We investigated the timing jitter of superconducing nanowire single-photon detectors (SNSPDs) and found a strong dependence on the detector response. By varying the multi-layer structure, we observed changes in pulse...

No abstract

No abstract

No abstract

Rapid development in integrated optoelectronic devices and quantum photonic architectures creates a need for optical fiber to chip coupling with low losses. Here we present a fast and generic approach that allows temperature stable self-aligning connections of nanophotonic devices to optical fibers. We show that the attainable precision of our approach is equal to that of DRIE-process based couplings. Specifically, the initial alignment precision is 1.2±0.4 µm, the average shift caused by mating < 0.5 µm, which is in the order of the precision of the concentricity of the employed fiber, and the thermal cycling stability is < 0.2 µm. From these values the expected overall alignment offset is calculated as 1.4 ± 0.4 µm. These results show that our process offers an easy to implement, versatile, robust and DRIE-free method for coupling photonic devices to optical fibers. It can be fully automated and is therefore scalable for coupling to novel devices for quantum photonic systems.

We investigate the growth conditions for thin (≤ 200 nm) sputtered aluminum (Al) films. These coatings are needed for various applications, e.g. for advanced manufacturing processes in the aerospace industry or for nanostructures for quantum devices. Obtaining high-quality films, with low roughness, requires precise optimization of the deposition process. To this end, we tune various sputtering parameters such as the deposition rate, temperature and power, which enables 50 nm thin films with a root mean square (RMS) roughness of less than 1 nm and high reflectivity. Finally, we confirm the high quality of the deposited films by realizing superconducting single-photon detectors integrated into multi-layer heterostructures consisting of an aluminum mirror and a silicon dioxide dielectric spacer. We achieve an improvement in detection efficiency at 780 nm from 40 % to 70 % by this integration approach.

No abstract