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Published August 18, 2021 | Supplemental Material
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Near-Infrared Active Metasurface for Dynamic Polarization Conversion


Control of optical polarization is central to harnessing the properties of electromagnetic radiation for many applications, including 3D imaging and quantum computation. However, conventional optical polarizing components are typically bulky and static, that is, fixed in their degree of polarization control. Active metasurfaces have potential for versatile polarization control in a compact form factor by temporally modulating electromagnetic amplitudes and phase between orthogonal electric field components. Here, dynamic control of the polarization state of reflected light from an active metasurface is demonstrated. The metasurface uses indium tin oxide (ITO) as an active element in an array of aluminum nanoantennas operating in the telecom range. Applying an electrical bias between the ITO layer and the back reflector modulates the carrier concentration in ITO at the gate-dielectric/ITO interface, resulting in complex refractive index modulation in the epsilon-near-zero condition. This index modulation alters the degree of excitation of plasmonic modes corresponding to the orthogonal polarization components, leading to polarization modulation. By suitably biasing the metasurface, linearly polarized incident light can be converted to cross-polarized, circularly polarized or elliptically polarized light upon reflection. Dynamic control of the reflected polarization state has potentially wide applications in dynamic wave plates, spatial light modulators, and adaptive wavefront control.

Additional Information

© 2021 Wiley-VCH GmbH. Issue Online: 18 August 2021; Version of Record online: 14 June 2021; Manuscript revised: 01 May 2021; Manuscript received: 02 February 2021. This work was supported by the Air Force Office of Scientific Research under Grant FA9550-19-1-0279. The authors used facilities supported by the Kavli Nanoscience Institute (KNI). P.C.W. acknowledges the support from Ministry of Science and Technology, Taiwan (Grant numbers: 108-2112-M-006-021-MY3; 107-2923-M-006-004-MY3) and the support in part by Higher Education Sprout Project, Ministry of Education to the Headquarters of University Advancement at National Cheng Kung University (NCKU). P.C.W. also acknowledges the support from Ministry of Education (Yushan Young Scholar Program), Taiwan. The authors declare no conflict of interest. Data Availability Statement: Research data are not shared.

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Supplemental Material - adom202100230-sup-0001-suppmat.pdf


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August 22, 2023
October 23, 2023