Time and frequency pump-probe multiplexing to enhance the signal response of Brillouin optical time-domain analyzers

• Published in: Optics Express (ISSN: 1094-4087), vol. 22, num. 23, p. 28584-28595
• Washington: Optical Society of America, 2014

A technique to enhance the response and performance of Brillouin distributed fiber sensors is proposed and experimentally validated. The method consists in creating a multi-frequency pump pulse interacting with a matching multi-frequency continuous-wave probe. To avoid nonlinear cross-interaction between spectral lines, the method requires that the distinct pump pulse components and temporal traces reaching the photo-detector are subject to wavelength-selective delaying. This way the total pump and probe powers launched into the fiber can be incrementally boosted beyond the thresholds imposed by nonlinear effects. As a consequence of the multiplied pump-probe Brillouin interactions occurring along the fiber, the sensor response can be enhanced in exact proportion to the number of spectral components. The method is experimentally validated in a 50 km-long distributed optical fiber sensor augmented to 3 pump-probe spectral pairs, demonstrating a signal-to-noise ratio enhancement of 4.8 dB.

Reference

• EPFL-ARTICLE-203397
• doi:10.1364/OE.22.028584
• View record in Web of Science

Record created on 2014-11-15, modified on 2017-05-10