TOMSK, Jan 26 – RIA Tomsk, Karina Sapunova. Scientists of Tomsk State University suggested to use digital holograms and electromagnetic terahertz radiation to look for defects in crystals which are used for medical, military and other lasers, the press service of the university reported on Thursday.
It is explained that synthetic crystals are used in lasers of medical, defensive or other appointment. Scratches, roughnesses and other defects on their surface can be eliminated when processing a crystal. It is more difficult to find internal defects which lead to destruction of elements, as crystals are opaque, and it is impossible to liquidate them.
"Quality control of crystals is made by means of beam tests during which those samples which have defects collapse. However some defective crystals pass this test. <…> Researchers of TSU suggest to reveal internal defects of crystals by means of the nondestructive methods based on digital holography and use of terahertz radiation", – is said in the message.
It is noted that now residents of Tomsk within a state task develop more effective technique which will allow to combine these ways of research. The group of scientists of TSU Laboratory for Radiophysical and Optical Methods of Environmental Research received financing of 30 million rubles for the next three years."There are bases to assume that spectral properties of defective crystals have features in terahertz area. Therefore we expect that, investigating these properties of a crystal, we will able to draw conclusions on existence of defects in it", – the Head of Laboratory, the vice rector Victor Dyomin quoted in the message.
It is specified that so far scientists work a technique on ZnGeP2 crystals (compound of zinc, germanium and phosphorus) which is made by the partner of the project – the Tomsk LLC Laboratory of Optical Crystals. These crystals made in Tomsk and several foreign companies, on their basis unique lasers for noninvasive medicine, defensive and other purposes are created.