High-Q Resonances in Hybrid Plasmonic-Photonic Metasurfaces

Area of Science:

• Photonics
• Plasmonics
• Metasurfaces

Background:

• High-quality (high-Q) factor plasmonic resonances are crucial for optical sensing and nanolasing.
• Radiative and Ohmic losses typically limit Q factors in plasmonic systems.
• Bound states in the continuum (BICs) offer a route to high-Q resonances.

Purpose of the Study:

• To develop a hybrid plasmonic-photonic system supporting multiple high-Q resonances.
• To investigate the formation of BICs through engineered hybridization.
• To demonstrate enhanced light-matter interactions using these high-Q resonances.

Main Methods:

• Engineering hybridization between a dielectric slab waveguide and a plasmonic nanoparticle lattice.
• Fabricating two-dimensional silver nanoparticle arrays in a dielectric slab waveguide.
• Utilizing nonlocal resonant modes near BIC conditions for luminescence enhancement.

Main Results:

• Achieved multiple high-Q resonances in the short-wave near-infrared regime.
• Observed a maximum Q factor of ~2140 at λ = 985 nm.
• Demonstrated significantly enhanced upconversion luminescence from erbium ions.

Conclusions:

• The hybrid system effectively supports high-Q resonances by forming BICs.
• Enhanced electric fields distributed away from the metal minimize losses.
• The metasurface shows promise for applications requiring high Q factors and strong light-matter interactions.