J.-P. Elbers

Influence of the dispersion map on limitations due to cross-phase modulation in WDM multispan transmission systems

We determine system limitations due to cross-phase modulation (XPM) for non-zero dispersion shifted fiber by experiments and simulations. For the worst case of full dispersion compensation in each span we find a maximum power law whereas for appropriate undercompensation XPM can be efficiently suppressed.

SRS crosstalk in preemphasized WDM systems

With a new simple model for stimulated Raman scattering crosstalk and an 30 dBm system experiment we found that the shortest and longest wavelength channels are affected most by SRS crosstalk independent of the preemphasis.

Limitations of dispersion-managed DWDM systems due to cross-phase modulation

We show that a similar relationship also applies to XPM. We determine the maximum XPM-limited transmission distance on standard single mode fibre (SSMF) and non-zero dispersion shifted fibre (NZDSF). Fully compensated fibre spans with an optimum post-compensation at the receiver (RX) site are assumed as a typical dispersion map in todays terrestrial DWDM systems. The dependence of our results on the channel spacing, the channel count and the residual dispersion is discussed.

Performance evaluation of a CDMA system using broadband sources

A rigorous numerical model for the performance evaluation of multiple access systems with broadband sources is presented. The model is applied to analyse a spectrally coded CDMA system using frequency periodic optical filters. Newly obtained results are discussed.

Germany-wide DWDM field trial: transparent connection of a long haul link and a multiclient metro network

We report on error-free multiclient transmission over a Germany-wide all-optical, configurable DWDM system. The performance of the transparent connection of a metropolitan area network and a bi-directional long haul system is investigated under real-world conditions. We report on the topology of SIEMENS part of the Germany-wide field trial KOMNET and results of transparent interconnections between different optical domains.

Practical method to measure optical SNR in multi terabit systems

A practical method to measure OSNR is reported. In contrast to previous procedures, this method does not need changes in the transmission line. We demonstrate the robustness against distortions induced by dispersion and self-phase modulation.

Monitoring the optical performance in a transparent and configurable metro area network

We report on experimental results of optical performance monitoring (OPM) in a transparent optical network transmitting channels modulated at 10 Gb/s. This experiment was performed in an entirely field installed DWDM ring network (DWDM ring capacity: 80/spl times/10 Gb/s) with configurable optical add drop multiplexers (OADMs) at different locations within the city of Berlin, Germany.

Optimized dispersion management for transparent optical networks

We optimize the dispersion management in transparent optical networks where sufficient system performance must be guaranteed for each path in the network having an arbitrary length of one fiber span up to a maximum span number.

DWDM field trial: optical performance monitoring in a transparent and configurable multiclient metropolitan network

In this paper we present the topology of an optically transparent DWDM network testbed (part of the KomNet field-trial). We show results of our investigation on performance monitoring in the optical layer of this complex network. The testbed consists of a remotely configurable DWDM metropolitan area ring network (capable of transport up to 80x10 Gb/s) with two OADMs and one HUB/OXC and a long-haul bi-directional DWDM link (16x10 Gb/s, 8 spans over 750 km).

Optimized dispersion maps for suppression of cross-phase modulation in WDM systems

Based on an analytical model which is verified by numerical simulations, we study the influence of the dispersion map on XPM induced signal degradations in long-haul WDM systems for different fibre types. Distributed undercompensation is shown to be an optimum choice for 10 Gb/s per channel transmission. Statistical studies of map variations confirm, that moderate deviations from the optimum dispersion map further reduce the XPM limited reach. For transmission over standard single-mode fibre, XPM generated in the dispersion compensating fibers which are required for a compensation of the large dispersion of the transmission fiber may impose a stringent limitation for terrestric ultra-long haul systems.