Coherent interconversion of signals between optical and mechanical domains is enabled by optomechanical interactions. Extreme light-matter coupling produced by confining light to nanoscale mode volumes can then access single mid-infrared (MIR) photon sensitivity. Here, we used the infrared absorption and Raman activity of molecular vibrations in plasmonic nanocavities to demonstrate frequency upconversion. We converted approximately 10-micrometer-wavelength incoming light to visible light by surface-enhanced Raman scattering (SERS) in doubly resonant antennas that enhanced upconversion by more than 10¹⁰. We showed 140% amplification of the SERS anti-Stokes emission when an MIR pump was tuned to a molecular vibrational frequency, obtaining lowest detectable powers of 1 to 10 microwatts per square micrometer at room temperature. These results have potential for low-cost and large-scale infrared detectors and spectroscopic techniques.

中文翻译：

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双波长纳米天线中分子频率上变频检测中红外光

通过光机械相互作用实现了光域和机械域之间信号的相干相互转换。通过将光限制在纳米级模式体积中产生的极端光-物质耦合可以访问单个中红外 (MIR) 光子灵敏度。在这里，我们使用等离子体纳米腔中分子振动的红外吸收和拉曼活性来证明频率上转换。我们通过双谐振天线中的表面增强拉曼散射 (SERS) 将大约 10 微米波长的入射光转换为可见光，该天线将上转换增强了 10 ^10以上. 当 MIR 泵被调谐到分子振动频率时，我们展示了 SERS 反斯托克斯发射的 140% 放大，在室温下获得每平方微米 1 到 10 微瓦的最低可检测功率。这些结果具有低成本和大规模红外探测器和光谱技术的潜力。