Transfer-printed single photon sources coupled to wire waveguides

TL;DR

This paper presents a transfer printing method to integrate quantum dot single photon sources with photonic integrated circuits, achieving high coupling efficiency and enabling scalable quantum photonic applications.

Contribution

It introduces a novel transfer printing technique for integrating independent single photon sources with PICs, overcoming material and fabrication incompatibilities.

Findings

Achieved waveguide coupling efficiency >99% with quantum dot SPSs.

Successfully integrated two SPSs into a waveguide.

Demonstrated high-performance coupling suitable for large-scale quantum applications.

Abstract

Photonic integrated circuits (PICs) are attractive platforms to perform large-scale quantum information processing. While highly-functional PICs (e.g. silicon based photonic-circuits) and high-performance single photon sources (SPSs, e.g. compound-semiconductor quantum dots (QDs)) have been independently demonstrated, their combination for single-photon-based applications has still been limited. This is largely due to the complexities of introducing SPSs into existing PIC platforms, which are generally realized with different materials and using distinct fabrication protocols. Here, we report a novel approach to combine SPSs and PICs prepared independently. We employ transfer printing, by which multiple desired SPSs can be integrated in a simple pick-and-place manner with a theoretical waveguide coupling efficiency >99%, fulfilling the demanding requirements of large-scale quantum applications. Experimentally, we demonstrated QD-based SPSs with high waveguide coupling efficiencies, together with the integration of two SPSs into a waveguide. Our approach will accelerate scalable fusion between modern PICs and cutting-edge quantum technologies.