Yu Yu Stepanov

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.

Kilowatt-range high-repetition-rate excimer lasers

High-power operation of excimer lasers was investigated using UV-preionization schemes based on a dielectric surface creeping discharge. The design and operation of the high average power excimer laser systems are described. A large-aperture (10 X 7 cm2) XeCl laser with UV preionization can produce 10 J per pulse at a repetition rate of up to 100 Hz. When the aperture was decreased, the XeCl laser operated at repetition rates of up to 500 Hz and could produce average output power of more than 600 W.

Intense high-repetition-rate excimer lasers and applications

Building of high average output power excimer lasers requires the solution of several complex problems. The main challenge is the creation of a uniform discharge which can be easily reproduced even at high pulse repetition rates. Some approaches to solving this problem are discussed. They resulted in creation of lasers with aperture of 4 sq cm operating at 1 kHz producing the output of 420 W at 308 nm. A large-aperture XeCl laser can produce 10 J per pulse at 50 Hz.