Terahertz rays are electromagnetic pulses which has a frequency in the Terahertz range. Hence called as T-rays. One Terahertz (THz) has a frequency of 10{+1}{+2} (one thousand billion hertz), a frequency range which places T-rays between microwaves and infrared radiation in the electromagnetic family.
There are two main methods of producing T-rays, _ the Free Electron Laser and down conversion of pulses from visible lasers. Although worldwide study of T-rays is in its infancy, it has the potential for many applications not only to complement X-rays but also in certain circumstances, replace them.For ex, T-rays can detect different substances with great sensitivity (in ways X-rays, MRI and Infrared Lasers cannot), an ability that has strong significance for medical, agricultural, food and wine industries. They also are not cancerous, unlike X-rays. Plastics are transparent to T-rays, which gives many security applications. They are non-ionising, which means they do not cause cell damage like X-rays or even UV light.
Source : The Hindu
