Search

Photon sources are fundamental components for any quantum photonic technology. The ability to generate high count-rate and low-noise correlated photon pairs via spontaneous parametric down-conversion using bulk crystals has been the cornerstone of modern quantum optics. However, future practical quantum technologies will require a scalable integration approach, and waveguide-based photon sources with high-count rate and low-noise characteristics will be an essential part of chip-based quantum technologies. Here, we demonstrate photon pair generation through spontaneous four-wave mixing in a silicon micro-ring resonator, reporting separately a maximum coincidence-to-accidental (CAR) ratio of 602 ± 37 (for a generation rate of 827kHz), and a maximum photon pair generation rate of 123 MHz ± 11 kHz (with a CAR value of 37). To overcome free-carrier related performance degradations we have investigated reverse biased p-i-n structures, demonstrating an improvement in the pair generation rate by a factor of up to 2 with negligible impact on CAR., QN/Quantum Nanoscience, Applied Sciences

Quantum photonics is a promising technology for implementing quantum information tasks. We demonstrate integration of multiple photon pair sources together with a circuit enabling creation and manipulation of photon pairs in a monolithic silicon-on-insulator chip., QN/Quantum Nanoscience, Applied Sciences

Since 2004 there is a growing global awareness of the risks that tsunamis pose to coastal communities. Despite the fact that these events were already an intrinsic part of the culture of some countries (such as Chile and Japan), in many other places they had been virtually unheard of before 2004. Nevertheless, the frequent reoccurrence of these events in recent years has led to the emergence of a “tsunami culture” in many areas of the world, which has resulted in increased awareness, disaster preparedness and willingness of local populations to evacuate when the threat of these events arises. This paper will explore these cultural issues using as a basis questionnaires carried out by the authors during their own field visits to the last three major events (in Japan, Chile and Indonesia), and interpret these through the willingness of coastal communities to build protection measures along the shore and the impact that these can have on sustainable development., Hydraulic Engineering, Civil Engineering and Geosciences