Ultrafast upconversion superfluorescence with a sub-2.5 ns lifetime at room temperature

Area of Science:

• Nanoscience and Nanotechnology
• Quantum Optics
• Materials Science

Background:

• Photon upconversion in lanthanide-doped nanoparticles is crucial for many applications.
• Current limitations include low quantum efficiency and long radiative lifetimes, hindering time-dependent nanophotonics.

Purpose of the Study:

• To report ultrafast upconversion superfluorescence with sub-2.5 ns lifetimes in lanthanide-doped nanoparticles at room temperature.
• To demonstrate control over emission lifetime manipulation.

Main Methods:

• Excitation of Nd3+-concentrated nanoparticles using an 800-nm femtosecond-pulsed laser.
• Observation and analysis of collective coherent emission and Burnham-Chiao ringing.
• Manipulation of excitation power and emitting sample length.

Main Results:

• Achieved ultrafast upconversion superfluorescence with lifetimes below 2.5 nanoseconds.
• Generated a large number of correlated dipoles (N=912) leading to amplified intensity and faster radiative decay rates.
• Demonstrated lifetime manipulation across a wide range (μs to sub-ns) by controlling experimental parameters.

Conclusions:

• Ultrafast upconversion superfluorescence is achievable in lanthanide-doped nanoparticles.
• This phenomenon offers significant improvements in emission speed and lifetime control.
• Potential applications include quantum counting and high-speed super-resolution bioimaging.