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Metasurface measuring twisted light in turbulence
Publikationstyp
Journal Article
Date Issued
2022-09-09
Sprache
English
Author(s)
Dinter, Thomas
Li, Chenhao
Kühner, Lucca
Journal
Volume
9
Issue
9
Start Page
3043
End Page
3051
Citation
ACS Photonics 9 (9): 3043-3051 (2022)
Publisher DOI
Scopus ID
Publisher
American Chemical Society
Orbital angular momentum (OAM) of light represents an independent degree of freedom using orthogonal helical modes for optical and quantum multiplexing, offering great potential to transform future ultrahigh-bandwidth information systems. Practical OAM communication systems suffer from turbulence-induced phase distortions to the propagating beams, decreasing the orthogonality of OAM modes through introduced modal crosstalk. To date, optical systems used for measuring OAM orthogonality breakdown in different turbulence conditions are too bulky and slow (e.g., one OAM mode at a time) for any practical use. Here, we demonstrate the use of an ultrathin OAM mode-sorting metasurface for characterizing the OAM orthogonality breakdown under different turbulence conditions. Our approach allows the measurement of the whole OAM spectrum at the same time. This metasurface exhibits strong OAM selectivity with an average modal crosstalk below -42.4 dB for OAM modes with topological charges ranging from -15 to +15. Our results suggest that higher-order OAM modes are as robust as lower-order modes in particular turbulence environments, paving the way for future practical free-space OAM communications harnessing high-dimensional OAM multiplexing. We demonstrated that a flat optical device with a small form factor can be integrated with practical communication systems for compact, fast, and efficient generation and detection of twisted light.
Subjects
atmospheric turbulence
metasurface
orbital angular momentum
structured light
DDC Class
600: Technology