Temperature-Insensitive Pressure Sensor Based on All-Fused-Silica Extrinsic Fabry-Perot Optical Fiber Interferometer

A novel high sensitivity pressure sensor based on all-fused-silica extrinsic Fabry-Perot optical fiber interferometer, which exhibits extreme low temperature dependence, has been developed. The sensor can approach a sensitivity of 5.18 nm/KPa (35.72 nm/psi), a resolution of 38 Pa (0.005 psi). Due to epoxy-free bonding and reserving a vent hole between the fiber and the ferrule in the process of laser heating fusion bonding, the temperature dependence is significantly reduced to the 0.011 nm/degrees C, and pressure measurement error is limited within 0.0021 KPa/degrees C (0.0003 psi/degrees C). The operating point does not shift with backpressure change due to the vent hole. The sensor is able to be used in the liquid measurement, environmental monitoring, and other industrial applications in harsh environment.