Quasi-BIC Mode Lasing in a Quadrumer Plasmonic Lattice

Area of Science:

• Nanophotonics
• Metamaterials
• Condensed Matter Physics

Background:

• Plasmonic nanoparticle lattices are key for light-matter interactions, lasing, and Bose-Einstein condensation.
• Complex unit cell designs in these lattices remain underexplored.
• Bound states in the continuum (BICs) offer topologically protected optical modes with theoretically infinite quality factors.

Purpose of the Study:

• To investigate lasing in complex quadrumer nanoparticle lattices.
• To explore the potential of quasi-BIC modes in these structures.
• To demonstrate topological properties of the lasing modes.

Main Methods:

• Theoretical modeling of plasmonic lattices.
• Fabrication of quadrumer nanoparticle arrays.
• Polarization-resolved emission measurements.
• Analysis of topological charge and mode characteristics.

Main Results:

• Quadrumer nanoparticle lattices achieve lasing in a quasi-BIC mode.
• The lasing mode exhibits a significant out-of-plane polarization.
• The mode possesses a topological charge, confirmed by theory and experiment.
• High quality factors (high-Q) are achievable for these out-of-plane BIC modes.

Conclusions:

• Complex multiparticle unit cells, like quatromers, are powerful for designing advanced nanostructures.
• Topologically protected high-Q modes can be realized in periodic nanostructures.
• Quadrumer lattices offer a novel platform for exploring quasi-BIC lasing with unique polarization properties.