Joerg-Peter Elbers

Measurement of the dispersion tolerance of optical duobinary with an MLSE-receiver at 10.7 Gb/s

We experimentally demonstrate a significant improvement in the dispersion tolerance of optical duobinary modulation when employing an MLSE instead of a standard receiver. We show that the improvement critically depends on the MLSE design.

Demonstration of the First Real-Time End-to-End 40-Gb/s PAM-4 for Next-Generation Access Applications Using 10-Gb/s Transmitter

We demonstrate the first known experiment of a real-time end-to-end 40-Gb/s pulse amplitude modulation (PAM)-4 system for next-generation access applications using 10-Gb/s class transmitters only. Based on the measurement of a real-time 40-Gb/s PAM system, low-cost upstream and downstream link power budgets are estimated. Up to 27 and 25 dB power budgets for 10- and 20-km standard single-mode fiber upstream links using erbium-doped fiber amplifiers (EDFA) preamplifiers are achieved. For downstream links using booster EDFAs and avalanche photodiode receivers, power budgets of 26.5 and 24.5 dB are feasible for 10- and 20-km SMFs, respectively. In addition, we show that colorless 40-Gb/s PAM-4 transmission over 20-km SMF in the C-band is achievable.

First real-time 400G PAM-4 demonstration for inter-data center transmission over 100 km of SSMF at 1550 nm

Real-time transmission of 400G (8×50G DWDM) PAM-4 signals for data center interconnects up to 100 km SSMF is successfully demonstrated. All channels stay well below the 802.3bj KR4 FEC limit, thus allowing error free transmission.

A flexible, ethernet fronthaul for 5th generation mobile and beyond

Using Ethernet in the fronthaul can deliver the statistical multiplexing gains offered by the new functional splits proposed for the radio access network, but latency and delay variations are challenges that must be overcome.

Tunable WDM-PON System with Centralized Wavelength Control

We report on the state of the art and future prospects and challenges of optical access networks. Details on a recent field demonstration of a novel tunable WDM-PON system with novel T-SFP+ modules will be presented. Furthermore, the concept of centralized wavelength control of the optical network unit wavelengths will be explained as well as different realization options of pilot-tone based communication channels. Finally, a control concept for tuning the DS-DBR laser will be shown.

Field demonstration of a tunable WDM-PON system with novel SFP+ modules and centralized wavelength control

We report on a demonstration of a novel tunable WDM-PON system over 25km of field deployed fiber. We show error-free operation at 1GbE with sensitivity better than -30dBm and centralized control of the ONU wavelengths.

Tuning of an SG-Y branch laser for WDM-PON

We report wideband tuning and wavelength stabilization of a low-cost SG-Y branch laser without cooler over >;10°C temperature drift by means of a wavelength locker which is shared between all channels in a WDM-PON system.

Simulation and modeling of photonic WDM systems

A general modeling and simulation strategy suitable for the theoretical analysis of wavelength division multiplexed (WDM) fiber-optical systems is presented. We give a detailed explanation of component models and algorithms of different complexity and accuracy which can be used throughout the simulation. Transmitter chirp and noise, fiber dispersion and nonlinearity, imperfect filter and multiplexer characteristics, amplified spontaneous emission noise of the optical amplifiers, crosstalk in network elements such as optical add/drop multiplexers or optical cross-connects, and the polarization-dependence of the components are taken into account. Methods for a performance evaluation by means of eye patterns, spectral power densities, the optical signal-to- noise ratio, the Q-factor and the bit error rate are also addressed. Based on this work, a complete design environment consisting of a graphical network editor and an independent simulation engine (FOCUSS, Fiber Optic CommUnication System Simulator) has been implemented in C++. Simulation examples are presented here e.g. for wavelength-routed networks.

High-capacity DWDM/ETDM transmission

Summary form only given. High-capacity, terrestrial optical transmission systems are now being widely deployed offering aggregate capacities >1 Tb/s over distances of >1,000 km. They use dense wavelength-division multiplexing (DWDM) techniques in combination with high-speed electrical time-division multiplexing (ETDM) to minimize the cost per bit and kilometre whilst maintaining flexibility and scalability at the same time. This paper reviews the current state-of-the-art of high-capacity, terrestrial DWDM/ETDM systems in research and development. It explains design rules and limitations fundamental to these systems and discusses challenges and enabling technologies for next-generation optical networks employing transparent photonic switching.

On MLSE Reception of Chromatic Dispersion Tolerant Modulation Schemes

Maximum likelihood sequence estimation (MLSE) in the electrical domain at the receiver of an optical fibre link is investigated as a means to improve the dispersion tolerance of the modulation formats chirped NRZ (CNRZ) and optical duobinary modulation (ODB).