Probing Mid-Infrared Phonon Polaritons in the Aqueous Phase
Probing Mid-Infrared Phonon Polaritons in the Aqueous Phase
复制标题
探测水相中的中红外声子极化子
DOI：
10.1021/acs.nanolett.0c01199
复制
发表时间：
2020
期刊：
影响因子：
10.8
通讯作者：
Xu, Xiaoji G.
中科院分区：
文献类型：
--
作者：
Wang, Haomin;Janzen, Eli;Wang, Le;Edgar, James H.;Xu, Xiaoji G.
声子极化激元（PhPs）是在杂化电磁场作用下的声子集体振荡，它集中了与分子振动相匹配的中红外光场。PhPs的利用为化学传感工具和极化激元增强纳米光谱学提供了希望。然而，由于缺乏水中原位红外纳米成像方法，对水相中PhPs的研究和创新仍然停滞不前。来自水的强红外吸收阻止了散射型近场显微镜在中红外中的光学传递和检测。在这里，我们提出了我们的解决方案：液相峰力红外（LiPFIR）显微镜的激发PhPs引起的光热响应的检测。在水相中测量了10 B同位素富集的h-BN中PhPs的特征干涉条纹，并提取了它们的色散关系。LiPFIR能够测量流体相中的中红外PhPs，开启了水中中红外声子极化的可能性并促进了其发展。
Phonon polaritons (PhPs) are collective phonon oscillations with hybridized electromagnetic fields, which concentrate mid-infrared optical fields that can match molecular vibrations. The utilization of PhPs holds the promise for chemical sensing tools and polariton-enhanced nanospectroscopy. However, investigations and innovations on PhPs in the aqueous phase remain stagnant because of the lack ofin situmid-infrared nanoimaging methods in water. Strong infrared absorption from water prohibits optical delivery and detection in the mid-infrared for scattering-type near-field microscopy. Here, we present our solution: the detection of photothermal responses caused by the excitation of PhPs by liquid phase peak force infrared (LiPFIR) microscopy. Characteristic interference fringes of PhPs in10B isotope-enrichedh-BN were measured in the aqueous phase and their dispersion relationship extracted. LiPFIR enables the measurement of mid-infrared PhPs in the fluid phase, opening possibilities and facilitating the development of mid-IR phonon polaritonics in water.