Plasmonic sensing using Babinet's principle

Area of Science:

• Nanophotonics and Plasmonics
• Materials Science
• Chemical and Biomedical Sensing

Background:

• Sensing local material property variations (refractive index, thickness) is crucial in chemistry and biomedicine.
• Localized surface plasmons (LSPs) in nanostructures offer environmental sensitivity for sensing applications.
• Babinet's principle relates complementary structures, suggesting potential for enhanced sensing capabilities.

Purpose of the Study:

• To explore Babinet's principle using complementary metal-dielectric plasmonic nanostructures (particle-dimers and aperture-dimers).
• To investigate the physical understanding of complementary localized surface plasmon resonances (LSPRs).
• To exploit these structures for dielectric sensing applications.

Main Methods:

• Numerical and experimental evaluation of LSPRs in complementary plasmonic particle-dimers and aperture-dimers.
• Utilizing electron energy loss spectroscopy (EELS) for physical characterization.
• Assessing dielectric sensing performance in two configurations: thin film atop structures and analyte surrounding structures.

Main Results:

• Demonstrated complementary nature of LSPRs in particle-dimer and aperture-dimer structures.
• Achieved dielectric sensing with sensitivity up to approximately 650 nm/RIU for thin dielectric films.
• Validated the approximate applicability of Babinet's principle for these plasmonic sensing systems.

Conclusions:

• Complementary plasmonic nanostructures effectively exploit Babinet's principle for enhanced sensing.
• The developed structures show promise for sensitive detection of local material property changes.
• This work provides a foundation for designing advanced plasmonic sensors for various scientific fields.