Asymmetric chiroptical effect from chiral medium filled golden slit grating on substrate

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• Chiroptical effects are crucial for understanding light-matter interactions in chiral systems.
• Existing chiral metamaterials often exhibit limited asymmetry or complex fabrication.
• Interface effects in nanostructures are key to novel optical phenomena.

Purpose of the Study:

• To report a giant and robust asymmetric chiroptical effect (ACOE) in a novel chiral medium filled golden slit grating on glass substrate (CMGSG-GS).
• To elucidate the origin of this ACOE, attributing it to interface asymmetry influencing electromagnetic cross-coupling.
• To differentiate this effect from those observed in Faraday media and planar anisotropic chiral metamaterials.

Main Methods:

• Fabrication of chiral medium filled golden slit gratings on glass substrates (CMGSG-GS).
• Characterization of optical properties, including polarization eigenstates and transmission matrices.
• Theoretical analysis of electromagnetic cross-coupling influenced by interface asymmetry.

Main Results:

• Observation of a giant and robust ACOE in the CMGSG-GS.
• Demonstration that the ACOE originates from interface asymmetry, distinct from other chiral systems.
• Analysis showing polarization eigenstates are co-rotating elliptical states, largely direction-independent.
• Transmission matrices for opposite directions are normal, lacking symmetry despite geometric symmetry.

Conclusions:

• The developed CMGSG-GS exhibits a unique ACOE driven by interface asymmetry.
• This ACOE provides a measurable parameter for investigating interfacial events.
• The findings offer new insights into light-matter interactions at asymmetric interfaces in nanostructures.