Nonlinear mixing of optical vortices with fractional topological charge in Raman sideband generation

2016 IOP Publishing Ltd. We studied the nonlinear parametric interaction of femtosecond fractionally-charged optical vortices in a Raman-active medium. Propagation of such beams was described using the Kirchhoff-Fresnel integrals by embedding a non-integer 2 phase step in a Gaussian beam profile. When using fractionally-charged pump or Stokes beams, we observed the production of new topological charge and phase discontinuities in the Raman field. These newly generated fractionally-charged Raman vortex beams were found to follow the same orbital angular momentum algebra derived by Strohaber et al (2012 Opt. Lett. 37 3411) for integer vortex beams.

Strohaber, J., Boran, Y., Sayrac, M., Johnson, L., Zhu, F., Kolomenskii, A. A., & Schuessler, H. A.

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