Terahertz Emitter Addresses Obstacles to Use for Noninvasive Industrial Inspections

High performance and low-power driven terahertz (THz) emitters could possibly address critical challenges facing industrial applications of this new technology.

Researchers from the National University of Singapore (NUS) have made a major technological breakthrough in terahertz technology; they have developed THz emitters that can be mass-produced at low cost to generate THz waves. The emitters can also function on flexible surfaces without compromising performance.

Low-cost THz radiation sources which can be powered by a low-power laser. The novel invention is a major technological breakthrough and addresses a critical challenge for industrial application of THz technology. Courtesy of NUS.

The research team led by associate professor Yang Hyunsoo and Wu Yang from the Department of Electrical and Computer Engineering at the NUS Faculty of Engineering and NUS Nanoscience and Nanotechnology Institute collaborated with researchers from the Institute of Materials Research and Engineering under Singapore's Agency for Science, Technology and Research, as well as Tongji University in China.

“Our invention is a big step forward in THz technology and we believe that this will greatly accelerate its application in various fields. For instance, in the area of safety surveillance, our invention can contribute toward miniaturization of bulky THz systems to be used in the detection of dangerous chemicals and explosives for protection against hostile threats,” said Yang. “Fabricating our device on a flexible surface also opens up many exciting possibilities for it to be incorporated into wearable devices.”

Being nonionizing as well as nondestructive, THz waves can pass through nonconducting materials, making them ideal for applications in industrial settings. However, current THz sources are large, multi-component systems that are heavy and expensive. Such systems are also hard to transport, operate and maintain. The flexible, low-cost THz radiation sources developed by the research team potentially pave the way for greater adoption of THz technology and contribute toward the commercialization of a wide range of THz applications.

Developed using metallic thin film heterostructures that are 12-nm thick, the novel radiation sources emit broadband THz waves with a higher power output than a standard 500-mm thick rigid electro-optical crystal emitter. The novel emitters can be powered by a low-power laser, lowering the operating cost substantially.

“Our team's THz emitters have displayed better performance compared to existing devices in many aspects. At the same time, we have also developed a fabrication process to produce these novel THz emitters in large quantities at a low cost," said Wu.

The researchers are also looking into enhancing THz emission for specific wavelengths, which will be beneficial for a wide range of THz-related studies and applications. The research team has filed a patent for the invention and hopes to work with industry partners to further explore various applications of this novel technology.

The research has been published in the journal Advanced Materials (doi: 10.1002/adma.201603031).