Lucent turns to mirrors for optical switching

MURRAY HILL, N.J. - Lucent has taken the electricity out of switched optical networks.

The company next year plans to ship the WaveStar LambdaRouter, an all-optical device that switches light from one fiber to another without first converting the light to an electrical signal and then back to an optical one.

It is this electrical detour that slows traffic on today's fiber-optic networks. While the new Lucent gear is aimed squarely at service providers, enterprise networks could be the ultimate beneficiaries if carriers are able to offer higher-speed services more widely.

A single LambdaRouter can switch up to 40 gigabits of traffic, the capacity of 256 separate optical fibers, each carrying a single wavelength. With wave-division multiplexing, each fiber can carry more than one wavelength, increasing the potential capacity of the device.

While calling the device breakthrough technology, one analyst says the LambdaRouter still has to prove itself. The key questions Lucent has yet to answer are whether the devices will scale as large as carriers will need and whether they will be inexpensive enough to make them worthwhile, according to Dana Cooperson, a senior analyst with RHK, a consulting firm in San Francisco.

Lucent claims the Lambda-Router will cut carrier operating expenses by 25%.

Despite its name, the device is not actually a router. It is more akin to a cross-connect, a static switch in conventional telephone networks. Each Lambda-Router can take 256 fibers in and put 256 fibers out. The traffic is carried on waves of light that are switched through the LambdaRouter using two banks of adjustable, circular mirrors that are each a half millimeter in diameter (see graphic).

Lucent claims a series of LambdaRouters can be configured easily by a carrier to quickly provision light paths across a network.

Select carriers will get LambdaRouters to test in July, and the boxes will ship in December 2000. Lucent would not say how much the boxes will cost.

Lucent: www.lucent.com