Faster chips require built-in optics.
In response to an applied voltage, infrared light is emitted through the window between the bottom contacts. Silicon microchips, the thumbnail-sized microprocessors that constitute the brains of a PC, are heading for a disaster created by their own remarkable success. As chips get faster, the electrons that carry messages through the tiny metal wires within the integrated circuit are having a hard time keeping up. One place where this looming problem is particularly acute is in the ultrafast clocks used to pace computation. Soon, says Lionel Kimerling, director of MIT's Microphotonics Center, electrons moving through metal wires will simply be too slow to keep pace.