Spectral conversion of mid-infrared (MIR) radiation to visible (VIS) and near-infrared (NIR) wavelengths is a fundamental technology for spectroscopy and imaging; however, current MIR-to-VIS/NIR conversion technology is limited to nonlinear optics with bulky crystals or resonant nanocavities. Here we report lanthanide-based MIR-to-NIR nanotransducers that enable broadband MIR sensing at room temperature by harnessing ratiometric luminescence changes. The ratiometric luminescence of lanthanide nanotransducers in the NIR region can be incoherently modulated by MIR radiation in the 4.5–10.8 µm wavelength range. Ratiometric modulation of luminescence enables a detection limit of ~0.3 nW × µm⁻² with an internal quantum efficiency on the order of 3 × 10⁻³. The ratiometric sensor based on lanthanide nanotransducers does not require cryogenic cooling, polarization control, phase matching or nanoantenna design for light confinement. We also developed a camera with lanthanide nanotransducers, which enable room-temperature MIR imaging. We anticipate that these lanthanide nanotransducers can be extended to MIR light manipulation at the microscale for chip-integrated device applications.

中红外 (MIR) 辐射到可见 (VIS) 和近红外 (NIR) 波长的光谱转换是光谱学和成像的基本技术；然而，当前的 MIR 到 VIS/NIR 转换技术仅限于具有大块晶体或谐振纳米腔的非线性光学器件。在这里，我们报告了基于镧系元素的 MIR 到 NIR 纳米传感器，该传感器通过利用比率发光变化在室温下实现宽带 MIR 传感。NIR 区域中镧系元素纳米传感器的比率发光可以被 4.5–10.8 µm 波长范围内的 MIR 辐射非相干调制。发光的比例调制能够实现~0.3 nW × µm ^-2的检测限，内部量子效率约为 3 × 10 ^-3. 基于镧系元素纳米传感器的比率传感器不需要低温冷却、偏振控制、相位匹配或用于光限制的纳米天线设计。我们还开发了一种带有镧系元素纳米传感器的相机，可以实现室温 MIR 成像。我们预计这些镧系元素纳米传感器可以扩展到微尺度的 MIR 光操作，用于芯片集成设备应用。