Picosecond stimulated Raman scattering at 3000 and 3430 cm-1 OH vibrations without optical breakdown

Opt Lett. 2020 Oct 1;45(19):5624-5627. doi: 10.1364/OL.402358.

Abstract

For the first time, to the best of our knowledge, stimulated Raman scattering (SRS) of picosecond laser pulses without optical breakdown has been detected simultaneously (as the first Stokes and anti-Stokes paired components) at ∼3430 and ∼3000cm-1 vibrations of water OH band. These components were generated coaxially to the pump beam in the forward direction as axial and conical ring beams, respectively, when the pump beam was focused at the water-air interface. We suggest an explanation of these new SRS phenomena by non-collinear four-wave parametric interaction.