Research interests in our group

In our studies three different laser-spectroscopic methods are involved: Laser-induced breakdown spectroscopy (LIBS), Raman spectroscopy as well as time-resolved photoluminescence (or laser-induced fluorescence) spectroscopy.

• Laser-induced breakdown spectroscopy (LIBS) is a powerful tool for analyzing solid materials. With LIBS laser beam is focused on the material to cause energy enough to cause plasma. Characteristic emission spectrum can be measured directly from the sample surface and no preparation is needed. LIBS is able to detect all elements in the periodic table, including light and non-conductive elements
• Raman spectroscopy is very informative and rapid analysis technique. Raman spectroscopy gives information about vibrational, rotational and low-frequency modes of the studied material. Raman spectrum provides fingerprint by which molecules can be identified.
• Luminescence of mineral is related on lattice properties and luminescence centers, also called as activators. With luminescense spectroscopy, energy levels of the luminescence centers can be detected. Luminescence centers have characteristic states and energy levels. These are related on physical properties of the specific material and activator. In photoluminescence studies, material is excited with laser beam and measurable luminescence emission occurs when electron transfers from higher energy level to lower one. Luminescence has properties related to quantum yield and lifetime. With time-resolved photoluminescence spectra, different luminescence centers can be recognized.

FIGURE: Minerals high-resolution LIBS spectra.

FIGURE: Raman spectrum of calcite mineral. Raman modes translation (T), libration (L), in-plane bend (v4) and symmetric stretch (v1) can be detected

FIGURE: Photoluminescence spetrum of calcite mineral with Mn-substitution caused red luminescence.

 

Selected publications

Romppanen S., Häkkänen H., Kaski S., Singular value decomposition approach to the yttrium occurrence in mineral maps of rare earth element ores using laser-induced breakdown spectroscopy, Spectrochimica Acta B 134 (2017) pp. 69-74

Pavel Porızka Saara Kaski Ales Hrdlicka, Pavlına Modlitbova, Lucia Sladkova, Heikki Häkkänen, David Prochazka,Jan Novotny, Petr Gadas, Ladislav Celko, Karel Novotny and Jozef Kaiser, Detection of fluorine using laser-induced breakdown spectroscopy and Raman spectroscopy, Journal of Analytical Atomic Spectrometry (2017), DOI: 10.1039/c7ja00200a

Ojansivu, M. & Vanhatupa, S. & Björkvik, L. & Häkkänen, H. & Kellomäki, M. & Autio, R. & Ihalainen, J. & Hupa, L. & Miettinen, S. Bioactive glass ions as strong enhancers of osteogenic differentiation in human adipose stem cells, Acta Biomaterialia, 21 (2015), pp. 190-203

M. Myllys, H. Häkkänen, J. Korppi-Tommola, K. Backfolk, P. Sirviö, and J. Timonen, X-ray microtomography and laser ablation in the analysis of ink distribution in coated paper Journal of Applied Physics 117 (2015), pp.144902

Ruokola, P., Dadu E., Kazmertsuk, A. Häkkänen, H., Marjomäki, V., Ihalainen, J.A. Raman Spectroscopic Signatures of Echovirus 1 Uncoating, Journal of Virology, 89 (2014), pp. 8504-8513

M. Pouzar, Kratchvil, T., Kaski S., Kaiser, J., Knotek, P., Capek, L., Cernohorsky, T.: “Effect of particle size distribution in laser-induced breakdown spectroscopy analysis of mesoporous V-SiO2 catalysts” Journal of Analytical Atomic Spectrometry 26 (2011) 2281-2288

Novotny, K., Stankova, A.,  Häkkänen, H., Korppi-Tommola, J.,Otruba, V., Kanicky, V., Analysis of powdered tungsten carbide hard-metal precursors and cemented compact tungsten carbides using laser-induced breakdown spectroscopy, Spectrochimica Acta Part B-Atomic Spectroscopy  Volume: 62   Issue: 12   Special Issue: SI   pp. 1567-1574   DOI: 10.1016/j.sab.2007.10.020  (2007) pp. 1567-1574

Kaski, S. Häkkänen,H.,  Korppi-Tommola, J.  Determination of Cl/C and Br/C ratios in pure organic solids using laser-induced plasma spectroscopy in near vacuum ultraviolet, Journal of Analytical Atomic Spectrometry 19 (2004) 474-478

Kaski, S., Häkkänen, H., Korppi-Tommola, J., Laser-induced plasma spectroscopy to as low as 130 nm when a gas-purged spectrograph and ICCD detection are used,  Applied Optics,   42   (2003)   pp. 6036-6039    

Kaski, S., Häkkänen, H., Korppi-Tommola, J., Sulfide mineral identification using laser-induced plasma spectroscopy., Minerals Engineering   16 (2003)   pp. 1239-1243   

Lindblom, J., Hölsä, J., Papunen, H., Häkkänen, H., Mutanen, J., Differentiation of natural and synthetic gem-quality diamonds by luminescence properties Optical Materials, 24 (2003)  pp. 243-251   

Lindblom, J., Hölsä, J., Papunen, H., Häkkänen, H., Luminescence study of defects in synthetic as-grown and HPHT diamonds compared to natural diamonds, American Mineralogist   90   (2005) pp. 428-440   

Kaski, Saara; Hakkanen, Heikki; Korppi-Tommola, Jouko, Laser-induced plasma spectroscopy in near vacuum ultraviolet using ordinary spectrograph and ICCD, Trends in Optics and Photonics 81(Laser Induced Plasma Spectroscopy and Applications), (2002), pp. 99-101 

Häkkänen, H., Houni, J., Kaski, S., Korppi-Tommola, J.E.I., Analysis of paper by laser-induced plasma spectroscopy, Spectrochimica Acta Part B-Atomic Spectroscopy   56 (2001) pp. 737-742

Häkkänen, H.J., Korppi-Tommola, J.E.I., Laser-induced plasma emission spectrometric study of pigments and binders in paper coatings: Matrix effects, Analytical Chemistry,   70 (1998)   pp. 4724-4729   

Häkkänen, H.J., Korppi-Tommola, J.E.I., UV-Laser Plasma Study of Elemental Distributions of Paper Coatings, Appl. Spectrosc., 49 (1995) pp. 1721-1728

Häkkänen, H.J., Korppi-Tommola, J.E.I., Laser-induced fluorescence imaging of paper surfaces, Appl. Spectrosc., 47 (1993) pp. 2122-2125