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| 11. |
- Abdellaoui, G., et al.
(författare)
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Meteor studies in the framework of the JEM-EUSO program
- 2017
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Ingår i: Planetary and Space Science. - : Elsevier. - 0032-0633 .- 1873-5088. ; 143, s. 245-255
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Tidskriftsartikel (refereegranskat)abstract
- We summarize the state of the art of a program of UV observations from space of meteor phenomena, a secondary objective of the JEM-EUSO international collaboration. Our preliminary analysis indicates that JEM-EUSO, taking advantage of its large FOV and good sensitivity, should be able to detect meteors down to absolute magnitude close to 7. This means that JEM-EUSO should be able to record a statistically significant flux of meteors, including both sporadic ones, and events produced by different meteor streams. Being unaffected by adverse weather conditions, JEM-EUSO can also be a very important facility for the detection of bright meteors and fireballs, as these events can be detected even in conditions of very high sky background. In the case of bright events, moreover, exhibiting some persistence of the meteor train, preliminary simulations show that it should be possible to exploit the motion of the ISS itself and derive at least a rough 3D reconstruction of the meteor trajectory. Moreover, the observing strategy developed to detect meteors may also be applied to the detection of nuclearites, exotic particles whose existence has been suggested by some theoretical investigations. Nuclearites are expected to move at higher velocities than meteoroids, and to exhibit a wider range of possible trajectories, including particles moving upward after crossing the Earth. Some pilot studies, including the approved Mini-EUSO mission, a precursor of JEM-EUSO, are currently operational or in preparation. We are doing simulations to assess the performance of Mini-EUSO for meteor studies, while a few meteor events have been already detected using the ground-based facility EUSO-TA.
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| 12. |
- Abdellaoui, G., et al.
(författare)
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First observations of speed of light tracks by a fluorescence detector looking down on the atmosphere
- 2018
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Ingår i: Journal of Instrumentation. - : IOP PUBLISHING LTD. - 1748-0221. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- EUSO-Balloon is a pathfinder mission for the Extreme Universe Space Observatory onboard the Japanese Experiment Module (JEM-EUSO). It was launched on the moonless night of the 25(th) of August 2014 from Timmins, Canada. The flight ended successfully after maintaining the target altitude of 38 km for five hours. One part of the mission was a 2.5 hour underflight using a helicopter equipped with three UV light sources (LED, xenon flasher and laser) to perform an inflight calibration and examine the detectors capability to measure tracks moving at the speed of light. We describe the helicopter laser system and details of the underflight as well as how the laser tracks were recorded and found in the data. These are the first recorded laser tracks measured from a fluorescence detector looking down on the atmosphere. Finally, we present a first reconstruction of the direction of the laser tracks relative to the detector.
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| 15. |
- Frank, TD, et al.
(författare)
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Global, regional, and national incidence, prevalence, and mortality of HIV, 1980-2017, and forecasts to 2030, for 195 countries and territories: a systematic analysis for the Global Burden of Diseases, Injuries, and Risk Factors Study 2017
- 2019
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Ingår i: The lancet. HIV. - 2352-3018. ; 6:12, s. E831-E859
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Tidskriftsartikel (refereegranskat)
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| 22. |
- Roelfsema, P. R., et al.
(författare)
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SPICA-A Large Cryogenic Infrared Space Telescope : Unveiling the Obscured Universe
- 2018
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Ingår i: Publications Astronomical Society of Australia. - : Cambridge University Press (CUP). - 1323-3580 .- 1448-6083. ; 35
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Tidskriftsartikel (refereegranskat)abstract
- Measurements in the infrared wavelength domain allow direct assessment of the physical state and energy balance of cool matter in space, enabling the detailed study of the processes that govern the formation and evolution of stars and planetary systems in galaxies over cosmic time. Previous infrared missions revealed a great deal about the obscured Universe, but were hampered by limited sensitivity. SPICA takes the next step in infrared observational capability by combining a large 2.5-meter diameter telescope. cooled to below 8 K, with instruments employing ultra-sensitive detectors. A combination of passive cooling and mechanical coolers will be used to cool both the telescope and the instruments. With mechanical coolers the mission lifetime is not limited by the supply of cryogen. With the combination of low telescope background and instruments with state-of-the-art detectors SPICA provides a huge advance on the capabilities of previous missions. SPICA instruments offer spectral resolving power ranging from R similar to 50 through 11 000 in the 17-230 mu m domain and R similar to 28.000 spectroscopy between 12 and 18 mu m.SPICA will provide efficient 30-37 mu m broad band mapping, and small field spectroscopic and polarimetric imaging at 100, 200 and 350 mu m. SPICA will provide infrared spectroscopy with an unprecedented sensitivity of similar to 5 x 10(-20) W m (-2) (5 sigma/1 h)-over two orders of magnitude improvement over what earlier missions. This exceptional performance leap, will open entirely new domains in infrared astronomy; galaxy evolution and metal production over cosmic time, dust formation and evolution from very early epochs onwards, the formation history of planetary systems.
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| 23. |
- Fukuzawa, H., et al.
(författare)
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Electron spectroscopy of rare-gas clusters irradiated by x-ray free-electron laser pulses from SACLA
- 2016
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Ingår i: Journal of Physics B-Atomic Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 49:3
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Tidskriftsartikel (refereegranskat)abstract
- We have measured electron energy spectra and asymmetry parameters of Ar clusters and Xe clusters illuminated by intense x-rays at 5 and 5.5 keV. A velocity map imaging spectrometer was developed for this purpose and employed at an x-ray free-electron laser facility, SACLA in Japan. The cluster size dependence and the peak fluence dependence of the electron spectra and asymmetry parameters are discussed.
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| 24. |
- Ito, H., et al.
(författare)
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Comparison of analytical methods for profiling N- and O-linked glycans from cultured cell lines
- 2016
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Ingår i: Glycoconjugate Journal. - : Springer Science and Business Media LLC. - 0282-0080 .- 1573-4986. ; 33:3, s. 405-415
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Tidskriftsartikel (refereegranskat)abstract
- The Human Disease Glycomics/Proteome Initiative (HGPI) is an activity in the Human Proteome Organization (HUPO) supported by leading researchers from international institutes and aims at development of disease-related glycomics/glycoproteomics analysis techniques. Since 2004, the initiative has conducted three pilot studies. The first two were N- and O-glycan analyses of purified transferrin and immunoglobulin-G and assessed the most appropriate analytical approach employed at the time. This paper describes the third study, which was conducted to compare different approaches for quantitation of N- and O-linked glycans attached to proteins in crude biological samples. The preliminary analysis on cell pellets resulted in wildly varied glycan profiles, which was probably the consequence of variations in the pre-processing sample preparation methodologies. However, the reproducibility of the data was not improved dramatically in the subsequent analysis on cell lysate fractions prepared in a specified method by one lab. The study demonstrated the difficulty of carrying out a complete analysis of the glycome in crude samples by any single technology and the importance of rigorous optimization of the course of analysis from preprocessing to data interpretation. It suggests that another collaborative study employing the latest technologies in this rapidly evolving field will help to realize the requirements of carrying out the large-scale analysis of glycoproteins in complex cell samples.
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| 25. |
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| 26. |
- Luis, R. S., et al.
(författare)
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Demonstration of a 1 Pb/s spatial channel network node
- 2019
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Ingår i: IET Conference Publications. - : Institution of Engineering and Technology.
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Konferensbidrag (refereegranskat)abstract
- We experimentally demonstrate a petabit-class hierarchical SDM switching node with granularity from 10 Tb/s to 1 Pb/s. We address spatial bypassing network scenarios, optical channel grooming, spatial multiplex section protection switching, and optical channels using coupled and uncoupled spatial channels.
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| 27. |
- Tachibana, T., et al.
(författare)
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Nanoplasma Formation by High Intensity Hard X-rays
- 2015
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Ingår i: Scientific Reports. - : Springer Science and Business Media LLC. - 2045-2322. ; 5
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Tidskriftsartikel (refereegranskat)abstract
- Using electron spectroscopy, we have investigated nanoplasma formation from noble gas clusters exposed to high-intensity hard-x-ray pulses at similar to 5 keV. Our experiment was carried out at the SPring-8 Angstrom Compact free electron LAser (SACLA) facility in Japan. Dedicated theoretical simulations were performed with the molecular dynamics tool XMDYN. We found that in this unprecedented wavelength regime nanoplasma formation is a highly indirect process. In the argon clusters investigated, nanoplasma is mainly formed through secondary electron cascading initiated by slow Auger electrons. Energy is distributed within the sample entirely through Auger processes and secondary electron cascading following photoabsorption, as in the hard x-ray regime there is no direct energy transfer from the field to the plasma. This plasma formation mechanism is specific to the hard-x-ray regime and may, thus, also be important for XFEL-based molecular imaging studies. In xenon clusters, photo-and Auger electrons contribute more significantly to the nanoplasma formation. Good agreement between experiment and simulations validates our modelling approach. This has wide-ranging implications for our ability to quantitatively predict the behavior of complex molecular systems irradiated by high-intensity hard x-rays.
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| 28. |
- Vanham, D., et al.
(författare)
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Physical water scarcity metrics for monitoring progress towards SDG target 6.4 : An evaluation of indicator 6.4.2 Level of water stress
- 2018
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 613, s. 218-232
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Forskningsöversikt (refereegranskat)abstract
- Target 6.4 of the recently adopted Sustainable Development Goals (SDGs) deals with the reduction of water scarcity. To monitor progress towards this target, two indicators are used: Indicator 6.4.1 measuring water use efficiency and 6.4.2 measuring the level of water stress (WS). This paper aims to identify whether the currently proposed indicator 6.4.2 considers the different elements that need to be accounted for in a WS indicator. WS indicators compare water use with water availability. We identify seven essential elements: 1) both gross and net water abstraction (or withdrawal) provide important information to understand WS; 2) WS indicators need to incorporate environmental flow requirements (EFR); 3) temporal and 4) spatial disaggregation is required in a WS assessment; 5) both renewable surface water and groundwater resources, including their interaction, need to be accounted for as renewable water availability; 6) alternative available water resources need to be accounted for as well, like fossil groundwater and desalinated water; 7) WS indicators need to account for water storage in reservoirs, water recycling and managed aquifer recharge. Indicator 6.4.2 considers many of these elements, but there is need for improvement. It is recommended that WS is measured based on net abstraction as well, in addition to currently only measuring WS based on gross abstraction. It does incorporate EFR. Temporal and spatial disaggregation is indeed defined as a goal in more advanced monitoring levels, in which it is also called for a differentiation between surface and groundwater resources. However, regarding element 6 and 7 there are some shortcomings for which we provide recommendations. In addition, indicator 6.4.2 is only one indicator, which monitors blue WS, but does not give information on green or green-blue water scarcity or on water quality. Within the SDG indicator framework, some of these topics are covered with other indicators.
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| 31. |
- Eriksson, Tobias, 1986, et al.
(författare)
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Experimental Investigation of Crosstalk Penalties in Multicore Fiber Transmission Systems
- 2015
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Ingår i: IEEE Photonics Journal. - : Institute of Electrical and Electronics Engineers (IEEE). - 1943-0655. ; 7:1
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally study the impact of crosstalk in multicore fibers, using polarization-multiplexed quadrature phase-shift keying signals. Using a 7-core fiber, we perform single-span transmission experiments, where the level of crosstalk to the core under test can be varied. We find the penalty in the required optical signal-to-noise ratio (OSNR), compared to a system with no crosstalk, for different signal-to-crosstalk ratios and at different pre-forward-error-correction target bit-error rates (BERs). We show that, for a 1-dB penalty, a 15.7-dB signal-to-crosstalk ratio can be tolerated at BER = 1 x 10(-3). We also perform recirculating loop experiments with varying amount of crosstalk per span to find the impact on the achievable transmission distance.
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| 32. |
- Eriksson, Tobias, 1986, et al.
(författare)
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Single parity check-coded 16QAM over spatial superchannels in multicore fiber transmission
- 2015
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Ingår i: Optics Express. - : The Optical Society. - 1094-4087 .- 1094-4087. ; 23:11, s. 14569-14582
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally investigate single-parity check (SPC) coded spatial superchannels based on polarization-multiplexed 16-ary quadrature amplitude modulation (PM-16QAM) for multicore fiber transmission systems, using a 7-core fiber. We investigate SPC over 1, 2, 4, 5 or 7 cores in a back-to-back configuration and compare the sensitivity to uncoded PM-16QAM, showing that at symbol rates of 20 Gbaud and at a bit-error-rate (BER) of 10(-3), the SPC superchannels exhibit sensitivity improvements of 2.7 dB, 2.0 dB, 1.7 dB, 1.3 dB, and 1.1 dB, respectively. We perform both single channel and wavelength division multiplexed (WDM) transmission experiments with 22 GHz channel spacing and 20 Gbaud channel symbol rate for SPC over 1, 3 and 7 cores and compare the results to PM-16QAM with the same spacing and symbol rate. We show that in WDM signals, SPC over hl1 core can achieve more than double the transmission distance compared to PM-16QAM at the cost of 0.91 bit/s/Hz/core in spectral efficiency (SE). When sharing the parity-bit over 7 cores, the loss in SE becomes only 0.13 bit/s/Hz/core while the increase in transmission reach over PM-16QAM is 44 %. (C) 2015 Optical Society of America
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| 35. |
- Luis, R. S., et al.
(författare)
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Spectral efficiency limits in crosstalk-impaired multi-core fiber links
- 2018
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Ingår i: Proceedings of SPIE - The International Society for Optical Engineering. - : SPIE. - 0277-786X .- 1996-756X. ; 10551
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Konferensbidrag (refereegranskat)abstract
- Downloading of the abstract is permitted for personal use only. We review the latest advances on ultra-high throughput transmission using crosstalk-limited single-mode multicore fibers and compare these with the theoretical spectral efficiency of such systems. We relate the crosstalkimposed spectral efficiency limits with fiber parameters, such as core diameter, core pitch, and trench design. Furthermore, we investigate the potential of techniques such as direction interleaving and high-order MIMO to improve the throughput or reach of these systems when using various modulation formats.
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| 36. |
- Puttnam, Benjamin, et al.
(författare)
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High-capacity MCF transmission with wideband comb
- 2017
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Ingår i: Optics InfoBase Conference Papers. - 2162-2701. ; Part F40-OFC 2017, s. M2J.4-
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Konferensbidrag (refereegranskat)abstract
- We describe experiments combining high core-count, homogeneous single-mode multicore fibers with a wideband comb for high-capacity transmission without high-order MIMO reception and demonstrate wideband transmission with coded modulation up to 12,300 km.
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| 37. |
- Puttnam, Benjamin, et al.
(författare)
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High Capacity Transmission Systems Using Homogeneous Multi-Core Fibers [Invited]
- 2017
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 35:6, s. 1157-1167
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Tidskriftsartikel (refereegranskat)abstract
- We discuss optical transmission using homogeneous, single-mode, multicore fibers. We first describe the key fiber properties that can affect transmission, such as intercore crosstalk and the variation of propagation delay between cores, and the consequences of these properties on spatial super-channel transmission. We then describe a series of experiments and demonstrations of system features including self-homodyne detection and joint spatial superchannel modulation before discussing their suitability to high-capacity transmission.
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| 38. |
- Puttnam, Benjamin, et al.
(författare)
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Impact of inter-core crosstalk on the transmission distance of QAM formats in multi-core fibers
- 2015
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Ingår i: 2015 International Conference on Photonics in Switching. - 9781479988211 ; , s. 55-57
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Konferensbidrag (refereegranskat)abstract
- We investigate the transmission distance of three QAM modulation formats, in the presence of inter-core crosstalk in a 7-core fiber. We show that crosstalk limits transmission distance for all formats with a greater impact on higher order modulation formats. For a crosstalk level equivalent to equal signal launch power in each core, we measure a reduced transmission distance at BER=1.5×10-2 of 17%, 23% and 36% for PDM-QPSK, PDM-16QAM and PDM-64QAM respectively. © 2015 IEEE.
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| 39. |
- Puttnam, Benjamin, et al.
(författare)
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Impact of Intercore Crosstalk on the Transmission Distance of QAM Formats in Multicore Fibers
- 2016
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Ingår i: IEEE Photonics Journal. - 1943-0655. ; 8:2
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Tidskriftsartikel (refereegranskat)abstract
- We investigate the impact of intercore crosstalk on the achievable transmission distance of three square quadrature amplitude modulation (QAM) formats. We show that increasing intercore crosstalk across an 18 dB range starting from -43.4 dB/100 km reduces the achievable transmission distance for all formats, with a greater impact on higher order modulation formats. For a crosstalk level arising from equal signal launch power in each core of a homogeneous 7-core fiber, we measure a reduced transmission distance at BER = 1.5 × 10-2 of 24%, 38% and 54%, for polarization-division-multiplexed-quadrature phase-shift keying (PDM-QPSK), PDM-16QAM, and PDM-64QAM, respectively. Finally, we investigate the potential impact that dynamic crosstalk variation could have in transmission systems based on multicore fiber and estimate the achievable reach for an outage probability of 1 × 10-5 in the presence of dynamically varying intercore crosstalk.
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| 40. |
- Puttnam, B. J., et al.
(författare)
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0.715 Pb/s transmission over 2,009.6 km in 19-core cladding pumped EDFA amplified MCF link
- 2019
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Ingår i: Optics InfoBase Conference Papers. - : OSA - The Optical Society. - 9781943580538
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Konferensbidrag (refereegranskat)abstract
- We demonstrate 0.715 Pb/s recirculating transmission through 19 cores of 31.4 km MCF amplified with C+L-band, cladding-pumped, multi-core EDFAs; transmitting 345×24.5 GBd PDM-16QAM signals over 2009.6 km for 1.44 Exb/s×km throughput-distance product.
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| 41. |
- Puttnam, B J, et al.
(författare)
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8007 km C + L band transmission over MCF with 19-core cladding-pumped EDFA
- 2019
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Ingår i: 45th European Conference on Optical Communication, ECOC 2019. - : Institution of Engineering and Technology (IET).
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Konferensbidrag (refereegranskat)abstract
- We investigate an MCF link using a C+L-band, 19-core, cladding-pumped EDFA over trans-oceanic distances measuring a fully decoded throughput of 18.6 Tb/s and 14.5 Tb/s at a distance of 8007 km for an inner and outer-ring cores respectively.
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| 42. |
- Puttnam, Benjamin J., et al.
(författare)
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Characteristics of homogeneous multi-core fibers for SDM transmission
- 2019
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Ingår i: APL Photonics. - : AIP Publishing. - 2378-0967. ; 4:2
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Tidskriftsartikel (refereegranskat)abstract
- We describe optical data transmission systems using homogeneous, single-mode, multi-core fibers (MCFs). We first briefly discuss space-division multiplexing (SDM) fibers, observing that no individual SDM fiber offers overwhelming advantages over bundles of single-mode fiber (SMF) across all transmission regimes. We note that for early adoption of SDM fibers, uncoupled or weakly coupled fibers which are compatible with existing SDM infrastructure have a practical advantage. Yet, to be more attractive than parallel SMF, it is also necessary to demonstrate benefits beyond improved spatial spectral efficiency. It is hoped that the lower spread of propagation delays (skew) between spatial channels in some fibers can be exploited for improved performance and greater efficiency from hardware sharing and joint processing. However, whether these benefits can be practically harnessed and outweigh impairments or effort to mitigate cross talk between spatial channels is not yet clear. Hence, focusing on homogeneous MCFs, we first describe measurements and simulations on the impact of inter-core cross talk in such fibers before reporting experimental investigation into the spatial channel skew variation with a series of the experimental results including a comparison with SMF in varying environmental conditions. Finally, we present some system and transmission experiments using parallel recirculating loops that enable demonstration of both multi-dimensional modulation and joint digital processing techniques across three MCF cores. Both techniques lead to increased transmission reach but highlight the need for further experimental analysis to properly characterize the potential benefits of correlated propagation delays in such fibers.
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| 43. |
- Puttnam, B. J., et al.
(författare)
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Transmission and Crosstalk Measurements in MC-EDFA amplified 19-core link
- 2019
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Ingår i: OECC/PSC 2019 - 24th OptoElectronics and Communications Conference/International Conference Photonics in Switching and Computing 2019. - : Institute of Electrical and Electronics Engineers (IEEE).
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Konferensbidrag (refereegranskat)abstract
- We investigate long-haul, wideband transmission of PDM-QPSK and PDM 16-QAM in an MCF link amplified in a C+L-band,19-core cladding pumped EDFA and measure a combined fiber/EDFA crosstalk penalty of 14% for lone-wavelenetli L-band channel.
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| 44. |
- Rademacher, G., et al.
(författare)
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High capacity transmission with few-mode fibers
- 2019
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Ingår i: Journal of Lightwave Technology. - 0733-8724 .- 1558-2213. ; 37:2, s. 425-432
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Tidskriftsartikel (refereegranskat)abstract
- We experimentally investigate high-capacity few-mode fiber transmission for short and medium-haul optical links. In separate experiments, we demonstrate C + L band transmission of 283 Tbit/s over a single 30 km span and recirculating loop transmission of 159 Tbit/s over 1045 km graded-index three mode fiber. The first experiment reached a data-rate per fiber mode within 90% of the record data-rates reported in the same transmission bands for single-mode fibers. The second experiment demonstrated the feasibility of reaching high data-rates over long distance few-mode fiber transmission, despite strong impairments due to mode-dependent loss and differential mode delay.
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| 45. |
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| 46. |
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| 47. |
- Spinoglio, L., et al.
(författare)
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- 2017
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Ingår i: Publications Astronomical Society of Australia. - : Cambridge University Press (CUP). - 1323-3580 .- 1448-6083. ; 34
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Tidskriftsartikel (refereegranskat)abstract
- IR spectroscopy in the range 12-230 mu m with the SPace IR telescope for Cosmology and Astrophysics (SPICA) will reveal the physical processes governing the formation and evolution of galaxies and black holes through cosmic time, bridging the gap between the James Webb Space Telescope and the upcoming Extremely Large Telescopes at shorter wavelengths and the Atacama Large Millimeter Array at longer wavelengths. The SPICA, with its 2.5-m telescope actively cooled to below 8 K, will obtain the first spectroscopic determination, in the mid-IR rest-frame, of both the star-formation rate and black hole accretion rate histories of galaxies, reaching lookback times of 12 Gyr, for large statistically significant samples. Densities, temperatures, radiation fields, and gas-phase metallicities will be measured in dust-obscured galaxies and active galactic nuclei, sampling a large range in mass and luminosity, from faint local dwarf galaxies to luminous quasars in the distant Universe. Active galactic nuclei and starburst feedback and feeding mechanisms in distant galaxies will be uncovered through detailed measurements of molecular and atomic line profiles. The SPICA's large-area deep spectrophotometric surveys will provide mid-IR spectra and continuum fluxes for unbiased samples of tens of thousands of galaxies, out to redshifts of z similar to 6.
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