Huygens description of resonance phenomena in subwavelength hole arrays

We develop a point-scattering approach to the plane-wave optical transmission of subwavelength metal hole arrays. We present a real space description instead of the more conventional reciprocal space description; this naturally produces interfering resonant features in the transmission spectra and makes explicit the tensorial properties of the transmission matrix. We give transmission spectra simulations for both square and hexagonal arrays; these can be evaluated at arbitrary angles and polarizations.Comment: 5 pages, 3 figure

Evolution of and additional functionalities to the city energy planning platform MEU

The MEU GIS-enabled web-platform has been developed in close collaboration with four Swiss cities: it enables detailed monitoring and planning for both energy demand and supply at individual building and neighborhood level (http://meu.epfl.ch). Whereas the first version of the MEU platform allowed launching calculations for only up to several hundreds of buildings at a time, the refactored version presently gives access to entire cities comprising several thousands of buildings with the same level of detail. On one hand, the code architecture has been thoroughly revised and consolidated while, on the other hand, the databases for the four partner cities are being completed, checked, corrected and eventually made completely available for several years. A large test campaign is thus underway on the refactored version of the MEU platform. In the upcoming months, the latter will present all the functionalities of the prototype version, i.e. include the construction and evaluation of complex energy scenarios. New functionalities are concomitantly being added to the MEU platform, in particular at the level of the energy networks. Indeed, in the prototype version, the latter were only displayed but no network attributes (except geo-referencing) were neither introduced nor used in calculations. The envisioned new functionalities will enable to start filling this important usability gap by adding network detailed attributes to the database structure and by allowing pre-dimensioning calculations based on selected energy scenarios and including the networks characteristics (available power, temperatures/pressures, limiting dimensions, aso.). The energy supply side aspects will thus be quantitatively be taken into account, along with the implications in terms of network extension/densification precisely determined. The natural gas network, which is – and shall continue to be - broadly present in all four partner cities, representing up to 30 % of the overall final territorial energy consumption, will be used as the first test case, in close collaboration with local multi-energy utilities

How can ski resorts get smart? Transdisciplinary approaches to sustainable winter tourism in the European Alps

Climate change and the call for reduction of greenhouse gas emissions, the efficient use of (renewable) energy, and more resilient winter tourism regions, forces ski resorts across the European Alps to look for \u201csmart\u201d approaches to transition towards a sustainable, low-carbon economy. Drawing on the smart-city concept and considering the different historical developments of Alpine resorts, the Smart Altitude Decision-Making Toolkit was developed using a combination of an energy audit tool, a WebGIS, and collaborative and innovative living labs installed in Les Orres (France), Madonna di Campiglio (Italy), Krvavec (Slovenia), and Verbier (Switzerland). This step-by-step Decision-Making Toolkit enables ski resorts to get feedback on their energy demand, an overview of the locally available sources of renewable energy, and insights regarding their potential for improving their energy efficiency by low-carbon interventions. The Decision-Making Toolkit is suitable for knowledge transfer between stakeholders within living labs and moreover provides the flexibility for tailor-made low-carbon strategies adapting to the unique assets and situatedness of ski resorts

Improvement of infrared single-photon detectors absorptance by integrated plasmonic structures

Plasmonic structures open novel avenues in photodetector development. Optimized illumination configurations are reported to improve p-polarized light absorptance in superconducting-nanowire single-photon detectors (SNSPDs) comprising short- and long-periodic niobium-nitride (NbN) stripe-patterns. In OC-SNSPDs consisting of ~quarter-wavelength dielectric layer closed by a gold reflector the highest absorptance is attainable at perpendicular incidence onto NbN patterns in P-orientation due to E-field concentration at the bottom of nano-cavities. In NCAI-SNSPDs integrated with nano-cavity-arrays consisting of vertical and horizontal gold segments off-axis illumination in S-orientation results in polar-angle-independent perfect absorptance via collective resonances in short-periodic design, while in long-periodic NCAI-SNSPDs grating-coupled surface waves promote EM-field transportation to the NbN stripes and result in local absorptance maxima. In NCDAI-SNSPDs integrated with nano-cavity-deflector-array consisting of longer vertical gold segments large absorptance maxima appear in 3p-periodic designs due to E-field enhancement via grating-coupled surface waves synchronized with the NbN stripes in S-orientation, which enable to compensate fill-factor-related retrogression.United States. Dept. of Energy (Frontier Research Centers

Système de management énergétique territorial ::une plateforme web cartographique pour la planification de la politique énergétique locale

La plateforme MEU est un outil au service des collectivités, des entreprises d’approvisionnement en énergie et des gestionnaires de réseaux de distribution. L’outil crée une «photographie énergétique » détaillée de la ville pour un instant donné. Il permet de monitorer et planifier tant la demande que l’approvisionnement énergétique d’un bâtiment, d’un quartier ou d’une ville. Via la création de scénarios, l’utilisateur pourra ensuite prendre les meilleures décisions énergétiques possibles pour le futur. La plateforme sera commercialiser en fin 2016 par Navitas Consilium SA