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.
@article{arxiv.2101.02837,
title = {Passive frequency conversion of ultraviolet images into the visible using perovskite nanocrystals},
author = {Jad Salman and Mahesh K. Gangishetty and Bryan E. Rubio-Perez and Demeng Feng and Zhaoning Yu and Zongzhen Yang and Chenghao Wan and Michel Frising and Alireza Shahsafi and Daniel N. Congreve and Mikhail A. Kats},
journal= {arXiv preprint arXiv:2101.02837},
year = {2021}
}