Polarization effects in the diffraction of light by a planar chiral structure

Area of Science:

• Optics and Photonics
• Condensed Matter Physics
• Materials Science

Background:

• Chiral materials exhibit unique light-matter interactions.
• Polarization eigenstates are crucial for understanding light behavior.
• Lorentz reciprocity is a fundamental principle in wave physics.

Purpose of the Study:

• To analyze polarization changes of light diffracted by planar chiral arrays.
• To investigate the implications of the Lorentz reciprocity lemma on chiral diffraction.
• To identify reciprocal and nonreciprocal components of polarization azimuth rotation.

Main Methods:

• Analysis based on the Lorentz reciprocity lemma.
• Investigating polarization eigenstates for forward and backward diffraction.
• Decomposition of polarization azimuth rotation into reciprocal and nonreciprocal parts.

Main Results:

• Demonstration of biorthogonality in polarization eigenstates for opposite diffraction directions.
• Identification of both reciprocal and nonreciprocal contributions to polarization azimuth rotation.
• Correlation of observed polarization effects with structural and element chirality.

Conclusions:

• The study elucidates the interplay between chirality and polarization phenomena in diffractive arrays.
• Biorthogonality of eigenstates is a key consequence of reciprocity in chiral gratings.
• Both array-level and element-level chirality significantly influence diffracted light polarization.