Thermal conductivity measurements play a crucial role in most areas of the applied physical sciences, thereby constantly demanding for new non-invasive methods capable of providing high-resolution spatial mapping of absolute thermal conductivities on heterogeneous samples ranging from solid-state bulk materials to low-dimensionality structures. In this work, we lay the theoretical foundations and provide the experimental demonstration of a novel method for quantitative thermal conductivity mapping at tunable ∼10-μm resolution, by non-contact infrared photo-activated thermography. Starting from Fourier’s heat transfer law, we surmise a universal dependence of the thermal response of a laser-irradiated sample on its thermal conductivity, irrespectively of density and specific heat capacity. We demonstrate such a dependence over the three conductivity decades 0.1–100 W/mK by finite-element numerical simulations, and exploit it for proof-of-principle single-point thermal conductivity measurements on both thermally thick and thermally thin reference solid samples. We exemplify the feasibility of space-resolved measurements on eighteenth-century tin organ pipe fragments, where the product of the thermal conductivity times the sample thickness, imaged at 40-μm sub-diffraction resolution, is pointed out as a relevant parameter for the non-destructive characterization of the sample conservation state. By coupling temperature maps with the extraction of thermal properties at high spatial resolution, our approach significantly expands the capability of state-of-the-art infrared imaging technology in fully capturing the compositional heterogeneity and/or functional state of the imaged materials.

热导率测量在应用物理科学的大多数领域中都起着至关重要的作用，因此不断要求能够提供高分辨率的绝对非热导率的非侵入性方法的空间映射，以绘制从固态散装材料到低密度固体样品的非均质样品上的绝对热导率。维度结构。在这项工作中，我们奠定了理论基础，并提供了通过非接触式红外光激活热成像技术在可调的〜10μm分辨率下进行定量热导率测绘的新方法的实验证明。从傅立叶的热传递定律出发，我们推测激光辐照样品的热响应普遍依赖于其热导率，而与密度和比热容量无关。我们通过有限元数值模拟证明了在三个电导率几十年0.1–100 W / mK上的这种依赖性，并将其用于对热厚和热薄参比固体样品的原理单点热导率测量。我们举例说明了在18世纪的锡器官管碎片上进行空间分辨测量的可行性，其中热导率乘以样品厚度的乘积（以40μm次衍射分辨率成像）被指出为非样品保存状态的破坏性表征。通过将温度图与以高空间分辨率提取的热特性结合起来，