A Highly Sensitive Dual Optical Fiber Parallel FPI Pressure Sensor

In recent years, the optical fiber pressure sensors have been widely used in the fields, such as medical diagnosis and environmental monitoring, among others. However, the sensitivity of traditional optical fiber pressure sensors falls short of meeting the requirements for high-precision measurement. In this article, a highly sensitive dual optical fiber parallel Fabry–Pérot interferometer (FPI) pressure sensor is proposed, accompanied by the theoretically analyze about its working principle, along with a simulation model for optical fiber deformation and optical field intensity analysis. Finally, an experimental platform is built, and the performance of the proposed sensor is tested and evaluated. The experimental results show that, in the pressure range of 0–1 N, the sensitivity is 29.91 nm/N for the single optical fiber FPI pressure sensor and 227.21 nm/N for the dual optical fiber parallel FPI pressure sensor. Additionally, the temperature sensitivity of this sensor turns out to be 0.075 nm/°C, indicating that it is almost unaffected by temperature and has great repeatability. This design provides a new solution for high-precision measurement of optical fiber pressure sensors.