Sensitivity-enhanced temperature and strain sensor based on a UFPMF Sagnac loop cascaded with a SCMOF probe

• Published in: Sensors and actuators. A. Physical. 2023-10, Vol.361, p.114610, Article 114610
• Main Authors: Zuo, Cheng, Wu, Kaiyang, Shi, Jinhui, Guang, Dong, Wu, Xuqiang, Yu, Benli
• Format: Article
• Language: English
• Subjects: Fabry-Perot interferometer; Fiber Sagnac interferometer; Strain sensor; Temperature sensor; Vernier effect
• ISSN: 0924-4247; 1873-3069
• DOI: 10.1016/j.sna.2023.114610

A sensitivity-enhanced temperature and strain sensor based on a fiber Sagnac interferometer (FSI) cascaded with a suspended-core microstructured optical fiber (SCMOF) Fabry-Perot probe is proposed and experimentally demonstrated. The FSI consisted of a certain length of high birefringence ultra-fine polarization maintaining fiber (UFPMF) as the sensing interferometer. The cascaded Fabry-Perot interferometer (FPI) is fabricated by fusion splicing a SCMOF tip with a single mode fiber (SMF) as the reference interferometer. By adjusting the length of the UFPMF in the FSI, the free spectral ranges (FSRs) of the FSI and FPI can be easily made similar, thus creating a Vernier effect and achieving enhanced sensitivity. The experimental results show that under the influence of the Vernier effect, the temperature sensitivity and strain sensitivity of the cascaded sensors are 30.909 nm/℃ and −52.57 pm/με, respectively. With the advantages of simple production, easy fabrication, and high sensitivity, this sensor has a wide application prospect in the fields of aerospace and precision measurement. [Display omitted] •A sensitivity-enhanced temperature and strain sensor based on vernier effect is proposed.•The FPI is an ideal reference interferometer that is insensitive to temperature and strain compared to the FSI.•The length of the sensing fiber for FSI sensing is significantly reduced due to the high birefringence coefficient of UFPMF.•The production of both interferometers requires only simple fusion splicing and cleaving.•The temperature sensitivity and strain sensitivity of the cascaded sensors are 30.909 nm/℃ and −52.57 pm/με, respectively.