Passive frequency conversion of ultraviolet images into the visible using perovskite nanocrystals

TL;DR

This paper presents a passive imaging system that converts ultraviolet light to visible green light using perovskite nanocrystals, enabling superimposed UV-visible imaging with high efficiency and near-diffraction-limited resolution.

Contribution

It introduces a novel passive down-conversion imaging system utilizing CsPbBr3 nanocrystals for efficient UV to visible frequency conversion in a simple optical setup.

Findings

Achieves near-diffraction-limited imaging performance.

Enables superimposed UV and visible imaging.

Demonstrates high-efficiency passive frequency conversion.

Abstract

We demonstrate a passive down-conversion imaging system that converts broadband ultraviolet light to narrow-band green light while preserving the directionality of rays, and thus enabling direct down-conversion imaging. At the same time our system has high transparency in the visible, enabling superimposed visible and ultraviolet imaging. The frequency conversion is performed by a subwavelength-thickness transparent downconverter based on highly efficient CsPbBr3 nanocrystals incorporated into the focal plane of a simple telescope or relay-lens geometry. The resulting imaging performance of this down-conversion system approaches the diffraction limit. This demonstration sets the stage for the incorporation of other high-efficiency perovskite nanocrystal materials to enable passive multi-frequency conversion imaging systems.