Prototype double-pulse BOTDR for measuring distributed strain with 20-cm spatial resolution

We have developed a prototype Brillouin optical time-domain reflectometry (BOTDR) system, called a double-pulse BOTDR (DP-BOTDR) system, for measuring distributed strain and temperature along fiber with a sub-meter spatial resolution. Oscillatory and steep power spectra of Brillouin backscattered signal have been observed with the DP-BOTDR, which allows us to measure Brillouin frequency shift accurately with a high spatial resolution. We confirmed that our prototype DP-BOTDR system enables us to measure the distributed Brillouin frequency shift, i.e., the distributed strain and temperature, with a spatial resolution of 20 cm and an accuracy of plusmn1 MHz.