Terahertz waves have frequencies higher than microwaves and lower than infrared and visible light. Where optical light is blocked by most materials, terahertz waves can pass straight through, similar to microwaves. If they were fashioned into lasers, terahertz waves might enable “T-ray vision,” with the ability to see through clothing, book covers, and other thin materials. Such technology could produce crisp, higher-resolution images than microwaves, and be far safer than X-rays.
The reason we don’t see T-ray machines in, for instance, airport security lines and medical imaging facilities is that producing terahertz radiation requires very large, bulky setups or devices, many operating at ultracold temperatures, that produce terahertz radiation at a single frequency — not very useful, given that a wide range of frequencies is required to penetrate various materials.
Now researchers from MIT, Harvard University, and the U.S. Army have built a compact device, the size of a...
learn more
