Polarization Conversion and "Focusing" of Light Propagating through a Small Chiral Hole in a Metallic Screen

TL;DR

This study investigates how light's polarization and intensity are affected when passing through a tiny, twisted metallic hole, revealing polarization conversion and focused transmission effects dependent on the hole's chirality.

Contribution

It demonstrates the polarization-dependent transmission and focusing effects in chiral holes, highlighting the role of hole geometry and incident wave polarization in light manipulation.

Findings

Polarization conversion peaks near the hole's size wavelength.

Strong field concentration occurs when hole chirality matches wave polarization.

Transmission efficiency varies with the mutual orientation of hole twist and wave polarization.

Abstract

Propagation of light through a thin flat metallic screen containing a hole of twisted shape is sensitive to whether the incident wave is left or right circularly polarized. The transmitted light accrues a component with handedness opposite to the incident wave. The efficiency of polarization conversion depends on the mutual direction of the hole's twist and the incident light's wave polarization handedness and peaks at a wavelength close to the hole overall size. We also observed a strong transmitted field concentration at the center of the chiral hole when the handedness of the chiral hole and the wave's polarization state are the same.