Analysis of nonlinear fitting methods for distributed measurement of temperature and strain over 36 km optical fiber based on spontaneous Brillouin backscattering

作者：Kwon Hyungwoo; Kim Suhwan; Yeom Sehyuk; Kang Byoungho; Kim Kyujin; Kim Taeheok; Jang Hangseok; Kim Jeehyun^*; Kang Shinwon

来源：Optics Communications, 2013, 294: 59-63.

DOI：10.1016/j.optcom.2012.12.012

• Spontaneous Brillouin scattering
• Distributed sensing
• Nonlinear curve fitting
• BOTDR

We experimentally analyzed two different nonlinear fitting methods for a Brillouin optical time domain reflectometery (BOTDR) system. By measuring the spontaneous Brillouin frequency and comparing a Lorentzian fit with a Voigt fit, we confirmed that the accuracy of the Lorentzian fit was higher than that of the Voigt fit. We also performed long-range distributed measurements using coherent detection system with a 36 km long-range optical fiber. The extinction ratio of optical pulse was improved by employing an acousto-optic modulator (AOM). As a result, we could successfully measure the Brillouin frequency shift (BFS) using a Lorentzian fit algorithm in order to calculate applied temperature and strain in the optical fiber.

• 出版日期2013-5-1