Optimized Designs for Telecom-Wavelength Quantum Light Sources Based on Hybrid Circular Bragg Gratings

TL;DR

This paper presents optimized hybrid circular Bragg Grating designs for telecom-wavelength quantum light sources, achieving high photon extraction, robustness to fabrication imperfections, and efficient fiber coupling, advancing practical quantum communication technologies.

Contribution

The study introduces novel, robust CBG designs with high efficiency and fiber coupling optimized for telecom wavelengths, validated through comprehensive simulations.

Findings

Photon extraction efficiency > 95%

Coupling efficiency up to 77% with standard fibers

Design robustness against fabrication imperfections

Abstract

We present a design study of quantum light sources based on hybrid circular Bragg Gratings (CBGs) for emission wavelengths in the telecom O-band. The evaluated CBG designs show photon extraction efficiencies > 95% and Purcell factors close to 30. Using simulations based on the finite element method, and considering the influence of possible fabrication imperfections, we identify optimized high-performance CBG designs which are robust against structural aberrations. In particular, full 3D simulations reveal that the designs show robustness regarding deviations of the emitter position in the device well within reported positioning accuracies of deterministic fabrication technologies. Furthermore, we investigate the coupling of the evaluated hybrid CBG designs to single-mode optical fibers, which is particularly interesting for the development of practical quantum light sources. We obtain coupling efficiencies of up to 77% for off-the-shelf fibers, and again proof robustness against fabrication imperfections. Our results show prospects for the fabrication of close-to-ideal fiber-coupled quantum light sources for long distance quantum communication.