Next-Generation LIBS: The Power of Picosecond Lasers in Material Analysis

Laser technologies are advancing rapidly, pushing physical boundaries while becoming more affordable and accessible. This progress is particularly evident in the systems we use for our LIBS experiments. While nanosecond lasers have long been the standard for our measurements, picosecond lasers are increasingly favored for their distinct advantages.

The defining difference between nanosecond and picosecond lasers lies in pulse duration. Picosecond lasers produce ultrashort pulses, which results in reduced laser-to-matter interaction and thus significantly lower mechanical and thermal stress on the sample. Lesser shock and thermal damage is essential for both preserving the integrity of sensitive materials, but also quality of obtained spectra, thus ensuring accurate and repeatable results.

One of the other standout features of picosecond lasers is their ability to achieve consistently smaller and well defined measurement spots, typically ranging between 10 and 20 micrometers. This precision allows for more detailed analysis of various materials, even those with complex or heterogeneous subtle structures. Smaller measurement spots also enhance depth profiling, enabling fine steps that achieve resolutions in the range of tens of nanometers. As shown in the picture below, after 3 shots, the depth was approximately 200 nm, and after 50 shots, the depth reached 2.8 µm. This level of detail opens the door to in-depth investigations of material composition and structure that were previously unattainable.

Another critical advantage of picosecond lasers is their ability to deliver cleaner spectra. The shorter pulse duration minimizes noise and interference, producing higher-quality data. When used in conjunction with AtomTrace Vacuum Chamber and inert gas environment such as Argon or Helium under lower pressure, implementation of these lasers for analysis further improves the signal-to-noise ratio, ensuring even greater reliability and precision in measurements.

Additionally, studies such as the one by Roldán et. al. (2021) and Paris et. al. (2019) suggest that picosecond lasers can significantly enhance  the accuracy of calibration-free LIBS. This method, which determines elemental composition without the need for reference materials or certified standards, stands to benefit greatly from the precision and clarity offered by these advanced lasers.

Based on the advantages we’ve observed, we decided to actively participate in the co-development of such a laser system. As a result, we now have access to a laser that guarantees enhanced precision and improved data quality, perfectly suited to our needs in material analysis.

If you’re curious about what a picosecond laser can achieve with your samples, don’t hesitate to reach out to us for an analysis. We’d be happy to demonstrate its transformative capabilities.

Cited publications:

ROLDÁN, Alicia Marín, Vishal DWIVEDI, Matej PISARČÍK, et al., 2021. LIBS investigation of metals suitable for plasma-facing components: Characteristics and comparison of picosecond and nanosecond regimes. Fusion Engineering and Design[online].172. 

PARIS, P, J BUTIKOVA, M LAAN, A HAKOLA, I JÕGI, J LIKONEN, E GRIGORE a C RUSET, 2019. Comparison of LIBS results on ITER-relevant samples obtained by nanosecond and picosecond lasers. Nuclear Materials and Energy [online]. 18, 1-5. ISSN 2352-1791. 

Used Featured Picture:

https://www.sciencing.com/create-laser-beam-5143714/