Distributed Temperature and Strain Discrimination with Stimulated Brillouin Scattering and Rayleigh Backscatter in an Optical Fiber

• Main Authors: Xiaoyi Bao, Liang Chen, Da-Peng Zhou, Wenhai Li
• Format: Article
• Language: English
• Published: MDPI AG 2013-01-01
• Series: Sensors
• Subjects: optical fiber sensors; temperature and strain discrimination; stimulated Brillouin scattering; Rayleigh scattering
• Online Access: http://www.mdpi.com/1424-8220/13/2/1836

A distributed optical fiber sensor with the capability of simultaneously measuring temperature and strain is proposed using a large effective area non-zero dispersion shifted fiber (LEAF) with sub-meter spatial resolution. The Brillouin frequency shift is measured using Brillouin optical time-domain analysis (BOTDA) with differential pulse-width pair technique, while the spectrum shift of the Rayleigh backscatter is measured using optical frequency-domain reflectometry (OFDR). These shifts are the functions of both temperature and strain, and can be used as two independent parameters for the discrimination of temperature and strain. A 92 m measurable range with the spatial resolution of 50 cm is demonstrated experimentally, and accuracies of ±1.2 °C in temperature and ±15 με in strain could be achieved.