Correlations between intensity fluctuations within stimulated Brillouin waveforms generated by scattering of Q-switched pulses in optical fiber

We present a detailed experimental study of the statistical properties of pulsed stimulated Brillouin scattering in optical fiber using single-mode pump pulses with durations comparable to the phonon lifetime but much shorter than the fiber transit time. Under these conditions the temporal dynamics of the scattered light is stochastic and results in the generation of scattered intensity waveforms with complex structures. We provide experimental evidence and simple theoretical arguments to interpret the energy fluctuations when varying fractions of the scattered waveforms are integrated and statistically analyzed. Two-point intensity correlation functions are used to determine to what extent the complex intensity waveforms represent sequences of statistically independent scattering events. (C) 2004 Elsevier B.V. All rights reserved.