“…The FBG interrogator is a device that analyzes the data of the FBG by monitoring the central wavelength change. Several approaches for FBG interrogation have been reported in the literature, such as the scanning Fabry-Pérot (FP) cavity [8,9], tunable lasers [10,11], and volume phase grating-based spectrometers [12,13]. However, most traditional interrogators usually suffer from the high price and bulky volume, which limits their applications in some emerging fields, such as unmanned aerial vehicle (UAV) monitoring, lithium-ion battery status monitoring [14], and in-situ three-dimensional (3D) shape sensing [15][16][17][18].…”