Lasing Spaser in Photonic Crystals

Area of Science:

• Nanophotonics
• Materials Science
• Quantum Optics

Background:

• Plasmonic nanolasers (spasers) are advanced coherent light sources.
• Gold nanospheres with dye molecules function as spasers.
• Photonic crystals (PhCs) offer external feedback for optical devices.

Purpose of the Study:

• To integrate spasers into a 3D PhC film.
• To investigate the resulting coherent electromagnetic radiation.
• To analyze the performance enhancement of spasers within a PhC.

Main Methods:

• Fabrication of spasers using gold nanospheres, silica shells, and dye molecules.
• Infiltration of spasers into a 3D silica-based photonic crystal film.
• Characterization of the optical emission properties and threshold behavior.

Main Results:

• The PhC-spaser hybrid structure acts as a coherent electromagnetic radiation source.
• Phase-locking of spasers within the PhC resulted in "lasing spaser" phenomenon.
• Observed "Star-of-David" far-field radiation patterns due to Brillouin zone boundary effects.
• Achieved an 80-fold decrease in spaser generation threshold and narrowed emission peaks.

Conclusions:

• Integrating spasers into PhCs enhances their performance as coherent light sources.
• The PhC provides distributed feedback, improving spaser efficiency and coherence.
• This hybrid system demonstrates a promising approach for advanced photonic applications.