基于双细锥型结构的M-Z干涉仪的光纤湿度传感器

Optical fiber humidity sensors based on M-Z interferometerswith double fine cone structure

目的:提出一种基于双细锥型结构的M-Z干涉仪的光纤传感器,并通过分析传感器结构制作和传感原理,验证其传感性能。方法:利用特种光器件精密微加工平台(LDS2.5,3SAE Technologies,Inc/美国)制作双细锥形结构,锥形直径为40μm,双锥间距离为2 cm,锥形渐变区域为500μm,在RH40%~80%范围内进行实验。结果:通过实验验证了在20℃~95℃温度范围内其最大灵敏度为208.6 pm/℃、在RH50%~70%和70%~80%的湿度变化范围内传感器的灵敏度分别为-0.019 dB/%RH、-0.055 dB/%RH。结论:双细锥形结构光纤传感器具有尺寸紧凑、结构简单、成本较低、灵敏度较高等优点,有良好的湿度线性响应关系,可通过强度变化或者波长解调实现温湿度的测量。

Aims:This paper proposes an optical fiber sensor based on M-Z interferometers with double fine cone structure,analyzes the sensor structure fabrication and sensing principle,and verifies its sensing performance.Methods:A special optical device precision micromachining platform(LDS2.5,3SAE Technologies,Inc/USA)was used to make a double-fine cone structure with a cone diameter of 40μm,a distance between the double cones of 2 cm,and a tapered gradient area of 500μm.The experiment was conducted in the humidity range of RH40%~80%.Results:Experiments verified that the maximum sensitivity was 208.6 pm/℃in the temperature range of 20℃~95℃;and the sensitivity of the sensor was-0.019 dB and-0.055 dB in the humidity range of RH50%~70%and RH70%~80%,respectively.Conclusions:The optical fiber sensor with double fine tapered structure has the advantages of compact size,simple structure,low cost and high sensitivity.It has a good linear response of humidity and can achieve temperature and humidity measurement through intensity change or wavelength demodulation.