New Engineered Material for All-Optical Communications

Researchers at Purdue University have created a new “plasmonic” material that could be used to make devices for optical communication that is ten times faster than conventional technology. The new material can change how much light is reflected while requiring less power than other “all-optical” semiconductors—devices that don’t use any electrical signals, but instead use optical pulses for the data stream and control signals. “Low power is important because if you want to operate very fast – and we show the potential for up to a terahertz or more – then you need low energy dissipation,” said researcher Nathaniel Kinsey. “Otherwise, your material would heat up and melt when you start pushing it really fast.”

The researchers made the material from aluminum-doped zinc oxide (AZO), and they can engineer the film to modulate the amount of reflection depending on the intended application. The AZO sheets could one day be used for high-speed optical communications, because they work in the near-infrared range of the spectrum and is compatible with the complementary metal–oxide–semiconductor (CMOS) manufacturing process used to construct integrated circuits.

“For industrial applications you can’t go to really high fabrication temperatures because that damages underlying material on the chip or device,” Kinsey said. “An interesting thing about these materials is that by changing factors like the processing temperature you can drastically change the properties of the films. They can be metallic or they can be very much dielectric.”