But, on backbones, all optical switches and the amazing micro-mirror arrays that power them have already become a reality. CIR's report points out that, today, some of the biggest names in the telecommunications equipment industry have begun to offer OEO switches. They take optical signals, run them through an electronic switching matrix, and then pump them out as optical signals at the other end. Such OEO products, which are being manufactured by BrightLink, Ciena, Cisco, Not Tellium, Sycamore and others combine the high degree of intelligence associated with conventional switches with the high capacities of optical platforms. CIR believes that while it is far from a proven technology, the backing for MEMS coming from powerful vendors such as Lucent, Nortel, and Siemens gives it a lot of clout in the marketplace.
Nothing is certain in the optical switching business.
The scalability of MEMS is still in question, with rival technologies such a liquid crystal technology or Agilent's new optical switching technology looming on the horizon. There are still significant problems with all-optical switching. Higher-level network layer switching, which requires decoding inner layers of packet data to get routing information, remains difficult, as does the need to regenerate signals as they degrade, which requires a conversion to electrical signals and then an optical transmission. But there has been significant progress in this area. The frequency density of fiber transmission techniques keeps rising, offering more flexibility and ever-greater throughput on optical links.