Design and performance analysis of all-dielectric reflective, metalens for LWIR applications

Abstract Reflective metalenses with multilayer substrates offer low-loss wavefront control in the LWIR range but remain underexplored and highly dependent on material choice. Here, we report a comprehensive numerical investigation into the design of LWIR reflective metalenses employing dielectric di...

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Main Authors: Sani Mukhtar, Jaime Viegas
Format: Article
Language:English
Published: Nature Portfolio 2025-07-01
Series:Scientific Reports
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Online Access:https://doi.org/10.1038/s41598-025-09823-0
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author Sani Mukhtar
Jaime Viegas
author_facet Sani Mukhtar
Jaime Viegas
author_sort Sani Mukhtar
collection DOAJ
description Abstract Reflective metalenses with multilayer substrates offer low-loss wavefront control in the LWIR range but remain underexplored and highly dependent on material choice. Here, we report a comprehensive numerical investigation into the design of LWIR reflective metalenses employing dielectric distributed Bragg reflectors (DBRs) substrates composed of high-index semiconductors (Si, Ge, GaAs) and zinc-based dielectric compounds (ZnO, ZnSe, ZnS). We systematically evaluate nine DBR material combinations to assess their impact on the focusing efficiency, reflectivity, and focal spot characteristics. The designed metalens, with an aperture diameter of $$\:\sim1$$ $$\:\text{m}\text{m}$$ and a focal length of 0.7 $$\text{m}\text{m}$$ , operate at a design wavelength of $$\:10.6$$ $$\:\mu\text{m}$$ . All configurations achieve high reflectance $$\:(>\:90\%)$$ over a broad spectral range, with Si/ZnSe and GaAs/ZnO based designs exhibiting the highest focusing efficiencies of $$\:\sim83.5\%$$ and $$\:\sim82.7\%,$$ respectively, at Numerical Aperture (NA) $$\:\approx\:\:0.6$$ . All the examined configurations provide nearly complete $$0-2\pi$$ phase coverage, yielding diffraction-limited focal spot sizes ranging from $$\:\:0.96\lambda\:$$ to $$\:1.02\lambda$$ . We further analyze the impact of NA and metasurface unit cell periodicity ( $$P$$ ) on the lens performance, demonstrating that smaller unit cell periods improve phase discretization and optical response uniformity, while increasing NA results in tighter focal spots, with diminishing improvements near the diffraction limit.
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spelling doaj-art-b476c86c762f4fda8e83ef19273cc7b12025-08-20T03:45:20ZengNature PortfolioScientific Reports2045-23222025-07-0115111310.1038/s41598-025-09823-0Design and performance analysis of all-dielectric reflective, metalens for LWIR applicationsSani Mukhtar0Jaime Viegas1Department of Electrical Engineering, Khalifa University of Science and TechnologyDepartment of Electrical Engineering, Khalifa University of Science and TechnologyAbstract Reflective metalenses with multilayer substrates offer low-loss wavefront control in the LWIR range but remain underexplored and highly dependent on material choice. Here, we report a comprehensive numerical investigation into the design of LWIR reflective metalenses employing dielectric distributed Bragg reflectors (DBRs) substrates composed of high-index semiconductors (Si, Ge, GaAs) and zinc-based dielectric compounds (ZnO, ZnSe, ZnS). We systematically evaluate nine DBR material combinations to assess their impact on the focusing efficiency, reflectivity, and focal spot characteristics. The designed metalens, with an aperture diameter of $$\:\sim1$$ $$\:\text{m}\text{m}$$ and a focal length of 0.7 $$\text{m}\text{m}$$ , operate at a design wavelength of $$\:10.6$$ $$\:\mu\text{m}$$ . All configurations achieve high reflectance $$\:(>\:90\%)$$ over a broad spectral range, with Si/ZnSe and GaAs/ZnO based designs exhibiting the highest focusing efficiencies of $$\:\sim83.5\%$$ and $$\:\sim82.7\%,$$ respectively, at Numerical Aperture (NA) $$\:\approx\:\:0.6$$ . All the examined configurations provide nearly complete $$0-2\pi$$ phase coverage, yielding diffraction-limited focal spot sizes ranging from $$\:\:0.96\lambda\:$$ to $$\:1.02\lambda$$ . We further analyze the impact of NA and metasurface unit cell periodicity ( $$P$$ ) on the lens performance, demonstrating that smaller unit cell periods improve phase discretization and optical response uniformity, while increasing NA results in tighter focal spots, with diminishing improvements near the diffraction limit.https://doi.org/10.1038/s41598-025-09823-0MetasurfaceReflective metalensLong-wave infrared (LWIR)Focusing efficiencyCoupling effectsMaterial selection
spellingShingle Sani Mukhtar
Jaime Viegas
Design and performance analysis of all-dielectric reflective, metalens for LWIR applications
Scientific Reports
Metasurface
Reflective metalens
Long-wave infrared (LWIR)
Focusing efficiency
Coupling effects
Material selection
title Design and performance analysis of all-dielectric reflective, metalens for LWIR applications
title_full Design and performance analysis of all-dielectric reflective, metalens for LWIR applications
title_fullStr Design and performance analysis of all-dielectric reflective, metalens for LWIR applications
title_full_unstemmed Design and performance analysis of all-dielectric reflective, metalens for LWIR applications
title_short Design and performance analysis of all-dielectric reflective, metalens for LWIR applications
title_sort design and performance analysis of all dielectric reflective metalens for lwir applications
topic Metasurface
Reflective metalens
Long-wave infrared (LWIR)
Focusing efficiency
Coupling effects
Material selection
url https://doi.org/10.1038/s41598-025-09823-0
work_keys_str_mv AT sanimukhtar designandperformanceanalysisofalldielectricreflectivemetalensforlwirapplications
AT jaimeviegas designandperformanceanalysisofalldielectricreflectivemetalensforlwirapplications