Brillouin Optical Time Domain Analysis in Silica Fibers at 850-nm Wavelength.

Brillouin scattering properties of silica fibers at 850-nm wavelength were experimentally investigated using a Brillouin optical time-domain analysis scheme. In the single-mode 780-HP fiber, the Brillouin frequency shift (BFS) and full width at-half maximum of the Brillouin gain spectrum were found to be $\sim 19$ 795 and 90 MHz, respectively. The estimated peak Brillouin gain is {0.32} \,\,\,{ {(mW)}}^{{-1}} . The temperature and strain dependences of BFS were determined as well. Distributed sensing capability was demonstrated at a minimum spatial resolution of 1.5 m and a fiber length of 100 m. As a proof-of-principle, the temperature and strain dependences of the BFS in SFM-28 fiber have been determined at 850- and 1550-nm wavelengths, suggesting its possible use for temperature/strain discrimination. [ABSTRACT FROM PUBLISHER]