Strong mode coupling-enabled hybrid photon-plasmon laser with a microfiber-coupled nanorod

Area of Science:

• Photonics and Nanotechnology
• Plasmonics
• Laser Physics

Background:

• Single plasmonic nanoparticles offer sub-diffraction limit radiation, a key goal for nanolasers.
• High Ohmic loss in plasmonic materials hinders practical nanolaser development.

Purpose of the Study:

• To demonstrate lasing from a single plasmonic nanoparticle.
• To overcome inherent Ohmic losses in plasmonic nanolasers through strong coupling.
• To achieve single-mode laser emission at room temperature.

Main Methods:

• Coupling a gold nanorod (GNR) to the whispering gallery cavity of a dye-doped polymer microfiber.
• Utilizing strong mode coupling to enhance optical coherence.
• Measuring laser emission characteristics, including threshold and linewidth.

Main Results:

• Direct observation of lasing in a microfiber-coupled single plasmonic nanoparticle.
• Achieved single-mode laser emission from the GNR at room temperature.
• Observed a low lasing threshold of 2.71 MW/cm² and a linewidth narrower than 2 nm.

Conclusions:

• Strong mode coupling between plasmonic nanoparticles and microcavities is a viable strategy for practical nanolasers.
• This hybrid approach effectively mitigates Ohmic losses, enabling efficient light emission.
• The demonstrated GNR-microfiber system represents a significant advancement in nanoscale laser technology.