基于马赫-曾德干涉的全光纤双参量传感器

提出一种基于S形-错位结构的全光纤马赫-曾德干涉仪（MZI）双参量传感器。该传感结构是采用单模光纤在光纤熔接机中通过简单的放电和熔接等步骤制备而成。顺时针扭转时, 传感器的传输光谱向短波长方向偏移; 逆时针扭转, 向长波长方向偏移。对传感器的实验研究结果表明，该传感器在光纤横截面上顺时针和逆时针两个旋转方向上的扭曲传感灵敏度分别为?223 pm/(rad·cm?1), 140 pm/(rad·cm?1)，且可实现扭转方向的判别，在一定应变范围内的应变灵敏度为0.145×106 dB/ε(这里ε为应变)，且温度交叉灵敏度极小，可忽略不计。因此，这种基于单模光纤的纤芯-包层MZI双参量传感器具有传感灵敏度高，体积小巧，工艺简单，成本低廉且可判别扭转方向的优点，有望成为众多双参量测量操作中良好的候选仪器之一。

All-fiber dual-parameter sensor based on Mach-Zehnder interference

This paper proposes an all-fiber Mach-Zehnder Interference (MZI) dual-parameter sensor based on S-shaped-dislocation structure. The sensor is prepared by using fusion splicer through simple discharge and fusion splicing steps, with pieces of single-mode fibers. When the rotator is twisting clockwise, the transmission spectrum of the sensor shifts to the short wavelength direction; when it is twisting counterclockwise, the transmission spectrum shifts to the different direction. The sensor’s torsion experimental results show that the torsion direction can be distinguished, and the torsion sensitivity in the clockwise and counterclockwise rotation directions on the fiber cross-section is ?223 pm/(rad·cm?1), 140 pm/(rad·cm?1), respectively. The strain sensitivity within a certain strain range is 0.145×106 dB/ε (where ε is strain), and the temperature cross sensitivity is extremely small and can be ignored. Therefore, this dual-parameter sensor based on the SMF core-cladding MZI interferometer has the advantages of high sensing sensitivity, small size, simple process, low cost, and distinguishable torsion direction. It is expected to become a good candidate instruments in many dual-parameter measurement operations.