Stimulated Brillouin scattering in electrolytic solutions

An experimental investigation was made of the dependence of the power of stimulated Brillouin scattering (SBS) on the pump power and also of the dependence of the shift of the SBS components in several aqueous solutions of acids and salts on their concentration. The SBS gain was greatly affected even by low concentrations (of the order of a few percent by weight) and the change in gain altered the SBS signal amplitude by several orders of magnitude. The investigated salts reduced the gain, acids (with the exception of H₂SO₄) increased the gain, and sulfuric acid first increased and then strongly reduced the gain. The observed dependences could be explained by a change in the absorption of hypersound resulting from the frequency shift of relaxation processes of the dissociation-association type.