Performance improvement of Brillouin based distributed fiber sensors employing wavelength diversity techniques (Invited Paper)

The sensing performance in Brillouin-based distributed fiber sensors is ultimately depends on the signal-to-noise ratio (SNR) of the received signal. In order to enhance the SNR, thus improve the sensing performance, several wavelength diversity techniques have been proposed. This paper presents the current wavelength diversity techniques employed in both Brillouin optical timedomain reflectometry (BOTDR) and Brillouin optical time-domain analysis (BOTDA) systems. So far, the best SNR improvement in BOTDR system is 4.85 dB with a 25 km sensing fiber, whereas, 4.8 dB in BOTDA system with a 50 km sensing fiber