• Українська
  • English
  • Русский
ISSN 2415-3400 (Online)
ISSN 1028-821X (Print)

Time parameters of optimal emission spectrum registration using millisecond laser pulses

Dzubenko, MI, Dehtiarov, АV, Kolpakov, SN, Priyomko, AA


O.Ya. Usikov Institute for Radiophysics and Electronics of the NASU
12, Acad. Proskura St., Kharkov, 61085, Ukraine

V.N. Karazin Kharkiv National University
4, Svoboda Sq., Kharkiv, 61022, Ukraine

E-mail: mid41@ukr.net

Language: ukranian


Subject and Purpose. Emission spectra of copper-silver alloys are examined for various recording durations. The radiation coming to the photodetector of the spectrometer consists of the reflected laser radiation and the line spectra of vapors formed by the test substance and the heated material in condensed phase. As the spectrum recording time increases, the background component builds up substantially. The purpose of the work is to study the interaction conditions of millisecond laser pulses with the metals and determine recording time parameters of the optical radiation signal in an effort to achieve an optimal recording of the emission spectrum in the range 400…800 nm

Methods and Methodology. The main problem with emission spectrum recording is a persistent thermal component. The laser pulse shape for the optimal recording of the emission spectrum is theoretically calculated. The purity of the emission spectrum depends on its recording duration. The matter of persistent thermal component minimization in laser emission analysis implies the optimal shaping of the laser pulse and its maintenance during the operation. Empirical guidelines exist that the optimal time of the emission spectrum recording is 1...3 ms at a laser pulse duration of 5 ms.

Results. It has been found that the main factors affecting the intensity ratio of the continuous and line spectra are thermophysical properties of the metal and a laser pulse shape, especially the value of its trailing edge steepness. Lasers with quasi-optimal pulse shape enable us to increase a maximum frequency of optimal emission-spectrum recording in laser emission analysis. For a 3 ms duration and a 10 J energy of the pulse, the maximum laser frequency at which the laser emission analysis is still possible can be 70...75 Hz.

Conclusion. The process of laser emission analysis optimization consists in optimal laser pulse shaping and its maintenance during the operation.

Keywords: duration, emission spectrum, laser cutting, laser pulse, laser welding, pulse shape

Manuscript submitted  12.05.2020
Radiofiz. elektron. 2020, 25(4): 30-37
Full text (PDF)

1. Kinkade, K., Nogee, A., Overton, G., Belforte, D., Holton, C., 2018. Annual Laser Market Review & Forecast: Lasers enabling lasers. Laser Focus World, 54(1), pp. 42-67.
2. Portable LIBS-spectrometer Rigaku Katana. Available at: http://ccsservices.ru/catalog/libs-spektrometry/portativnyy-libs-spektro...
3. Laser Analyzer elemental composition NanoLIBS-Q. Available at: https://www.czl.ru/catalog/spektr/libs-spectrometers/nanolibs-q-spektrom...
4. Portable Laser Spectrometer (LIBS) for metals, soils, ores, sands, fertilizers, etc. Available at: https://www.iskroline.ru/spectrometers/sciapslibs/
5. Kayukov, S.V., 1999. Processing of metals by pulse laser radiation of millisecond range of duration. Bull. Samara Scientific Center of the Russian Academy of Sciences, 1, pp. 39-50 (in Russian).
6. Afanasyev, O.V., Lalazarova, N.A., Fedorenko, E.P., 2013. Use of low-power lasers in industrial technology. In: Radiotekhnika. Kharkov: NURE Publ. 175, pp. 63-67 (in Russian).
7. Krivtsun, I.V., Semenov, I.L., Demchenko, V.F., 2010. Numerical analysis of the processes of heating and convective evaporation of metal in pulse laser treatment. The Paton Welding J., 1, pp. 2-6.
8. Vorobev, V.S., 1993. Plasma Arising from the Interaction of Laser Radiation with Solid Targets. Usp. Fiz. Nauk, 163(12), pp. 51-82 (in Russian). DOI: https://doi.org/10.3367/UFNr.0163.199312b.0051
9. Demtroder, W., 1985. Laser spectroscopy. Translated from English and ed. by I.I. Sobel'man. Moscow: Nauka Publ. (in Russian).
10. Dzyubenko, M.I., Kiselev, V.K. heads of R&D, 2011. Development and Application of Quasi-Optical and Optical Methods and Techniques in Radiophysical Research in the Terahertz Region of Spectrum: report on R&D "Oplot". O.Ya. Usikov Institute for Radiophysics and Electronics of the NASU, Kharkov, Ukraine. Book 3. GR No. 0107U001081 (in Russian).
11. Kushida, T., 1965. Laser Induced Temperature Radiation. Jap. J. Appl. Phys., 4(1), pp. 73-84. DOI: https://doi.org/10.1143/JJAP.4.73
12. Ryvkin, S.M., Salmanov, V.M., Yaroshetsky, I.D., 1968. Thermal radiation of silicon under the action of laser radiation. Phys. Solid State, 10, pp. 1052-1060 (in Russian).
13. Ready, J.F., 1974. Effects of High-Power Laser Radiation. Translated from English. Moscow: Mir Publ. (in Russian).