一种低成本FBG高温传感器的研究

采用相位掩模法,利用紫外光在载氢普通掺锗单模石英光纤中制作出光纤布拉格光栅(FBG)。同时,将反射率为17dB的光栅FBG1和反射率为41dB的光栅FBG2置于30～1000℃的高温炉内进行温度特性比较实验。在30～870℃范围内FBG1和FBG2两者中心波长随温度的变化趋势一致,且两个光栅反射波长都在870℃时消失,当温度继续升高到900℃时,仅有FBG2再次出现反射率为1dB的反射峰。对经过高温处理后的FBG2再次进行30～1000℃温度测量实验,温度灵敏度为0.02nm/℃,线性度为0.999。实验结果表明,对于具有高反射率的FBG进行高温热处理后,其可以在30～1000℃的温度范围内进行传感测量,且中心波长随温度变化呈良好的线性关系。利用该方法可以制作出低成本的可用于高温环境测量的FBG温度传感器。

Research on Low-cost FBG High-temperature Sensor

Fiber Bragg gratings(FBG) were fabricated in Ge-doped single mode fiber by UV exposure through phase mask. FBG1 and FBG2 sensors with different refractive indexed of 17 dB and 41 dB were monitored from 30 ℃ to 1 000 ℃ to make comparisons of their temperature characteristics. It was showed that the reflective wavelength for both FBG gratings disappeared at 870 ℃. However, when the temperature was up to 900 ℃, the reflective peak with the reflective index of 1 dB only appeared for FBG2. Then FBG2 was again monitored from 30 ℃ to 1 000 ℃ to make temperature measurement., with the temperature sensitivity of 0.02 nm/℃ and the linearity of 0. 999. The results show that the annealed FBG with higher refleetivity can measure temperature ranging from 30 ℃ to 1 000 ℃, and the range can be increased by using annealing treatment. And this method can be used to fabricate low-cost FBG sensors for high temperature measurements.