Sub-Wavelength and Nanophotonics
Sub-wavelength and nanophotonics is a scientific field focused on controlling and manipulating light at scales smaller than the wavelength of the light itself, often on the order of nanometers. At these scales, traditional optical laws break down, and new phenomena emerge, allowing for the design of innovative materials and devices with unique optical properties. This includes phenomena like plasmonics, where light interacts with free electrons in metals, and the creation of optical nanostructures that can guide, trap, or enhance light in ways that were previously thought impossible. Sub-wavelength and nanophotonics hold great promise for advancing technologies in imaging, sensing, communication, and even energy harvesting. By overcoming the diffraction limit of light, this field opens the door to ultra-compact devices that can manipulate light with unprecedented precision, enabling the development of next-generation optical systems for a variety of applications, from medical diagnostics to quantum computing.
The following publications exemplify our recent research endeavors.
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.
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.
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