摘要:提出一种干涉式全光纤传感器,能够同时实现对折射率和轴向拉力或温度进行双参数测量。传感器由一个微腔和一个纤芯失配衰减器组成。其中微腔结构是由飞秒激光加工光纤纤芯形成,直径和深度分别是6μm和2.5μm。该干涉式传感器可以获得20dB的高品质干涉对比度。传感器透射谱波长为1496.68nm和1533.18nm的两个衰减峰对应的折射率灵敏度分别为-29.91nm/RIU和-16.72nm/RIU,拉力灵敏度分别为-1.55pm/με和--0.31pm/με。实验结果表明,传感器通过灵敏度矩阵可以同时测量折射率和轴向拉力或温度两个参数。
An inline fiber sensor is proposed for simultaneously measure refractive index (RI) and axial strain or tem- perature and axial strain. The proposed sensor consists of a microcavity and a fiber core-offset attenuator. The microcavi- ty with the diameter of 6htm and the depth of 2.5ptm is embedded in the fiber core fabricated by a femtosecond laser. High quality interference spectra with a fringe visibility around 20dB are observed. For attenuation peak wavelengths at 1496.68nm and 1533. 18nm, the RI sensitivities are --29. 91nm/RIU and --16. 72nm/RIU, the strain sensitivities are --1.55pm/με and --0. 31pm/με, respectively. The experimental results demonstrate that the sensor is able to achieve simultaneous measurements of refractive index and axial-strain or temperature by sensitivity matrix.