SPEEDING NET TRAFFIC WITH TINY MIRRORS
ow does a condensed-matter physicist become the leading optical communications expert, one responsible for building a device so powerful that it can direct 10 times the traffic of today's Internet in one second?
Ask David Bishop and most likely he'll boil it down to one word: reinvention. Bishop, who is director of the Micro Mechanics Research Department at Lucent Technologies' Bell Labs, likes to reinvent himself. From a career that started with experiments in liquid helium and went on to low-temperature superconductors, scientific equipment building and microelectromechanical structures, and now involves designing high-speed optical switches . . . "Who knows where I'm going to end up?" he mused. "What I do know is that the process has been a lot of fun."
It's been a lot of fun for Bell Labs too. Less than a year ago Lucent Technologies was able to announce that it had blown open the electronic-networking logjam with the industry's first MEMS-based high-capacity, all-optical router. The LambdaRouter uses microscopic mirrors that instantaneously send optical signals from fiber to fiber in the network. Its array of 256 mirrors-each the size of the head of a pin-can be tilted to steer lightwave signals from one optical fiber to another.
The obvious design advantage: no electronic conversion. "We have reached an electronic bottleneck in lightwave systems," said Bishop. "Moore's Law says that transistors double in speed roughly every 18 months, but Butters' Law says the amount of data coming out of an optical fiber is doubling every nine months." (Gerry Butters heads Lucent's Optical Networking Group.)
The traditional way to switch signals coming out of an optical fiber involves converting them to electrons and then using integrated circuits to switch the signals and reconvert them to photons. "The problem is that the amount of data coming out of an optical fiber is overwhelming the ability of any kind of electronic circuit to deal with it," said Bishop. "Clearly there is a major bottleneck where the need to convert signals from optics back to electronics-and then switch it and then convert the optics-is slowing down the network. We have known for a long time that this was going to happen. Now we are actually witnessing it."
Dealing with the electronic traffic jam provided Bishop and his team with the idea for a MEMS-based all-optical switch. "The good news is that just about the time the need presented itself-a year and a half ago-the technical solution also presented itself," he said. "We realized that we had found the holy grail that for decades people in lightwave systems had been talking about."
The result is a data-rate-independent switch that can handle a petabit-that's a thousand terabits. "Here people are struggling with building terabit routers and terabit electronic boxes," said Bishop. "But by doing it all optically you can deal with a petabit of data-essentially equal to every human being on the planet simultaneously making a telephone call."
For Bishop, the sudden success has been an extraordinary opportunity to participate in something truly revolutionary. "It's been the most challenging and also the most rewarding 18 months of my career," he said. "There aren't many times where you have the chance to work on something that really knocks the applecart over. It's really been exhilarating."
For the moment, Bishop is absorbed in making sure that Lucent capitalizes on this work. The process of transferring the technical achievement into a commercial success interests him. "Right now customers are looking at this gizmo and asking, 'really, does this work?' "
But apart from the technical and commercial fascination, he is also propelled by the social consequences. Optical networking is rapidly bringing down the cost of networking, making it available to everyone.
"A few hundred years from now the Internet will be viewed on the same level as the printing press-a technological development that in a short period of time allowed every human being on the planet to be connected to every other human being," he said. "This is going to blur the lines of status, education and money. The playing field is wide open. Someone in Timbuktu will have the same opportunity to access every bit as much information as someone in Manhattan. This is going to have a huge impact on how the world works. I don't think we quite understand yet, but there will be no stopping it."
And where does Bishop see himself five years from now? "I just may start thinking, 'well, it could be time for old D. J. Bishop to try something else.' That's the beauty of Bell Labs. Every five years or so I like to walk into my boss' office and say, 'I think it's time to try something different. . . .' "