Large-area multiwavelength and polarization-insensitive metalenses via multilayer Huygens metasurfaces

Fuente: arXiv
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Autori principali: Jordaan, Joshua, Minovich, Alexander, Neshev, Dragomir, Staude, Isabelle
Natura: Preprint
Pubblicazione: 2024
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author Jordaan, Joshua
Minovich, Alexander
Neshev, Dragomir
Staude, Isabelle
author_facet Jordaan, Joshua
Minovich, Alexander
Neshev, Dragomir
Staude, Isabelle
contents Metalenses, advanced nanostructured alternatives to conventional lenses, significantly enhance the compactness and functionality of optical systems. Despite progress in monochromatic applications, scaling metalenses to centimeter-sized apertures for broadband or multiwavelength use remains challenging due to limitations in achieving the necessary group delay (GD) with current materials. In this study, we introduce a novel multiwavelength, polarization-insensitive metalens design operating in the near-infrared (NIR). Our approach employs multiple Huygens' metasurface layers, each optimized to modulate a specific wavelength while maintaining high transmittance and minimal phase disturbance at other wavelengths. We demonstrate a metalens operating at 2000 and 2340 nm with a numerical aperture (NA) of 0.11. In simulation, the metalens achieves a normalized modulation transfer function (MTF) that is nearly exactly diffraction-limited. The absolute focusing efficiencies are 65% and 56%, corresponding to relative efficiencies of 76% and 65% compared to an ideal lens of the same dimensions. The meta-atoms are designed using an inverse shape-optimization method that ensures polarization insensitivity and high tolerance to layer misalignment. The proposed design is compatible with large-area nanofabrication techniques, allowing metasurface layers to be fabricated individually and assembled into the final device. This innovative approach is also generalizable to any arbitrary multiwavelength phase profile beyond that of simple lensing.
format Preprint
id arxiv_https___arxiv_org_abs_2410_20043
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Large-area multiwavelength and polarization-insensitive metalenses via multilayer Huygens metasurfaces
Jordaan, Joshua
Minovich, Alexander
Neshev, Dragomir
Staude, Isabelle
Optics
Applied Physics
Metalenses, advanced nanostructured alternatives to conventional lenses, significantly enhance the compactness and functionality of optical systems. Despite progress in monochromatic applications, scaling metalenses to centimeter-sized apertures for broadband or multiwavelength use remains challenging due to limitations in achieving the necessary group delay (GD) with current materials. In this study, we introduce a novel multiwavelength, polarization-insensitive metalens design operating in the near-infrared (NIR). Our approach employs multiple Huygens' metasurface layers, each optimized to modulate a specific wavelength while maintaining high transmittance and minimal phase disturbance at other wavelengths. We demonstrate a metalens operating at 2000 and 2340 nm with a numerical aperture (NA) of 0.11. In simulation, the metalens achieves a normalized modulation transfer function (MTF) that is nearly exactly diffraction-limited. The absolute focusing efficiencies are 65% and 56%, corresponding to relative efficiencies of 76% and 65% compared to an ideal lens of the same dimensions. The meta-atoms are designed using an inverse shape-optimization method that ensures polarization insensitivity and high tolerance to layer misalignment. The proposed design is compatible with large-area nanofabrication techniques, allowing metasurface layers to be fabricated individually and assembled into the final device. This innovative approach is also generalizable to any arbitrary multiwavelength phase profile beyond that of simple lensing.
title Large-area multiwavelength and polarization-insensitive metalenses via multilayer Huygens metasurfaces
topic Optics
Applied Physics
url https://arxiv.org/abs/2410.20043