Newswise — Conventional computer processors have pretty much maxed out their “clock speeds” — a measurement of how fast they can toggle on and off — due to limitations of electronic switching. Scientists looking to make improvements in computer processors have become intrigued by the potential of all-optical switching, which uses light instead of electricity to control how data is processed and stored on a chip.
Researchers at the U.S. Department of Energy’s (DOE) Argonne National Laboratory and Purdue University have recently created a new kind of all-optical switch that could realize this potential. “Previous iterations of optical switches had fixed switching times that were ‘baked in’ to the device upon its fabrication,” said Argonne’s Soham Saha, one of the laboratory’s Maria Goeppert Mayer postdoctoral fellows who is working in the Argonne Center for Nanoscale Materials, a DOE Office of Science user facility..
Saha and his colleagues have made an optical switch out of two different materials, each with a different switching time. One material, aluminum-doped zinc oxide, has a switching time in the picosecond range, while the other material, plasmonic titanium nitride, has a switching time more than a hundred times slower, in the nanosecond range.
“When you use optical components instead of electronic circuits, there are no resistive-capacitive delays, which means that in theory you could operate these chips a thousand times faster than conventional computer chips,” Saha said.
The difference in switching times between the two metal components means that the switch can be more flexible and used to both transmit data quickly while also storing it effectively, according to Saha. “The bimetallic nature of the switch means that it can be used for multiple purposes depending on the wavelength of the light that you use,” he said. “When you want slower applications, like memory storage, you switch with one material; for faster applications, you switch with the other one. This capability is new.”
In the experimental configuration, the materials of the switch function as light absorbers or reflectors, depending on the wavelength of operation. When they are switched on by a light beam, they switch state.
Controlling the speed of all-optical switches is crucial for optimizing their performance in various applications. These findings offer promise for the development of highly adaptable and efficient switches in fields like enhanced fiber optic communication, optical computing and ultrafast science.
The ability to adjust switch speeds also brings us closer to bridging the gap between optical and electronic communications, enabling faster and more efficient data transmission.
This research provides valuable insights into the fundamental understanding of all-optical switches and paves the way for the design of advanced devices for computing and telecommunications.
A paper based on the research, “Engineering the temporal dynamics of all-optical switching with fast and slow materials,” appeared in September 21 online edition of Nature Communications. In addition to Saha, Argonne authors include Benjamin Diroll and Richard Schaller. Also contributing from Purdue University are Mustafa Goksu Ozlu, Sarah N. Chowdhury, Samuel Peana, Zhaxylyk Kudyshev, Zubin Jacob, Vladimir M. Shalaev, Alexander V. Kildishev and Alexandra Boltasseva.
The research was funded by the DOE’s Office of Basic Energy Sciences, as well as the Office of Naval Research and the Air Force Office of Scientific Research.
About Argonne’s Center for Nanoscale Materials
The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE’s Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.
Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation’s first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America’s scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy’s Office of Science.
The U.S. Department of Energy’s Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.
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