Generation of tunable optical skyrmions on Skyrme-Poincar\'e sphere

TL;DR

This paper introduces a new family of tunable optical skyrmions, demonstrating their topological transformations and visualizations, with experimental generation using digital holography.

Contribution

It presents the first theoretical and experimental realization of tunable optical skyrmions and introduces the Skyrme-Poincaré sphere for visualizing their topological evolution.

Findings

Successful experimental generation of tunable optical skyrmions

Demonstration of topological transformations between skyrmion types

Validation of theoretical predictions with digital holography

Abstract

In recent time, the optical-analogous skyrmions, topological quasiparticles with sophisticated vectorial structures, have received an increasing amount of interest. Here we propose theortically and experimentally a generalized family of these, the tunable optical skyrmion, unveiling a new mechanism to transform between various skyrmionic topologies, including N\'eel-, Bloch-, and antiskyrmion types, via simple parametric tuning. In addition, Poincar\'e-like geometric representation is proposed to visualize the topological evolution of tunable skyrmions, which we termed Skyrme-Poincar\'e sphere, akin to the spin-orbit representation of complex vector modes. To generate experimentally the tunable optical skyrmions we implemented a digital hologram system based on a spatial light modulator, showing great agreement with our theoretical prediction.