2.5. OPTICAL NETWORKING IN OPTICAL COMPUTING
Modern business and warfare technologies demand vast flows of data, which pushes classic electrical circuits to their physical limits. Computer designers are increasingly looking to optics as the answer. Yet, optical computing (processing data with photons instead of electrons) is not ready to jump from lab demonstrations to real-world applications .
Fortunately, there is a middle ground—engineers can mix optical interconnects and networking with electronic circuits and memory. These hybrid systems are making great strides toward handling the torrents of data necessary for new applications .
The trend began at the biggest scales. Fiber optics has replaced copper wiring at long distances, such as communications trunks between cities. More recently, engineers have also used optical networking to link nearby buildings. And, with the introduction of a new parallel optics technology called VCSEL (short for vertical cavity surfacing emitting laser), they have even used optics to connect computer racks inside the same room. VCSEL now connects routers, switches, and multiplexers .
But the trend has stalled there. As systems designers use optics on ever-smaller applications, the next step should be to use them on PC boards and backplanes. And theoretically, the step after that would be to build computer chips that run on photons instead of electrons. Such a chip would be free of electrical interference, so that it could process jobs ...