Plasmonic crystal for efficient energy transfer from fluorescent molecules to long-range surface plasmons

Area of Science:

• Optics and Photonics
• Materials Science

Background:

• Surface plasmon polaritons (SPPs) are electromagnetic waves coupled to the electron oscillations on a metal surface.
• Efficient coupling of light to SPPs is crucial for applications in sensing, imaging, and photovoltaics.
• Traditional metallic thin films often support short-range SPPs, limiting their utility in certain applications.

Purpose of the Study:

• To investigate corrugated metallic thin film structures for enhanced light-matter interactions.
• To theoretically evaluate the coupling efficiency of fluorescent molecule energy to long-range surface plasmon modes.
• To compare the performance of corrugated films with uncorrugated metallic thin films.

Main Methods:

• Theoretical calculation of coupling efficiency using the rigorous coupled-wave approach (RCWA).
• Modeling of corrugated metallic thin film structures.
• Analysis of energy transfer from excited fluorescent molecules to plasmon modes.

Main Results:

• Corrugated metallic thin films support long-range surface plasmon modes.
• Maximum coupling efficiency achieved was 55%.
• This efficiency is more than double that of uncorrugated metallic thin films.

Conclusions:

• Corrugated metallic thin films offer a significant enhancement in coupling efficiency to long-range surface plasmon modes.
• The demonstrated efficiency suggests potential for improved performance in plasmonic devices and applications.
• This work provides a theoretical foundation for designing advanced plasmonic nanostructures.