Development of fiber Bragg grating sensor systemusing wavelength-swept fiber laser

Abstract

Fiber Bragg grating (FBG) sensors based on the wavelengthdivision multiplexing technology are ideally suited forstructural health monitoring. In many applications, it is desirable to form several arrays of optical fiber sensors tomonitor the response of structures. In the present study, weconstructed an improved FBG sensor system using a wavelength-swept fiber laser which exhibits high output powerfor several sensor arrays. A fiber cavity etalon was alsofabricated for the calibration of the nonlinear output wavelength of a laser and for scaling the information in thewavelength domain for signal processing. The constructed FBGsensor system with the fiber cavity etalon and a reference FBGwas applied for strain measurements of a laminated compositepanel under axial compressive loading. In order to monitor thestructural strain in real time, the signal-processing programwas constructed using LabVIEW software for storing andvisualizing data from the FBG sensors. Experiments showed thatthe constructed FBG sensor system and the real-timesignal-processing program could successfully monitor the strainof composite laminates. This improved FBG sensor system could beuseful for large structures which require a large number ofsensor arrays.