The new product "represents the next logical step in utilizing silicon photonics for low-cost assembly," says Alan Willner, professor of electrical-engineering systems at the University of Southern California. "The ability to house together various optical components makes for an even more compelling argument why 40-gigabit-per-second optical cables can beat out copper," he says.

And the market for such devices is definitely good, says Fred Zieber, president of Pathfinder Research, a technology-analysis firm. "It's a great product for things like server farms and computer complexes," he says. "And that market's growing pretty doggone fast."

Luxtera may have to overcome the obstacle of being a startup and therefore not well known and trusted in the industry, Zieber says. But he adds that the reliability of its product could give the company an advantage. "They're not using arcane material and not putting a lot of chips together to do this. All of that should give you a more rugged package."

Gunn is confident that the cable will find customers, and as the transceiver chips are manufactured in larger numbers, their cost could drop to the point that silicon-based optical cables can even compete with copper--something that nonsilicon optical cables will never do. As costs fall, Gunn notes, silicon photonics could move beyond simply providing connections between systems. "Looking further out, silicon photonics will address bottlenecks within systems," he says. Home computers whose circuitry used silicon photonics instead of copper wiring, he adds, would be faster and keep power consumption to a minimum.