Directing fluorescence with plasmonic and photonic structures

Area of Science:

• Optics and Photonics
• Materials Science
• Chemical Physics

Background:

• Traditional fluorescence emission is omnidirectional, limiting collection efficiency.
• Plasmonic and photonic structures can mold optical energy flow.
• Tailoring emission directivity is crucial for advanced fluorescence applications.

Purpose of the Study:

• To investigate the use of plasmonic and photonic substrates for directional fluorescence emission.
• To explore near-field interactions between fluorophores and engineered optical modes.
• To demonstrate control over emission patterns for improved fluorescence-based technologies.

Main Methods:

• Incorporation of fluorophores into planar metallic, dielectric, and hybrid substrates.
• Utilizing surface plasmons, Bloch surface waves, and Fabry-Pérot modes for emission coupling.
• Analysis of reflectivity dispersion diagrams to understand mode profiles and emission patterns.
• Review of plasmonic nanoantennas for fluorescence beam steering.

Main Results:

• Surface-plasmon-coupled emission observed in metal-dielectric substrates with distinct dispersion and polarization.
• Sharply directional Bloch surface wave-coupled emission achieved in one-dimensional photonic crystals.
• Beaming emission normal to the substrate achieved using metal-dielectric-metal and plasmonic-photonic hybrid substrates.
• Demonstrated potential of plasmonic nanoantennas for controlling fluorescence beams.

Conclusions:

• Engineered plasmonic and photonic structures enable precise control over fluorescence emission directionality.
• This control facilitates spatial and spectral multiplexing, improving assay and device capabilities.
• Future applications include advanced fluorescence assays, instrumentation, diagnostics, and emissive devices.