New material sets stage for ultra-fast optical computing

Georgia Tech scientists are using specially designed organic dyes that can process and redirect light without the need to be converted to electricity first.

Traditional computing equipment, such as network routers, can receive light signals off fiber optic cables, but all data is internally processed using traditional electronic chips.

Using all light, however, an optical-router could lead to transmission speeds as high as 2000 gigabits per second, five times faster than current technology.

This work provides proof that at least from a molecular point of view, we can identify and produce materials that have the right properties for all-optical processing, said Seth Marder, a professor in the Georgia Tech School of Chemistry.

This opens the door for looking at this issue in an entirely different way.

The organic dye materials developed by the Georgia Tech team reacts to light by changing its refractive index, effectively changing the direction of the light.

Collaborators in Georgia Tech's Center for Organic Photonics and Electronics (COPE) have been working on the molecules for several years, refining their properties so it redirects the light without interfering with the information it carries.

For this class of molecules, we can with a high-degree of reliability predict where the molecules will have both large optical nonlinearities and low two-photon absorption, said Marder.

At the  present time, the solution only works in liquid form. For their materials to have practical value, the researchers will have to incorporate them in a solid phase, as well as address other challenges.

We have to figure out how to pack them together so they have a high density and useful physical forms that would be stable under operation, said co-author Joseph Perry, also a professor in the Georgia Tech School of Chemistry and Biochemistry.

Perry and Marder emphasize that many years of research remain ahead before their new materials will be practical. But they believe the approach they've developed charts a path toward all-optical systems.

The research was funded by the National Science Foundation (NSF), the Defense Advanced Research Projects Agency (DARPA) and the Office of Naval Research (ONR).