ISSN 0021-3454 (print version)
ISSN 2500-0381 (online version)
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Summaries of the issue

PROMISING LASER TECHNOLOGIES

HIGH POWER LASER PROPULSION Rezunkov Yuri A.
7
Development of new transportation systems for satellite launching and space vehicle missions based on the use of high-power lasers is analyzed. Achievement of high energy efficiency of thrust production as well as minimization of propellant consumption are considered as principal concerns of high-power laser propulsion development. The consideration is based on experimental study of interaction of pulsed laser radiation with various propellants.

LASER-ASSISTED PROCESSING

AN EXPERT SYSTEM FOR LASER MICROPROCESSING MODE OPTIMIZATION Eugeny P. Markin, Alexander K. Lozovoy, Smirnov N Sergey, Yuri G. Yakhontov
13
An expert system for decision making in laser microprocessing mode optimization is proposed. Current processing results are evaluated with the use of optoelectronic sensors data.
AN EXPERT SYSTEM FOR LASER MICROPROCESSING MODE OPTIMIZATION Viktor P. Bessmeltsev, Evgeny D. Bulushev, Nikolay V. Goloshevsky
17
An expert system for decision making in laser microprocessing mode optimization is proposed. Current processing results are evaluated with the use of optoelectronic sensors data.
PULSED LASER ASSISTED FORMING OF THIN SHEET METAL Andrey D. Kochetov, Petrov Andrei Anatolievich
22
Process of laser bending of alloyed steel sheets of 0,3 to 1,1 mm thickness is analyzed. Pulse Nd:YAG laser (average rower of 200 W, pulse duration of 0,1—10 ms) is employed and programmable 6-axis robot Motoman SSF-2000 is used for formation of illuminated area of irregular-shaped details. Experimental results show that bend angle may be varied through a wide range depending on the laser-processing mode.

LASER-ASSISTED MODIFICATION AND STRUCTURING OF SURFACE

LASER-INDUCED SILICON SURFACE STRUCTURING FOR SOLAR CELL APPLICATION Eugeny V. Khaydukov, Olga D. Khramova, Vasilina V. Rocheva, Dmitry A. Zuev, Oleg A. Novodvorsky, Andrey A. Lotin, Liubov S. Parshina, Alexander Yu. Poroykov, Mikhail A. Timofeev, Gennady G. Untila
26
Creation of laser-induced morphology features of the c-Si and mc-Si with the use of 532 nm Nd: YAG laser nanosecond pulses in vacuum and СО2 atmosphere is investigated. Specimens of 20×20 mm laser-textured mc-Si wafers with typical pillar array structures of aspect ratio (depth to width) greater than or equal to 3 and weighted effective reflectance below 3 % are obtained.
32
Laser-induced modification of photosensitive glass-ceramic material under YAG:Nd second harmonic picosecond pulses is observed. A method for such modification based on laser processing and subsequent heat treatment is developed. Comparison with infrared femtosecond modification is performed.
37
Redistribution of elements in joints of steel plates after laser welding is studied. Laser emission spectral analysis (LIBS) reveals the following trends of horizontal and vertical migration of alloying elements: Mn towards the front side of the weld joint, Al towards the back side with concentration at the central line. Dependences of the redistribution on welding type and parameters are studied.
FORMATION OF PERIODIC STRUCTURES AT THE SURFACE OF SILICATE UNDER RESONANT ACTION OF CO2 LASER IRRADIATION Anel F. Mukhamedgalieva, Anatoly M. Bondar, Irina V. Velesevich, Зильбершмидт М. Г., Vladimir B. Laptev, Igor M. Shvedov
42
Periodical structures formed at the surface of a natural silicate (quartz, fused silica, nepheline, and rodonite) under the action of pulsed CO2 laser radiation (pulse energy of 1 J, pulse duration of 70 ns) is studied. High resolution optical microscope is used for observation of laser spot characteristics and IR reflection spectroscopy is applied to investigate the surface features before and after exposure to CO2 laser irradiation. The period of the structures obtained is found to be of about 7,3 μm for crystal quartz and about 8 μm for fused silica at laser frequency of 975 cm–1.
COLOR IMAGE FORMATION AT LASER OXIDATION OF METALS Горный С. Г., Odintsova Galina V, Mikhail I. Patrov, Konstantin V. Yudin
47
Experimental results and theoretical analysis of color image formation at laser oxidation of stainless steel surface are presented. A method is proposed for choice of laser radiation parameters to ensure a desirable color of the film.

LASER TECHNOLOGIES FOR CLEANING AND ARTWORKS RESTORATION

LASER-ASSISTED GRAFFITI PAINTS REMOVAL Boris Novikov, Yuri V. Chikhalev, Elena Shakhno
53
It's hard to imagine a view of a modern city without some drawings and inscriptions, usually called “graffiti”. Traditional cleaning methods do not meet modern requirements. Investigation of possibilities of laserassisted paints removal is performed. The optimal conditions for various paints removing from different surfaces are established.
LASER CLEANING OF SCREENED PRINTING ROLLS Andrey A. Samokhvalov, Michail Yarchuk
56
Technology of dry laser cleaning of screened printing rolls of various types of paint is developed. Safety of the method of pollution removal is confirmed experimentally for various microreliefs of printing roll ceramic coat.
LASER-ASSISTED RAIL CLEANING TO ENHANCE THE FRICTION COEFFICIENT Petrov Andrei Anatolievich, Alexander S. Maznev, Andrey M. Evstafiev, Anna A. Kalinina
61
Application of fiber laser for cleaning of various types of pollution from railway is studied both theoretically and experimentally with q-switched pulsed Ytterbium fiber laser (average power 50 W, pulse width 100 ns). The friction coefficient is shown to increase for 30 % as a result of laser-assisted rail cleaning.
ON FEASIBILITY OF SPECTROSCOPIC CONTROL OVER LASER CLEANING PROCESS Волков С. А., Timofey Mutin, Смирнов В. Н.
65
Spectroscopic analysis of laser plume is used for checking quality of laser cleaning of surfaces. Results of experimental study of the approach are presented. A model method is proposed for estimation of deactivation coefficient from data obtained in experiments carried out with nonradioactive isotopes of most persistent radioactive pollutants.
69
Feasibilities of laser technologies in restoration of pieces of art made of precious metals are demonstrated by the example of restoration of the M. I. Likhacheva treasure.

OPTICAL CONTROL METHODS

REMOTE TESTING OF MICROLENS WITH THE USE OF LOW-COHERENCE INTERFEROMETRY AND OPTICAL COHERENCE TOMOGRAPHY Volynsky Maxim Alexandrovich, Elena A. Vorobyeva, Gurov Igor P, Margaryants Nikita B.
75
Main features of low-coherence interferometric methods and optical coherence tomography as applied to high-resolution investigation of surface micro relief and microstructure of samples of various materials are considered. Results are presented of practical employment of the two methods for study of a polymer material surface, microstructure of a paper sample, and for analysis of lacquer layer microstructure carried out for assessment of condition of a painting for further restoration with the use of laser technologies.
82
Basic ideas of near-field microscopy with a linear nanoprobe scanning a sample surface at a subwavelength distance are discussed. The probe in question is a noble-metal nanowire supporting surface plasmons. In conformity with the near-field microscopy of a magnetic domain, the polarization effects and plasmon-enhanced intensity of magnetooptical scattering are studied depending on the probe location.