87 research outputs found
Analytical Performance Estimation Methods for Modern Optical Communications systems
No full textIn this paper we present two different analytical tools for fast performance estimation of optical transmission systems based on both direct detection (DD) and coherent detection (CoD). We introduce the main equations used to model the communications systems and then validate the analytical results against full time domain numerical simulations. Several scenarios are considered ranging from short reach transmission over multimode fiber (MMF), to long-haul ROADM-based links and coherent detection. Our findings show an excellent agreement in every investigated condition based on realistic device parameters and advanced modulation formats typical of modern high-speed communications
An Analytical Model for Coherent Transmission Performance Estimation After Generic Jones Matrices
No full textIn this paper, we propose the extension of a previously
presented analytical model for the estimation of the signal-to-noise
ratio (SNR) at the output of an adaptive equalizer in polarization
multiplexed (PM)-QAM coherent optical systems when transmission
is modeled as a generic 2 × 2 frequency dependent transfer
function matrix.We present the model and then we statistically test
its accuracy in two possible application environments. Our findings
show a remarkable agreement between time-domain simulations
and analytical results, with average SNR discrepancies of the order
of 0.1 dB. We believe our model can find important applications
in next generation physical layer aware network planning tools
that need to take into account polarizati on dependent loss/gain
and strong filtering, for instance in ultra high baud rate coherent
systems
Advances in Optical Fiber Communications
No full textGiven the increasing importance of a globally interconnected world, driven by modern digital services and the need for fast and reliable access to digital resources, communications networks are one of the key infrastructures in today’s society [...
An analysis of daily power consumption under different On-Off IP-over-WDM translucent design approaches
No full textOn the energy and cost trade-off of different energy-aware network design strategies
No full textWe compare different energy-aware network design strategies that adapt network resources utilization to traffic variations. We show how to achieve, without extra devices, up to 26% energy savings with respect to a 100Gb/s static network
WSS requirements in next-Generation wavelength switched optical networks
No full textWe investigate how the WSS port-count requirement scales with traffic, transmission technologies, fiber types and amplification schemes in future WSONs. The highest benefits come with the Hybrid-EDFA implementatio
MMF-based Data Center Interconnect using Commercial Coherent Transceivers
No full textIn this manuscript we present an experimental analysis of a multi-mode fiber (MMF) link based on coherent detection. We propose the use of a commercial coherent transceiver to increase the transmission speed of a short-reach optical communication system over 300 m OM3 fiber. The performance of the system is studied in terms of bit rate as a function of the power budget margin (PBM) defined as the extra attenuation that can be introduced on the optical path. We investigate polarization multiplexed (PM) QPSK and 16-QAM modulation formats achieving up to 400 Gbps net bit rate transmission. Moreover, we analyze the impact of the lateral offset introduced by the connectors between MMF segments, showing decreasing PBM for increasing lateral offset. Nevertheless, PBM in excess of 28 dB for PM-QPSK modulation at 100G and 200G, 23 dB for 200G PM-16QAM modulation and 16 dB for 400G PM-16QAM, shows that commercial coherent transceivers can be used on MMF links up to much higher bit rates than those achieved by current VCSEL+direct detection based systems, provided that connections along the MMF have connectors connectors with offsets in the 3 μm to 6 μm range
Spontaneous pump depolarization in ultralong cavity Raman fiber laser amplifiers
No full textWe present an experimental demonstration of polarization-independent performance in a forward and backward-pumped 2nd-order ultralong cavity Raman laser amplifiers with highly polarized pumps. Our findings show that the depolarization of the Stokes component due to gain saturation leads to polarization-insensitive performance in terms of output gain and relative intensity noise in the signal. These results pave the way for the use of individual highly polarized low-RIN semiconductor laser diodes in Raman-amplified optical communications
Algorithm Optimization for Rockfalls Alarm System Based on Fiber Polarization Sensing
No full textThe mountain scenario is often subject to catastrophic events such as rockfalls and avalanches, potentially dangerous for both people and civil infrastructures. Early-warning alarm systems that in case of such events can immediately turn on a traffic light on a mountain road and send remote alarms to control rooms, have already been developed in the geotechnical engineering sector, but all have some limitations and/or very high costs. In this work we propose an immediate-warning monitoring system based on fiber polarization sensing. Anomalies such as rockfalls and avalanches would change the instantaneous birefringence of the fiber installed in the area to be monitored, and can be sensed by looking at the state of polarization at the fiber output. The novelty of our paper is the development of an algorithm that is able to detect dangerous events, which we experimentally emulated on a reduced scale physical model of a mountain slope, in which fibers have been buried in different configurations. Our findings show that the system can correctly sense all the experimentally generated rockfall phenomena and for all the installed fiber configurations, and it is also robust to false alarms, provided that the monitoring algorithm main parameters are properly set
- …
