Reflective metalens with an enhanced off-axis focusing performance

Zahrah Alnakhli, Ronghui Lin, Che-Hao Liao, Abdulrahman El Labban, Xiaohang Li

Research output: Contribution to journalArticlepeer-review


Metalenses are one of the most promising metasurface applications. However, all-dielectric reflective metalenses are rarely studied, especially regarding their off-axis focusing performance. After experimentally studying the material optical properties in this work, we propose reflective metalens based on titanium dioxide (TiO2) and silicon dioxide (SiO2), which operate at a visible wavelength of 0.633 µm. Unlike conventional reflective metalenses based on metallic mirrors, the proposed device was designed based on a modified parabolic phase profile and was integrated onto a dielectric distributed Bragg reflector periodic structure to achieve high reflectivity with five dielectric pairs. The focusing efficiency characteristics of the metalens were experimentally studied for beam angles of incidence between 0∘ and 30∘. The results reveal that the focusing efficiency for the modified metalens design remains higher than 54%, which is higher than 50%, making it promising for photonic miniaturization and integration.
Original languageEnglish (US)
Pages (from-to)34117
JournalOptics Express
Issue number19
StatePublished - Sep 2 2022

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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