User:Cymru.lass/terahertz

Terahertz tomography is a class of tomography where sectional imaging is done by terahertz radiation, a band of frequencies between those of infrared and microwaves. The waves used in terahertz tomography range in wavelength from 0.3 to 10 THz (1 THz = 1012 Hz). Because terahertz radiation can "see" what visible light and IR can not see, unique information can be obtained by terahertz tomography. This is in a sense similar to X-ray imaging techniques, although terahertz radiation is non-ionizing, and thus less harmful to humans. Terahertz radiation can be used to create a three-dimensional image using techniques similar to that of traditional X-ray computed tomography. Due to the lower penetration power of terahertz radiation, terahertz tomography can be used to produce images of materials such as plastic more easily than X-rays.

Terahertz tomography was first described by researchers in Optics Letters 2002, where it was called T-ray computed tomography. The researchers used a sapphire laser to generate pulses of terahertz radiation, taking over an hour to generate an image size of 10,000 pixels (0.01 megapixels). More recently-developed techniques image subjects much faster, on the order of minutes as opposed to hours. Modern techniques allow for a resolution of 0.4 mm, and enable easier differentiation between materials than traditional computed tomography.