“Our invention is a step forward in THz technology and we believe it will accelerate its application in various fields,” explained NUS associate professor Yang Hyunsoo. “For instance, our invention can contribute towards the miniaturisation of bulky THz systems to detect dangerous chemicals and explosives.
“Affordable and high performance THz screening devices could also improve disease diagnosis and benefit patients. Furthermore, fabricating our device on a flexible surface also opens up possibilities for it to be incorporated into wearable devices.”
Other potential applications include compact devices for fast and accurate identification of defects in chips; advanced, non-invasive imaging techniques that could detect tiny tumours; and wearable sensors that can detect chemical agents.
“Traditional methods of generating THz waves, such as through the excitation of electro-optical crystals or photoconductive antennas, often require expensive and bulky high power lasers or expensive and sophisticated device fabrication processes,” said Dr Wu Yang from the NUS.
Developed using 12nm thick metallic heterostructures, a large wafer-scale film can be deposited and diced to create a large quantity of ready-to-use devices.
The radiation sources are said to emit broadband THz waves with a higher power output than a standard 500µm electro-optical crystal emitter. In addition, the novel emitters can be powered by a low power laser.
Moving forward, the team plans to build a spectroscopy system based on its THz emitters. The researchers are also looking into enhancing THz emission for specific wavelengths.