Terahertz in the news: Hi-tech defence systems could be used to tackle security threats

Y.Mallikarjun http://www.thehindu.com/todays-paper/tp-national/tp-andhrapradesh/hitech-defence-systems-could-be-used-to-tackle-security-threats/article4467920.ece

A cutting-edge technology that is being developed for missile applications could also be employed for tackling homeland security threats, particularly in public places like malls and cinema halls, according to a defence scientist.

With explosives being used with impunity and devastating effect by terrorists in public places, terahertz technology is one such know-how which could be used with some modifications for screening of weapons, explosives, concealed objects and biohazards, said V.G. Borkar, Technology Director (Electromagnetics) Research Centre Imarat (RCI), a premier facility of the Defence Research and Development Organisation here. He said RCI has established a laboratory for using terahertz technology for defence applications.

Electromagnetic radiation

Terahertz electromagnetic radiation lies in the frequency spectrum gap between infrared and microwaves and referred to as THz waves. The regime ( 0.3-30 THz) has abundant possibilities in sensing, imaging and communications.

Suitable

He said the characteristics of THz waves make them suitable for the application in the domains of security and threat detection as explosives and related compounds (ERCs), drugs and other bio-molecules often have distinct intermolecular vibration modes in the THz spectral range. Researchers refer to these modes as “spectroscopic fingerprints”.

Dr. Borkar said, “These fingerprints due to vibration modes can allow identification of unknown substances.” Combining this detection capability with the ability of THz to penetrate through non-polar, dielectric materials such as paper, cardboard, plastic, wood, leather, textiles and ceramics provides a base for potentially useful tools for military and security applications.

Low photon energy

While the biggest advantage with this technology was that THz waves were not harmful to biological tissues due to their low photon energy, its shortcoming was that it could scan and capture the image of the entire body. He said that during its use, a person would have to pass through TH beam emitted and transmitted by antennae.

Although expensive, these systems could be developed in the country as security was of paramount importance, he added.