Optical Quasiparticles: Skyrmions, Bimerons and Skyrmionic Hopfions in Paraxial Laser Beams

Skyrmions, merons, bimerons, and skyrmionic hopfions are quasiparticles which have stable topological textures. They have been observed across multiple physical domains including nucleons, water waves, magnetic materials, electromagnetic fields, condensed-matter physics, liquid crystals, and Bose-Einstein condensates. The nontrivial topological texture of these quasiparticles exhibited promising applications across several research fields including cosmology, particle physics, superfluids, high-energy physics, optics, condensed matter, early-universe cosmology, cold quantum matter, and liquid crystals. These quasiparticles have most recently been observed in paraxial vector beams. Due to the inhomogeneous polarization distribution of vector beams, the quasiparticle textures reside in the Stokes vector fields. Here, we review recent developments in paraxial quasiparticle research and provide detailed information on their fundamental properties and future prospects. We discuss various techniques which have been used to experimentally generate these quasiparticles and we examine a number of their proposed applications. Notably, this review offers insight into the concepts and techniques which can be applied to the generation of optical skyrmions in paraxial laser beams, and investigates their intriguing applications across both fundamental and applied optics.