Vibrational strong coupling is a phenomenon in which a vibrational transition in a material placed inside a photonic structure is hybridized with its optical modes to form composite light–matter excitations known as vibro-polaritons. Here we demonstrate a new concept of vibrational strong coupling: we show that a monolithic photonic crystal, made of a resonant material, can exhibit strong coupling between the optical modes confined in the structure and the terahertz vibrational excitations of the same material. We study this system both experimentally and numerically to characterize the dispersion of the photonic modes for various sample thicknesses and reveal their coupling with the vibrational resonances. Finally, our time-domain THz measurements allow us to isolate the free induction decay signal from the grating modes as well as from the vibro-polaritons.

中文翻译：

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自耦合太赫兹光子晶体中的强耦合

振动强耦合是一种现象，其中放置在光子结构内的材料中的振动跃迁与其光学模式混合以形成称为振动极化子的复合光物质激发。在这里，我们展示了振动强耦合的新概念：我们表明，由谐振材料制成的单片光子晶体可以在结构中限制的光学模式与相同材料的太赫兹振动激发之间表现出强耦合。我们通过实验和数值研究该系统，以表征各种样品厚度的光子模式的色散，并揭示它们与振动共振的耦合。最后，