Temporally resolved ring-shaped patterns beyond the phase-matching angle in the Stokes and anti-Stokes waves

Abstract

Angular intensity distributions of the Stokes and anti-Stokes waves are analyzed spatially and temporally by the temporally resolved symmetric Gauss–Laguerre decomposition method. Not only the phase-matching angle but also the diffractive propagation in the medium plays an important role in the evolution of the ring-shaped pattern of the anti-Stokes wave. We simulate the sudden breakup in the spatial shape of the first Stokes wave reported by Wada et al. [Opt. Commun. 88, 146 (1992)], using the experimental conditions to investigate the energy flow during multiwave mixing. The ring generation is caused by the second Stokes wave in stimulated Raman scattering rather than by the anti-Stokes wave in parametric four-wave mixing.