Stimulated Stokes and anti-Stokes Raman scattering in liquid acetone with a Bessel beam

Abstract

The first to third Stokes, and first and second anti-Stokes components of stimulated Raman scattering in acetone generated with a conical J 0 Bessel–Gauss beam were investigated experimentally and theoretically as a function of pump cone angle ϑ P. From the observed first Stokes spot and cone the latter is caused by gain guiding. All other Stokes and anti-Stokes cones are generated in cascaded four-wave mixing processes. Cone angles are discussed in terms of longitudinal and transverse wave vector matching. Experiments where an azimuthal part of the cone of the pump beam was blocked demonstrate exact non-planar phase matching over a wide range of pump cone angles for the first and second anti-Stokes cones.