Breakthroughs in capacity, power consumption set to revolutionize photonics

For years, organic electro-optic polymers have held the promise of vastly improving technologies such as communications, data processing and image displays. Now it appears scientists are on the verge of breakthroughs that will bring dramatic progress in materials, as well as the devices in which they are used, setting the stage for a virtual revolution.

Simply put, electro-optic polymers are being used to make devices that take information that typically has been transmitted electronically and transfer it to optical systems that use light. The latest developments will affect not just how much information can be sent at one time but also the power required to transmit the information.

The newest materials have made possible something called wavelength division multiplexing, a process that can separate a beam of light into perhaps 100 different colors and impose as much as 50 gigabits of information on each color. At that rate, a beam of light could transmit 5 terabits — or about 625 gigabytes — of data per second, and could move data equivalent to what is in the Library of Congress in about 30 seconds.

The capabilities of the most recently developed materials are about five times greater than those of standard lithium niobate crystals, said Larry Dalton, a University of Washington chemistry professor and director of the Science & Technology Center on Materials and Devices for Information Technology Research. He will discuss some of the center’s work during a topical lecture Friday at the American Association for the Advancement of Science meeting in Seattle.

Dalton also said the newest materials require less than one-fifth the voltage (less than 1 volt) needed for lithium niobate, the best naturally occurring material for transferring data from electronic to optical transmission and for many years the industry standard.

“What this shows is that people have done far better than nature could ever do in this process,” Dalton said. “It’s a perfect example of nanoscopic engineering. The reason we’re seeing improved performance is the rational design of new materials with new properties.”

The newest materials represent a nearly fivefold improvement in capability in just four years. At that rate, long before the end of this year material capabilities will reach benchmarks set for 2006 in the original National Science Foundation proposal for the center. Even more ambitious goals have been set by the Defense Advanced Research Projects Agency, a major supporter of electro-optic materials research.

The center (http://stc-mditr.org), which has seven core research partners and involves 13 universities, was established at the UW two years ago by the National Science Foundation. Besides NSF support that could reach $40 million over 10 years, the center has been championed by a number of public and private agencies that could push its total support to nearly $100 million over 10 years.

The center’s work will be the subject of two AAAS symposia, 21st Century Photonics, at 9:30 a.m. and 2:30 p.m. Sunday. Alvin Kwiram, a UW chemistry professor and the center’s executive director, organized the sessions and presenters include Dalton; Alex Jen, a UW professor of material science and engineering; and Bruce Robinson, also a UW chemistry professor. Other presenters are from the University of Southern California; the University of California, Santa Barbara; Princeton University; the University of California, Berkeley; the California Institute of Technology; Cornell University; the Georgia Institute of Technology; Pacific Northwest National Laboratories; and Lockheed Martin Advanced Technology Center.

Discussions will cover recent advancements that are making possible technology that until recently was only a fanciful vision, Dalton said.

For instance, components now can be made so small and power efficient that they can be arranged in flexible, foldable formats yet experience no optical loss or change in power requirements until the material is wrapped around a cylinder as tiny as 1.5 millimeters, a little bigger than a paper clip.

Such materials can be used to create space-based phased array radar systems for surveillance and telecommunications applications. Each face of a phased array typically has thousands of elements that work in a complex interdependence. A major advantage of the new material is that the entire radar system can be launched in a very compact form, then unfurled to its full form once it reaches orbit, Dalton said. Deployment costs can be greatly reduced because of low power requirements and the much-reduced weight of the material being sent into space. Techniques to mass-produce the tiny foldable components, which should reduce costs even further, are being developed with the California Institute of Technology, he said.

The newest materials have immediate applications in a number of other technologies as well, Dalton said. For instance, photonic elements can make it possible for a cellular telephone to transmit a large amount of data with very low power requirements, allowing a device that is very efficient to be made very compact. Similarly, the materials can bring greater efficiency and affordability to optical gyroscope systems, commonly used in aircraft navigation but also adaptable for other uses if costs are low enough.

In addition, photonics can be used instead of coaxial cable to manufacture a variety of components in satellites, reducing the weight of the components as much as 75 percent and so greatly cutting the overall weight of a satellite.

“The cost of getting something up into space is horrendous because of weight, so anything that reduces weight and power requirements is of immediate importance,” Dalton said.