High-performance designs for fiber-pigtailed quantum-light sources based on quantum dots in electrically-controlled...

Area of Science:

• Quantum optics
• Nanophotonics
• Solid-state physics

Background:

• Quantum light sources are essential for quantum information processing.
• Efficient fiber coupling and high Purcell factors are critical for device performance.
• Electrically tunable quantum emitters offer advanced control capabilities.

Purpose of the Study:

• To numerically investigate and optimize directly fiber-coupled hybrid circular Bragg gratings (CBGs) with electrical control.
• To achieve high fiber coupling efficiency and Purcell factors for quantum dot applications.
• To ensure device robustness against fabrication tolerances.

Main Methods:

• Utilized a surrogate model combined with Bayesian optimization for device design.
• Investigated hybrid CBGs with dielectric planarization and transparent contact materials.
• Analyzed performance across 930 nm, telecom O-band, and C-band wavelengths.

Main Results:

• Achieved > 86% direct fiber coupling efficiency (> 93% into NA 0.8) and Purcell factors > 20.
• Demonstrated robust telecom-band designs with expected efficiencies of (82.2±4.1)-5.5+2.2% and Purcell factors up to (23.2±2.3)-3.0+3.2.
• Confirmed electrical field strengths sufficient for Stark-tuning of quantum dots.

Conclusions:

• The study provides blueprints for high-performance, fiber-pigtailed, electrically controlled quantum dot CBG devices.
• Optimized designs offer excellent coupling efficiency and Purcell factors for quantum information applications.
• The developed approach ensures robustness against fabrication imperfections, paving the way for practical quantum technologies.