Dutch researchers create record-breaking 3300km optical link to Geneva

July 10, 2012 // By Nick Flaherty
SURFnet, the National Research and Education Network (NREN) in the Netherlands, has demonstrated a record-breaking 3300km optical fibre link between Amsterdam and Geneva.

The 100Gbps coherent field trial between the National Supercomputing Center (SARA) in Amsterdam and CERN (Conseil Européen pour la Recherche Nucléaire - European Organization for Nuclear Research) in Geneva used single carrier technology and soft decision forward error correction (SD-FEC) on only erbium doped fiber amplifiers (EDFAs).
To further demonstrate the subsystem’s performance, the embedded fiber link comprised a combination of the relatively high-nonlinear TW+ and TWRS fibers. Furthermore, the circuit was optically looped back in Geneva, creating a 3,300km circuit. The looped-back 3,300km link operated error-free for more than 23 hours (BER<10-15) over the entire C-band and over a range of launch powers, highlighting the true upgrade potential of this link to 8Tbps in the future using 100Gbps coherent transponders.
“This trial is another clear demonstration that coherent 100Gbps PM-QPSK transmission technology is tolerant to a very large range of impairments (i.e. chromatic dispersion, polarization mode dispersion, noise) and allows the use of alien wavelengths in research networks over DWDM systems from multiple vendors,” said Roeland Nuijts, Optical Network Architect for SURFnet. “Transmission distance and tolerance against different impairments will be critical going forward as we look to build out international networks across geographic and administrative borders in order to realize a global facility for research networking.”
The subsystem from Opnext consists of a suite of OTS-100FLX 100Gbps flexponder line cards and a newly released OTS-mini ETSI shelf with a 4RU small form factor. “It is great to see the results of our 100Gbps coherent product development deliver both the capacity and reach needed to scale next-generation optical networks around the world,” said Mike Chan, President of Opnext’s subsystems business unit. “SURFnet’s 3,300km field trial really pushed us, and our 100Gbps coherent technology met the challenge.”