Terahertz technologies are being developed to create imaging devices that can see through objects.
Back in 1998, Sony accidentally sold about 700,000 camcorders with lenses that use IR light to achieve a certain x-ray capability that can "see" through dark, thin clothing. While a similar feature never surfaced on the video camera and still camera market again, researchers believe they can go a step further and build imaging devices that are leverage terahertz electromagnetic waves to construct images.
Source
Linear Mode
