High-efficiency, 80-mm aperture metalens telescope

TL;DR

This paper presents the development of a high-efficiency, large-aperture metalens telescope fabricated using a scalable process, enabling practical applications in large optical systems like telescopes and planetary observation.

Contribution

First demonstration of a wafer-scale, 80-mm aperture metalens telescope using a mass production-friendly fabrication process.

Findings

Achieved diffraction-limited performance in near-infrared

High peak focusing efficiency of 80.84% at 1450 nm

Successfully captured lunar surface images with the metalens telescope

Abstract

Metalenses, artificially engineered subwavelength nanostructures to focus light within ultrathin thickness, promise potential for a paradigm shift of conventional optical devices. However, the aperture sizes of metalenses are usually bound within hundreds of micrometers by the commonly-used scanning-based fabrication methods, limiting their usage on practical optical devices like telescopes. Here, for the first time, we demonstrate a high-efficiency, single-lens, refractive metalens telescope. We developed a mass production-friendly workflow for fabricating wafer-scale (80-mm aperture) metalenses using deep-ultraviolet (DUV) photolithography and a multi-exposure process involving reticle rotation and pattern stitching to leverage the radial symmetry of metalenses. Our metalens works in the near-infrared region (1200 - 1600 nm) with diffraction-limited performance and a high peak focusing efficiency of 80.84% at 1450 nm experimentally. Based on the metalens, we built a single-lens telescope and acquired images of the lunar surface, revealing its geographical structures. We believe our demonstration of the metalens telescope proves the exciting potential lying in the metasurfaces and could bring new possibilities for areas involving large optical systems, including geosciences, planetary observation, and astrophysical science.