Elodie Balmefrezol

Optical regeneration at 40 Gb/s and beyond

As optical amplifiers have opened new perspectives for optical communication systems with ultrahigh capacities and long-haul transmission distances (more than 1 Tb/s over 10 000 km), fundamental limits are being felt. In order to overcome these propagation impairments, another technology revolution is soon required. Promising developments concern in-line all-optical regeneration, which makes it possible to transmit optical data over virtually unlimited distances. In this paper, we recall the basic principles of optical regeneration in optical communication systems and review the current technology alternatives foreseen for future 40-Gb/s transmission system implementation, as investigated in Alcatel Research and Innovation. The alternative offered by optoelectronic regeneration is also discussed, so as to identify and highlight the advantages of the all-optical approach.

Cascade of 100 optical 3R regenerators at 40 Gbit/s based on all-active Mach Zehnder interferometers

The operation of an optical 3R regenerator combining monolithic integrated semiconductor optical amplifier-based Mach Zehnder interferometers is demonstrated at 40 Gbit/s. 100 regenerators have been cascaded in a recirculation loop including 40 km of dispersion shifted fibre.

Comparative Study of Crosstalk Created in 50 GHz-Spaced Wavelength Selective Switch for Various Modulation Formats at 43 Gbit/s

We investigate the tolerance of PSBT, DQPSK and RZ-DQPSK formats to in-band crosstalk at 43 Gbit/s when considering 50 GHz-spaced Wavelength Selective Switches. We show that PSBT and DQPSK exhibit the best margins versus crosstalk.

Crosstalk analysis applied to wavelength selective switches

We show that the tolerance to in-band crosstalk due to a slight misalignment of the filtering function can be relaxed. Such impairment may occur in case of WSS requiring accurate alignments of several optical elements

Low input power all-optical 3R regenerator based on SOA devices for 42.66 Gbit/s ULH WDM RZ transmissions with 23 dB span loss and all-EDFA amplification

An all-optical 3R regenerator based on cascaded XGM-SOA and SOA-MZI is implemented in an all-EDFA 42.66 Gbit/s SMF/DCF dispersion-managed RZ loop with -11 dBm input power, yielding a BER of 1.6.10/sup -4/ after 30,000 km in WDM environment with four 200 GHz-spaced adjacent channels.

System design tool for high bit rate terrestrial transmission systems with coherent detection

Coherent detection offers the ability to compensate for linear transmission impairments such as fiber chromatic dispersion and polarization-mode dispersion in the digital domain, thereby enabling dispersion-uncompensated optical transmission for high performance and high cost effectiveness. In dispersion-uncompensated transmission systems, the statistics of optical nonlinearity induced distortions have been proven to be essentially Gaussian-distributed, and new physical models have emerged showing profound differences with respect to legacy systems based on direct detection. From such differences stems the need to adapt the design tool to capture these new propagation properties. In that respect, we propose a model for performance prediction, which is used to derive a simple yet effective feasibility parameter to be embedded in the design tool. The feasibility parameter is experimentally validated with real time product transponders, and realistic system configurations: a precision of ±0.5 dB is achieved for 40 Gb/s, 100 Gb/s and 400 Gb/s coherent channels, which represents an improvement of more than 3 dB over the design tool using the nonlinear phase shift as the criterion.

400 Gb/s Real-Time Trials on Commercial Systems for Next Generation Networks

We report the results of a field trial carrying 400-Gb/s real-time dual-carrier PDM-16QAM signals over a 550-km-long commercial system. After the examination of the propagation nonlinear noise statistics nature, we analyze the accuracy of a performance prediction model based on Gaussian nonlinear distortions on the lab replica of on-the-field conditions. Further on, we demonstrate the compatibility of 400-Gb/s real-time dual-carrier PDM-16QAM signals with legacy systems based on a 50-GHz channel grid, yielding 4 b/s/Hz of spectral efficiency over 550-km transmission. In the last part of the paper, we review recently published field trials employing real time 400 Gb/s dual-carrier PDM-16 QAM channels and discuss the potential of such transponders to further increase spectral efficiency beyond 4 b/s/Hz forming superchannels and to be configured by software according to traffic demand.

400Gb/s trials on commercial systems using real-time bit-rate-adaptive transponders for next generation networks

We review recent field trials employing real time 400Gb/s dual-carrier PDM-16 QAM channels. The results demonstrate their compliance not only with nowadays 50-GHz grid network but also with next generation flexgrid networks carrying super-channels.

Associating optical regeneration and dispersion management for 43Gbit/s long-haul transmissions

We review different techniques for 43Gbit/s Optical Regeneration targeting ultra long-haul transmissions or/and terrestrial networking applications in association with Dispersion Management. Principles of operation and recent system experiments are described.

Optical signal regeneration for 40Gbit/s transmission systems

In this paper, we review different techniques for Optical Regeneration targeting either ultra long-haul transmission or/and terrestrial networking applications. Principles of operation as well as recent system experiments are described.