For designers of fiber optic systems, the goal has always been to provide more capacity at lower cost per bit. For more than 20 years, the capacity of systems has doubled every 18 months, while the cost of transporting a bit has been halved every nine months. And there has never been any doubt about the need for bandwidth: Historically, network providers and other users have absorbed every bit of bandwidth that was available and have demanded more. But the technological athletics required to make those big jumps often stretches the resources of system designers, until suppliers ramp up the batch fabrication processes and exploit the economies of scale that help reduce costs. What's more, while the need for more bandwidth is a certainty, predicting exactly where, when and how much is needed is anything but certain…