Every time someone sends a message or posts to TikTok, it takes thousands of optical and electrical connections to get that message through. But what if there was a way to manipulate the power of light to create technology that makes these connections more stable and more energy efficient?
That’s precisely what Tingyi Gu is working on in the University of Delaware’s Department of Electrical and Computer Engineering (ECE). But she’s trying to control the direction of light for more important reasons than sharing the latest social media trend.
“Now is the era of information,” said Gu. “This is specifically working with the power required to distribute that information, trying to reduce and improve that power efficiency.”
Gu, a highly decorated early-career researcher who joined UD faculty in 2016, was recently awarded with the Young Faculty Award by the Defense Advanced Research Projects Agency (DARPA) to further her research on nanophotonics and silicon photonics to improve digital communications. The award, granted to more than a dozen early career researchers annually, aims to “identify and engage rising stars” and grant exposure to Department of Defense needs.
In her work, she’s finding new, more efficient ways to engineer photonics, like the technology used in integrated circuits to convert signals from fiber to electric, like what happens each time signals go through a cell phone tower.
“The DARPA YFA is one of the top honors for early career faculty, where it is clear that Dr. Gu is recognized as one of the rising stars in optics and photonics,” said Jamie Phillips, chair of ECE and a previous DARPA Young Faculty Award honoree. “The award not only provides recognition and resources to engage in fundamental research, but also to develop ideas in context of national security needs. Tingyi's project explores a unique optical interaction called a chiral exceptional point to advance photonic systems on a chip for applications including computing, communications and sensors.”
To make improvements, Gu is using applied physics and the concept of chirality — which essentially determines the direction of an object — to manipulate the direction and speed of photons on a circuit. Instead of conventional systems that rely on fibers, Gu’s design would rely on photonic signals, specifically designed to enhance power efficiency. This work can improve technologies used in communications devices by the military and beyond.
''This project has given me a great opportunity to explore and learn nanophotonics and integrated photonics,” said Hwaseob Lee, the lead researcher on this project and who was recently awarded his doctorate on this topic. “Controlling the direction of light propagation on-chip is a new way for enhancing the device performance. I get to learn the end-to-end process of the design, numerical simulation, fabrication and testing of those specially designed chips.''
The award comes with about $500,000 in funding, which Gu said will support one postdoc and two graduate students working on device fabrications and new photonic designs, such as sensors used in optical communication systems like those used by aircraft, over the next two years.
During the two years of the project, Gu said she expects to develop a photonic design for computer chips that performs better and faster, while using less power. Modern-day data centers burn a significant amount of energy by running central processing units that rely on optical interconnections converting energy between wireless and fibers.
“Research is a bridge that connects theoretical knowledge and world applications. By understanding this connection, it is possible to create many fascinating tools to establish a better life,” said graduate student Lorry Chang. “UD offers a lot of cool equipment to design, manufacture and analyze optical devices, just like people who use advanced tools in science fiction movies. Finally, I am very grateful to Dr. Gu for giving me the opportunity to participate in this interesting integrated photonic device project."
Cutting power consumption by even 10% by incorporating Gu’s new technology could mean significant energy efficiency improvements by an order of magnitude, which could in turn address some climate change-related emissions. But in a relatively new field — these technologies have been around only since the 2000s — the cost of creating these kinds of photonic interconnect chips remains high.
“Scientists come up with fascinating ideas. It’s an engineer’s job to take those sprouted ideas into application to improve things in the real world,” Gu said. “It’s not guaranteed, but we know this is going to be significant in terms of power efficiency improvements.”
The DARPA honor marks the latest research grant awarded to Gu, who has based a lot of the photonic-focused work she does on how to improve its applications for the military and defense purposes. In 2017, she received an Early Career Faculty (ECF) Award from NASA and was selected for the Air Force Office of Scientific Research (AFOSR) Young Investigator Program. In 2020, she was selected for the Army Research Office Young Investigator Program.
Not only does this DARPA award highlight Gu’s unique work at such an early stage in her career, but it also provides an opportunity to expand educational opportunities in a specialized field that requires years of training.