Silicon on Sapphire Speeds Chip Communication

The insulating properties of sapphire have been heralded as a boon to smaller, low-power chip design, but researchers at Johns Hopkins University in Baltimore are focusing on the gem's optical potential for laser chip communication at speeds a hundred times faster than are possible through conventional technology.

The researchers' microsystem uses 850-nm vertical-cavity lasers from Emcore Corp. in Somerset, N.J., and specially designed vertical-cavity lasers from the Army Research Laboratory in Adelphi, Md. Signals can be transferred through the sapphire between portions of the same chip or, by means of an optical fiber, to another chip without the typical parasitic components of metal wires or semiconductors.