New structure for bit synchronization in a terabit-per-second optical interconnection network

A novel structure has been designed for bit synchronization in a terabit-per-second optical interconnection network with adjustable optical delay lines. The two-stage network consists of 1024 optical links connected to a central switching module. A distributed optical clock network is designed for bit synchronization at each node computer. Zero link setup time can be achieved by precisely matching the phases of each pair of clock and signal. The link-to-link switching time can be reduced to less than 20 ns in the two-stage network. Even in a three-stage network that can accommodate 32,768 optical links, the link switching time can be maintained below 30 ns. At the same time, a total bidirectional bandwidth of 98.304 Tbit/s can be obtained. Since bit synchronization is achieved entirely in the optical domain, this structure is independent of link transmission rates.