Nature of intensity and phase modulations in stimulated Brillouin scattering

The nature of stimulated Brillouin scattering (SBS) temporal modulations for a focused beam in a finite-length cell with homogeneous medium is examined numerically. The finite phonon lifetime produces deterministic oscillations at the threshold while the inclusion of the random noise as an initiation source of SBS leads to stochastic fluctuations in Stokes intensity and phase. A unified study of both modulations under different parameters is presented. The results indicate a large useful parameter space for excellent Stokes beam quality.