Mona Jarrahi: Development of terahertz devices opens doors for numerous applications

Despite a wide range of potential applications, the terahertz field is not as well-known as the optical or microwave fields, explained University of California, Los Angeles (UCLA), associate professor Mona Jarrahi during a recent tour of her lab.

As a result, she said, terahertz researchers find they have to do more explaining about the technology's potential when discussing how it might contribute to solutions to other researchers' problems.

The unique spectral signatures of many molecules when exposed to terahertz waves allow for identification of many chemicals and materials, so the technology lends itself to many potential applications.

The SPIE Senior Member has been working in the terahertz domain for nearly a decade and knows from firsthand experience why the field has struggled to find wide acceptance:

"The radiation power of sources is not very high, the detection sensitivity of detectors is not very high, and the available devices that show good performance often don't offer compact, low-cost platforms," Jarrahi said

Dr. Jarrahi and her team at UCLA began working on creating terahertz sources and detectors that could help bridge these gaps.

Based on accolades, their efforts seem to be working. Jarrahi has earned numerous awards for her research, including a Presidential Early Career Award for Scientists and Engineers in 2014. In 2016 she was one of five inaugural Moore Inventor Fellows named by the Gordon and Betty Moore Foundation.

"We are trying to really pinpoint major challenges that we have on the device side." Jarrahi said. At the same time, "whenever we come up with better device performance, that motivates us to look at potential applications that were stopped up to this point because of lack of those functionalities. So we are also looking at a lot of applications."

Focusing on just one application would be a challenge for the lab, which collaborates on work ranging from cancer detection to planetary gas sensing and other diverse areas.

"We plan to continue expanding on our developments in developing better terahertz sources and detectors," Jarrahi said. "A technique that we use employing metallic nanostructures to enhance light-matter interaction to offer better efficiencies has a lot of potential. So far we have had technical challenges in terms of fabricating these kinds of structures, so there is a lot of room to improve functionalities of these devices.

"Going specifically to the terahertz domain was mainly motivated because of the challenges," Jarrahi continued. "I was interested in challenging projects, hard problems. This is an excellent field with a lot of unsolved problems and challenges."