Edouard Brainis

Nanoscale and Single-Dot Patterning of Colloidal Quantum Dots.

Using an optimized lift-off process we develop a technique for both nanoscale and single-dot patterning of colloidal quantum dot films, demonstrating feature sizes down to ~30 nm for uniform films and a yield of 40% for single-dot positioning, which is in good agreement with a newly developed theoretical model. While first of all presenting a unique tool for studying physics of single quantum dots, the process also provides a pathway toward practical quantum dot-based optoelectronic devices.

On‐Chip Integrated Quantum‐Dot–Silicon‐Nitride Microdisk Lasers

Hybrid silicon nitride (SiN)-quantum-dot (QD) microlasers coupled to a passive SiN output waveguide with a 7 µm diameter and a record-low threshold density of 27 µJ cm-2 are demonstrated. A new design and processing scheme offers long-term stability and facilitates in-depth QD material and device characterization, thereby opening new paths for optical communication, sensing, and on-chip cavity quantum optics based on colloidal QDs.

Fabrication and characterization of on-chip silicon nitride microdisk integrated with colloidal quantum dots.

We designed and fabricated free-standing, waveguide-coupled silicon nitride microdisks hybridly integrated with embedded colloidal quantum dots. An efficient coupling of quantum dot emission to resonant disk modes and eventually to the access waveguides is demonstrated. The amount of light coupled out to the access waveguide can be tuned by controlling its dimensions and offset with the disk edge. These devices open up new opportunities for both on-chip silicon nitride integrated photonics and novel optoelectronic devices with quantum dots.

Broadband enhancement of single photon emission and polarization dependent coupling in silicon nitride waveguides

Single-photon (SP) sources are important for a number of optical quantum information processing applications. We study the possibility to integrate triggered solid-state SP emitters directly on a photonic chip. A major challenge consists in efficiently extracting their emission into a single guided mode. Using 3D finite-difference time-domain simulations, we investigate the SP emission from dipole-like nanometer-sized inclusions embedded into different silicon nitride (SiNx) photonic nanowire waveguide designs. We elucidate the effect of the geometry on the emission lifetime and the polarization of the emitted SP. The results show that highly efficient and polarized SP sources can be realized using suspended SiNx slot-waveguides. Combining this with the well-established CMOS-compatible processing technology, fully integrated and complex optical circuits for quantum optics experiments can be developed.

Progress towards on-chip single photon sources based on colloidal quantum dots in silicon nitride devices

New results on integration of colloidal quantum dots (QDs) into SiN microstructures are reported, including QD positioning with nanometric accuracy and the efficient coupling of their emission to waveguides and cavities. The results are relevant to on-chip quantum optics and information processing.