Physicists explore a safe alternative to x-ray security scanners

Physicists explore a safe alternative to x-ray security scanners. A team of physicists at the University of Sussex are developing the science to create a safe and efficient 'paint' that can reveal, with terahertz (THz) radiation, the contents of luggage or objects hidden in clothing. THz radiation could replace the use of harmful x-rays and ultraviolet light in security scanners. It cannot pass through water, which is why it does not pose a health risk to living tissue, but it can penetrate fabrics, plastics and wood to give internal images similar to an x-ray. Lying between microwaves and infrared in the electromagnetic spectrum it, as with all other radiation, travels at the speed of light - but has a lower frequency than x-rays and ultraviolet. Although its existence has been known for decades, the technology to harness it and use it in a meaningful capacity has not been readily available. However, a team at the Emergent Photonics Laboratory at the University of Sussex have come up with a simple demonstration that shows how the surfaces of objects up to any size can potentially be made into bright terahertz emitters.