OPTICAL MULTIPLE-ACCESS MESH-CONNECTED BUS INTERCONNECTS

We consider networks for interconnecting parallel computers that are p arameterized by their degree (fan-out) of switches that are used to bu ild the network. Electronic networks tend towards the small fan-out/la rge diameter end of the spectrum due to limitations on the fan-out of electronic switches. The fan-out of systems of optical switches. Thus it has been suggested that optics can be used to build the complete ne twork which is the most desirable of Clos's family of networks. Even o ptics, however, has limits on the fan-out of switches in any given con figuration. Thus in this paper, we describe an implementation of a net work with a significantly smaller degree and slightly larger network d iameter than the complete network. The network that we implement is ca lled the mesh-connected bus network. We remark, however, that it is es sentially an implementation of the second most desirable network in th e family of networks defined by Clos, which is widely referred to as t he Clos network. We implement the network using novel free-space optic al interconnection techniques along with a multiple-access scheme base d on wavelength-division multiplexing.