Search results for "ELECTRONICS"
showing 10 items of 4340 documents
Chromatic Dispersion Control in Mode-Locked Yb-Doped Fiber Lasers Based on a Microstructured Optical Fiber
2013
We present an experimental study on the use of solid core microstructured optical fibers (MOF) for managing the chromatic dispersion in an Yb-doped fiber laser passively mode-locked by a saturable absorber. The performance of the laser, in terms of pulse width and repetition rate, was investigated as a function of the net cavity dispersion.
Experimental quantification of useful and parasitic absorption of light in plasmon-enhanced thin silicon films for solar cells application
2016
AbstractA combination of photocurrent and photothermal spectroscopic techniques is applied to experimentally quantify the useful and parasitic absorption of light in thin hydrogenated microcrystalline silicon (μc-Si:H) films incorporating optimized metal nanoparticle arrays, located at the rear surface, for improved light trapping via resonant plasmonic scattering. The photothermal technique accounts for the total absorptance and the photocurrent signal accounts only for the photons absorbed in the μc-Si:H layer (useful absorptance); therefore, the method allows for independent quantification of the useful and parasitic absorptance of the plasmonic (or any other) light trapping structure. W…
Energy management of a thermally coupled fuel cell system and metal hydride tank
2019
International audience; Being produced from renewable energy, hydrogen is one of the most efficient energy carriers of the future. Using metal alloys, hydrogen can be stored and transported at a low cost, in a safe and effective manner. However, most metals react with hydrogen to form a compound called metal hydride (MH). This reaction is an exothermic process, and as a result releases heat. With sufficient heat supply, hydrogen can be released from the as-formed metal hydride. In this work, we propose an integrated power system of a proton exchange membrane fuel cell (PEMFC) together with a hydride tank designed for vehicle use. We investigate different aspects for developing metal hydride…
A coupled lossy local-mode theory description of a plasmonic tip
2012
International audience; We investigate power propagation in a metal-coated tapered optical fiber. We analyze in detail the conversion from the fiber core guided mode to a surface plasmon polariton (SPP) confined at the tip apex. To this aim, we adapt coupled local-mode theory to include lossy modes. Two distinct regimes are identified. In the case of thin metal coating, a strong coupling regime occurs between a core guided mode and a SPP with good conversion efficiency. In the case of thick metal coating, a very weak coupling occurs. Finally, energy confinement and the role of Joule losses are discussed in the near-infrared and visible ranges. Moreover, the coupled equations derived for loc…
Efficient unidirectional nanoslit couplers for surface plasmons
2007
5 pages, 4 figures.
Modulation of surface plasmon coupling-in by one-dimensional surface corrugation
2008
Surface plasmon-polaritons have recently attracted renewed interest in the scientific community for their potential in sub-wavelength optics, light generation and non-destructive sensing. Given that they cannot be directly excited by freely propagating light due to their intrinsical binding to the metal surface, the light-plasmon coupling efficiency becomes of crucial importance for the success of any plasmonic device. Here we present a comprehensive study on the modulation (enhancement or suppression) of such coupling efficiency by means of one-dimensional surface corrugation. Our approach is based on simple wave interference and enables us to make quantitative predictions which have been …
Improving the efficiency of light-emitting diode based on a thiophene polymer containing a cyano group
2007
Abstract We report on the overall improvement of a single layer organic light-emitting diode device based on poly{[3-hethylthiophene]-co-3-[2-( p -cyano-phenoxy)ethyl]thiophene} or namely PTOPhCN. This polymer was recently developed by adding a cyano group as a side-chain substituent of the thiophenic backbone onto the main polymer chain and showed promising results for light-emitting diode devices. Using an improved device layout, bright red electroluminescence was obtained at 4 V and showed a luminance of about 400 cd/m 2 at 8 V with current densities in the order of 6000 A/m 2 .
Linear Non Linear Digital control for DC/DC Converters with fast transient response PARTE II
2009
This article presents a digital control that improves the stability of the system, solves the problem of the limit cycle, shortens the recovery time and limits the overcoming of the rectified output voltage. The digital linear-nonlinear control function for DC / DC converters is described. The simulation model in the mixed environment of matlab-simulink / active -hdl is described. Preliminary results of the preliminary hardware test on a step-down-phase converter are presented and simulation and experimental results are also presented.
Linear Non Linear Digital control for DC/DC Converters with fast transient response PARTE I
2009
This article presents a digital control that improves the stability of the system, solves the problem of the limit cycle, shortens the recovery time and limits the overcoming of the rectified output voltage. Describes the linear digital nonlinear control function for DC / DC converters. The simulation model in the mixed environment of matlab-simulink / active -hdl is described. Preliminary results of the preliminary hardware test on a step-down-phase converter are presented and simulation and experimental results are also presented.
Active-fixation coronary sinus pacing lead extraction: A hybrid approach
2012
Cardiac resynchronization therapy (CRT) can be considered as the standard treatment for patients suffering from heart failure (NYHA III–IV), severely reduced left ventricular (LV) function, and wide QRS complexes. Over the past years, the lead systems used to stimulate the left ventricle have evolved technically from epicardial approaches to a transvenous access accompanied by a significant reduction of procedure-related complication rates [1]. However, even today, LV dislodgement rates ranging 5–10% and the instability of thresholds over time remain the greatest challenges with transvenous LV leads in CRT. Therefore, a special LV lead utilizing active fixation (the Attain StarFix® active f…