The continuing success of wavelength division multiplexing (WDM) seems to have put to rest any concerns about the accessibility of bandwidth, even in the face of the Internet's exponential growth. However, while it has lent some control over future transport challenges, WDM has also raised the question of hot to route the capacity explosion it has enabled. The problem is with the somewhat misleadingly named optical switching technology. These switches have at their core an electronic layer that some predict will form bottlenecks as escalating photonic traffic passes through. Because photonic switches redirect light without converting it, they are transparent to call network protocols, bit rates and channel counts. Photonics presents several other advantages over optical-to-electrical technology...