Highly directional emission from a quantum emitter embedded in a hemispherical cavity

Area of Science:

• Optics and Photonics
• Quantum Engineering
• Materials Science

Background:

• Solid-state quantum emitters are crucial for quantum technologies.
• Efficient light extraction from emitters in high dielectric environments remains a challenge.
• Existing microcavity designs often struggle with integration and efficiency.

Purpose of the Study:

• To design and analyze a novel solid-state, micron-sized hemispherical cavity.
• To enhance the extraction efficiency of embedded quantum emitters.
• To provide a design guideline for optimizing such microcavity structures.

Main Methods:

• Development of a simple analytical model for cavity design.
• Finite-difference time-domain (FDTD) simulations for detailed analysis.
• Fabrication and characterization of monolithic hemispherical cavities.

Main Results:

• Achieved up to 90% extraction efficiency for cavity modes.
• Demonstrated a Purcell enhancement factor greater than 2.
• Obtained a quality factor of approximately 50.
• Exhibited Gaussian-like far-field beam profiles with low divergence.

Conclusions:

• The designed hemispherical cavity significantly enhances light extraction efficiency.
• The cavity structure is suitable for solid-state emitters in high dielectric media, like quantum dots and diamond defects.
• This work provides a promising platform for advancing solid-state quantum emitter applications.