We present an experimental evidence of \emph{topological} Hall-effect in an all-optical third-order nonlinear optical process via spatial symmetry-breaking in pseudo-spin textures created by a spatially-structured pump laser beam. The experimental configuration consists of a moderately-focused pump laser beam undergoing a parametric interaction with an organic solvent (toluene) and an off-resonant laser beam probes the non-trivial spatial magnetization textures created by the pump beam. The phase-profile of the transmitted probe beam is extracted using phase-retrieval algorithms for ascertaining the topological charge which is shown to be consistent with the estimation of Berry's curvature that we obtain via paraxial approximation-based modeling of third-order nonlinear interaction.
@article{arxiv.2510.01820,
title = {Topological Hall effect in nonlinear optics},
author = {Soumik Nandi and Arannya Ghosh and Ashok K Mohapatra and Ritwick Das},
journal= {arXiv preprint arXiv:2510.01820},
year = {2025}
}