Generation of Vectorial Optical Fields with Polarization Variation along Propagation Paths via Dielectric...

Area of Science:

• Optics and Photonics
• Metasurface Engineering
• Structured Light

Background:

• Vectorial optical fields (VOFs) with polarization singularities are crucial for fundamental physics and optical communications.
• Controlling polarization evolution along the propagation path is a key challenge in VOF generation.

Purpose of the Study:

• To demonstrate a method for generating VOFs with longitudinally evolving polarization distributions.
• To achieve dynamic polarization evolution from radial to azimuthal polarization along the optical path.
• To offer a flexible design strategy for creating VOFs with arbitrary polarization orders.

Main Methods:

• Utilizing spin-multiplexing metasurfaces to introduce a propagation path-dependent phase difference.
• Superposing two orthogonal circularly polarized components to engineer polarization evolution.
• Experimental verification of polarization distributions along the propagation path.

Main Results:

• Successful generation of VOFs with seamlessly varying polarization distributions along the propagation axis.
• Observed polarization evolution from radial to azimuthal polarization.
• Experimental results validated against theoretical predictions on higher-order Poincaré spheres.
• Demonstrated generation of dual VOFs with distinct polarization evolutions.

Conclusions:

• Spin-multiplexing metasurfaces provide a powerful platform for dynamic VOF generation.
• The proposed design strategy allows for flexible engineering of longitudinally varying VOFs.
• This work opens new possibilities for applications in light-matter interactions, structured light, and polarization engineering.