Terahertz frequencies are said by the team to be an underused part of the electromagnetic spectrum and could be useful for biological sensing and medical imaging, as well as chemical identification and material characterisation.
One component which researchers are aiming to make more efficient is a terahertz detector. By operating across a broader bandwidth, the nanoscale antenna array developed by the UCLA team can extract more information about a material’s characteristics. For example, its better signal-to-noise ratio means it can find faint target signals, meaning it can be tuned to detect certain chemicals in miniscule amounts.
“Up close, it looks like a row of small grates,” said researcher Nezih Tolga Yardimci, pictured. “We specifically designed the dimensions of the nanoantenna elements and their spacing such that an incoming terahertz beam is focused into nanoscale dimensions, where it interacts with a stream of optical pump photons to produce an electrical signal proportional to the terahertz beam intensity.”
Associate professor Mona Jarrahi added: “The broad operation bandwidth and high sensitivity of this new type of terahertz detector extends the scope and potential uses of terahertz waves for many imaging and sensing applications.”