Non-spreading meronic spin defects around optical vortices

Area of Science:

• Optics and Photonics
• Topological Physics

Background:

• Optical vortices are lines of vanishing intensity and undefined phase in light fields.
• These vortices exhibit unique polarization properties, including longitudinal polarization and topological spin textures.
• Existing polarization textures lack robustness against perturbations.

Purpose of the Study:

• To describe the topologies of transverse spin associated with paraxial vortex beams.
• To highlight the diversity of topological structures in different spaces (spin unit sphere, Poincaré sphere).
• To discuss the mechanisms behind the subwavelength localization of these spin textures.

Main Methods:

• Analysis of the spin field structure around optical vortex phase singularities.
• Investigation of topological features including point defects and meronic textures.
• Examination of propagation dynamics and subwavelength confinement properties.

Main Results:

• Identified unique spin field structures with topological texture and defect characteristics.
• Demonstrated deep-subwavelength confinement of the normalized spin field around the vortex line.
• Showcased enhanced robustness of these textures against isotropic perturbations like atmospheric turbulence.

Conclusions:

• The described transverse spin topologies are intrinsic features of paraxial vortex beams.
• Subwavelength localization and topological nature contribute to their robustness.
• These findings offer insights into novel tailored polarization textures with enhanced stability.