With the ever-growing performance of processor chips, the data flow to and from a processor has to scale accordingly. This is where today’s copper wires are approaching their physical limitations. Optics has several key advantages over copper, the most compelling of which are the higher data densities and longer distances that can be achieved. Furthermore, optical links are not only unaffected by electromagnetic interference, they also consume less power, which is becoming increasingly important as data rates continue to rise. Optical interconnect technology is well known from fiber networks for telecommunications. Additional research is required, however, before optical technology can be incorporated into computing systems.
IBM Research partnered with Swiss-based printed-circuit board manufacturer Varioprint AG and French-based IntexyS Photonics to develop a cost-competitive, card-to-card optical interconnect solution. The first prototype is now being presented at Electronica 2006 in Munich, the world’s largest trade fair of the electronics industry. The prototype consists of optically enabled printed circuit boards equipped with high-density, 120 gigabit per second opto-electronic modules and fiber-optic interfaces.
“At IBM, we consider the interconnect bandwidth density to be a major challenge in next-generation server systems. The data flow to and from computer processors is increasingly limited by electrical interconnects as we know them today. Optical links can provide the additional bandwidth capacity that is required to scale the interconnect system with the increasing performance of today’s processors,” states Dr. Bert Offrein, manager of the Photonics group at IBM’s Zurich Research Laboratory and one of the chief designers of the optical interconnect prototype.
Offrein and his team have devised clever ways to integrate optical waveguides directly into the printed circuit board (PCB). The PCB prototypes are embedded with an array of 12 optical waveguides having a pitch of 250 micrometers, the entire width of which is only 3 mm.
“This prototype is an important step towards low-cost manufacturing and assembly of optical interconnect technology for intra-system data links. Integration and the use of standard manufacturing processes were crucial factors,” explains Max Gmuer, project leader at Varioprint.
Another challenge in terms of costs and efficiency has been the integration of the electro-optical components that convert electrical signals from the processor into optical signals, which are then transmitted through the optical waveguides and a fiber cable to the receiver card, where they are converted back into electrical signals. High-density, opto-electronic modules with a bandwidth of 120 gigabits per second have been developed in collaboration with IntexyS Photonics. The optoelectronic conversion is performed by an array of 12 lasers or detectors, each of which can process 10 gigabits of data per second. IBM researchers have developed ways to easily assemble and align the opto-electronic elements with the waveguides. Standardized optical interfaces make the technology compatible with established fiber-optic technology.
This prototype is clearly a decisive step toward bringing PCB-level technology to the market place. “Now we have to intensify our collaboration with vendors to build a network of suppliers. At the same time, some elements of this technology still need to mature,” remarks Offrein and adds, “Our goal is to develop a general optical technology platform that can be used for IBM’s systems as well as for other applications.”
Visit the Optical Interconnect Prototype Demo at the Electronica 2006, Varioprint booth in Hall B1, Booth 632.
Presentations on this topic will be given by IBM researchers Dr. Christoph Berger and Dr. Roger Dangel at the International Symposium on Photonic Packaging at Electronica 2006, Conference Room KC 32, 9.00 am – 5.00 pm.
A detailed program can be found here: http://www.mcc-pr.de/...
Made in IBM Labs
IBM is dedicated to driving the development of a wide range of emerging technologies, including advanced systems technologies such as optical interconnects. These technologies, however, are not created in a vacuum by IBM alone. They are increasingly the result of collaborative innovation through IBM's research and development engagements with industrial R&D partners, customers, business partners, universities and other parties. Bringing IBM's prized R&D resources closer to its customers worldwide is a key goal of IBM.
About the IBM Zurich Research Laboratory
The IBM Zurich Research Laboratory (ZRL), which is celebrating its 50th anniversary in 2006, is the European branch of IBM Research. This network of some 3200 employees in eight laboratories around the globe is the largest industrial research organization in the world. World-class research and outstanding scientific achievements—including two Nobel prizes—are associated with this lab. The spectrum of research activities at ZRL ranges from exploratory research to the development of computer systems and software to the designing of novel business models and services that are becoming available "On Demand". www.zurich.ibm.com
About Varioprint AG
Swiss-based Varioprint was founded in 1970. Despite the increasingly sophisticated demands of an international market—including globalization, overcapacity in the industry and price pressure—Varioprint has been able to establish itself firmly as one of the leading PCB suppliers in Switzerland. The strategy of positioning the company in the highest technology segment with such products as high-density interconnects, microvias, fine pitch and high frequency has resulted in its exceptional growth. www.varioprint.ch
About IntexyS Photonics
French-based IntexyS SA was founded in mid-2002 by well-established and reknowned technical and marketing managers from companies throughout the semiconductor electronic and optoelectronic industry. IntexyS designs, manufactures and markets highly integrated components and optical sub-assemblies for high-speed equipment and systems. The company provides multi-standard-compliant (Xenpak, Xpak/X2, XFP) transmitter and receiver solutions. www.intexysphotonics.com
High-resolution images are available for download at: http://www.zurich.ibm.com/...