Birth of Silicon's Optical Age

The worldwide web is largely an optical network where hundreds of kilometres of glass fibre carry data to and fro.
Electro-optical modulators-devices which convert optical information into electrical, and vice versa-are used in thousands on the Internet. Ironically, inside the millions of personal computers, which connect to the Net, copper is still the preferred connection material, and today's processors which house nearly a billion transistors on a matchbox-sized slab of silicon, use micro-thin tracks of copper to carry the bits of data.