Optical microscope picture

Optical microscope picture showing electric field distribution. © Agency for Science, Technology and Research

Scientists in Singapore and the UK have developed a new way to create terahertz radiation (or T-rays), the technology behind full-body security scanners. They say their new, stronger and more efficient T-rays could be used to make better medical scanners and may lead to innovations similar to the “tricorder” scanner used in Star Trek.

T-rays are waves in the far infrared part of the electromagnetic spectrum that have wavelengths hundreds of times longer than visible light. Such waves are already in use in airport security scanners and prototype medical scanning devices. T-rays can sense molecules such as those present in cancerous tumours and DNA, because every molecule has its unique signature in the terahertz range.

However, T-rays need to be created at very low temperatures, which requires a vast amount of energy. Consequently, existing T-ray imaging devices have low output power and are very expensive.

Now, an international team of researchers have found a way to produce T-rays at room temperature, and have created a much stronger directional beam than was previously thought possible. This breakthrough will allow future T-ray systems to be smaller, more portable, easier to operate, and much cheaper.

The new technology could provide part of the functionality of a Star Trek-like medical “tricorder” – a portable sensing, computing and data communications device – since the waves are capable of detecting biological phenomena such as increased blood flow around tumorous growths.

The team creates a strong beam of T-rays by shining light of differing wavelengths on a pair of special electrodes – two pointed strips of metal separated by a 100 nanometre gap. Electromagnetic waves are produced by an interaction between the pulses of light and a powerful current passing between the electrodes. The unique tip-to-tip electrode structure greatly enhances the terahertz field and amplifies the waves generated.

Lead author Dr Jing Hua Teng from the A*STAR Institute of Materials Research and Engineering (IMRE) in Singapore explains, “The secret behind the innovation lies in the new nano-antenna that we had developed and integrated into the semiconductor chip. These created much stronger terahertz fields that generate a power output that is 100 times higher than conventional antenna structures.”

Research co-author Stefan Maier, said: “T-rays promise to revolutionise medical scanning to make it faster and more convenient.”

For further information contact:

Dr Teng Jing Hua
Institute of Materials Research and Engineering
Agency for Science, Technology and Research
(A*STAR), Singapore
Email: jh-teng@imre.a-star.edu.sg