Metallization packaging method for FBG vibration sensor

A metallization packaging technology for fiber Bragg grating (FBG) vibration sensor was investigated in the paper, including surface metallization and laser welding packaging of FBG. The FBGs and fiber ends were pre-plated with sliver by magnetron sputtering method, and then plated with nickel by electrolytic plating. Finally, the plated components were packaged in the sensor structure through laser welding to shape a fully metalized packaged FBG sensor. To verify the effect of FBG vibration sensor metallization packaging, the performance of sensors were tested and compared to that of sensors with epoxy package. It was found that the resonant frequency increased by 50% to 1495Hz, the acceleration sensitivity decreased by 15% to about 60 mV/ms^-2, the linear measurement range increased about 20% up to 12 m/s², the repeatability error was less than 4.7%, and the matching state of double FBGs did not vary with temperature. The results show that the metalized packaging method is feasible for FBG sensors and can improve their performance and long-term stability.