Technology Close-Up: Micromirrors Relieve Communications Bottlenecks

David Bishop, Randy Giles and Charles Roxlo, Lucent Technologies' Bell Labs & Lucent Technologies

Information is the lifeblood of global commerce in the 21st century, and networks are its veins and arteries. But even the highest-capacity optical networks are subject to "thromboses" -- bottlenecks that thwart and complicate delivery of the gigantic capacities that are added to optical networks year after year.

The most pervasive of the bottlenecks for communications carriers are the switching and cross-connect fabrics that switch, route, multiplex, demultiplex and restore traffic in optical networks. Transmission systems move information as photons, but switching and cross-connect fabrics until now have largely been electronic, requiring costly, time-consuming, bandwidth-limiting optical-to-electronic-to-optical conversions at every network connection and crosspoint.

Carriers must keep their networking capabilities in step with the giant bandwidth capabilities that are provided by their fiber optic transmission systems. They need to ensure that networks are adaptive, flexible and expandable to keep up with the constant demands for more bandwidth and for new service capabilities that are enabled by greater capacities.

The traditional approach used inexpensive electronics to minimize the use of expensive photonics.

That approach is reversing because of one overarching trend: Light speed is faster than Moore's Law. Photonics is becoming far cheaper and far faster than electronics. The price/performance innovation rate for photonics doubles every nine months vs. 18 to 24 months for silicon integrated circuits. The result: As photonics gets cheaper, optical networks become more pervasive, reaching ever-farther to the edges of networks.