Promises and prospects of optoelectronic computing

The various concepts of how optoelectronics can be applied to computing have evolved over the past few years. There is less discussion of the use of nonlinear optical materials in computing, except in special-purpose, analog processors and more discussions of optical interconnections for digital computers. The near-term applications being discussed are for interconnections between computers. Longer term applications include high-speed, multiple-wavelength, channels in guided paths; and free-space interconnections that allow high parallelism, and large fan in, and fan out. The guided-wave interconnections in some cases have direct connections, but switchable interconnections in a network are more useful. Increases in performance are possible through architectural and circuit changes that are made possible by using optical interconnections