Optimized configuration for high resolution distributed sensing using Brillouin echoes
A novel configuration has been developed to optimize the response of Brillouin echoes for distributed fibre sensing. Fully resolved measurements of the Brillouin frequency shift of a 5cm spot perturbation have been performed using a 500 ps (5cm) pulse width. The linewidth of the measured Brillouin gain spectrum remains comparable to the intrinsic linewidth for any pulse width. The high accuracy and inherent stability of the technique have been successfully verified.