FBG Arrays for Quasi-Distributed Sensing: A Review

Fiber Bragg grating (FBG) array is a powerful technique for quasi-distributed sensing along the entire length of sensing fiber with fast response and high precision. It has been widely used for temperature, strain, and vibration monitoring. In this review work, an overview on the recent advances of FBG arrays is conducted. Firstly, the fabrication methods of FBG array are reviewed, which include femtosecond laser system and online writing technique. Then, the demodulation techniques for FBG arrays are presented and discussed. Distributed static sensing can be performed by demodulating wavelength shift of each FBG, while phase demodulation techniques with low noise are employed for dynamic vibration sensing. Simultaneous distributed dynamic and static sensing system based on FBG array is also outlined. Finally, possible future directions are discussed and concluded. It is believed that the FBG array has great development potential and application prospect.