arXiv subjects

Mattia Cantono

Publications and source records attributed to Mattia Cantono.

4 recordsLinked to original sources

arXiv2022

Frequency stability and phase noise measurements of a 5,860 km-long intercontinental seafloor optical fibre cable

Optical clock comparison via optical fibre links has been achieved over continental scales, but has not yet been demonstrated intercontinentally. The transfer of ultra-stable optical frequencies over transoceanic distances is a challenging task, as the seafloor cable architecture prevents the use of environmental noise suppression techniques currently employed on land-based metrological links. As a fundamental first step towards devising suitable frequency transfer techniques to enable future clock comparison on a global scale, here we show the free-running frequency stability and phase noise measurements of a transatlantic seafloor optical link between the UK and Canada. To the best of our knowledge, these are the first ever measurements of an intercontinental optical fibre link.

physics.ins-det↗

arXiv2022

Solar storms and submarine internet cables

Coronal mass ejections (CMEs) can trigger geomagnetic storms and induce geoelectric currents that degrade the performance of terrestrial power grid operations; in particular, CMEs are known for causing large-scale outages in electrical grids. Submarine internet cables are powered through copper conductors spanning thousands of kilometers and are vulnerable to damage from CMEs, raising the possibility of a large-scale and long-lived internet outage. To better understand the magnitude of these risks, we monitor voltage changes in the cable power supply of four different transoceanic cables during time periods of high solar activity. We find a strong correlation between the strength of the high-frequency geomagnetic field at the landing sites of the systems and the line voltage change. We also uncover that these two quantities exhibit a near-linear power law scaling behavior that allows us to estimate the effects of once-in-a-century CME events. Our findings reveal that long-haul submarine cables, regardless of their length and orientation, will not be damaged during a solar superstorm, even one as large as the 1859 Carrington event.

physics.space-ph↗

arXiv2019

Observing the Effect of Polarization Mode Dispersion on Nonlinear Interference Generation in Wide-Band Optical Links

With the extension of the spectral exploitation of optical fibers beyond the C-band, accurate modeling and simulation of nonlinear interference (NLI) generation is of the utmost performance. Models and numerical simulation tools rely on the widely used Manakov equation (ME): however, this approach when considering also the effect of polarization mode dispersion (PMD) is formally valid only over a narrow optical bandwidth. In order to analyze the range of validity of the ME and its applicability to future wide-band systems, we present numerical simulations, showing the interplay between NLI generation and PMD over long dispersion-uncompensated optical links, using coherent polarization division multiplexing (PDM) quadrature amplitude modulation (QAM) formats. Using a Monte-Carlo analysis of different PMD realizations based on the coupled nonlinear Schrödinger equations, we show that PMD has a negligible effect on NLI generation, independently from the total system bandwidth. Based on this, we give strong numerical evidence that the ME can be safely used to estimate NLI generation well beyond its bandwidth of validity that is limited to the PMD coherence bandwidth.

eess.SP↗

arXiv2018

Introducing the Generalized GN-model for Nonlinear Interference Generation including space/frequency variations of loss/gain

We develop and present a generalization of the GN-model - the generalized Gaussian noise (GGN) model - to enabling a fair application of GN-model to predict generation of nonlinear interference when loss parameters relevantly vary with frequency and/or distributed amplification applies selectively to portions of the exploited spectrum and/or stimulated-Raman-scattering-induced crosstalk is relevant.

physics.optics↗