Sandia LabNews

EMCORE, Sandia team up to develop high-speed optical transceiver modules for short-haul communications

EMCORE Corp. and Sandia have teamed up to develop high-speed optical transceiver modules that promise to make short-haul fiber optic communications faster and less expensive.

Over the past year-and-a-half some 50 Sandians from Centers 1300, 1700, 2300, 2600, 2900, 9100, and 14100 have worked with EMCORE’s Fiber Optical Components Division to develop a high-speed parallel array "transceiver." It consists of an array of vertical cavity surface-emitting lasers (VCSELs) on the transmission end and an array of photodiodes at the receiving end of fiber optics.

EMCORE will open a 67,000-square-foot manufacturing plant next month at the Sandia Science and Technology Park to further develop and produce the product. Robert Bryan, former Sandian and current vice president for EMCORE’s Fiber Optic Components Division, says the company has already hired nearly 100 people to work on the project and anticipates hiring "hundreds more" as the product line grows.

"The development of this technology represents a substantial investment for EMCORE in terms of money and time," Bryan says. "We chose Sandia to help with the product development because of the Labs’ unique set of capabilities — primarily in the area of microsystems integration — that can’t be found anywhere else."

EMCORE is already marketing to potential customers the 12 x 1.25 GB/s transceiver, which has the receiver and transmitter in separate packages, and its cousin, the Very Short Reach OC-192 Parallel Array Transponder, which puts both the receiver and transmitter on one board. EMCORE is the only company in the country manufacturing the transponder.

The market for EMCORE’s transceiver and transponder will be Internet service providers which would use the devices for short haul data transfer — distances of 300 meters or less.

Long relationship

EMCORE and Sandia’s relationship dates to 1993 and a series of cooperative research and development agreements (CRADAs) and work-for-others agreements. Bryan says when EMCORE officials realized they wanted to jumpstart work on the transceiver line, they turned to Sandia, knowing the Labs could "get the new technology up and running quickly."

Sandia’s Integrated Microsystems Dept. 1738, under the direction of Manager Mike Daily, conducted a feasibility study to see what it would take to put together a transceiver device that could be easily manufactured. Based on the report, presented in January 2000, EMCORE officials decided to proceed with the project.

Fifteen months later Sandia and EMCORE have a working transceiver designed for low-cost, high-volume production manufacturing.

The transceiver consists of two parts — a transmitter and receiver. On the outside the transmitter and receiver look alike, but inside they are different.

The transmitter consists of a high-speed driver integrated circuit (IC) and a 12-VCSEL array chip — a type of laser where photons bounce vertically between mirrors grown into the structure and then shoot straight up from the wafer surface. The VCSEL is used to transform electronic signals to optical signals that travel through the fiber optic cables.

At the receiving end is a single chip array of 12 gallium arsenide photo detectors that convert the light back to electronic pulses and a high speed receiver IC to shape the electronic pulses.

Two challenges

Dave Peterson (1738), who led the Sandia high-speed parallel optical transceiver development effort, says two challenges had to be overcome before a device with the potential of easy manufacturing was possible.

"First the units had to be designed to align the laser arrays and fiber cable to within 10 microns in all three dimensions even though the fiber cable is manually plugged and unplugged multiple times by field service technicians," Dave says. "This was no easy task."

The laser array inside the transceiver must be within microns of — but not touching — the fibers for the device to function.

The second challenge was to meet the high-speed data-transfer requirements while keeping the laser light intensity low enough to meet eye safety certification standards. A unique feedback control approach was used to meet these requirements by controlling the laser outputs.

Bryan anticipates that the EMCORE/Sandia-developed transceiver and transponder initiative will be highly successful. This is partly because the demand for the modules exceeds the supply — and the company that can come up with an inexpensive way to manufacture the modules will be the winner.

"I believe in the long run we will be that winner," Bryan says. "Our advantage is that our devices are easier to make and easier to use than others on the market."