Surface plasmon enhanced fluorescence: self-consistent classical treatment in the quasi-static limit

Area of Science:

• Optics and Photonics
• Materials Science
• Physical Chemistry

Background:

• Enhanced molecular emission near interfaces is crucial for physical and biological applications.
• Classical electromagnetism provides a framework for understanding these phenomena.
• Dielectric and metallic interfaces, particularly core-shell nanoparticles, influence light-matter interactions.

Purpose of the Study:

• To develop an exact, self-consistent analytical theory for surface-enhanced fluorescence (SEF).
• To investigate the influence of excitation/fluorescence frequencies and emitter-nanoparticle distance on SEF.
• To determine optimal configurations for SEF using core-shell nanoparticles.

Main Methods:

• Classical electromagnetism treatment.
• Development of a self-consistent analytical theory for SEF.
• Analysis of emitter proximity to core-shell metal-dielectric nanoparticles.

Main Results:

• The theory predicts fluorescence enhancement at intermediate emitter-nanoparticle distances.
• Emission quenching into non-radiative surface plasmon (SP) modes dominates at short distances.
• Optimal emission enhancement conditions were determined for two core-shell configurations.
• The model shows good agreement with published experimental data.

Conclusions:

• The developed theory accurately models surface-enhanced fluorescence (SEF) near core-shell nanoparticles.
• The findings provide insights into optimizing SEF for spectroscopic applications.
• The model is applicable to analyzing and enhancing various SP-enhanced fluorescence spectroscopy techniques.