针对深井温度变化小, 提出了一种可用于深井温度测量的高灵敏度光纤温度传感器。两根陶瓷插芯从铝管的两端插入构成外腔式光纤法珀干涉仪(EFPI)结构, 用螺钉固定插芯, 再用高强度的环氧树脂密封该结构, 达到防水防尘效果。金属铝和陶瓷插芯具有不同的热膨胀系数, 温度的变化将引起EFPI腔长变化, 采用高灵敏度光纤白光干涉测量技术, 就可以通过测量EFPI腔长获得被测温度。分别在固定温度和不同温度下, 对腔长为 146.5μm的 EFPI光纤温度传感器进行了连续测量。测量结果表明, 高灵敏度EFPI光纤温度传感器的腔长-温度灵敏度为260nm/℃, 温度测量分辨率为0.002℃。

提出了一种基于飞秒激光加工技术制作的微纳光纤高温压力传感器。用飞秒激光在光纤端面加工出法珀腔, 制作出的全光纤法珀干涉型压力传感器, 从室温到1100℃范围进行了压力温度试验。在不同温度下, 压力传感器都有良好的线性输出特性, 短时间工作温度超过1100℃, 能够满足高温环境下压力测量的需求。

By using a graded-index multimode fiber (GI-MMF) with a relatively flat index profile and high refractive index of the fiber core, a microextrinsic fiber-optic Fabry?P′erot interferometric (MEFPI) strain sensor is fabricated through chemical etching and fusion splicing. Higher reflectance of the microcavity is obtained due to the less-curved inner wall in the center of the fiber core after etching and higher index contrast between the GI-MMF core and air. The maximum reflection of the sensor is enhanced 12 dB than that obtained by etching of the Er- or B-doped fibers. High fringe contrast of 22 dB is obtained. The strain and temperature responses of the MEFPI sensors are investigated in this experiment. Good linearity and high sensitivity are achieved, with wavelength-strain and wavelength-temperature sensitivities of 7.82 pm/\mu \varepsilon and 5.01 pm/?C, respectively.