Bell Labs Scientists Demo First Long-Distance Triple-Terabit Transmission

Using three 100-kilometer fiber spans, the researchers transmitted 40 gigabits (billion bits) over each of 40 wavelengths, or colors, of light in the conventional C-band frequency range and 40 gigabits (Gb/s) over each of 42 channels in the long-wavelength L-band range.

They used both dense wavelength division multiplexing (DWDM), a technology that combines multiple wavelengths onto a single fiber, and distributed Raman amplification, a technique that allows optical fiber to amplify the signals traveling through it.

“This is a milestone on the road to super-high-capacity long-reach transmission,” said Alastair Glass, executive director of the Bell Labs Photonics Research Lab. “It proves the practicality of 40Gb/s systems with repeater spacing typical of today’s networks.”

The research team presented its results in one of a dozen Bell Labs technical talks given in post-deadline, late-breaking-news sessions at the Optical Fiber Communications (OFC) Conference last week.

“The 3.28-terabit transmission experiment, along with other Bell Labs post-deadline reports – on all-optical cross connects – demonstrate that Lucent Technologies is uniquely positioned to provide the next-generation optical-layer network,” said Harry Bosco, group president of Lucent’s Optical Networking Group.

Bell Labs is celebrating its 75th anniversary this year. One of the most innovative R&D entities in the world, Bell Labs has generated some 40,000 inventions since 1925. It has played a pivotal role in inventing and perfecting key communications technologies for most of the twentieth century, including transistors, digital networking and signal processing, lasers and fiber-optic communications systems, communications satellites, cellular telephony, electronic switching of calls, touch-tone dialing, and modems.

Today, Bell Labs continues to be a haven for some of the best scientific minds. With more than 30,000 employees located in 25 countries, it is the largest R&D organization in the world dedicated to communications and the world's leading source of new communications technologies. For more information on Bell Labs, visit http://www.bell-labs.com.

Lucent Technologies, headquartered in Murray Hill, N. J., designs, builds, and delivers a wide range of public and private networks, communications systems and software, data networking systems, business telephone systems, and microelectronics components. Bell Labs is the research and development arm for the company. For more information on Lucent Technologies, visit its Web site at http://www.lucent.com.

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Bell Labs Post-Deadline PapersOptical Fiber Communications (OFC) Conference 2000

3.28-Tb/s (82x40Gb/s) transmission over 3x100km nonzero-dispersion fiber using dual C- and L-band hybrid Raman/Erbium-doped inline amplifiers, T.N. Nielsen, A.J. Stentz, K. Rottwitt, D.S. Vengsarkar, L.Hsu, P.B. Hansen, J.H. Park, K.S. Feder, T.A. Strasser, S. Cabot, S. Stulz, C.K. Kan, A.F. Judy, J. Sulhoff, S.Y. Park, L.E. Nelson, L. Gruner-Nielsen. Transmission of a record aggregate capacity of 3.28-Tb/s (82x40Gb/s PRBS 231-1 NRZ) over 3x100km of a demonstration TrueWave® fiber with very low dispersion slope. The system for the first time incorporates dual C- and L-band transmission and distributed Raman amplification in addition to the 40Gb/s line rate.

Ultra-dense terabit capacity WDM transmission in L-band, A.K. Srivastava, S. Radic, C. Wolf, J.C. Centanni, J.W. Sulhoff, K. Kantor, Y. Sun. Error-free transmission of 100 wavelength-division-multiplexed (WDM) 10-Gb/s channels with 25 GHz spacing over 400 km of non-zero dispersion shifted fiber. High spectral efficiency of 0.4b/s/Hz was achieved combining distributed Raman and erbium doped fiber amplifiers.

1.6 Tb/s (40X40 Gb/s) total capacity 4-node optical networking with fully programmable A/D devices, Hyang K. Kim, S. Chandrasekhar, Torben Nielsen, Chris Doerr, Larry Stulz, Larry Buhl, Rene Monnard, Stojan Radic, Martin Zirngibl. A 4-node dynamically reconfigurable optical network, using integrated add/drop devices, is demonstrated. Aggregate capacity of 1.6 Tb/s (40 X 40 Gb/s), spectral efficiency of 0.4 bits/s/Hz, Q values larger than 18 dB and wide tolerance to wavelength mis-alignment are key results.

Fully provisioned 112x112 micro-mechanical optical cross connect with 35.8Tb/s demonstrated capacity, D.T. Neilson, V.A. Aksyuk, S. Arney, N.R. Basavanhally, K.S. Bhalla, D.J. Bishop, B.A. Boie, C.A. Bolle, J.V. Gates, A.M. Gottlieb, J.P. Hickey, N.A. Jackman, P.R. Kolodner, S.K. Korotky, B. Mikkelsen, F. Pardo, G. Raybon, R. Ruel, R.E. Scotti, T.W. Van Blarcum, C.R. Giles, L. Zhang. Presentation of a scalable, fully provisioned 112x112 micro-mechanical optical cross connect with mean insertion loss of 7.5dB @ 1550nm into single-mode optical fiber and <10ms switching speed is presented. 35.8Tbit/s aggregate capacity was demonstrated with 320Gbit/s TDM signals.

Demonstration of distributed mesh restoration and auto-provisioning in a WDM network using a large optical cross-connect, N. Agrawal, E.S. Tentarelli, N.A. Jackman, L. Zhang, S.K. Korotky, B.H. Lee, S. Baroni, B.M. Comissiong, J.M. Hitchcock, Y.R. Bing, J.P. Hickey, A.M. Gottlieb, K.S. Bhalla, T.W. Van Blarcum, D.T. Neilson, C.R. Giles, V.A. Aksyuk, S. Arney, N.R. Basavanhally, D.J. Bishop, B.A. Boie, C.A. Bolle, J.V. Gates, P.R. Kolodner, F. Pardo, R. Ruel, R.E. Scotti. The first demonstration of distributed restoration and auto-provisioning for the WDM mesh network, using four nodes, five links, and twelve 2.5 Gb/s unidirectional demands. The measured restoration time is <50 ms.

2.5 Gb/s transmission over 680 km using a fully stabilized 20 channel DBR laser with monolithically integrated semiconductor optical amplifier, photodetector, and electroabsorption modulator, L.J.P. Ketelsen, J.E. Johnson, D.A. Ackerman, L. Zhang, M.S. Hybertsen, K.G. Glogovsky, M.W. Focht, C.L. Reynolds, C.W. Lentz, T.L. Koch, Lucent Tech., K.K. Kamath, W.A. Asous, C.W. Ebert, M. Park, R.L. Hartman. The first demonstration of a fully functional 2.5 Gb/x EA-modulated wavelength-selectable laser module meeting all long-haul transmission requirements for stability, chirp, power and linewidth over 20 channels on a 50 GHz grid. Based on a highly integrated InP chip comprising a DBR laser, semiconductor optical amplifier, power monitor, and EA-modulator, the module also contains optics to ensure simultaneous long-term wavelength and mode stability.

Compact and fully packaged wavelength converter with integrates delay loop for 40 Gb/s RZ signals, J. Leuthold, C.H. Joyner, B. Mikkelson, G. Raybon, J.L. Pleumeekers, B.I. Miller, K. Dreyer, C.A. Burrus. The first high-speed all-optical wavelength converter, with monolithically integrated delay loop and high extinction-ratio tuning abilities in a simple configuration with only one semiconductor optical amplifier has been realized and successfully tested for 40 Gbit/s RZ format signals.

Automatic wavelength channel-by-channel equalizer, C.R. Doerr, L.W. Stulz, R. Pafchek, L. Gomez, M. Cappuzzo, A. Paunescu, E. Laskowski, L. Buhl, H.K. Kim, S. Chandrasekhar. A wavelength equalizer that can automatically control individual channel powers in a 40-channel system, yet gives no distortion to channels that already have the same power as their neighbors. It has <6.8 dB insertion loss over 32-nm, 9-13 dB attenuation range, and <0.18 dB polarization/time-dependent loss.

Compact, in-line, all fiber polarimeter using fiber gratings, P.S. Westbrook, T.A. Strasser, Bell Labs, with T. Erdogan, Univ. of Rochester. A compact, low loss, low cost in-fiber polarimeter using a UV induced waveplate and fiber gratings. The polarimeter has accuracy comparable to commercial devices, is wavelength insensitive over 70nm, and is tested in control loop that actively stabilizes a random input polarization.

320 Gb/s single-channel pseudo-linear transmission over 200 km of non-zero-dispersion fiber, G. Raybon, B. Mikkelsen, R.-J. Essiambre, A.J. Stentz, T.N. Nielsen, K. Dreyer, J.E. Johnson, L. Hsu, D.W. Peckham, L. Gruner-Nielsen. Single-channel transmission at 320 Gbit/s over a record 200 km (2 x 100 km) of nonzero-dispersion fiber. Semiconductor based transmitter, demultiplexer and clock recovery was employed as well as uncorrelated multiplexing in the transmitter.

Cancellation of all Kerr nonlinearities in long fiber spans using a LiNbO3 phase conjugator and Raman amplification, I. Brener, B. Mikkelsen, K. Rottwitt, W. Burkett, G. Raybon, J.B. Stark, K. Parameswaran, M.H. Chou, E.E. Chaban, R. Harel, S. Kosinski, D.L. Philen, Bell Labs, with M.M. Fejer, Stanford Univ. A LiNbO3 phase-conjugator and Raman pumping in fiber are used in order to cancel all Kerr nonlinearities in long fiber spans. This effect is demonstrated in single and multichannel transmission at 10, 40, and 100 Gb/s.

All-optical time-slot-interchange and wavelength conversion using difference-frequency-generation and FBGs, M.C. Cardakli, D. Gurkan, S.A Havstad, A.E. Willner, Univ. of Southern California; K.R. Parameswaran, M.M. Fejer, Stanford Univ/.; I. Brenner, Bell Labs. Simultaneous all-optical time-slot-interchange and wavelength conversion of a 2.5-Gb/s bit stream. Used different frequency generation (DFG) as a wavelength converter and FBGs as optical buffers. This technique is reconfigurable, scalable and employs high-extinction-ratio DFG-based time-slot-switching.

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