Wang Mohan, Yang Yang, Huang Sheng, Wu Jingyu, Zhao Kehao, Li Yuqi, Peng Zhaoqiang, Zou Ran, Lan Hui, Ohodnicki Paul R, Lu Ping, Buric Michael P, Liu Bo, Yu Qingxu, Chen Kevin P
Opt Express. 2020 Jul 6;28(14):20225-20235. doi: 10.1364/OE.395382.
This paper presents a method of using femtosecond laser inscribed nanograting as low-loss- and high-temperature-stable in-fiber reflectors. By introducing a pair of nanograting inside the core of a single-mode optical fiber, an intrinsic Fabry-Perot interferometer can be created for high-temperature sensing applications. The morphology of the nanograting inscribed in fiber cores was engineered by tuning the fabrication conditions to achieve a high fringe visibility of 0.49 and low insertion loss of 0.002 dB per sensor. Using a white light interferometry demodulation algorithm, we demonstrate the temperature sensitivity, cross-talk, and spatial multiplexability of sensor arrays. Both the sensor performance and stability were studied from room temperature to 1000°C with cyclic heating and cooling. Our results demonstrate a femtosecond direct laser writing technique capable of producing highly multiplexable in-fiber intrinsic Fabry-Perot interferometer sensor devices with high fringe contrast, high sensitivity, and low-loss for application in harsh environmental conditions.
本文提出了一种利用飞秒激光写入纳米光栅作为低损耗且高温稳定的光纤内反射器的方法。通过在单模光纤纤芯内部引入一对纳米光栅，可以创建用于高温传感应用的本征法布里-珀罗干涉仪。通过调整制造条件来设计光纤纤芯中写入的纳米光栅的形态，以实现0.49的高条纹可见度和每个传感器0.002 dB的低插入损耗。使用白光干涉解调算法，我们展示了传感器阵列的温度灵敏度、串扰和空间复用能力。通过循环加热和冷却，研究了从室温到1000°C的传感器性能和稳定性。我们的结果表明，飞秒直接激光写入技术能够生产出具有高条纹对比度、高灵敏度和低损耗的高度可复用的光纤内本征法布里-珀罗干涉仪传感器装置，适用于恶劣环境条件。
