Lyot-Sagnac与Fabry-Pérot级联增敏的光纤温度传感器

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中图分类号：TP394.1;TH691.9 文献标志码：Adoi：10.37188/CO.2025-0068 CSTR：32171.14.CO.2025-0068

Sensitivity-enhanced fiber-optic temperature sensor using cascaded Lyot-Sagnac and Fabry-Pérot interferometers

ZHANG Guo-sheng*， CHEN Yu-lei， CHAI Guo-qiang，HAN Jian-ning （School ofPhysics and Information Engineering，Shanxi Normal UniversityTaiyuan O3oo31，China） * Corresponding author，E-mail： opticalzgs@163.com

Abstract： To effectively enhance detection sensitivity and practicality，this paper proposes a fiber-optic temperature sensor based on a cascaded Lyot-Sagnac sensing structure sensitized by the Vernier effect and a Fabry-Perot interferometer （FPI）. The Lyot-Sagnac structure is fabricated by splicing polarization-maintaining fibers （PMFs） of different lengths with a 90∘ rotation， while the FPI is constructed using a hollow-core photonic crystal fiber （HCPCF） as the Fabry-Perot cavity. The results of theoretical analysis demonstrates that the Lyot-Sagnac structure fabricated via the 90∘ rotated splicing method exhibits a well-defined output spectral envelope.When cascaded with an FPI， it can significantly improve temperature detection sensitivity through the Vernier effect. The experimental results show that the temperature sensitivity of the cascaded sensor is 12.56nm∘C and 92.77nm/∘C when utilizing PMFs of different lengths in the Lyot-Sagnac sensor structure as the sensing regions. Compared to the standalone Lyot-Sagnac interferometeric structure，the sensitivity of the proposed sensor is improved by approximately 57 times. In addition， under the same measurement bandwidth， the measurement range of PMF1 mode is 9.3 timesthat of PMF2 mode.Therefore， compared to the traditional vernier-effect-based fiber-optic temperature sensors， the dual-response-mode temperature sensor proposed in this paper not only exhibits superior detection sensitivity， but also enables effective adaptation to application scenarios requiring different detection ranges and sensitivity levels using the same spectral detection equipment， providing a new idea for developing tunable-performance fiber-optic temperature sensors.

Key Words： fiber-optic temperature sensor;Lyot-Sagnac structure; vernier effect; Fabry-Perot interferometer

1引言

光纤传感器，因其超高的检测灵敏度、良好的抗电磁干扰能力和轻巧便捷的传感结构等独特优势，在传感技术领域已获得广泛应用。（剩余14294字）