A model of spontaneous Brillouin scattering as the noise source for stimulated scattering

A model of spontaneous Brillouin scattering in the presence of a high power pump beam has been developed and incorporated into a wave optics model of backward stimulated Brillouin scattering, providing a realistic distributed noise source for the numerical evaluation of the stimulated process. The model is used to assess the location of the dominant noise contributions in determining the reflectivity and conjugation fidelity of the Stokes return. The effect of f-number and power over threshold is evaluated. The model is validated with experimental data on threshold and conjugation fidelity in the presence of a pump beam with a periodic phase aberration.<
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