Plasmonic Double-Hole Bull's Eye Nanoantenna for Far-Field Polarization Control

Area of Science:

• Photonics and Nanotechnology
• Plasmonics and Light-Matter Interactions

Background:

• Conventional polarization conversion methods face limitations in device size and integration.
• Plasmonic nanostructures offer a promising alternative for miniaturized optical components.

Purpose of the Study:

• To investigate the polarization conversion properties of a plasmonic bull's eye antenna.
• To demonstrate its functionality as a miniature on-chip polarization converter.

Main Methods:

• Numerical simulations and experimental investigations were performed.
• Polarimetric imaging via back focal plane (BFP) microscopy was employed.
• Stokes parameter analysis was utilized to characterize polarization transformations.

Main Results:

• The bull's eye antenna structure successfully converts light polarization, including linear to circular and vice versa.
• Polarization conversion efficiency is sensitive to the grating's periodicity.
• Asymmetric scattering produced distinct Stokes parameter patterns for various incident polarizations.

Conclusions:

• The plasmonic nanostructure functions as an effective miniature on-chip polarization converter.
• This research offers insights into nanoscale plasmonic manipulation of light polarization.
• Potential applications include polarization-controlled emitters and advanced sensing technologies.