66 research outputs found
GEOSUD SDI: accessing Earth Observation data collections with semantic-based services
Ponencias, comunicaciones y pĂłsters presentados en el 17th AGILE Conference on Geographic Information Science
"Connecting a Digital Europe through Location and Place", celebrado en la Universitat Jaume I del 3 al 6 de junio de 2014.Ecosystems and territories are complex systems involving multidisciplinary approaches on different time scales and different locations. Yet,
mastering the spatial information on these systems is critical to lead a relevant environmental research, as well as addressing efficient public
policies. Although the volume of Earth Observation ( EO) data generated these last years greatly increased, their usages are still too limited
when it comes to environmental issues. So as to remedy to this underutilisation, the GEOSUD (GEOinformation for Sustainable
Development) project had undertaken to deploy a national Spatial Data Infrastructure (SDI) to ease access to high resolution and very high
resolution satellite images for public stakeholders and scientists. This paper gives an overview of this infrastructure and places emphasis on
the innovative components that fit the specific needs in terms of images discovery of the GEOSUD community. These components relies on
domain controlled vocabularies, which can assist both experts and non-experts in the field of remote sensing in their search of the
appropriate material to suit their needs
Dispersion uncompensated IM/DD transmissions of 12GHz-wide multi-band OFDM over 100km with a D-EML
International audienceGeneration of optical SSB signals by a D-EML is extended to its whole bandwidth. In an SSB context, 12GHz multi-band OFDM signal is transmitted through 100km intensity modulation/direct detection dispersive channel without frequency fading
Colorless FSK Demodulation and Detection With Integrated Fabry-Perot-Type SOA/REAM
A receiver for optical frequency modulated signals, based on colorless demodulation and detection, is presented. An integrated combination of semiconductor optical amplifier (SOA) and reflective electroabsorption modulator (REAM) is designed to obtain a comb-like spectral detection function, replacing the typically required costly frequency discrimination filter. The spectral properties of the designed SOA/REAM chip are discussed and the reception of a 10-Gb/s optical frequency modulated downstream signal is demonstrated, proving the applicability as receiving optical subsystem in the customer premises equipment of fiber-to-the-home access networks with wavelength reuse for upstream transmission and no downstream crosstalk.Peer ReviewedPostprint (published version
Architecture WDM-PON achromatique utilisant des lasers Fabry-Perot verrouillés en longueur d'onde par injection optique
Session orale 8 « SystÚmes et réseaux de Télécommunication » [Je1.6]National audienceUne architecture de réseau d'accÚs optique multiplexé en longueur d'onde (WDM-PON) utilisant des émetteurs achromatiques à base de lasers Fabry-Perot verrouillés en longueur d'onde par injection optique est proposée. Une source multi-longueur d'onde composée d'un seul laser à modes bloqués à bùtonnets quantiques est utilisée pour verrouiller les lasers Fabry-Perot. La transmission bidirectionnelle de 8 canaux sur 20 km de fibre dans une telle architecture a été réalisée à 2,5 Gb/s par canal et un bilan optique total de 23 dB a été obtenu
Laser Fabry-Perot verrouillé en longueur d'onde par injection optique pour le réseau d'accÚs
session orale Lu2 « Amplificateurs et Lasers Ă semi-conducteurs » [Lu2.2]National audiencePour les futurs rĂ©seaux d'accĂšs optique multiplexĂ©s en longueur d'onde (de type WDM-PON), des Ă©metteurs optiques bas-coĂ»ts et identiques pour chaque abonnĂ© sont souhaitables. Ces composants doivent pouvoir ĂȘtre modulĂ©s Ă 10 Gbps, tout en ayant une accordabilitĂ© en longueur d'onde. Cette derniĂšre propriĂ©tĂ© peut-ĂȘtre assurĂ©e en verrouillant un laser Fabry-Perot multimode par injection optique. Nous prĂ©sentons les propriĂ©tĂ©s d'un tel laser injectĂ© : son efficacitĂ© en verrouillage, la rĂ©duction du bruit d'intensitĂ© et l'amĂ©lioration trĂšs importante de la frĂ©quence de relaxation
Bidirectional Transmission in Colourless WDM-PON based on Injection-Locked Fabry-Perot Laser at 2.5 Gbit/s using Low-Cost Seeding Source
oral session 6.5 " WDM-PON and OCDMA " [6.5.1]International audienceError-free transmission over 20km of 8-channels for both downstream and upstream in colourless WDM-PON based on injection-locked Fabry-Perot laser is experimentally demonstrated at 2.5Gbit/s, using a single quantum dash mode-locked laser as multi-wavelength seeding source
AWG-DBR-based WDM transmitter fabricated in an InP generic foundry platform
We report a novel narrow-linewidth WDM transmitter operating at 10 Gbps per transmission channel with 275 kHz optical linewidth. The device, which integrates an AWG-based laser using selective DBR-mirrors with a Mach-Zehnder modulator array, has been fabricated in a multi-project wafer run in a generic InP-based foundry process.</p
Bidirectional 2.5-Gb/s WDM-PON Using FP-LDs Wavelength-Locked by a Multiple-Wavelength Seeding Source Based on a Mode-Locked Laser
Topic "Networks and Systems"International audienceWe experimentally investigate the operation of a cost-effective wavelength-division-multiplexed passive optical network (WDM-PON) based on wavelength-locked Fabry-PĂ©rot laser diodes (FP-LDs). A single quantum-dash passively mode-locked laser (QD-MLL) is combined with an arrayed waveguide grating in WDM-PON architecture to provide a low-noise, coherent multiwavelength seeding source to injection-lock the FP-LDs for both downstream and upstream. The results show that the QD-MLL-injected FP-LD has the same performance when compared to the case of injection-locking by a low-noise external cavity laser. Error-free bidirectional transmission over 25 km for 16 channels with 42.7-GHz channel spacing is demonstrated at 2.5 Gb/s in the C-band and an optical budget higher than 30 dB is reached
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