Miniaturized Fiber Bragg Grating High Pressure Sensor Encapsulated by Metal Capillary Tube

The fiber grating pressure sensor is difficult to be used in the ultra-high pressure narrow environment due to the limitation of the package structure size and the strength of the sensitive element. For this reason, a miniaturized fiber grating sensor structure scheme with metal capillary package is proposed and simulated. The sensor is fabricated to achieve a miniaturization of 1mm. In the ultra-high pressure range of 150 MPa, it exhibits a pressure sensitivity coefficient of -5.4 pm/MPa, demonstrating good linearity and robustness.