Scientists of Far Eastern Federal University (FEFU) and the Far Eastern Branch of the Russian Academy of Sciences (FEB RAS) have discovered a new characteristics of vortex laser pulses to create metallic nanoneedles. This effect can be used to increase the amount of information in laser recording and to increase the data transfer speed in information systems. The results of the research have been published in a series of articles in reputable scientific journals Optics Express, Applied Physics Letters, ACS Applied Materials & Interfaces.
According to Aleksandr Kuchmizhak, Research Associate, Department of Theoretical and Nuclear Physics, FEFU School of Natural Sciences, the research team carried out a series of experiments on microscopic printing with special laser pulses on gold and silver films. As a result, spiral-conical structures—nanoneedles of less than 1 micron in size—appeared on their surface, which are twisted in the direction of rotation of the irradiating optical vortex.
“The optical vortex is one of the most interesting types of laser beams. Its feature is that the wavefront propagates in space like a drill in the course of propagation. When exposed to a metal film, it melts it at the impulse point and draws out of it a microscopic needle twisted in the direction of rotation of the vortex. We dedicated a special research for the study of the physical properties of this process,” said Aleksandr Kuchmizhak.
The young scientist explained that the study of vortex beams is a popular trend in modern physics. Their properties can be used in different areas: for the development of laser printing technologies, laser surface treatment and information transfer in computer systems. Spiral structures are also interesting from a fundamental point of view, since helicity is inherent in most of the DNA molecules of a human being. Such a wide range of possible applications of such structures makes the search of simple methods of their creation particularly interesting for researchers.
The scientists of FEFU and FEB RAS Yuri Kulchin, Oleg Vitrik, Sergei Syubaev, Alexey Zhizhchenko, Eugene Pustovalov, as well as scientists from Moscow Lebedev Physical Institute, St. Petersburg ITMO University, and Samara State University took part in the research.
The study of laser radiation and laser recording is a promising area for the research of the FEFU School of Natural Sciences. Dozens of works by university staff in international scientific journals are devoted to this issue. One of the latest publications was made in collaboration with scientists from Australia and France, and the illustration from this article graced the cover of the May issue of the Applied Physics Letters.