Ultrafast all-optical switches in fiber networks

A generalized exclusive-OR (GEO) module that is a logical representation of the ultrafast fiber switch is introduced as a design tool. Simple systems using from two to four GEO modules illustrate the architectural considerations for using the ultrafast gates. For example, ultrafast gates are attractive for self-routing, packet-switching applications when the header is in the same form as the payload or data. In addition, packet switching naturally lends itself to a hybrid speed system since fast gates are required for the header and slower switches can route the data. Ultrafast gates can contribute toward three general network tasks in a packet switching environment. First, ultrafast access is required to strobe and remove the header. Second, the header must be decoded and the information used to set several slower exchange/bypass switches to route the packet. Finally, when the packet reaches its destination, fast gates must down-convert the information to bit rates accessible by electronic shift registers.<>