Improving the performance of bright quantum dot single photon sources using amplitude modulation

TL;DR

This paper demonstrates that synchronized amplitude modulation can significantly enhance the purity, indistinguishability, and temporal coherence of single photons emitted from quantum dot sources, improving their suitability for quantum technologies.

Contribution

The study introduces a flexible amplitude modulation technique to improve quantum dot single photon sources, applicable post-fabrication and independent of device geometry.

Findings

Enhanced single photon purity and indistinguishability

Improved temporal overlap of emission events

Applicable to various solid-state single photon sources

Abstract

Single epitaxially-grown semiconductor quantum dots have great potential as single photon sources for photonic quantum technologies, though in practice devices often exhibit non-ideal behavior. Here, we demonstrate that amplitude modulation can improve the performance of quantum-dot-based sources. Starting with a bright source consisting of a single quantum dot in a fiber-coupled microdisk cavity, we use synchronized amplitude modulation to temporally filter the emitted light. We observe that the single photon purity, temporal overlap between successive emission events, and indistinguishability can be greatly improved with this technique. As this method can be applied to any triggered single photon source, independent of geometry and after device fabrication, it is a flexible approach to improve the performance of solid-state systems, which often suffer from excess dephasing and multi-photon background emission.