Optical positioning of single quantum dots in micropillar with >65% extraction efficiency for on-demand quantum light sources

TL;DR

This paper demonstrates precise optical positioning of single quantum dots within micropillars, achieving over 65% photon extraction efficiency for on-demand quantum light sources, with enhanced brightness and low multi-photon probability.

Contribution

It introduces an optimized two-color photoluminescence imaging technique for accurate quantum dot positioning and integrates them into micropillars to enhance photon extraction efficiency.

Findings

Position uncertainty less than 20 nm.

Achieved 68% photon extraction efficiency.

Low multi-photon probability ($g^{2}(0)$=0.144).

Abstract

We report optical positioning single quantum dots (QDs) in planar cavity with an average position uncertainty $<$20 nm using an optimized two-color photoluminescence imaging technique. We create single-photon sources based on these QDs in determined micropillar cavities. The brightness of the QD fluorescence is greatly enhanced on resonance with the fundamental mode of the cavity, leading to an high extraction efficiency of 68%$\pm$6% into a lens with numerical aperture of 0.65, and simultaneously exhibiting low multi-photon probability ($g^{2}(0)$=0.144$\pm$0.012) at this collection efficiency.