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.

我们展示了一种被动下转换成像系统，该系统将宽带紫外光转换为窄带绿光，同时保持光线的方向性，从而实现直接下转换成像。同时，我们的系统在可见光中具有高透明度，可以叠加可见光和紫外成像。频率转换由基于高效 CsPbBr ₃的亚波长-厚度透明下变频器执行纳米晶体并入简单望远镜或中继透镜几何结构的焦平面。这种下转换系统的最终成像性能接近衍射极限。该演示为结合其他高效钙钛矿纳米晶体材料以实现被动多频转换成像系统奠定了基础。