V. S. Mezhevov

Materials processing by high-repetition-rate pulsed excimer and carbon dioxide lasers

Recently created pulsed gas lasers with high pulse repetition rate produce radiation in the IR [ V. Yu. Baranov , in Molecular Gas Lasers. Physics Applications, VelikhovE. P., Ed. ( Mir, Moscow, 1981), pp. 252– 255] and the UV ( V. Yu. Baranov , in Proceedings, International Conference on Lasers, 14–18 Dec. 1981, pp. 968– 974) regions of the spectrum. These lasers are widely used in research on the selective excitation of matter. This field of study includes laser isotope separation { G. I. Abdushelashvili , Kvantovaya Elektron. (Moscow)9, 743 ( 1982) [ Sov. J. Quantum Electron.12, 459 ( 1982)]} and laser-induced chemical reactions [ V. Yu. Baranov , Preprint IAE 3693/13 ( Moscow, 1982)]. But there are few publications dealing with uses of high-repetition-rate lasers for materials processing, although this problem undoubtedly is of considerable scientific interest.

Average power limitations in high-repetition-rate pulsed gas lasers at 10.6 and 16 μm

Processes resulting in average power limitations in high-repetition-rate pulsed lasers are studied. The description and performance of a CO(2) laser with an average power up to 10 kW as well as of an optically pumped CF(4) laser are given.

Analysis of gaseous mixtures with multifrequency NH3 laser spectrometer

Abstract The first results of quantitative analysis of gaseous mixtures with aid of laser spectrometer, based on a pulsed NH 3 laser with optical pump of the TEA CO 2 laser are reported. In the first part the general properties of the NH 3 laser are briefly described along with a theoretical model and some results of numerical modeling. The main difference of the laser is simultaneous multifrequency generation. In the second part of the paper, results of measurements of partial pressures of multicomponent admixtures in atmospheric pressure air are presented. It is experimentally shown, that at least four-component admixture can be analyzed with this type of spectrometer. This result can be used as preliminary step in development of a new type of remote laser spectrometer.

Displacement Of Molten Metal Under High-Repetition-Rate Pulsed Irradiation

The processes occuring due to high-pulse-repetition rate laser beam interaction with metals have been studied by now very poorly both theoretically and experimentally. In the same time, first high repetition rate (HRR) pulsed laser applications to materials processing attract some interest to such a study. The investigation of possible improvement, theof the cw-laser-induced processes by using cw and HR R lasers together is also prospective. The melt removal mechanisms studied both theoretically and experimentally are the subject of the present paper. The pulse approximation of hydrodynamical equations is valid to describe the molten metal motion generated by laser puls of 1-100 μs duration. Reasonable agreement between theoretical estimations of velocity and escape time of the melt and experimental data was achieved. High-repetition rate pulsed processing was also investigated. The model of deep penetration by a HRR laser is put forward. It explaines the greater penetration ability of a HRR laser as compared to the cw laser of the same output power.