Single-shot laser-induced breakdown spectroscopy using various duration pulses generated by a compact master oscillator power amplifier fiber laser

Palásti, Dávid Jenő and Casian Plaza, Fernando Alexander and Bélteki, Ádám and Kohut, Attila and Makkos, L. and Galbács, Gábor (2025) Single-shot laser-induced breakdown spectroscopy using various duration pulses generated by a compact master oscillator power amplifier fiber laser. OPTICS AND LASER TECHNOLOGY, 192. No. 114120. ISSN 0030-3992

Text SinglepulsefiberlaserLIBSJOLT2025.pdf - Published Version Restricted to Repository staff only Download (3MB) | Request a copy

Abstract

Pulsed fiber lasers using the master oscillator power amplifier (MOPA) topology have characteristics that are very promising not only for industrial, but also for analytical applications to be carried out in the field, in harsh environments. Newer commercial models of such lasers offer pulse shape programming and widely variable pulse repetition rates, which carry a unique potential for laser-induced breakdown spectroscopy (LIBS) which has not been really explored until now. In the present study we carried out a detailed investigation of the utilization of various pulse shape profiles (waveforms) provided by a commercial fiber laser (Nanopulse 5020-EP, Trumpf, Germany) in LIBS. The 1062 nm fiber laser was used with pulse durations ranging from 8 ns to 2000 ns and pulse energies from 0.35 to 5mJ. Comparisons of cases when the pulse energy was fixed and the pulse duration and pulse shape was varied were also realized. We found that the plasma excitation temperatures are around 9000 K. One of the analytical benefits observed was that the spectra recorded with zero gate delay are highly free from any continuum spectral background and that the lines of the ambient gas. The wavelength- and time-resolved plasma emission was studied for several elements in plasmas generated on steel and silicon samples. It was found that the LIBS emission intensities are higher for higher energy and shorter pulses, but for up to a 190–320 ns pulse duration, the sensitivity of the measurements is about the same. The effect of the pulse shape on the emission intensities was also studied and it was revealed that the leading part (head) of the pulse has a much stronger effect than the tailing part. It was concluded that the best LIBS spectra can be recorded when the largest possible fraction of the pulse energy is carried by the pulse head, but the pulse tail also significantly contributed to the plasma emission. The overall analytical performance of the compact fiber laser LIBS setup was also tested against a desktop 266 nm LIBS setup (J-200 Applied Spectra, USA) on a series of steel certified reference materials. It was found that the two systems have comparable detection limits, in the 0.03 to 0.5 m/m% range for Cu, Al, V, Mn and Cr.

Actions (login required)

Edit Item