Big Blue joins the club:
eetimes.com
IBM lays plans for optical transport
By Loring Wirbel
EE Times
(08/16/00, 3:21 p.m. EST)
EAST FISHKILL, N.Y. — IBM Microelectronics plans to put its development muscle behind a unique array of processes and parts for optoelectronic transmission that includes silicon germanium (SiGe) transceivers, semiconductor lasers and arrayed waveguide components. The variety of projects gives the group one of the busiest agendas within the company's wired communications business unit.
The most aggressive activity for the fall, said Dale Crist, business line manager for transport at the unit, will involve the development of framer and serializer/deserializer (serdes) products covering both OC-192 Sonet and 10-Gbit Ethernet. Fundamentally, said Crist, "our group covers everything from framers to fiber."
The kind of package integration IBM achieved with its popular GBIC module at 1-Gbit rates will be augmented in markets such as multichannel serial interconnect, very-short-reach optics and 10-Gbit Ethernet in all its suggested serial and parallel flavors. Crist said that IBM can use SiGe processes to develop small individual laser driver, transimpedance amp and post-amp components, which can then be combined in low-cost plastic packages, often using silicon optical bench hybrid technologies.
IBM enhanced its own expertise in framers and serdes devices in June, when the company signed a design and distribution pact with Multilink Technologies Corp. (Santa Monica, Calif.), a small specialist working on 10-Gbit mux/demux and clock-recovery devices.
Crist said that IBM and Multilink must still resolve the degree to which they will fully coordinate product plans or offer directly competing parts. However, Multilink is being given access to IBM's SiGe process development plans, and the two companies will collaborate closely on plans for OC-768 (40-Gbit) transmission. Based on the latest plans of OEMs and carriers, Crist said the work on 40-Gbit components comes none too soon.
"I've talked with equipment vendors in recent weeks who would like to see engineering samples of OC-768 components right now," Crist said. "If you would have asked me a year ago on the plans for OC-768, based on what we saw with OC-192, I would have guessed it would have taken another year for real interest in 40-Gbit networks to develop."
Accelerated development
That means IBM must accelerate its SiGe and copper interconnect development plans to meet the schedules that the wired communications group, particularly the transport line of business, would like to see. Crist said that the technology groups in Burlington, Vt., as well as the long-term R&D group at IBM's Zurich (Switzerland) Research Laboratory, almost dread seeing representatives of the wired communications group approach them, since the broadband group is more aggressive in its demands than virtually any other IBM Microelectronics group, save perhaps ASICs.
Because optoelectronic components are in overall shortage, meeting capacity requirements for lower-integration 10-Gbit products remains a key demand, Crist said. At the same time, "silicon optical bench integration is driving everything. We're still at [the] very early stages of bringing in the Zurich waveguide technology, but some people are very hungry for those types of integrated components."
IBM's waveguide breakthrough was to use a silicon oxynitride layer between two silicon dioxide layers in order to implement a series of thermally controlled Mach-Zehnder interferometers with tight curves in a small region on a silicon die. The achievement was made in 1998-1999 as part of the Cobnet (Corporate Optical Backbone Network) project, which was funded by Europe's Advanced Communications Technologies and Services group.
The oxynitride process forms the basis of photonic switches that have currently been demonstrated in 8 x 8 and 32 x 32 arrays, used for planar waveguide add-drop switch functions.
"In theory, we could scale this technology to make the waveguides the basis for fairly large nonblocking switches," Crist said. "My goal now is to bring the Zurich waveguide technology into production as part of a standard semiconductor production effort." |
