闪烁探测器中空间信息的纳米光子学调控
Nanophotonic control of spatial information in scintillation detectors
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中文总结 AI 辅助
该研究将超表面透镜与块状闪烁体集成，通过纳米光子波前调控分离X射线吸收与光学成像，可降低CT所需X射线剂量5倍、提高分辨率带宽25倍，实现高分辨率低剂量X射线成像。
中文摘要 AI 辅助
X射线可应用于医学、安全检查、材料科学等领域的非侵入式成像，但现代系统仍受限于需在更低辐射剂量下分辨更精细结构的需求。闪烁体是探测X射线的主要材料，却存在长期存在的权衡问题：厚闪烁体能有效吸收X射线，但在其体积内产生的光学光子会在探测前扩散，导致空间信息退化。现有闪烁体架构大多通过使用像素、柱状晶体或微结构通道对光进行物理限制来保持分辨率。在此，我们证明高分辨率探测并不需要对闪烁光进行体积限制。将超表面透镜（metalens）直接集成到块状闪烁体上，利用纳米光子波前调控，可优先将体积内产生的闪烁光中的高空间频率信息传递到探测器，同时保留厚闪烁体对X射线的吸收能力。我们通过实验恢复了无机和生物样本X射线图像中的精细空间细节。在与计算机断层扫描（CT）相关的探测器几何结构中，经实验验证的模型预测，与最先进的像素化闪烁体相比，所需X射线剂量可降低5倍，分辨率带宽可提高25倍。这些结果表明，波前工程可成为将高效X射线吸收与光学图像形成分离的途径，有望实现更高分辨率、更低剂量的CT。
英文摘要
X-rays enable non-invasive imaging across medicine, security, materials science, and beyond, yet modern systems remain constrained by the need to resolve finer structures at lower radiation dose. Scintillators are the dominant materials for detecting X-rays, but face a longstanding compromise: thick scintillators absorb X-rays effectively, whereas optical photons generated throughout their volume spread before detection, degrading spatial information. Existing scintillator architectures largely try to preserve resolution by physically confining light using pixels, columnar crystals, or microstructured channels. Here, we show that high-resolution detection does not require the volumetric confinement of scintillation light. A metalens integrated directly with a bulk scintillator uses nanophotonic wavefront control to preferentially transfer high-spatial-frequency information from volumetrically generated scintillation light to the detector, while retaining the X-ray absorption of a thick scintillator. We experimentally recover fine spatial detail in X-ray images of inorganic and biological specimens. In a detector geometry relevant to computed tomography (CT), the experimentally validated model predicts a fivefold reduction in required X-ray dose and a 25-fold increase in resolution bandwidth relative to a state-of-the-art pixelated scintillator. These results establish wavefront engineering as a route to separating efficient X-ray absorption from optical image formation, with the potential for substantially higher-resolution, lower-dose CT.
