Real time monitoring of a fiber fuse using an optical time-domain reflectometer.

We propose and experimentally demonstrate monitoring of a fiber fuse in real time using an optical time domain reflectometer (OTDR). When a fuse starts, a weak reflection of light occurs from the leading edge of the fuse where plasma and voids are being formed in the core. In this work, we examined the possibility of monitoring a fiber fuse from a remote location using an OTDR. We demonstrate a method that allows us detect a fuse progressing at remote locations (over kilometers away). It was found to be effective even in the presence of strong spurious backscattering, such as spontaneous Raman scattering due to a strong continuous wave pump. Moreover, from the progress of the reflection edge monitored by the OTDR, the fuse velocity could be readily determined.