Duration of a Stokes signal generated by stimulated Brillouin scattering of XeCl laser radiation

An experimental investigation was made of the feasibility of stimulated Brillouin scattering during an XeCl laser pump pulse of τ_1/2 = 80 ns duration. The duration of a Stokes pulse was found to depend on the absorption in the nonlinear medium employed. When this medium was heptane, the Stokes signal duration was τ_1/2 ~ 15 ns, but for SF₆ it was τ_1/2 ~ 70 ns. The most probable reason for the short duration of the Stokes signal was the loss of phase matching in the scattering process.