We report the demonstration of fiber Bragg grating (FBG) fabricated in silica capillary fiber by use of femtosecond laser. The FBG is inscribed in the silica cladding surrounding the air core by a transversal scanning method through a phase mask. Multimode resonances which result from the overlap of the grating structure and the cladding modes transmitting in the capillary fiber, are observed in the reflection spectra. Sensing capability the FBG is exemplified by infiltrating the hollow core with liquids of different refractive indices (RIs), and shift in resonant wavelengths is observed. The temperature characteristic is investigated with a heating treatment from room temperature to 1000°C. Linear wavelength response is exhibited, with temperature sensitivity of 8 pm/°C. The FBG can be finding applications as optofluidic element for biochemical sensing.

中文翻译：

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用于传感应用的飞秒激光器制造的毛细光纤布拉格光栅

我们报告了使用飞秒激光器在石英毛细管光纤中制造的光纤布拉格光栅 (FBG) 的演示。通过相位掩模，通过横向扫描方法将 FBG 刻在围绕空芯的二氧化硅包层中。在反射光谱中观察到由光栅结构和在毛细管光纤中传输的包层模式重叠引起的多模共振。FBG 的传感能力通过用不同折射率 (RI) 的液体渗入空心并观察到谐振波长的偏移来举例说明。温度特性通过从室温到1000℃的热处理进行研究。表现出线性波长响应，温度灵敏度为 8 pm/°C。