Tver State University, Tver, Russia:

I. A. Kaplunov, Professor, e-mail: Ivan.Kaplunov@tversu.ru

“National center of lser systems and complexes” JSC, Moscow, Russia:
V. E. Rogalin, Head of a sector

Plekhanov National Academy of Economics, Moscow, Russia:
S. A. Filin, Assistant Professor

Cleaning and preparation of metal surfaces is one of the main stages of technological process. These operations ensure high resource of final products for many areas of science, technology and industry. Problems due to surface contamination often arise in operation of high-power infrared gas lasers which have 100 percent resonator mirrors made of copper having higher reflectivity in the infrared range. For example, reflectivity of clean copper mirror surface at a wave length l = 10.6 μm can reach R = 0.990.002 [1]. Being operated, the copper mirror degrades under exposure and due to chemical contact with laser medium. As a consequence, the reflectivity can lower down to 0.96, which means the radiation leaks increase from 0.01 to 0.04 (4 times). No-touch surface cleaning methods enable partial recovery of reflectivity, and additional effect of laser cleaning improves mirror quality as compared with the fresh-polished mirrors (R = 0.985). This method can be applied to cleaning of comparatively expensive components made of non-ferrous metals and having polished surface or complex geometry (inner cavities), which can be damaged during cleaning or tolerate no efficient cleaning with any other methods.

This work was carried out in Tver State University with the support of Ministry of Education and Science of the Russian Federation in the framework of accomplishment of Federal Targeted program “Investigation and Engineering in High-Priority Lines of Development of Science and Technology in Russia for 2014–2020” agreement 14.577.21.0004.

1. Veyko V. P., Smirnov V. N., Chirkov A. M., Shakhno E. A. Lazernaya ochistka v mashinostroenii i priborostroenii (Laser purification in mechanical engineering and instrument-making). Saint Petersburg : National Research University of Information Technologies, Mechanics and Optics, 2013. 103 p.
2. Veyko V. P., Shakhno E. A. Izvestiya Rossiyskoy Akademii Nauk. Seriya fizicheskaya — Bulletin of Russian Academy of Sciences. Physics. 2001. Vol. 65, No. 4. pp. 584–587.
3. Drobot A. D., Ilin M. K., Rogalin V. E. et al. Elektronnaya tekhnika. Seriya: Lazernaya tekhnika i optoelektronika = Electronic engineering. Series: Laser technics and optoelectronics. 1990. No. 2. pp. 49–51.
4. Drobot A. D., Ilin M. K., Rogalin V. E. Sposob ochistki poverkhnosti izdeliy iz metallov i ikh splavov (Method of purification of surfaces of products, made of metals and their alloys). Patent RF, No. 2070621. Applied : September 13, 1989. Published: December 20, 1996.
5. Drobot A. D., Ilin M. K., Rogalin V. E. Sposob ochistki opticheskoy poverkhnosti izdeliy iz metallov i ikh splavov (Method of purification of optical surface of products, made of metals and their alloys). Patent RF, No. 2049155. Applied: March 07, 1986. Published: November 27, 1995.
6. Apollonov V. V., Vaskovskiy Yu. M., Zhavoronkov M. I., Prokhorov A. M., Rovinskiy R. E., Rogalin V. E., Ustinov N. D., Firsov K. N., Tsenina I. S., Yamshchikov V. A. Kvantovaya elektronika = Quantuum electronics. 1985. Vol. 12, No. 1. pp. 5–9.
7. Kelsall D. Measurements of Highly Reflecting Optical Coatings at 10.6 μ. Applied Optics. 1970. Vol. 9. pp. 85–90.
8. Nesmelov E. A., Potelov V. V., Senik B. N., Sukhachev A. B. Prikladnaya fizika = Applied physics. 2006. No. 6. pp. 146–148.
9. Potelov V. V. Steklo i keramika = Glass and Ceramics. 2009. No. 7. pp. 45–49.