Enhanced High-Temperature Gas Pressure Sensor based on a Fiber Optic Fabry-Pérot Interferometer Probe

The sensors capable of measuring a wide range of pressures at high temperatures are critically needed in the industrial fields. We propose an optical fiber tip probe pressure sensor based on Fabry-Pérot interferometer (FPI). This sensor is fabricated by splicing single-mode, multimode, and hollow-core fibers using arc discharge technology. Pressure is detected by demodulating the change in cavity length of the FPI. Experimental results show that the sensor's pressure sensitivity can reach -9.81 nm/MPa within a pressure range of 0-12 MPa. It maintains excellent optical properties from 20 to 1100°C, exhibiting a temperature sensitivity of 0.327 nm/°C. To enhance pressure measurement precision at high temperatures, a fiber Bragg grating is integrated into the FPI structure for temperature sensing and error correction. The simplicity and stability of the proposed sensor make it suitable for reliable gas pressure measurements in high-temperature environments.