Imaging in the solar-blind ultraviolet region offers significant advantages, including minimal interference from sunlight, reduced background noise, low false-alarm rates, and high sensitivity. Therefore, it has important applications in fire warning and detection, ozone-layer depletion monitoring, explosion detection, missile launch detection, and electrical discharge monitoring. However, conventional imaging systems in this spectral region are often limited by the bulkiness and complexity of traditional optical components, resulting in heavy and cumbersome systems.

The emergence of metasurfaces, which use two-dimensional arrays of nanoantennas to manipulate the properties of light, provides a powerful solution for developing miniaturized and compact optical systems. In this work, diamond metalenses were designed and fabricated to realize ultracompact solar-blind ultraviolet imaging. To demonstrate this concept, two representative imaging functions were presented: bright-field imaging and spiral phase contrast imaging.

Benefiting from the excellent properties of diamond, including its wide bandgap, high refractive index, outstanding chemical inertness, and high damage threshold, this work not only proposes a simple and feasible approach for achieving solar-blind imaging in an ultracompact form, but also highlights diamond as a highly promising material platform for developing miniaturized, lightweight, and robust imaging systems.

This work, entitled “Solar-blind ultraviolet imaging with a diamond metalens,” was published in Photonics Research in 2025.