Systems with a terahertz radiation

Chronicle

2019: The device allowing to change intensity of terahertz radiation using normal water

On May 26, 2019 it became known that in Russia develop the device allowing to change intensity of terahertz radiation using normal water. This type of radiation — an alternative to X-ray hazardous to health. It is supposed that this device will be able to be used including to pictures of teeth and search of hypodermic new growths.

At dental care and carrying out maxillary transactions apply X-ray to make the picture. Modern technologies minimize harm of X-ray, but it is still impossible to make it absolutely safe. Scientists consider an alternative the terahertz radiation which at certain parameters does not do harm to living tissues.

Apply difficult and expensive technologies, including metamaterials to creation of the terahertz systems which allow to manage intensity of this type of radiation. The group of physicists from St. Petersburg National Research University of Information Technologies, Optics Mechanics studied a possibility of use of water for management of properties of terahertz radiation. Earlier none of researchers used this substance because water extremely effectively absorbs this type of radiation. However it turned out that if to use very thin sheet of water, it can be managed.

Maria Zhukova told:

In our experiment radiation passed through a stream of a distilled water only one tenth millimeters thick. It is known that at high radiation intensity Wednesday shows nonlinear properties — special effects which can be recorded using special techniques. These nonlinearity can be connected with change of index of refraction — the value equal to the light speed relation in a vacuum to speed in this environment. We showed that, having passed through a thin sheet of water, terahertz radiation strongly changes the properties, and not just is absorbed.

Researchers drew a conclusion that water and other simple substances in the long term can be used for management of radiation parameters. Such knowledge will allow to bring closer implementation of more perfect technologies.

Nazar Nikolaev noted:

Terahertz radiation for use in medicine, certainly, has a potential. But, most likely, it will occupy in the future a certain niche and will begin to be used for the solution of highly specialized tasks. The matter is that terahertz radiation is strongly absorbed by water and its solutions, and the person to a large extent consists of water. And it complicates penetration of waves through soft fabrics. Nazar Nikolaev, research associate of Institute of automatic equipment and electrometry of the Siberian Branch of the Russian Academy of Science

But in enamel of teeth there is practically no water, and the sections affected with caries support her much more. Therefore using terahertz radiation it is possible to receive easily a picture of damages of teeth where areas with caries will be dark against the background of healthy light enamel.

Water not only absorbs, but also reflects a part of incident radiation, and on this effect it is possible to construct, for example, hypodermic visualization of concentration of water. For example, it will turn out to see skin sections under which intensively flows blood. It can be result of an injury, and can be caused by an oncological new growth.

However, as for security of radiation for the person, so far for terahertz range sanitary standards are not approved. Scientific groups conduct independent researches on interaction it with biological objects, but results are not always unambiguous. However it is considered to be that terahertz radiation with small energy is safe as comparable level of a wave are radiated even by a human body.

Despite some advantages of terahertz radiation while completely it is impossible to refuse application of X-ray, the engineer of laboratory of femtosekundny optics and femtotekhnologiya of ITMO Maxim Melnik believes. According to him, the terahertz radiation which is not damaging them gets into the tissues of a human body containing water all on the tenth shares of millimeter. If to make radiation more powerful, it will destroy living tissues. But when scanning not biological objects in which there is practically no water it is possible to use quietly more powerful terahertz radiation which, for example, can illuminate a suitcase through.

Further physics from ITMO is also going to expand the range of the used materials for management of terahertz radiation — including for creation of sources, receivers and transformers.

Physicists from ITMO notes high potential of terahertz radiation in the most different areas, and not just in medicine. For example, it can define existence of antibiotics and impurity in products, to be applied to customs examination of things. Using terahertz radiation it is also possible to check thickness of each layer of a tablet by stream production of drugs — important that the cover was dissolved not earlier and not later, than it is necessary^[1].

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