At first glance, silicon makes lousy photonic devices. Although it transmits microwaves, it doesn’t lase efficiently, nor do its optical properties change readily in response to an electric field. But Si has one big advantage. Thanks to the electronics industry’s 50-year investment in the material, devices made from Si are cheap, powerful, and versatile. If Si-based devices could manipulate photons, computers could tap directly into the optical lines that carry gigabytes of data per second. You could download a full, high-definition movie to your PC in seconds.
To achieve that vision, researchers first need to develop a suite of Si-based components, such as light sources, waveguides, modulators, and detectors. Of those, two are especially difficult to make: a semiconductor laser for generating light and a fast modulator for converting electrical signals into optical signals. Both goals remain, but the second now looks closer.
A team from Intel Corp has made...