Corning, Gore, and Siecor Demonstrate Multimode Fiber Capability

Corning Inc., Advanced Materialsed goal to use 850nm vertical cavity surface emitting laser (VCSEL) technology with laser-optimized, multimode fiber to enable a cost-effective transition to higher speed LANs, <%=company%> (Corning, NY), W.L. Gore & Associates Inc. (Newark, DE), and Siecor Corp. (Keller, TX) announced today the results of further testing of cabled Corning prototype multimode fiber. Successful demonstration of serial transmission at both 1 and 10 gigabits per second (Gbps) was achieved with Corning multimode fiber using Gore's high-speed 850nm VCSELs.

The fiber, best suited for high-speed transmission at Gigabit Ethernet (GbE) speeds or higher, is a prototype 50µm InfiniCor fiber optimized for 850nm operation. Gore is collaborating with optical fiber and cable manufacturers like Corning and Siecor to develop low cost VCSELs that will support 10 Gbps transmission.

Realistic tests
In its tests, Corning chose link lengths for testing that reflected realistic premises applications. According to a recent IEEE survey, 500 m at 10 gigabits per second covers 98% of in-building backbones in the premises market.

In August 1999, Corning and Gore achieved 600-m serial transmission at 10 Gbps over Corning multimode fiber using a Gore VCSEL. Using the knowledge gained from this and other testing, Corning says it can now produce highly repeatable enhanced short wavelength optimized fiber that is ideal for GbE as well as 10 Gbps.

In addition, the fiber prototype transmitted 2000 m at GbE speeds, as well as maintaining error-free transmission at 10 Gbps for 500 m.

"The 2000 m at GbE encompasses the limit of a multimode fiber campus backbone according to the Commercial Building Telecommunications Cabling Standard [TIA/EIA-568-A]," said Carolyn Case, Corning's premises product line manager.

To better simulate real world system conditions, the fiber was cabled by Siecor and multiple connectors were used in each experiment. The 850nm VSCEL was coupled to the fiber and the output pulses, converted into electrical pulses, displayed the bit pattern on the oscilloscope in the form of an eye diagram. The eye diagrams illustrated a very clear, well open-eye for both 1 and 10 Gbps modulation.

"We have gained a lot more knowledge about the expectations and capability of multimode fiber from these recent tests," said Bob Pollock, manager of market strategy for private networks at Siecor. "There is a big difference between testing bare fiber and cabled fiber with connectors. These tests show that optimized fiber and high-data-rate VCSELs will work in installed networks."

Edited by John Spofford