Silver nanowires as receiving-radiating nanoantennas in plasmon-enhanced up-conversion processes

Area of Science:

• Nanophotonics
• Materials Science
• Quantum Optics

Background:

• Rare earth-doped nanocrystals exhibit unique optical properties, including up-conversion luminescence.
• Plasmonics offers a route to manipulate light-matter interactions at the nanoscale.

Purpose of the Study:

• To demonstrate efficient plasmonic coupling between silver nanowires and rare earth-doped nanocrystals.
• To investigate the enhancement of up-converted emission and luminescence decay rates.
• To explore the control of plasmon-enhanced luminescence via laser polarization.

Main Methods:

• Fabrication of single silver nanowires.
• Synthesis of α-NaYF4:Er(3+)/Yb(3+) nanocrystals.
• Coupling experiments utilizing controlled laser polarization.
• Fourier plane imaging of angular-resolved emission patterns.

Main Results:

• A sevenfold increase in up-converted emission from proximity nanocrystals was observed.
• Significantly faster luminescence decay times were measured.
• Emission enhancement was strongly dependent on laser polarization, favoring parallel alignment with nanowire antennas.
• Plasmon-mediated luminescence was visualized as leakage radiation emitted through nanowire antennas.

Conclusions:

• Efficient plasmonic coupling between silver nanowires and rare earth-doped nanocrystals enhances up-converted emission.
• Nanowire antennas can act as conduits for plasmon-mediated luminescence.
• Laser polarization provides precise control over the observed plasmon enhancement effects.