Gas Pressure Sensor With Low Detection Limit Based on Fabry-Perot Interferometer and Intracavity Sensing of Fiber Ring Laser

The measurement of gas pressure with low detection limit is of great significance and remain challenging. In this work, a gas pressure sensing system with a low detection limit is proposed based on Fabry-Perot interferometer and intracavity sensing of fiber ring laser. A miniature pressure-sensitive fiber-optic Fabry-Perot interferometer is fabricated with polyimide film by a 3D printed resin shell. Then, it is coupled in a fiber ring laser. The reflection loss of the Fabry-Perot interferometer is modulated at different gas pressures. With the intracavity gas pressure sensing induced, the gas pressure can be measured by the output power of the fiber ring laser. The detection limit of the gas pressure sensing system has been greatly optimized from 0.155 KPa to 0.01 KPa. The temperature cross-sensitivity and measurement stability of the gas pressure sensing system are also analyzed. The proposed sensing method can be applied to similar sensors to optimize measurement detection limit.