Highly sensitive fiber-optic temperature sensor with compact hybrid interferometers enhanced by the harmonic Vernier effect

作者：Wenlong Yang, Rui Kun Pan, Liuyang Zhang, Yuqiang Yang, Linjun Li, Shuang Yu, Xiaoming Sun, Xiaoyang Yu · 发表于：Optics Express · 年份：2023 · DOI：10.1364/oe.485208 · 被引用次数：54 · 研究领域：Advanced Fiber Optic Sensors、Photonic and Optical Devices、Advanced Sensor Technologies Research

A compact fiber-optic temperature sensor with hybrid interferometers enhanced by the harmonic Vernier effect was proposed, which realized 36.9 times sensitization of the sensing Fabry-Perot interferometer (FPI). The hybrid interferometers configuration of the sensor consists of a FPI and a Michelson interferometer. The proposed sensor is fabricated by splicing the hole-assisted suspended-core fiber (HASCF) to the multi-mode fiber fused with the single-mode fiber, and filling polydimethylsiloxane (PDMS) into the air hole of HASCF. The high thermal expansion coefficient of PDMS improves the temperature sensitivity of the FPI. The harmonic Vernier effect eliminates the limitation of the free spectral range on the magnification factor by detecting the intersection response of internal envelopes, and realizes the secondary sensitization of the traditional Vernier effect. Combing the characteristics of HASCF, PDMS, and first-order harmonic Vernier effect, the sensor exhibits a high detection sensitivity of -19.22 nm/°C. The proposed sensor provides not only a design scheme for compact fiber-optic sensors, but also a new strategy to enhance the optical Vernier effect.