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

A novel high sensitivity pressure sensor based on all-fused-silica extrinsic Fabry–Pérot 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
${\rm nm}/^{\circ}{\rm C}$
, and pressure measurement error is limited within 0.0021
${\rm KPa}/^{\circ}{\rm C}$
(0.0003
${\rm psi}/^{\circ}{\rm C}$
). 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.