基于马赫-曾德尔干涉的球形结构光纤温度传感器

A temperature sensor using spherical-shaped fibers based on March-Zehnder interference

提出一种基于马赫-曾德尔干涉的球形结构光纤 温度传感器。该传感器通过在单模光纤上熔接两个球 形结构形成球形-单模-球形结构的马赫-曾德尔干涉仪。外界温度的变化会引起光纤包层 模的有效折射率变化, 从而导致干涉光谱的变化,通过检测干涉谷的特征波长漂移量,实现对温度的测量。实验结 果表明,在温度 变化范围为18～78℃时,当中间单模光纤长度为1.8cm时,传感器 的灵敏度为0.129nm/℃ ,当中间单模 光纤长度为2.4cm时,传感器灵敏度为0.121 nm/℃,当中间单模光纤长度为4.0cm时,传感器灵敏度为 0.070nm/℃。根据0.01nm的波长分辨率,该传感器可以实现温度 的分辨率为0.077℃。该球形结构的 光纤温度传感器灵敏度高、结构紧凑、制作简单、成本低廉,在温度检测方面具有良好的应用前景。

A temperature sensor using spherical-shaped fibers based on the March -Zehnder interference is proposed.The proposed fiber optic sensor ca n be achieved by cascading two spherical-shaped single mode fiber （SMF） structures.The effective refractive in dex of the cladding mode changes with the external temperature,and then the interference transmission sp ectra change accordingly.By observing the wavelength shifts of the interference dip,tempera ture can be measured. Experimental results show that when the temperature changes from 18℃ to 78℃, the sensitivity is 0.1297nm/℃ when the spacing of the two spherical-shaped structures is 1.8cm.And wh en the spacing is 2.4cm,the sensitivity is 0.1214nm/℃.When the spacing is 2.4cm,the sensitivity is 0.0704nm/℃. According to the wavelength resolution of 0.01nm,the sensor can achieve a resolution of 0.0771℃. The temperature sensor based on spherical-shaped fibers has many advantages,in cluding high sensitivity,compact,simple and low cost.Therefore,it has great pote ntial for measurement of temperature.