TNS3DI What is Terahertz? Why Important? Terahertz radiation – also known as submillimeter radiation, terahertz waves, tremendously high frequency (THF), T-rays, T-waves, T-light, T-lux or THz – consists of electromagnetic waves within the ITU -designated band of frequencies from 0.1 THz to 30 THz. One THz is 10 12 Hz or 1000 GHz. Wavelengths of radiation in the terahertz band correspondingly range from 3 mm down to 0.01 mm (or 10 μm ). Because terahertz radiation (T-ray) has a wavelength of millimeter and proceeds into shorter wavelengths, it is sometimes known as the submillimeter band, and its radiation as submillimeter waves, especially in astronomy . [1] T-ray can penetrate thin layers of materials but is blocked by thicker objects. T -ray beams transmitted through materials can be used for material characterizatio...