Measured reduction of guided-acoustic-wave Brillouin scattering in a fiber interferometer by time-delayed pulses

We measure the reduction of guided-acoustic-wave Brillouin scattering phase noise in an optical fiber interferometer by varying the time delay between an optical pulse pair. Excellent suppression of the phase noise is achieved when the pulses have parallel polarizations and are delayed by less than 100 ps, but orthogonal polarizations show a residual noise level that is due to the depolarized guided-acoustic-wave Brillouin scattering modes.