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Experiments also yield an unprecedented 3.2 bits/second Hertz (b/s/Hz) of spectral efficiency: Alcatel-Lucent today announced in a post deadline paper accepted at the OFC/NFOEC conference in Anaheim, California, that combined research teams from the United States and France successfully transmitted a world record 25.6 Terabits per second (Tb/s) of optical data over a single fiber strand, using 160 Wavelength-Division Multiplexed (WDM) channels - enough bandwidth to transmit the data from more 600 DVDs per second. These results far surpass the previous transmission record of 14 Tb/s, established in September 2006. Alcatel-Lucent was able to leverage its researchers’ skill in optimizing spectral efficiency in optical networks, using both wavelength and polarization multiplexing, and general mastery of the physical layer of optical networking. Also involved in this experiment were scientists from the National Institute of Information and Communications Technologies in Tokyo (NTIICT), and also from Sumitomo Osaka Cement in Chiba, Japan. This breakthrough in data transmission capacity adds to the company’s long list of terrestrial and submarine optical networking research milestones including the world’s first terabit transmission experiment, invention of non-zero dispersion fiber (NZDF), the first to break the 10 Tbit/s barrier for delivering data over a single optical fiber, the largest capacity ever transported over transoceanic distances (6Tbit/s), transmission of 100 Gbit/s data over 2,000 km, introduction of the L-Band amplifier, the first large-effective area fiber, and the first commercial all-Raman amplified DWDM system. “Optical networking is a critical enabler of the broadband IP revolution we are seeing throughout the world today,” said Romano Valussi, President of Alcatel-Lucent’s Optics activities. “The experience we are developing in these tests will help Alcatel-Lucent design the most efficient, highest bandwidth systems possible to benefit our customers when networks of this bandwidth will be deployed.” The experimental system transmitted 25.6Tbit/s of data through three 80-km spans. The data used wavelength division multiplexing in both the C(conventional) and L(long) wavelength bands and, to double the total capacity, polarization multiplexing in each wavelength was employed. Distributed Raman amplification was used to increase the received optical signal-to-noise ratio and to allow the use of a single dispersion-compensating fiber for both bands after each span. Maximizing spectral efficiency, which is the amount of information that can be transmitted within a unit bandwidth, was also critical to realizing this world record. In this experiment Alcatel-Lucent’s Bell Labs researchers in New Jersey and Alcatel-Lucent’s Research and Innovation researchers in France used an advanced signalling format called RZ-DQPSK (return to zero differential quadrature phase-shift keyed) to realize a record-breaking 3.2 bits/second/Hertz (b/s/Hz) of spectral efficiency. This is a significant improvement over today’s commercial systems that generally operate at spectral efficiencies of between 0.2 and 0.4 b/s/Hz.