30, 20, and 10 Years Ago in OPN

“Natural computational systems evolved with 3D interconnections readily accessible, and have taken advantage of these interconnections as evidenced by the brain and retina. Man-made computational hardware is currently restricted to two dimensions, but the limitations of these systems are apparent, and the drive toward massively parallel, three-dimensionally interconnected systems has been initiated. The addition of optical interconnections to existing hardware offers a simple method for introducing the third dimension to systems, but, since silicon dominates computational hardware, mixed-material systems offer the simplest path to fully integrated optical interconnection.”