Remote four-photon Raman scattering spectroscopy of seawater in situ

Remote spectroscopy of the optical Kerr effect, induced by the Raman scattering, was used to demonstrate the feasibility of measuring the background concentration of SO₄^2 – ions in seawater. Stimulated Brillouin scattering in seawater was observed in situ for the first time and its spectrum was determined in the region of totally symmetric vibrations of the SO₄^2 – ion.