Daniel L. Peterson

Polarization mode dispersion compensator field trial and field fiber characterization

Two high-PMD long distance routes were characterized and used to test an optical polarization mode dispersion compensator (PMDC) under field conditions. For this trial, 110 km routes with mean PMD values of 25 and 26.5 ps were provisioned with commercial WDM transport equipment and tested for several weeks. The route was comprised of three spans of characterized fiber that followed railroad tracks. We show the temporal variation of the output polarization state and the evolution of first- and second-order PMD spectra over 7 days. The deployment of a variablelength PMDC on these links allowed error-free transmission of an OC-192 signal. Splitting the output to receivers with and without PMDC demonstrated specific PMD events that caused errors in the absence of a PMDC.

Unrepeatered 100G Transmission Over 520.6 km of G.652 Fiber and 556.7 km of G.654 Fiber With Commercial Raman DWDM System and Enhanced ROPA

We report the results of 100G unrepeatered transmission aimed at achieving the longest distance without any inline active elements. The unrepeatered transmission system uses commercial distributed Raman pump modules, enhanced ROPA, and real-time processing coherent 100G transceivers (PM-QPSK) with soft-decision FEC. Two types of ultra-low loss fibers, G.652B and G.654B compliant, are fully characterized and used as span fiber. First, a single 100G channel is successfully transmitted over 520.6 km of G.652B fiber (86.2 dB) in a lab trial. Second, cabled large effective area, ultra-low loss G.654B fiber in a field environment is used as span fiber. A single 100G channel and four 100G channels are transmitted over 556.7 km (90.2 dB) and 523.2 km (84.8 dB), respectively.

Experimental Determination of System Outage Probability Due to First-Order and Second-Order PMD

In this paper, a polarization-mode dispersion (PMD) tolerance testing procedure for transponders and transmission systems is described. This method exploits programmable PMD sources for testing the first- and second-order joint probability density function to estimate the total PMD network outage. Experimental data show that first-order-only PMD testing is insufficient to quantify the tolerance of a transponder and may falsely underestimate network outage

Frequency and Duration of Communication System Outages Resulting From Polarization Mode Dispersion

In this paper, we employ measurements of transponder tolerance to both differential group delay (DGD) and second-order polarization mode dispersion (SOPMD) and of the temporal evolution of DGD and SOPMD in installed transmission systems to predict the influence of PMD on the rate and duration of PMD-induced system outages. An empirical 2-D random-walk model predicts that the outage rate and duration depends solely on the mean fiber DGD. We find that the step size of the random walk is nearly uncorrelated with the instantaneous value of the PMD. We then justify the assumptions of this procedure with a full numerical simulation and employ a biased Markov chain algorithm to generate highly accurate results for system outages where simplified models fail.

In-service light path PMD (polarization mode dispersion) monitoring by PMD compensation.

We describe a novel method of measuring PMD (polarization mode dispersion) of an in-service DWDM system by PMD compensation. We successfully demonstrate the method in a 1500-km ultra-long haul DWDM test bed. We further verify the feasibility of the method for in-service light path PMD monitoring in a field trial in a revenue-generating route in Verizon Network, and obtain an accurate PMD value without impacting live network traffic. The discrepancy between the measured and expected PMD values is less than 6% for all cases tested.

Field trial of in-service PMD measurement using idle DWDM channels in operational long haul network

In-service PMD measurement using idle channels in an operational DWDM long-haul network is realized with two novel measurement approaches during a field trial. Accurate PMD results are obtained without impacting live network traffic.

Dynamics of polarization fluctuations in aerial and buried links

The coherent optical systems based on polarization multiplexing deployed in core networks in the last years have generated a renewed interest for the study of polarization effects in fiber optic links [1]. Fluctuations of the state of polarization (SOP) of the optical signal, combined with polarization-dependent loss (PDL) and polarization mode dispersion (PMD), can affect the performance of coherent optical communication systems. The dynamics of the polarization fluctuations can be expected to be strongly dependent on the characteristics of the fiber plant. Some polarization measurement data have already been obtained using coherent transponders or a polarimeter, but on a few links only and mostly over short periods of time [2–6]. Recently, the results of a 22-month SOP activity monitoring on an in-service aerial installation of 750 km have been reported, which provides more insight into the polarization activity in optical ground wire (OPGW) fiber cables [7]. In this paper, we report on a long-term SOP activity monitoring on an experimental metro ring network using a polarimeter and a dual polarized, modulated with dual-polarization quadrature phase-shift keying (DP-QPSK) modem a 100 Gb/s. The temporal and frequency dynamics of the polarization fluctuations and SOP transients observed in the buried fiber plant are presented and compared to those reported in the aerial installation.

Field measurements of SOP transients in OPGW, with time and location correlation to lightning strikes

We monitored the state of polarization (SOP) of polarized light in an optical ground wire (OPGW) link located in North America using a test method and apparatus that measured Stokes space angular velocity and geographic location of SOP transients. We observed transients up to 5.1 Mrad/s and were able to correlate these events in both time and location to lightning strikes documented by the United States Precision Lightning Network (USPLN).

Polarization-multiplexed dispersion-managed four-soliton-channels wavelength-division multiplexing system with a bit-rate-length product of 2.9×1015

Abstract. A four-channel soliton system design is described that repre-sents an improvement on a previous study Opt. Express , 2007 . In thatstudy, a bit-rate-length BL product in excess of 2.0 1510 baud/kmfrom a dense-dispersion-managed DDM dual-soliton system wasachieved through numerical experimentation. Similar to the dual-solitondesign, a combination of polarization multiplexing and wavelength-division multiplexing is employed. Numerical experiments with four soli-ton channels, each carrying 80 Gb/s, are carried out over 10,000 km.Assystem parameters are optimized, the Q =6 threshold distance attainedis 9150 km, yielding a BL product of 2.9 1510 baud/km.

Progress in DWDM deployment in MCI's North American network

MCI owns network facilities in more than 140 countries and over 2,800 cities. MCI is in the midst of an ultra-long haul build of the North American network. This paper outlines MCIs plan and progress on this front.