Dark-field microscopy is a standard imaging technique widely employed in biology that provides high image contrast for a broad range of unstained specimens¹. Unlike bright-field microscopy, it accentuates high spatial frequencies and can therefore be used to emphasize and resolve small features. However, the use of dark-field microscopy for reliable analysis of blood cells, bacteria, algae and other marine organisms often requires specialized, bulky microscope systems, as well as expensive additional components, such as dark-field-compatible objectives or condensers^2,3. Here, we propose to simplify and downsize dark-field microscopy equipment by generating the high-angle illumination cone required for dark-field microscopy directly within the sample substrate. We introduce a luminescent photonic substrate with a controlled angular emission profile and demonstrate its ability to generate high-contrast dark-field images of micrometre-sized living organisms using standard optical microscopy equipment. This new type of substrate forms the basis for miniaturized lab-on-chip dark-field imaging devices that are compatible with simple and compact light microscopes.

暗场显微镜是生物学中广泛使用的标准成像技术，可为各种未染色的标本提供高图像对比度¹。与明场显微镜不同，它强调高空间频率，因此可用于强调和解决小特征。但是，使用暗场显微镜对血细胞，细菌，藻类和其他海洋生物进行可靠分析时，通常需要专用的笨重显微镜系统以及昂贵的附加组件，例如兼容暗场的物镜或聚光镜^{2。 3}。在这里，我们建议通过直接在样品基底内生成暗场显微镜所需的高角度照明锥，来简化暗场显微镜设备并缩小其尺寸。我们介绍了一种具有受控角度发射轮廓的发光光子基板，并展示了使用标准光学显微镜设备生成微米级生物体的高对比度暗场图像的能力。这种新型基板构成了与简单且紧凑的光学显微镜兼容的微型芯片实验室暗场成像设备的基础。