1. A parallel processing computer system comprising: a set of processors and a set of memories, each of said processors and each of said memories comprising an optical transmission node and an optical receiver node, a first multiwavelength optical sub-network for interconnecting the transmission nodes of said processors and the receiver nodes of said memories to enable a plurality of said processors to simultaneously optically transmit access requests to a plurality of said memories utilizing a plurality of optical wavelengths, and a second multiwavelength optical sub-network for interconnecting the transmission nodes of the memories and the receiver nodes of the processors to enable a plurality of said memories to simultaneously transmit responses to access requests to a plurality of said processors utilizing a plurality of optical wavelengths.