Blazar fits in a relatively new category called "optical active cable." It's meant to replace copper cabling without incurring the kind of cost that's kept fiber out of some applications. Optical active cable, and fiber in general, is touted as being lighter and more bendable than copper -- both factors being important in a crowded data center.

    Blazar targets rack-to-rack connections of 300 meters or less. Luxtera officials say they could probably go to 2 km, but there isn't much call for that kind of distance.

    Other companies offering optical active cable include Emcore Corp. (Nasdaq: EMKR - message board) and Zarlink Semiconductor Inc. (NYSE/Toronto: ZL - message board). But their top speed is 20 Gbit/s. Luxtera is hoping to leapfrog them by starting at 40-Gbit/s speeds -- four fibers of 10 Gbit/s apiece -- and that's where the silicon optics comes in.

    Blazar uses a single (non-CMOS) laser that supplies all four fibers. The laser's light gets sent through four silicon waveguides that modulate it, then send the light into the four fibers that are connected right onto the optical chip.

    The setup allows Luxtera to use a cheap, continuous-wavelength laser, rather than four lasers and four modulators, keeping the assembly compact.

    Everything interesting about Blazar, then, lies in that Luxtera chip with its modulators. The chip sits inside a non-removable connector on either end of the cable. In between is plain old singlemode fiber.

    "The fiber media itself is actually very cheap, about $1.20 a meter, whereas this copper cable sells for $15," Tlalka says.

    With Blazar, Luxtera will first target the InfiniBand market, later moving to 40-Gbit/s Ethernet as that standard evolves. (See 100-GigE, 40-GigE Live in Peace.)

    Luxtera plans to start sampling Blazar in the fourth quarter to a few customers. Full production won't come until mid-2008.