Phonon polaritons (PhPs) have a long lifetime and high confinement of light fields compared with their plasmonic counterparts in the mid-infrared range. Thus, PhPs are promising candidates for realizing vibrational strong coupling (VSC) with molecules. However, VSCs of PhPs in nanoresonators and thin films require the near-field technique and are limited to the transverse magnetic mode. Here we propose a new configuration based on the Tamm structure, which supports PhPs excited by the free-space incident light in both transverse-electric and transverse-magnetic modes. The VSC of a 300 nm thick molecular layer can be achieved with $21\,{{\rm cm}^{- 1}}$ Rabi splitting, according to the numerically obtained angle resolved reflectivity spectra with the transfer matrix method. Our findings provide a promising platform for applications in free-space sensing of vibrational modes and control of chemical reactions in compact devices.

中文翻译：

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Tamm声子极化子与有机分子之间的振动强耦合

相比于中红外范围的等离激元，声子极化子（PhPs）具有较长的寿命和较高的光场限制。因此，PhPs是实现与分子的振动强耦合（VSC）的有希望的候选者。然而，纳米谐振器和薄膜中PhP的VSC需要近场技术，并且仅限于横向磁模式。在这里，我们提出一种基于Tamm结构的新配置，该配置支持在横向电磁模式和横向电磁模式下由自由空间入射光激发的PhP。$ 21 \，{{\ rm cm} ^ {-1}} $可以实现300 nm厚的分子层的VSC。拉比分裂，根据数值获得的角度，用传递矩阵法解析反射光谱。我们的发现为在振动模式的自由空间感测和紧凑设备中的化学反应控制中的应用提供了一个有希望的平台。