基于飞秒激光制备的光子晶体光纤Fabry-Perot温度传感器

提出并设计了一种基于飞秒激光在光子晶体光纤(photonic crystal fiber,PCF)中制备光纤法布里-珀罗(Fabry-Perot,F-P)传感器的方法。采用飞秒脉冲激光作为加工光源,结合放大倍率100×的物镜以及三维加工平台在PCF侧面采用逐线刻写方式进行加工。通过对飞秒激光光斑在光纤上的聚焦位置以及刻写功率进行优化,在PCF上刻写了深度均为80μm、间隔为800μm的两条划线,实现了周期为0.98nm的全光纤F-P结构制备;实验中,对传感器在40~120℃温度范围内的光谱特性进行了测试与分析,每隔10℃进行一次数据采集,随着温度逐渐增加波长向长波方向漂移,通过对该采样点数据进行线性拟合,得到该测试点的波长温度灵敏度为9.73pm/℃,拟合线性度为0.997。

Study on temperature characteristics of PCF Fabry-Perot sensor fabricated by femtosecond laser

An all-fiber photonic crystal fiber(PCF) Fabry-Perot(F-P) sensor fabricated by femtosecond laser was designed and proposed in the paper.Femtosecond pulse laser was used as the processing light source,and the PCF side is processed by line-by-line engraving method with the object lens of 100× magnification and the three-dimensional processing platform.A pair of lines with 80 μm deep and 800 μm spaced was written by optimizing the laser focusing position and writing power on the side of PCF,and an all optical fiber F-P structure was prepared whose cycle was 0.98 nm;In the experiment,the spectral characteristics of the sensor in the temperature range of 40~120 ℃ were tested and analyzed,whose data acquisition was recorded at intervals of 10 ℃.As the temperature increased,the wavelength drifted toward the long wave direction.The temperature sensitivity and fitting linearity of the testing point,which were 9.73 pm/℃ and 0.997,were got via linear fitting the sampling data.