针对大于500℃的高温环境, 提出了一种可用于高温温度测量的高温光子晶体光纤(PCF)温度传感器。在光子晶体光纤末端熔接一段纯石英无芯光纤构成外腔式光纤法珀腔(EFPI)结构。纯石英无芯光纤在高温下的热膨胀和热光效应使得EFPI的光学腔长发生变化。结合光纤白光干涉测量技术, 通过测量EFPI的腔长得到被测温度。在不同温度环境下, 对腔长为175μm的EFPI光纤温度传感器进行连续测量。测量结果显示, 设计的高温光纤温度传感器在27~1100℃范围内, 腔长-温度三阶拟合精度达到99.95%, 腔长-温度灵敏度为(0.851+0.0023T-0.000000957T2)nm/℃, 其中在1100℃时, 温度测量分辨率为0.225℃。

A photonic crystal fiber (PCF) based high-temperature sensor is developed, which can be used in the temperature of higher than 500℃. The structure of the sensor is an Extrinsic Fabry-Perot Interferometer (EFPI) with a section of pure silica coreless fiber spliced to the end of a PCF. Thermal expansion and thermo-optic effect of the pure silica coreless fiber lead to the change of the optical cavity length. Based on the fiber optic white-light interferometry (WLI), the temperature is obtained by measuring the cavity length of the EFPI. The EFPI fiber optical temperature sensor with a cavity length of 175μm is measured in different temperature. The results show that the temperature fitting accuracy of 99.95% and the cavity length-temperature sensitivity of (0.851+0.0023T-0.000000957T2)nm/℃ are obtained within the temperature ranges from 27℃to 1100℃, and the temperature resolution is 0.225℃ at 1100℃.