Wavelength division multiplexers/demultiplexers for optical interconnects in massively parallel processing

Communication between computing systems is recognized as the main limitation to increase the speed of all-electronic systems beyond levels currently achieved in existing supercomputers. Optical in- terconnects hold great promise in eliminating current communication bottlenecks because of properties that stem from optics inherent paral- lelism. Wavelength-division multiplexing (WDM) technology, by which multiple optical channels can be simultaneously transmitted at different wavelengths through a single optical transmission medium, is a useful means of making full use of optics parallelism in an application of inter- connects for massive parallel processing. We first briefly review the bottlenecks of electrical interconnects in massively parallel processing. Then we discuss the advantages of optical interconnects and present our approach of optoelectronic interconnects in massively parallel pro- cessing by WDM technology. We then review the working principles of wavelength division (de) multiplexers (WD(D)M) for optical interconnects in massively parallel processing and address the optical design issues of WD(D)Ms. Finally, we report experimental data of WD(D)Ms for this ap- plication. The devices exhibit low insertion loss, high reliability, and low cost. © 2003 Society of Photo-Optical Instrumentation Engineers.