WAVELENGTH-DIVISION MULTIPLEXING FREE-SPACE OPTICAL INTERCONNECT NETWORKS FOR MASSIVELY-PARALLEL PROCESSING SYSTEMS

Wavelength-division multiplexing (WDM) techniques provide many advanta ges for building optical interconnect networks for massively parallel processing (MPP) systems. A design for a 1024-channel network for MPP systems based on the interconnection-cached network with vertical-cavi ty surface-emitting laser (VCSEL) arrays with one wavelength is descri bed. We then show how a WDM version with four different wavelengths ca n increase the channel density. We also show how a WDM system can redu ce the fan-in loss by a factor of 4. All the VCSEL's in each array are of the same wavelength, while different arrays use different waveleng ths. We describe our experimental WDM subsystem containing four VCSEL arrays, operating at wavelengths of 843, 950, 970, and 980 nm, and thr ee different WDM tilters for multiplexing-demultiplexing. We present t he operational results of the subsystem at 1 Gbit/s per channel. (C) 1 998 Optical Society of America.