Highly-sensitive FBG pressure sensor based on a 3D-printed transducer

In this work, we describe a fiber Bragg grating (FBG) pressure sensor with high sensitivity. The sensor exploits a 3D-printed mechanical transducer capable of converting the external pressure very efficiently into strain, measured by a first FBG, while a second one is used for temperature compensation. The pressure sensitivity of this sensor is found as high as 240 pm/kPa with an accuracy of 112 Pa over 10 kPa, which makes this sensor up to 80,000 times more sensitive than a bare fiber Bragg grating. Moreover, it is experimentally shown that it is capable of detecting fast dynamic pressure change up to 100 Hz. Thanks to these performances, this device can be used in many static and dynamic low-pressure measurement applications, and it is here demonstrated as a sub-millimetric surface water waves detector.