Distributed FBG Vibration Sensing Based on OFDR Employing a DFB-LD

A distributed fiber Bragg grating (FBG) sensing method for the high-speed measurement of structural vibration was proposed, With the combination of the optical frequency domain reflectometry (OFDR) technique and high speed tuning distributed feedback laser diode (DFB-LD), a good performance was achieved. The maximum reading rate of 100 kHz was obtained in the sensing system while maintaining a good spatial resolution about 1 cm, a fine stability less than 5 pm and an acceptable temperature linearity of 99.956%. Then, dynamic strain measurements with vibration from 800 Hz to 2.8 kHz were implemented in a sufficient system sampling rate of 100 kHz and the characteristics of the vibration sensor were obtained.