High-Quality-Factor Silicon-on-Lithium Niobate Metasurfaces for Electro-optically Reconfigurable Wavefront Shaping
journal contributionposted on 2022-02-03, 16:03 authored by Elissa Klopfer, Sahil Dagli, David Barton, Mark Lawrence, Jennifer A. Dionne
Dynamically reconfigurable metasurfaces promise compact and lightweight spatial light modulation for many applications, including LiDAR, AR/VR, and LiFi systems. Here, we design and computationally investigate high-quality-factor silicon-on-lithium niobate metasurfaces with electrically driven, independent control of its constituent nanobars for full phase tunability with high tuning efficiency. Free-space light couples to guided modes within each nanobar via periodic perturbations, generating quality factors exceeding 30,000 while maintaining a bar spacing of <λ/1.5. We achieve nearly 2π phase variation with an applied bias not exceeding ±25 V, maintaining a reflection efficiency above 91%. Using full-field simulations, we demonstrate a high-angle (51°) switchable beamsplitter with a diffracted efficiency of 93% and an angle-tunable beamsteerer, spanning 18–31°, with up to 86% efficiency, all using the same metasurface device. Our platform provides a foundation for highly efficient wavefront-shaping devices with a wide dynamic tuning range capable of generating nearly any transfer function.
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space light coupleslithium niobate metasurfaceshighly efficient wavefrontguided modes withinfull phase tunabilitycomputationally investigate highhigh tuning efficiencyusing fulltunable beamsteerertransfer functionshaping devicesreflection efficiencyplatform providesmetasurface devicemany applicationslifi systemsindependent controlincluding lidargenerating nearlyfield simulationsfactor siliconelectrically drivendiffracted efficiencyconstituent nanobarsbar spacingapplied bias91 %.