Varifocal metalens using tunable and ultralow-loss dielectrics
The field of flat optics that uses nanostructured, so-called metasurfaces, has seen remarkable progress over the last decade. Chalcogenide phase-change materials (PCMs) offer a promising platform for realizing reconfigurable metasurfaces, as their optical properties can be reversibly tuned. Yet, dem...
| Main Authors: | , , , , , , |
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| Format: | Journal article |
| Language: | English |
| Published: |
Wiley
2023
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| _version_ | 1797109538668675072 |
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| author | Wang, M Lee, JS Aggarwal, S Farmakidis, N He, Y Cheng, T Bhaskaran, H |
| author_facet | Wang, M Lee, JS Aggarwal, S Farmakidis, N He, Y Cheng, T Bhaskaran, H |
| author_sort | Wang, M |
| collection | OXFORD |
| description | The field of flat optics that uses nanostructured, so-called metasurfaces, has seen remarkable progress over the last decade. Chalcogenide phase-change materials (PCMs) offer a promising platform for realizing reconfigurable metasurfaces, as their optical properties can be reversibly tuned. Yet, demonstrations of phase-change metalenses to date have employed material compositions such as Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub>, which show high absorption in the visible to near-IR wavelengths particularly in their crystalline state, limiting the applicability. Here, by using a low-loss PCM Sb<sub>2</sub>Se<sub>3</sub>, for the first time, active polarization-insensitive phase-change metalenses at near-IR wavelengths with comparable efficiencies in both material states are shown. An active metalens with a tunable focusing intensity of 95% and a focusing efficiency of 23% is demonstrated. A varifocal metalens is then demonstrated with a tunable focal length from 41 to 123 µm with comparable focusing efficiency (5.7% and 3%). The ultralow-loss nature of the material introduces exciting new possibilities for optical communications, multi-depth imaging, beam steering, optical routing, and holography. |
| first_indexed | 2024-03-07T07:41:35Z |
| format | Journal article |
| id | oxford-uuid:e00f7637-d188-4ca1-82f8-ec6f3d64a827 |
| institution | University of Oxford |
| language | English |
| last_indexed | 2024-03-07T07:41:35Z |
| publishDate | 2023 |
| publisher | Wiley |
| record_format | dspace |
| spelling | oxford-uuid:e00f7637-d188-4ca1-82f8-ec6f3d64a8272023-05-02T09:55:24ZVarifocal metalens using tunable and ultralow-loss dielectricsJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:e00f7637-d188-4ca1-82f8-ec6f3d64a827EnglishSymplectic ElementsWiley2023Wang, MLee, JSAggarwal, SFarmakidis, NHe, YCheng, TBhaskaran, HThe field of flat optics that uses nanostructured, so-called metasurfaces, has seen remarkable progress over the last decade. Chalcogenide phase-change materials (PCMs) offer a promising platform for realizing reconfigurable metasurfaces, as their optical properties can be reversibly tuned. Yet, demonstrations of phase-change metalenses to date have employed material compositions such as Ge<sub>2</sub>Sb<sub>2</sub>Te<sub>5</sub>, which show high absorption in the visible to near-IR wavelengths particularly in their crystalline state, limiting the applicability. Here, by using a low-loss PCM Sb<sub>2</sub>Se<sub>3</sub>, for the first time, active polarization-insensitive phase-change metalenses at near-IR wavelengths with comparable efficiencies in both material states are shown. An active metalens with a tunable focusing intensity of 95% and a focusing efficiency of 23% is demonstrated. A varifocal metalens is then demonstrated with a tunable focal length from 41 to 123 µm with comparable focusing efficiency (5.7% and 3%). The ultralow-loss nature of the material introduces exciting new possibilities for optical communications, multi-depth imaging, beam steering, optical routing, and holography. |
| spellingShingle | Wang, M Lee, JS Aggarwal, S Farmakidis, N He, Y Cheng, T Bhaskaran, H Varifocal metalens using tunable and ultralow-loss dielectrics |
| title | Varifocal metalens using tunable and ultralow-loss dielectrics |
| title_full | Varifocal metalens using tunable and ultralow-loss dielectrics |
| title_fullStr | Varifocal metalens using tunable and ultralow-loss dielectrics |
| title_full_unstemmed | Varifocal metalens using tunable and ultralow-loss dielectrics |
| title_short | Varifocal metalens using tunable and ultralow-loss dielectrics |
| title_sort | varifocal metalens using tunable and ultralow loss dielectrics |
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