Large-scale passive photonic switch architecture

This paper describes some scalable photonic switch architectures based on passive star couplers and wavelength-division multiplexing. The development of these architectures is motivated by several implications to the use of passive photonics: low access latency, large switching capacity, improved fault tolerance, and bandwidth/spatial reconfiguration. Due to crosstalk and power budget factors, the number of separable wavelength channels with direct detection devices is limited. Scalability in the described architectures is achieved by efficiently combining wavelength and space division, using multiple star couplers. Two approaches are presented, both feature conflict-free communication: multi-access based on interleaved time-division multiple-access and virtual point-to-point based on multi-hop lightwave shuffle networks. Results concerning realization, delay-throughput performance, and wavelength assignment are summarized.