摘要
设计了一种基于谐波游标效应的光纤温度传感器,该传感器由光纤萨尼亚克干涉计(SI)和法布里-珀罗干涉计(FPI)级联而成,其中FPI的自由光谱范围近似为SI的整数倍。将FPI作为参考干涉计,通过改变SI中熊猫光纤的长度,分别制备了基于0阶、1阶和2阶谐波游标效应的光纤温度传感器。实验结果表明:当游标效应放大倍率相同时,0阶、1阶和2阶谐波游标效应对应的光纤传感器具有几乎相同的温度灵敏度,但谐波游标效应对应的熊猫光纤长度失谐量明显大于普通游标效应,且阶数越高对应的失谐量越大。从放大倍率控制和制备难度上讲,谐波游标效应明显优于普通游标效应。以上实验结果与理论分析结果相吻合。
Objective Fiber optic sensors play an important role in the field of optoelectronics and have advantages such as small size,light weight,high sensitivity,anti-electromagnetic interference,and remote sensing.Temperature detection is one of the most basic applications of fiber optic sensors.Optical fiber temperature sensing is mainly based on the fiber optic grating and interferometer structures.Fiber optic gratings have a relatively low sensitivity to temperature,typically in the order of pm/℃,whereas the temperature sensitivity of fiber interferometers,such as Fabry-Perot (FPIs),Mach-Zehnder (MZIs),and fiber Sagnac interferometers(SIs),is relatively high,reaching the order of nm/℃.However,in some application areas,a temperature sensitivity of the order of nm/℃still cannot meet the requirements.To further improve the sensitivity of optical fiber interferometers,researchers have recently proposed the ordinary vernier effect (OVE) and harmonic vernier effect (HVE).Both the OVE and HVE are based on two cascaded or parallel interferometers.However,unlike the OVE,the HVE breaks the restriction stating that the optical path differences of cascaded or parallel interferometers in the OVE must be approximately equal.The optical path difference of one interferometer in the HVE can be an integer multiple of that of the other interferometer.Therefore,compared to the OVE,the HVE increases the design freedom of the sensor,which can lower the preparation difficulty to some extent.However,to date,there has been no research reported on this issue.Therefore,this study conducts an in-depth investigation on this issue.Methods A fiber-optic temperature sensor based on the HVE generated by a cascaded SI and FPI is proposed,in which the free spectral range of the FPI is approximately a multiple of that of the SI.First,we derive the sensitivity and detuning of the proposed sensor when the HVE is generated and then verify them via experiments.To facilitate analysis and verification,the magnifications for different order HVEs are designed to have the same value.In the experiments,by fixing the length of the FPI and adjusting the panda fiber length in the SI,the sensor generates the 0th-(that is,the OVE),1st-,and 2nd-order HVEs with approximately the same magnification.Results and Discussions Both the simulation and experimental results show that when the free spectral ranges of the FPI and SI satisfy R_(FSR,FPI)=(i+1) R_(FSR,SI),the i-order HVE can be generated.If R_(FSR,FPI)>(i+1) R_(FSR,SI),the interference spectrum envelope gradually blueshifts with increasing temperature,whereas if R_(FSR,FPI)<(i+1) R_(FSR,SI),the interference spectrum envelope gradually redshifts with increasing temperature.For the 0th-,1st-,and 2nd-order HVEs,the temperature sensitivities of the sensor are 18.88,18.49,and 17.80 nm/℃,respectively.Compared with that of a single SI,their sensitivity is amplified by 10.12 times,10.10 times,and 9.64 times,respectively,with corresponding panda fiber length detunings of 48,90,and 150 mm,respectively.If the amplification is the same,the OVE and HVE have almost the same temperature sensitivity;however,the panda fiber length detuning of the HVE is significantly larger than that of the OVE,and the higher the order of the HVE,the larger the detuning.Conclusions A fiber-optic temperature sensor based on the HVE generated by a cascaded SI and FPI is proposed,in which the free spectral range of the FPI is approximately a multiple of that of the SI.By fixing the length of the FPI and adjusting the panda fiber length in the SI,0th-,1st-,and 2nd-order HVEs with approximately the same magnification are generated.Both the simulation and experimental results show that if the amplifications are the same,the OVE and HVE have almost the same temperature sensitivity;however,the panda fiber length detuning of the HVE is significantly larger than that of the OVE,and the higher the order of the HVE,the larger the detuning.Therefore,in terms of preparation difficulty,the HVE is evidently better than the OVE.
作者
杨玉强
李雨婷
牟小光
高佳乐
张钰颖
毕磊
Yang Yuqiang;Li Yuting;Mu Xiaoguang;Gao Jiale;Zhang Yuying;Bi Lei(Shenzhen Institute,Guangdong Ocean University,Shenzhen 518120,Guangdong,China;Guangdong Provincial Key Laboratory of Intelligent Equipment for South China Sea Marine Ranching,Guangdong Ocean University,Zhanjiang 524088,Guangdong,China;College of Mechanical Engineering,Guangdong Ocean University,Zhanjiang 524088,Guangdong,China;Research Center of Guangdong Smart Oceans Sensor Networks and Equipment Engineering,Guangdong Ocean University,Zhanjiang 524088,Guangdong,China;College of Continuing Education,Guangdong Ocean University,Zhanjiang 524088,Guangdong,China)
出处
《中国激光》
EI
CAS
CSCD
北大核心
2024年第13期233-242,共10页
Chinese Journal of Lasers
基金
广东省自然科学基金面上项目(2023A1515011212)
深圳市基础研究面上项目(JCYJ20210324122813036)
广东省普通高校重点领域专项(2021ZDZX1015)
广东海洋大学科研启动经费资助项目(060302112009)
广东海洋大学研究生教育创新计划(202328)。
