Bell Labs Scientists Use Cost-Effective, Innovative Technology to Quadruple Capacity of Optical Systems.

MURRAY HILL, N.J.--(BUSINESS WIRE)--June 8, 1999--

Researchers Use 40-Billion-Bit Multiplexing and Raman

Amplification to Transmit 1.6 Trillion Bits of

Data Per Second Over TrueWave(R) RS Optical Fiber

Scientists and engineers from Bell Labs, the research and development arm of Lucent Technologies (NYSE:LU), have demonstrated a prototype long-distance optical-transmission system that uses innovative technology to quadruple the capacity of today's commercial systems.

The Bell Labs scientists successfully transmitted 1.6 terabits (trillion bits) of information per second using 40 wavelengths --or colors -- of light, each carrying 40 gigabits (billion bits) per second. They used both dense wave division multiplexing (DWDM), a technology that combines multiple wavelengths on a single fiber, and distributed Raman amplification, a technique that allows optical fiber to amplify the signals traveling through it.

"A common rule of thumb says that a four-fold improvement in capacity, as with this system, results in cutting service-provider costs in half," said Gerry Butters, president of Lucent's Optical Networking Group, "and we expect this to apply to 40-gigabit channels, making this transmission rate the most cost-effective format for the future."

The transmission distance was 400 kilometers, with four 100-kilometer spans instead of the typical 80-kilometer distance between the optical amplifiers used to boost signals in long-distance systems, making the system compatible with current commercial networks.

Lucent will demonstrate this system at Telecom '99 in Geneva, Switzerland, in October.

The system also includes Lucent's TrueWave(R) RS fiber, a single-mode fiber specifically designed for optically amplified long-distance networks. It carried data signals over the conventional C-band wavelength range of optically amplified systems. Continuing research will focus on doubling the capacity again by using the longer-wavelength L-band range.

"Meeting the ravenous bandwidth demands of service providers will require new DWDM systems with significantly higher capacity than are available today," said Butters. "Once again, Bell Labs is leading the world in overcoming the problems associated with higher data rates."

Bell Labs provided the technology for Lucent's recently announced WaveStar(tm) 40G Express system, the industry's first transmission product carrying 40 gigabits per second on each wavelength. Building on this technology, the prototype system multiplies that capacity by 40, for a total capacity of 1.6 terabits, four times greater than Lucent's WaveStar OLS 400G -- the highest-capacity system currently available on the market.

Distributed Raman amplification increases the distance between the optical amplifiers used to boost data signals -- further cutting costs -- and allows higher data capacity by spacing wavelength channels closer together.

In typical optical systems, data signals travel through optical amplifiers -- optical fiber containing the rare-earth element erbium that is energized by pump lasers to boost the signals -- approximately every 80 kilometers. Using 40-gigabit technology without Raman amplification would require four times the amount of launched signal power, creating distorted signals and cross-talk between channels.

In the prototype system, the optical amplifiers are enhanced by Raman amplification, in which high-power laser light is sent in the direction opposite that traveled by the data signals, transforming part of the transmission fiber, itself, into an amplifier of the signals passing through it. Raman amplification is named after the scientist who discovered the phenomenon in the scattering of light called the Raman Effect, in 1928.

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.