Alcatel-Lucent announces new optical transmission records

Achievements include a transmission at 12.8 Terabit/s over a record distance of 2,550 km: Alcatel-Lucent confirmed its technical and scientific leadership in optical communications research with three post-deadline papers accepted at the European Conference and Exhibition on Optical Communication (ECOC) in Berlin. These papers are part of a total 38 papers presented at the conference by Alcatel-Lucent Bell Labs and Research & Innovation researchers, successfully demonstrating new advances in optical transmission and paving the way for the future introduction of 100 Gbit/s Ethernet optical networks. The major breakthroughs are: the transmission of 12.8 Terabit/s of data through a single optical fiber over a record distance of 2,550 km, a precursor for long-haul transmission at 100 Gbit/s per wavelength; a pioneering 8 Terabit/s data transmission using a simple and cost effective 100 Gbit/s channel modulation; and the first hybrid DWDM transmission of 100 Gbit/s and 40 Gbit/s channels in the same system, demonstrating migration and coexistence capabilities of both. “Positive results in these advanced tests further demonstrates our commitment to design the most efficient, highest bandwidth systems possible for the benefit of our customers,” said Romano Valussi, President of Alcatel-Lucent’s optics activities.“The 100 Gbit/s achievement further confirms our technology leadership in optical networking as a critical enabler of the IP network transformation.” The first experiment was achieved by Alcatel-Lucent’s researchers in Villarceaux, France. They demonstrated a 12.8 Terabit/s transmission on a single optical fiber, over the record distance of 2,550 km. As no previously reported experiment had achieved more than 10 Terabit/s were beyond 300 km, these results represent an improvement by a factor of more than 8. In this experiment 160 wavelength-division multiplexed (WDM) channels were modulated at 80 Gbit/s each. The system involved several innovations, namely polarization division multiplexing, multi-level optical modulation, coherent detection and powerful electrical signal processing. The second result was achieved by Alcatel-Lucent’s researchers from Stuttgart and Villarceaux. They realized a 8 Terabit/s Wavelength Division Multiplexing (WDM) transmission with 80 channels, each modulated at 100 Gbit/s, transmitted over 520 km. Such a density represents a breakthrough, as the channels were very densely packed, separated by no more than 100 GHz from each other. This modulation is a simple, robust and cost-effective way to generate and transmit a 100 Gbit/s bandwidth by channel. In the third experiment Bell Labs researchers in New Jersey demonstrated the first hybrid DWDM transmission of 100-Gbit/s and 40-Gbit/s channels in the same system, achieving a record overall spectral efficiency of 1.4 bits/s/Hz. This experiment is significant in that it demonstrates a feasible upgrade path for DWDM transport equipment to support 100-Gbit/s Ethernet channels using existing 50-GHz channel plans. These results are an extension of Alcatel-Lucent’s recent successful demonstration of a similar capacity upgrade - where researchers replaced 10-Gbit/s OOK channels with 40-Gbit/s DQPSK channels, co-existing with 40-Gbit/s DBPSK channels, in the same system (post-deadline paper at OFC/NFOEC 2007). For more information about ECOC: its Web site.