Topological Faraday Effect for Optical Vortices in Magnetic Films

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Quantum Optics

Background:

• The Faraday effect describes polarization rotation of light passing through a magnetic material.
• Traditional studies typically use plane waves, not considering light's orbital angular momentum.
• Optical vortex beams possess orbital angular momentum, offering new interaction possibilities.

Purpose of the Study:

• To experimentally demonstrate and characterize the topological Faraday effect.
• To investigate the influence of optical vortex beam properties on the Faraday effect.
• To explore the role of optical spin-orbit interaction in this phenomenon.

Main Methods:

• Experimental setup involving transmission of optical vortex beams through a transparent magnetic dielectric film.
• Measurement of polarization rotation for beams with varying topological charge and radial numbers.
• Theoretical analysis based on optical spin-orbit interaction principles.

Main Results:

• Demonstration of a distinct topological Faraday effect for optical vortex beams.
• Observed Faraday rotation differs from that of plane waves.
• Additional Faraday rotation shows a linear dependence on the beam's topological charge and radial number.

Conclusions:

• The topological Faraday effect is a measurable phenomenon influenced by light's orbital angular momentum.
• Optical spin-orbit interaction is key to understanding this effect.
• Optical vortex beams are valuable tools for probing magnetically ordered materials.