Utilization of a dispersion-shifted fiber for simultaneous measurement of distributed strain and temperature through Brillouin frequency shift

We propose and realize a new method that utilizes a dispersion-shifted fiber having compound compositions with different temperature coefficients in core to simultaneously measure the distributed strain and temperature based on Brillouin frequency shift. In a 3682-m sensing length of large-effective-area nonzero dispersion-shifted fiber, a temperature resolution of 5/spl deg/C, a strain resolution of 60 μ/spl epsi/, and a spatial resolution of 2 m are achieved simultaneously.