Microsphere-assisted generation of localized optical emitters in 2D hexagonal boron nitride

Area of Science:

• Materials Science
• Nanotechnology
• Quantum Optics

Background:

• Crystal defects in hexagonal boron nitride (hBN) show promise as nanoscale optical probes.
• Challenges exist in deterministic defect placement and controlling emission areas for reliable optical emitters.

Purpose of the Study:

• To develop a method for enhancing hexagonal boron nitride (hBN) defect generation and optical signal readout using microspheres.
• To improve the precision of defect placement and the efficiency of light collection for nanoscale optical applications.

Main Methods:

• Integration of microspheres with hBN crystal lattices.
• Focused femtosecond (fs) laser irradiation into a photonic nanojet (PNJ) for localized defect generation.
• Utilizing the whispering gallery mode (WGM) effect for enhanced light collection.

Main Results:

• Microsphere-assisted method reduced the emission area by a factor of 5.
• Achieved approximately a 10-fold increase in fluorescence collection efficiency compared to samples without microspheres.
• Demonstrated enhanced light-matter interactions at the nanoscale.

Conclusions:

• The microsphere integration technique offers precise control over hBN defect generation and signal readout.
• This advancement is crucial for developing advanced optical emitters in hBN.
• Potential applications include quantum technologies and nanoscale sensing.