American Chemical Society
nl1c04723_si_001.pdf (21.05 MB)

High-Quality-Factor Silicon-on-Lithium Niobate Metasurfaces for Electro-optically Reconfigurable Wavefront Shaping

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journal contribution
posted 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.