All-optical interconnects for massively parallel processing

We describe a flexible all-optical interconnect scheme for massively parallel processing, capable of providing 250 channels and an information capacity of 250 Gb/s. Using available and/or demonstrated technologies, we can build fully tunable transmitter arrays and receivers. These essentially act to create a randomly, accessible 250/spl times/250 crossbar switch, connecting up to 500 processors in a single-level system. The multiplexing and de-multiplexing can be done with sufficient speed to satisfy requirements for massive parallel processing. The crossbar switch can provide 250000 1-Mb packet connections per second. A multi-level system can provide thousands to millions of simultaneous connections, at the cost of greater control complexity. A reservation scheme for the control of the one- and two-level switch is illustrated and computer simulation of the scheme demonstrated. We also propose a "pilot" token scheme for the multi-channel Express Bus (E-bus) on which packet switching can be performed. We believe that recent advancements have made the system technically feasible, and (with OEIC integration) practical and cost effective. Other related interconnect/network issues are discussed.