针对环境测温, 特别是在复杂环境中温度传感器的小体积、低成本、抗干扰以及高灵敏度的要求, 提出了基于端面腐蚀的双法布里-珀罗光纤温度传感探头。以长为2 cm的光子晶体光纤作为第一个F-P腔体, 在它的一个端面熔接普通单模光纤, 熔接面形成第一个反射镜面; 然后, 在它另一个端面熔接多模光纤, 熔接面形成第二个反射镜面; 最后, 以多模光纤作为第二个F-P腔体, 并用氢氟酸将其刻蚀成探针结构, 同时在腔体末端形成了第三个反射镜面。以此复合结构作为传感探头, 结合多光束干涉的传感原理, 构造了双F-P结构的波长调制型传感器, 并搭建了温度传感测试系统。测试结果表明: 在28~81 ℃内, 随着温度增加, 该传感器的反射光谱波长逐渐红移, 温度与波长偏移量的线性相关系数高达0.998 37; 该传感器传感性能良好, 灵敏度达64.6 pm/℃。该传感器在复杂环境中对小范围温度测量具有潜在的应用价值。

To fulfill the requirements of small volume, low cost, anti-interference ability, high sensitivity, and real-time and accurate temperature measurement in a complex environment, a double Fabry-Pérot (F-P) fiber optical temperature sensor based on end-face corrosion was proposed. The sensor was fabricated by fusion Endlessly Photonic Crystal Fiber (EPCF) with a Multi-Mode Fiber (MMF). There are three F-P reflectors: one between the Single-Mode Fiber(SMF) and EPCF, one between EPCF and MMF, and one at the interface of MMF and air. The first F-P cavity was formed by the fusion of a SMF and a 2-cm EPCF, the second F-P cavity was formed by fusion splicing an MMF and EPCF; finally, a probe structure was obtained by hydrofluoric acid etching. A wavelength modulation sensor with double F-P structure was constructed by using the composite structure as the sensing probe and the multi-beam interference sensing principle. Simultaneously, a temperature sensing test system was constructed. Results show that in the range of 28-81 ℃, the wavelengths of the reflection spectra appear red-shifted with increasing temperature, and the linearity between temperature and wavelength shift is 0.998 37. The sensor has high sensitivity, which reaches up to 64.6 pm/℃. These sensors may have a potential application for small-range temperature measurements in complex environments.