Integration of a single photon source with a fibre-compatible photonic waveguide

The integration of a single photon source based on a solid-state emitter with a photonic structure remains challenging and specifically when it comes to be compatible with optical fibres. It is important to do so for quantum technologies where single photon sources constitute building blocks for many technologies. In this work, we demonstrate the integration of a single photon source, made of a colloidal semiconductor nanocrystal, with a photonic structure made of a glass waveguide obtained by the ion-exchange technique, which is a fibre-compatible platform used in telecom photonics. Using surface functionalisation and a secondary waveguide of titanium dioxide, we manage to couple single photons from the nanoemitter to the optical waveguide. We observe the single photon character is preserved and demonstrates a 1.2 Purcell factor. A coupling efficiency over 25% is expected thanks to the titanium dioxide secondary waveguiding layer, compared to around 2% obtained for simply positioning the nanocrystal on top of the waveguide alone. The optical waveguide is then pigtailed to an optical fibre to demonstrate a first proof of principle of an integrated single photon source at room temperature with a fibre-compatible platform made of glass with a coupling efficiency increase of 2.8.