Active Individual Nanoresonators Optimized for Lasing and Spasing Operation.

Area of Science:

• Plasmonics
• Nanophotonics
• Quantum Optics

Background:

• Plasmonic nanoresonators offer unique light-matter interactions for enhanced optical phenomena.
• Stimulated emission and spasing in nanostructures are crucial for next-generation light sources.

Purpose of the Study:

• To optimize plasmonic nanoresonators (gold nanorod and core-shell) for enhanced stimulated emission and spasing.
• To compare the performance of nanorod and core-shell resonators under varying dye concentrations for near-field and far-field emission.

Main Methods:

• Computational optimization of plasmonic nanoresonators with gain layers.
• Analysis of lasing thresholds, slope efficiency, and quantum efficiencies.
• Investigation of spectral switching and far-field emission characteristics.

Main Results:

• Gold nanorods show advantages at moderate dye concentrations (lower lasing threshold, higher efficiency).
• Core-shell nanoresonators are superior at high dye concentrations (spasing), offering better quantum efficiencies and bandwidth.
• Strong coupling of plasmonic modes governs the transition from lasing to spasing.

Conclusions:

• The choice between nanorod and core-shell plasmonic nanoresonators depends critically on dye concentration for optimal performance.
• Both designs can achieve efficient stimulated emission and spasing with tailored configurations.
• Understanding mode coupling is key to controlling lasing and spasing phenomena in nanophotonic devices.