Numerical Investigation of Light Emission from Quantum Dots Embedded into On-Chip, Low Index Contrast Optical Waveguides

TL;DR

This paper numerically studies how to optimize light emission coupling from quantum dots into low contrast optical waveguides, aiming to improve integrated quantum photonic device performance.

Contribution

It introduces a model for coupling efficiency calculation and demonstrates optimization strategies for waveguide dimensions and geometry to enhance light emission coupling.

Findings

Optimized waveguide dimensions increase coupling efficiency.

Lateral cropping of waveguides can double the coupling efficiency.

Purcell-enhancement and field profile optimization are effective strategies.

Abstract

Single-photon emitters integrated into quantum optical circuits will enable new, miniaturized quantum optical devices. Here, we numerically investigate semiconductor quantum dots embedded to low refractive index contrast waveguides. We discuss a model to compute the coupling efficiency of the emitted light field to the fundamental propagation mode of the waveguide, and we optimize the waveguide dimensional parameters for maximum coupling efficiency. Further, we show that for a laterally cropped waveguide the interplay of Purcell-enhancement and optimized field profile can enhance the coupling efficiency by a factor of about two.