Silicon Rich Nitride: A Platform for Controllable Structural Colors

Silicon-rich nitride (SRN), a high-refractive-index dielectric material, is pivotal for advanced metasurfaces. Adjusting the silicon-to-nitride ratio increases refractive index and slightly the absorption, especially in the blue spectrum, amplifying losses in nano-resonator-based metasurfaces. This study evaluates SRN for structural color applications, focusing on gamut coverage, saturation, and reflection amplitude. A higher silicon ratio enhances vividness, achieving 166% sRGB coverage and 38,000 dpi resolution. Fabricated samples showcased high-resolution images like a parrot and a rainbow. SRN outperforms other materials in CIE diagram coverage, underscoring its potential for photonic devices and high-resolution applications.

Oren Goldberg, Mazurski, Noa , and Levy, Uriel . 2024. “Silicon Rich Nitride: A Platform For Controllable Structural Colors”. Nanophotonics.

Publisher's Version

Download: 10.1515_nanoph-2024-0454.pdf

Near-IR Wide-Field-of-View Huygens Metalens for Outdoor Imaging Application

Recent advances in optical metalenses aim to create compact, cost-effective systems for focusing and imaging, driven by nanopatterned metasurfaces. A key challenge is achieving high performance with fabrication methods suitable for mass production. This paper introduces a Huygens nanoantenna-based metalens designed for outdoor photographic and surveillance applications in the near-infrared spectrum. The metalens delivers high-quality imaging across a wide field of view (±15°), marking the first successful implementation of metalenses for outdoor imaging. These results highlight the potential of metalenses for practical imaging applications and provide a foundation for advancing metalens technology in real-world scenarios.

Jacob Engelberg, Zhou, Chen , Mazurski, Noa , Bar-David, Jonathan , Kristensen, Anders , and Levy, Uriel . 2019. “Near-Ir Wide-Field-Of-View Huygens Metalens For Outdoor Imaging Application”. Nanophotonics, 9, 2, Pp. 361-370.  

Publisher's Version

Download: near-ir_wide-field-of-view_huygens_metalens_for_outdoor_imaging_application.pdf

Tunable Metasurface Using Thin Film Lithium-Niobate in the Telecom Regime

Metasurfaces have advanced significantly, enabling precise control over electromagnetic wave properties but remain limited by their static nature post-fabrication. This study introduces a reconfigurable metasurface for rapid optical tunability and modulation, utilizing aluminum nanodisks coated with indium tin oxide (ITO) on a lithium niobate (LiNbO₃) thin film with a chromium/gold substrate. Coupled resonances enhance electromagnetic field confinement, producing a narrow reflectance dip at 1.55 μm. The spectral position is tunable via the electro-optic Pockels effect by applying a bias voltage. The metasurface achieves a 40% modulation depth, enabling applications in tunable displays, spatial light modulators, beam scanning LiDARs, and free-space communication systems.

Aharon Weiss. 2021. “Tunable Metasurface Using Thin Film Lithium-Niobate In The Telecom Regime”.

Download: aharon_weiss_thesis.pdf