基于增强型谐波游标效应的光纤温度传感器

Fiber optic temperature sensor based on enhanced harmonic vernier effect

提出一种基于增强型谐波游标效应增敏的光纤温度传感器,该传感器由光纤萨格奈克干涉计(Sagnac Interferometer,SI)和法布里-珀罗干涉计(Fabry-Perot Interferometer,FPI)级联构成。通过控制FPI的自由光谱范围为SI的自由光谱范围的整数倍且两者具有相反的温度响应,实现增强型谐波游标效应。实验结果表明,增强型谐波游标效应和增强型普通游标效应具有几乎相同的温度灵敏度,分别为单个FPI和SI灵敏度的28.7倍和16.9倍,增强型谐波游标放大倍率分别为普通谐波游标放大倍率的3.4倍和1.8倍,但增强型谐波游标效应对应的熊猫光纤长度失谐量明显大于增强型普通游标效应,且阶数越高对应的失谐量越大,因此,增强型谐波游标放大倍率更容易控制和实现。该传感器在获取高灵敏度的同时,稳定性能好、制备成本低,具有非常好的应用前景。

The proposed temperature sensor utilizes the enhanced harmonic vernier effect in an optical fiber system,combining an optical fiber Sagnac interferometer(SI)with a Fabry-Perot interferometer(FPI).By aligning the FPI's free spectral range as a multiple of the SI's,with opposite temperature responses,the enhanced harmonic vernier effect is achieved.Experiments show that this effect and the enhanced normal vernier effect have comparable temperature sensitivity,being 28.7 and 16.9 times greater than those of single FPI and SI,respectively.In addition,the magnification of the enhanced harmonic vernier is 3.4 and 1.8 times that of the normal harmonic vernier.However,the detuning of the Panda fiber length for the enhanced harmonic vernier effect is significantly larger than for the enhanced normal vernier effect,with detuning increasing with order.The enhanced harmonic vernier's magnification is also easier to control at higher orders.The sensor demonstrates high sensitivity,excellent stability,and low preparation cost,offering promising prospects for practical applications.