We demonstrate a microfiber Bragg grating as the reflective refractometer with the function of self-photoheating. The rare earth-doped fiber provides not only the photosensitivity to the UV modulation but also the effective pump laser absorption and photoheating conversion. The rare earth-doped microfiber Bragg grating, which is cladding-removed by the hydrofluoric acid, can detect the tiny refractive index change with a resolution of 10-4 RIU scale. The self-photoheating could be realized by 980 nm pump absorption and non-radiative transition process of the ytterbium and erbium ions, which are well-preserved by the core structure after etching. Monitored by the reflective grating signal, the photoheating can manipulate 30 °C increase of the device in the air, 8 °C in the ethanol, and 4 °C in the water. The second time-scale heating/cooling response allows the sensor to act as ad optical switch for engineering temperature. The work may open a new route for accelerative biosensing and pollutant determination and treatment.

中文翻译：

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具有自光热操纵功能的稀土掺杂微纤维布拉格光栅折射率传感器


我们展示了一种微光纤布拉格光栅作为具有自光加热功能的反射式折光仪。稀土掺杂光纤不仅提供了对紫外调制的光敏性，而且还提供了有效的泵浦激光吸收和光热转换。氢氟酸去包层的稀土掺杂微光纤布拉格光栅可以检测微小的折射率变化，分辨率达到10-4 RIU量级。自光加热可以通过镱和铒离子的980 nm泵浦吸收和非辐射跃迁过程来实现，并且在蚀刻后被很好地保留在核心结构中。通过反射光栅信号监测，光加热可以控制装置在空气中升高 30°C，在乙醇中升高 8°C，在水中升高 4°C。第二时间尺度加热/冷却响应允许传感器充当工程温度的光学开关。这项工作可能为加速生物传感和污染物测定和处理开辟一条新途径。