SNR Enhanced Distributed Vibration Fiber Sensing System Employing Polarization OTDR and Ultraweak FBGs

作者：Wang, Xiangchuan; Yan, Zhijun; Wang, Feng; Sun, Zhongyuan; Mou, Chengbo; Zhang, Xuping^*; Zhang, Lin

来源：IEEE Photonics Journal, 2015, 7(1): 6800511.

DOI：10.1109/JPHOT.2015.2396010

• Fiber optics system
• fiber gratings
• distributed fiber sensor
• optical fiber polarization

A distributed fiber sensing system based on ultraweak FBGs (UWFBGs) assisted polarization optical time-domain reflectometry (POTDR) is proposed for load and vibration sensing with improved signal-to-noise ratio (SNR) and sensitivity. UWFBGs with reflectivity higher than Rayleigh scattering coefficient per pulse are induced into a POTDR system to increase the intensity of the back signal. The performance improvement of the system has been studied. The numerical analysis has shown that the SNR and sensitivity of the system can be effectively improved by integrating UWFBGs along the whole sensing fiber, which has been clearly proven by the experiment. The experimental results have shown that by using UWFBGs with 1: 1 x 10(-5) reflectivity and 10-m interval distance, the SNR is improved by 11 dB, and the load and vibration sensitivities of the POTDR are improved by about 10.7 and 9 dB, respectively.

• 出版日期2015-2
• 单位南京大学