物理学报2017，Vol.66Issue(9)：190-197,8.DOI:10.7498/aps.66.094205
基于游标效应的增敏型光纤法布里-珀罗干涉仪温度传感器
Sensitivity-enhanced temperature sensor with fiber optic Fabry-Perot interferometer based on vernier effect
摘要
Abstract
Fiber-optic temperature sensors have gained much attention owing to their intrinsic features of light weight, im-munity to electromagnetic interference, and capability for distributed measurement. Especially, temperature sensors based on Fabry-Perot interferometers (FPIs) are attractive owing to their advantages of compact size and convenient reflection measurement. However, due to the low thermal expansion or/and thermo-optic coefficient of fiber, the tem-perature sensitivities of these sensors are normally low (~10 pm/℃ or even lower). In order to improve the temperature sensitivity, a device with dual cascaded FPIs is proposed and demonstrated in this paper, which works on vernier effect and exhibits a much higher temperature sensitivity. The device is fabricated by splicing a short segment of large mode area (LMA) fiber to a short segment of capillary tube fused with a section of single-mode fiber to form an extrinsic Fabry-Perot interferometer with a glass cavity cascaded to an intrinsic FPI with a narrow air cavity. By setting the lengths of capillary tube and LMA fiber to allow similar free spectral ranges to be obtained, and superimposing of the reflection spectra of the two FPIs, the vernier effect can be generated. Firstly, the principle of temperature sensing based on vernier effect of this device is analyzed and simulated theoretically, and it is found that the temperature sensitivity can be improved significantly by using vernier effect compared with that of a single FPI with an air-cavity or glass cavity by directly tracing resonant dips/peaks. Then, the temperature responses of the FPI with single air-cavity and dual cascaded cavities are measured, respectively. Experimental results match well with the theoretical analysis carried out. The temperature sensitivity of the proposed sensor is improved greatly from 0.71 pm/℃ for a single FPI sensor with an air-cavity to 179.30 pm/℃ by employing the vernier effect. Additionally, the sensor exhibits good repeatability in a temperature range of 100–500 ℃. The proposed sensor has the advantages of compact size (<1 mm in dimension) and high sensitivity, which makes it promising for temperature sensing in a variety of industries, such as food inspection, pharmacy, oil/gas exploration, environment, and high-voltage power systems.关键词
光纤传感/法布里-珀罗干涉仪/游标效应/温度Key words
fiber optic sensors/Fabry-Perot interferometer/vernier effect/temperature引用本文复制引用
杨易,徐贲,刘亚铭,李萍,王东宁,赵春柳..基于游标效应的增敏型光纤法布里-珀罗干涉仪温度传感器[J].物理学报,2017,66(9):190-197,8.基金项目
国家自然科学基金青年科学基金(批准号: 61405184)和浙江省自然科学基金(批准号: LY17F050010)资助的课题.Project supported by the National Natural Science Foundation of China (Grant No. 61405184) and the Zhejiang ProvincialNatural Science Foundation of China (Grant No. LY17F050010). （批准号: 61405184）
