Detuned Brillouin amplification of OTDR signals with an enhanced signal-to-noise ratio

The technique known as external Brillouin amplification of Rayleigh scattering is characterized in the detuning regime. When employed as an amplifier of OTDR signals, it is shown that the signal-to-noise ratio is significantly improved for optimum pump Stokes detuning, leading to enhanced nanostrain sensitivity. This effect is due to the Brillouin bandwidth dependence on the Stokes power.