Abstract

A simply fabricated, highly sensitive, and inexpensive optical fiber temperature sensor is reported with a Fabry–Perot (FP) microcavity of controlled length. The microcavity with controllable length is fabricated by single-mode fiber (SMF) and polydimethylsiloxane (PDMS) for temperature sensing. After the PDMS is cured, the SMF is connected to the supercontinuum light source (SCLS) and the optical spectrometer analyzer (OSA) for online observation of the reflection spectrum. The micro-displacement platform is used to pull the SMF to form an air cavity. After the air cavity is stabilized, ultraviolet (UV) activated glue is used for packaging outside the PDMS. The FP microcavity is formed by the end face of the SMF and the face of PDMS. The length of the FP microcavity can be controlled online by the micro-displacement platform to a minimum of 15 µm. The free spectral range (FSR) may reach 74.8 nm and the interference fringe contrast (IFC) is up to 19.8 dB to allow sensitive measurements across a wide temperature range. The experiments demonstrate a high temperature sensitivity of 5.388 nm/°C from 33 to 93 °C with high repeatability and linearity (R²=0.9937). Stability experiments showed that the maximum changes in wavelength and intensity are only 45 pm and 0.035 dB, respectively. It is anticipated that the easily constructed, compact, and inexpensive fiber-optic temperature sensor will be employed in practical applications.

摘要

据报道，一种制造简单、高度灵敏且价格低廉的光纤温度传感器具有可控长度的法布里-珀罗 (FP) 微腔。长度可控的微腔由单模光纤（SMF）和聚二甲基硅氧烷（PDMS）制成，用于温度传感。PDMS固化后，SMF连接超连续谱光源（SCLS）和光谱分析仪（OSA），在线观察反射光谱。微位移平台用于拉动SMF形成气腔。气腔稳定后，使用紫外线 (UV) 活化胶在 PDMS 外部进行封装。FP 微腔由 SMF 的端面和 PDMS 的面形成。FP 微腔的长度可以通过微位移平台在线控制到最小 15 µm。自由光谱范围 (FSR) 可达 74.8 nm，干涉条纹对比度 (IFC) 高达 19.8 dB，可在宽温度范围内进行灵敏测量。实验证明在 33 至 93 °C 范围内具有 5.388 nm/°C 的高温灵敏度，具有高重复性和线性度（R ² =0.9937)。稳定性实验表明，波长和强度的最大变化分别仅为 45 pm 和 0.035 dB。预计这种结构简单、结构紧凑且价格低廉的光纤温度传感器将在实际应用中得到应用。