Researchers from the Institute of Materials Research and Engineering, a collaboration between A-STAR in Singapore and Imperial College in London, have come up with a new way to create electromagnetic Terahertz waves (T-rays). The new technology can make T-rays into a stronger, more directional beam than current methods. This could allow T-ray devices to become much smaller and cheaper in the future. The results of their study were published in Nature Photonics.
Current T-ray imaging devices, like airport full-body scanners, are very large and expensive, and consume large amounts of energy as well. A portable T-ray scanning device could in the future make a medical tricorder possible, as T-rays can detect certain biological processes, such as changes in blood flow. As every molecule has a unique signature in the THz range, T-rays can sense for specific molecules as well.
The innovation of this new technology lies in a new nano-antenna integrated into a semiconductor chip that can create much stronger THz fields and lead to higher resolution imaging.
Some details from the announcement:
“…the researchers demonstrated that it is possible to produce a strong beam of T-rays by shining light of differing wavelengths on a pair of electrodes – two pointed strips of metal separated by a 100 nanometre gap on top of a semiconductor wafer. The structure of the tip-to-tip nano-sized gap electrode greatly enhances the THz field and acts like a nano-antenna to amplify the wave generated. In this method, THz waves are produced by an interaction between the electromagnetic waves of the light pulses and a powerful current passing between the semiconductor electrodes. The scientists are able to tune the wavelength of the T-rays to create a beam that is useable in the scanning technology….”
Article in Nature Photonics: Greatly enhanced continuous-wave terahertz emission by nano-electrodes in a photoconductive photomixer