A stand-alone fiber-coupled single-photon source.

In this work, we present a stand-alone and fiber-coupled quantum-light source. The plug-and-play device is based on an optically driven quantum dot delivering single photons via an optical fiber. The quantum dot is deterministically integrated in a monolithic microlens which is precisely coupled to the core of an optical fiber via active optical alignment and epoxide adhesive bonding.

Single Quantum Dot with Microlens and 3D-Printed Micro-objective as Integrated Bright Single-Photon Source.

Integrated single-photon sources with high photon-extraction efficiency are key building blocks for applications in the field of quantum communications. We report on a bright single-photon source realized by on-chip integration of a deterministic quantum dot microlens with a 3D-printed multilens micro-objective. The device concept benefits from a sophisticated combination of in situ 3D electron-beam lithography to realize the quantum dot microlens and 3D femtosecond direct laser writing for creation of the micro-objective.

Advanced in-situ electron-beam lithography for deterministic nanophotonic device processing.

We report on an advanced in-situ electron-beam lithography technique based on high-resolution cathodoluminescence (CL) spectroscopy at low temperatures. The technique has been developed for the deterministic fabrication and quantitative evaluation of nanophotonic structures. It is of particular interest for the realization and optimization of non-classical light sources which require the pre-selection of single quantum dots (QDs) with very specific emission features.

Mode selection in electrically driven quantum dot microring cavities.

Within this paper a novel method for selecting certain lasing modes from a whispering gallery mode (WGM) spectrum of electrically pumped microrings is presented. Selection is achieved by introducing sub-wavelength sized notches of about 50 nm width and 500 nm depth to the sidewalls of ring shaped quantum dot micro cavities with 80 µm diameter and ridge widths below 2 µm. It is shown that the notches act as scattering centers, suppressing modes that have maxima in intensity at the notch position.