title: Dipole azimuthons and vortex charge flipping in nematic liquid crystals.
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.
authors: Nonlinear Physics Center, Research School of Physics and Engineering, The Australian National University, Canberra ACT 0200, Australia. yvi124@physics.anu.edu.au
authors: Yana V
authors: YV
authors: Izdebskaya
authors: Anton S
authors: AS
authors: Desyatnikov
authors: Gaetano
authors: G
authors: Assanto
authors: Yuri S
authors: YS
authors: Kivshar