The Way to Increase the Efficiency of Laser Systems Is Found

Scientists of Samara National Research University (Samara University) and their colleagues from other Russian scientific organizations created samples of diamond optical elements, which make it possible to focus the radiation of powerful technological CO2 lasers for processing materials in industry with high efficiency. The results are published in Diamond and Related Materials Journal.

For 20 years the employees of Samara University, the Image Processing Systems Institute of the Russian Academy of Sciences, a branch of the Federal Research Center for Crystallography and Photonics of the Russian Academy of Sciences (Samara), and the General Physics Institute of the Russian Academy of Sciences (Moscow) have conducted joint research in the field of creating diamond diffraction optics of the infrared range. In Samara, in particular, numerical methods and software were developed for calculating and modeling of diffractive optical elements. The methods for the synthesis of artificial polycrystalline diamond films and technologies for their microstructuring were developing in the scientific group of Academician of the RAS Vitaly Konov at the General Physics Institute of the RAS.

In the late 1990s, the first samples of optical elements on polycrystalline diamond films, designed to focus the radiation of powerful infrared lasers –  lenses and focusers, were created. According to the researchers, the new optical material has unique physical properties that are very close to the properties of natural diamonds. However, the technology that is still being used for manufacturing optical elements from this material limits the energy efficiency of the manufactured elements.

"At the General Physics Institute of the RAS there has been recently developed a new technology of forming a microrelief on a diamond surface with an almost continuous profile, which made it possible to create samples of diamond elements with an efficiency close to 100%", –  Head of Samara University Nanoengineering Department Vladimir Pavelyev told RIA Novosti.

 Since diamond has good thermal conductivity, new optical elements will make it possible to control the radiation from powerful technological CO2 lasers, which are widely used in production for metal processing (cutting, hardening, spraying) and other materials.

"Using this new approach it is possible to create elements that focus laser radiation in predetermined areas with high efficiency. Taking into account the widespread technological installations based on such lasers, we can talk about the high commercial potential of the work", – the scientist said. He also noted that the researchers learnt to focus the radiation of a powerful technological laser not only on a point, like an ordinary lens, but on any two-dimensional area (square, circle) with an efficiency close to 100%.

"Such problems arise when it is necessary to conduct laser surface treatment of a material (for example, metal hardening). We have the opportunity to simultaneously form a uniform distribution of the intensity of laser radiation in the treated area instead of point-by-point scanning", – said Pavelyev.

In addition, according to him, the developed technology will make it possible to carry out efficient division of the initial beam of the technological laser into a given number of beams with a given energy distribution between the beams and to focus radiation with a large depth of focus, which is important when a complex three-dimensional surface is laser processed.

Using the new technology, specialists have already created several samples of optical elements. In the future, they intend to develop and explore elements with more complex functionality. To reduce reflection of  diamond elements, it is supposed to use an antireflection coating for diamond optics, previously developed and studied in the framework of the joint work of JSC Ekran Scientific Research Institute (Samara), Samara University and the General Physics Institute of the RAS. 

Source: ria.ru