Simultaneous Measurement of Gas Pressure and Temperature Sensor Based on F-P Interference Using Hollow Core Bragg Fiber
Maocheng Guo, Qi Zhang, Zhixuan Su, Hongtian Zhu, Rui Liang, Chengfei Zhang, Bo Wang, Bin Guo, Yongqiu Zheng, Jiamin Chen, Zhenyin Hai, Chenyang Xue
Abstract
An optical fiber Fabry-Pérot interferometer (FPI) sensor offering simultaneous measurement of temperature and pressure is proposed. This sensor is constructed by fusion splicing a single-mode fiber-hollow core Bragg fiber-single-mode fiber (SMF-HCBF-SMF) structure. The HCBF serves as a pressure-sensitive unit on which gas channels are realized by femtosecond laser machining. The last segment of the SMF serves as a temperature-sensitive unit. The fast Fourier transform-minimum mean square error (FFT-MMSE) algorithm demodulates the sensor’s optical cavity lengths to realize the temperature and pressure measurement in the temperature range of 25 °C–600 °C. Experiments demonstrate that the sensor exhibits high linearity. The sensor’s pressure sensitivity decreases as temperature increases. At 25 °C and 600 °C, the pressure sensitivities are 158.3 and 51.9 nm/MPa, and the temperature sensitivity is 3.8 nm/°C. The pressure full-scale error is only 4% across the entire temperature range when using the temperature-pressure decoupling calculation method. The high-temperature and high-sensitivity characteristics of the proposed sensor highlight its potential for monitoring gas pressure in extremely high-temperature environments.