Dipole azimuthons and charge-flipping in nematic liquid crystals

Y. V. Izdebskaya, A. S. Desyatnikov, G. Assanto, and Y. S. Kivshar

Opt. Express 19 (22), 21457-66 (2011)

Abstract:

We demonstrate self-trapped laser beams carrying phase singularities in nematic liquid crystals. We experimentally observe the astigmatic transformation of vortex beams into spiraling dipole azimuthons accompanied by power-dependent charge-flipping of the on-axis phase singularity. The latter topological reactions involve triplets of vortex lines and resemble pitchfork bifurcations.