversion efficiency of 49% for this metalens are validated for both 532 nm and 633 nm, and the incidence wavelength can further change the focal lengths. This non-mechanical tunable metalens demonstrates the possibility of active varifocal metalenses. A dielectric metalens consisting of ultrahigh aspect ratio TiO 2 nanofins array is demonstrated to realize active multiband varifocal functionality. By regulating the orbital angular momentum, the focal length can be switched from 5 mm to 35 mm with large DOFs.
ISSN:2041-1723
2041-1723
DOI:10.1038/s41467-022-32044-2