1,036 research outputs found
Experimental demonstration of gridless spectrum and time optical switching
An experimental demonstration of gridless spectrum and time switching is presented. We propose and demonstrate a bit-rate and modulation-format independent optical cross-connect architecture, based on gridless spectrum selective switch, 20-ms 3D-MEMS and 10-ns PLZT optical switches, that supports arbitrary spectrum allocation and transparent time multiplexing. The architecture is implemented in a four-node field-fiber-linked testbed to transport continuous RZ and NRZ data channels at 12.5, 42.7 and 170.8 Gb/s, and selectively groom sub-wavelength RZ channels at 42.7 Gb/s. We also showed that the architecture is dynamic and can be reconfigured to meet the routing requirements of the network traffic. Results show error-free operation with an end-to-end power penalty between 0.8 dB and 5 dB for all continuous and sub-wavelength channels
A Novel QoS provisioning Scheme for OBS networks
This paper presents Classified Cloning, a novel QoS provisioning mechanism for OBS networks carrying real-time
applications (such as video on demand, Voice over IP, online
gaming and Grid computing). It provides such applications with a minimum loss rate while minimizing end-to-end delay and jitter. ns-2 has been used as the simulation tool, with new OBS modules having been developed for performance evaluation purposes. Ingress node performance has been investigated, as well as the overall performance of the suggested scheme. The results obtained showed that new scheme has superior performance to classical cloning. In particular, QoS provisioning offers a guaranteed burst loss rate, delay and expected value of jitter, unlike existing proposals for QoS implementation in OBS which use the burst offset time to provide such differentiation. Indeed, classical schemes increase both end-to-end delay and
jitter. It is shown that the burst loss rate is reduced by 50% reduced over classical cloning
321W average power, 1GHz, 20ps 1060nm pulsed fiber MOPA source
Pulses from a gain-switched laser diode were amplified in a fiber MOPA system to produce in excess of 320W of average power in 20ps pulses at 1GHz repetition rate at 1060nm
Characteristics and experiences of Chios breed
Discussed are the reproductive and productive characteristics of the dairy and prolific Chios sheep breed, originating from the homonymous Greek island. Besides the island, the breed is also raised in the Greek mainland, the westcoast of Turkey and in Cyprus. It is early maturing, with long reproductive reason and lambing period, extending from October to March. Inspite its high ovulation rate, repeatability estimates do not suggest the presence of fecundity genes. The average prolificacy ratio ranges between 1.80 and 2.0, with triplets and quadruplets not uncommon. The average exploitable milk yield varies between 180 and 200 kg, with occasionally reported productions of up to 400 and 500 kg. Repeatabilities of prolificacy and milk production based on island data were found 0.15 and 0.40, respectively. Heritability of milk yield from the island was 0.31 and 0.40, respectively, for second and third lactations. Recent estimates from Cyprus report values of 0.30 and 0.39 for 90-day milk and total milk yield, respectively. Other parameters and information on udder (mechanical milking), growth, and carcass characteristics as well as on crossbreeding trials are also reported. Some considerations are given with regard to potential and valorization of this highly productive sheep breed
Near-infrared Fourier transform room-temperature photoluminescence of erbium complexes
A modified Fourier transform (FT) Raman bench spectrometer designed for the detection of weak light emission in the 800â1700 nm wavelength region has been used to demonstrate the advantages of FT spectroscopy for measuring near-infrared photoluminescence spectra of lanthanide complexes with a good resolution and very good sensitivity. This apparatus has been tested with an ultraviolet laser source (325 nm) on three standard erbium complexes. The 4I13/24I15/2 emission of tris-(acetylacetonato) (1,10 phenanthroline) erbium [Er(acac)3(phen)], tris-(4,4,4,-trifluoro-1-(2 thenoyl)-1,3-butenedione) (1,10 phenanthroline) erbium [Er(TTFA)3(phen)] and tris(8-hydroxyquinolinato) erbium [Erq3] has thus been recorded in solution and in the solid state and compared with literature. ©2003 American Institute of Physics
Design Optimization of Uncoupled Six-core Fibers in Standard Cladding Diameter Using Artificial Intelligence
We report on ultra-wide-band and long-haul compatible 125”m six-core trench-assisted fiber designs. The AI-optimization process considers crosstalk, effective area, and bandwidth. We show that homogeneous cores can lead to low complexity yet high capacity fiber
Optimization of 125-mu m Heterogeneous Multi-Core Fibre Design Using Artificial Intelligence
We propose an automated heterogeneous trench-assisted multi-core fibre (MCF) design method. This method uses neural networks to speed up coating loss estimation by ⌠10^{6} times and using particle swarm optimization (PSO) algorithm to explore the optimal MCF design under various objectives and properties constraints. The latter reduces the permutation evaluations by ten orders of magnitude compared with the brute force method. The artificial intelligence (AI)-based method is used to design MCFs on two objectives: minimizing crosstalk (XT) and maximizing effective mode area ( A_{eff} ). By optimizing XT with different A_{eff} and cutoff wavelength constraints combinations for 6-core fibres, we achieved â92.1 dB/km ultra-low XT for C+L band fibre and â64 dB/km for E+S+C+L-band fibre. Meanwhile, we explored the upper limit of A_{eff} given different bandwidth constraints resulting in a 6.82 relative core multiplicity factor. We performed capacity analysis of fibres for two transmission lengths. It is shown that bandwidth is the dominant factor while the increase brought by A_{eff} and the penalty caused by XT are relevantly small. Our fibres exceed the cutoff-limited capacity of the 7-core fibre in literature by 35.1% and 84.8% for 1200 km and 6000 km transmission respectively
OSNR-aware control of optical white boxes on elastic optical networks
Asia Communications and Photonics Conferene (ACP) © OSA 2016 Results of optical white boxes on Elastic Optical Networks with adaptive modulation format and symbol rate simulations demonstrate that synthesized nodes improve capacity under low loads while preserving performance of existing ROADMs for higher loads
The dependence on oxygen fugacity of nickel and cobalt partitioning between olivine and silicate melt
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 1991.Includes bibliographical references (leaves 13-15).by Deborah A. Zervas.M.S
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