China North Industries Group Corporation has tested a new technology to detect stealth aircraft last week. The new device generates high-frequency terahertz radiation (T-ray) that penetrates composite materials to reach underlying metallic layers. The technology is used in industrial plants to spot product defects and to find a concealed weapon, however currently used terahertz generators have low power output. 

The rays fall on the spectrum between microwaves and light and cannot be produced by conventional radio or optical devices. With a more powerful version under development to put on an early warning aircraft or satellite to identify and track military aircraft, military applications for T-ray technology will be a game changer.