A long pulse bidirectional BOTDA technology developed for strain positioning and measurement. (November 2021)

• Record Type: Journal Article
• Authors: Jiang, Chao; Ma, Jie; Li, Min; Lu, Haifei; Wen, Xiaoyan; Su, Kai
• Is Part Of: Optics & laser technology. Volume 143(2022)
• Publication Date: 2021-11
• Subjects: Pulse subdivision -- Bidirectional BOTDA -- Long pulse -- Strain positioning -- Distribution sensing; Optics -- Periodicals; Lasers -- Periodicals; Electronic journals; 621.366
• DOI: 10.1016/j.optlastec.2021.107361
• Languages: English
• ISSNs: 0030-3992

Abstract

Highlights: A bidirectional exploration BOTDA method was developed for strain positioning and measurement. With this method a 1 m strained fiber segment on a 24, 752 m test fiber was positioned by a long pump pulse (larger than 50 ns). Restriction on spatial resolution of a conventional long pulse BOTDA system was removed. Signal-to-noise ratio could be significantly improved which is beneficial for long-distance distributed sensing. Influence of pulse width and Brillouin frequency interval between intrinsic/strained fiber on performance of the method was analyzed. Abstract: In this paper a long pulse bidirectional BOTDA technique was developed for strain positioning and measurement. Endpoints superposition phenomenon in series Brillouin spectra of a strained fiber detected by different long pulses was analyzed by pulse subdivision theory, based on which the bidirectional exploration BOTDA technique was proposed. With this method a 1 m strained fiber segment on a 24, 752 m test fiber was positioned by a long pump pulse (pulse width larger than 50 ns). Strain value of 1660 με was measured with an error of 10 με. Restriction on spatial resolution of a conventional long pulse BOTDA system was removed. Signal-to-noise ratio could be significantly improved which is beneficial for long-distance distributed sensing. Influence of pulse width and Brillouin frequency interval between intrinsic/strained fiber on performance of the method was analyzed. With the characteristic of simplicity, high spatial resolution and strong signal-to-noise ratio supported by a long pulse, the proposed method could find extensive application prospects in distribution sensing fields.