Surface polaritons comprise a wealth of light–matter interactions with deep sub-wavelength scale confinement of electromagnetic modes. However, their nanoscale localized dissipation and thermalization processes are not readily accessible experimentally. Here, we introduce photothermal force microscopy to image surface plasmon polaritons (SPPs) in monolayer graphene through their non-radiative SiO₂ substrate dissipation. We demonstrate the real-space SPP imaging via photo-induced atomic force detection, and from comparison with scattering-type scanning near-field optical microscopy imaging attribute the force response to substrate dissipation-enhanced thermal expansion. This work illustrates that nano-optical tip–sample induced dissipative forces facilitate a direct mechanical detection of surface polariton interactions with monolayer sensitivity.

中文翻译：

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单层石墨烯中表面极化子的基质增强光热纳米成像

表面极化子包含大量的光-物质相互作用，并具有电磁模式的深亚波长尺度限制。然而，它们的纳米级局部耗散和热化过程在实验上不易获得。在这里，我们将光热力显微镜通过其非辐射SiO ₂引入单层石墨烯的图像表面等离振子极化子（SPPs）。基板耗散。我们通过光诱导原子力检测演示了真实空间的SPP成像，并且通过与散射型扫描近场光学显微镜成像进行比较，将力响应对基板耗散增强的热膨胀进行了归因。这项工作表明，纳米光学针尖样品所产生的耗散力促进了具有单层灵敏度的表面极化子相互作用的直接机械检测。