T-ray

This terahertz "T-ray" technology combines imaging, real-time acquisition of terahertz waveforms and advanced signal processing techniques to obtain far-infrared images of objects and materials. In many cases, T-Ray^([sic]) images can also distinguish chemical compositions of the object. These features of T-ray imaging have generated interest in commercial applications in diverse areas as moisture analysis, quality control of plastic parts, packaging inspection, and trace gas analysis and monitoring.

Military officials believe T-rays could pinpoint the chemical constituents of anti-personnel mines, and spot terrorists carrying explosives into airports. Doctors are interested in T-rays because they are less damaging to living tissue than X-rays. Terahertz radiation is slightly more energetic than that of microwave ovens, and slightly less energetic than the infra-red light emitted by TV remote controls. […] Scientists are designing devices that can exploit the power of T-ray detection.

A useful property of T-rays is that dry, nonpolar, and nonmetallic substances such as paper, cardboard, and plastics are transparent in these^([sic – meaning this]) frequency band. As this includes many packaging materials, the implication is that T-rays have potential applications in quality control and security. The content of packages can be noninvasively probed and T-rays can produce a molecular fingerprint to identify the contents.

Researchers in Japan have smashed the record for wireless data transmission in the terahertz band, an uncharted part of the electro-magnetic spectrum. The data rate is 20 times higher than the best commonly used wi-fi standard. […] The research, published in Electronics Letters, adds to the idea that this "T-ray" band could offer huge swathes of bandwidth for data transmission. The band lies between the microwave and far-infrared regions of the spectrum, and is currently completely unregulated by telecommunications agencies. […] Until recently, the technology required both to generate and detect these "T-rays" has been too bulky, costly or power-hungry to offer a plausible alternative to existing devices tucked within smartphones or wi-fi routers. That looks set to change; in November electronic component firm ROHM demonstrated a 1.5Gb/s (1.5 billion bits per second) transfer rate at a frequency of 300GHz.