Laser and optical technologies

This group deals for a long time with advanced approaches and applications focused on various areas of applied optics. The main focus has been on proposals, analyses, designs and production of non-standard optical elements and systems (both imaging and non-imaging), e.g., optical systems of fluorescent detectors determined for cosmic rays research. Optical technologies (innovation of classical technologies for processing of hard and very hard materials, especially of glass) – rough and fine grinding, polishing, novel approach to surface glass processing using the subaperture method have been developed and employed. Related development has been performed in the area of optical layers and the methods of their analysis. 
The ability to manufacture ultra-lightweight mirror surfaces of large dimensions is a group specialty employed for instance in the Pierre Auger Observatory (PAO) located in Argentina (see, e.g., Nucl. Instrum. Meth. Phys. Res. Sec. A 2010, 620, 227). The success of PAO resulted in involvement in the international collaboration CTA – Cherenkov Telescope Array – where the subgroup develops measurement systems and methods for quality evaluation of production and service wear of mirror samples, supplied by different potential producers and intended for using in optical telescopes as detectors of cosmic rays (Astropart. Phys. 2013, 43, 3). Since both these projects rely on observation of secondary phenomena in the atmosphere, the fluorescence properties of the atmosphere have been of particular interest (Astropart. Phys. 2013, 42, 90). The need for long-time observation of the cloud-coverage and optical background of the night sky resulted in the design and construction of a specialized autonomous all-sky camera. The cameras have been in the possible locations of CTA observatories (four cameras are already installed in the USA and Argentina, one in Chile, Namibia, Canary Islands and Mexico), and are also included in Pierre Auger Observatory in Argentina as a part of observatory control system.
The subgroup contributes also to other tasks applicable in the industry (e.g., device controlling in real-time color markings of coil springs produced at production line for automotive industry, or research and optimization of optical systems for yarn quality management during its production). The involvement of the team in Pierre Auger and CTA collaborations resulted in contribution to more than 40 publications in Web-of-Science-registered journals. In these collaborations, the team closely cooperates with the Astroparticle physics group of the Institute of Physics of AS CR. 

In the area of material properties, the group was focused primarily on the experimental analysis of mechanical and tribological properties at small scales using the state of the art equipment and methods. In most cases the work was driven by both the scientific curiosity and the technological interest. Various types of materials were tested including thin films and coatings (ceramics, metals, nanocomposites) (Surf. Coat. Technol. 2011, 205, 3372, Surf. Coat. Technol. 2011, 205, 4052, Surf. Coat. Technol. 2012, 206, 3580), plasma sprayed coatings (Ceramics Int. 2010, 36, 2155), single crystals (Appl. Phys. Lett. 2014, 105, 082906) and other bulks. Depth sensing nanoindentation and scratch tests were performed at room temperature and at elevated temperatures up to 500 °C. It should be noted that this subgroup is the only one in the Czech Republic experienced in the high temperature measurements at nano/micro scale and belongs to a limited number of groups worldwide capable to explore nanomechanical properties at elevated temperatures. In case of thin films and plasma sprayed coatings the mechanical characteristics were correlated with the structure and with the parameters of the deposition process providing a comprehensive description of the studied material. Besides, the temperature stability of the films’ structure and mechanical properties was explored. Especially the potential of hard SiCN (Surf. Coat. Technol. 2014, 240, 76) and superhard B4C films were systematically studied. The research works dealing with thin films and coatings were mainly performed under the cooperation with the Institute for Problems of Materials Science, Academy of Sciences of Ukraine. In cooperation with the Virginia Polytechnic Institute and State University, a modified nonisothermal nanoindentation method was developed to directly detect the negative stiffness of ferroelectric material at its Curie point and to quantify the negative stiffness without the need for embedding it into a matrix. The feasibility of this in-situ method was demonstrated on the triglycine sulfate single crystal.

In the area of laser technologies, the overlap welding of thin stainless steel sheets was performed by means of the pulsed Nd:YAG laser system with variable laser parameters, that influence was investigated on the samples cross-sections by laser scanning microscopy. Numerical model of the pulsed welding was created by software SYSWELD with the goal to estimate the amount of the absorbed energy (Metallurg. Mater. Trans. B 2010, 41, 1108; Metallurg. Mater. Trans. B 2014, 45, 1116). The possibility of the on-line monitoring of the welding process was investigated both on our own Nd:YAG pulsed laser system and on industrial continual CO2 laser in LAMBRO 92 a.s. facility. UV – spectrometer or UV – photodiode data were collected and evaluated by the developed software LWM – Laser welding monitor (J. Mater Eng. Perf. 2012, 21, 764). Numerical model of the overlapped laser surface melting was created to demonstrate the influence of delay between the following spot application, spot axis stand-off and the processing speed on the resulting microstructure in the remelted region. Real samples were processed on high power diode laser in MATEX PM Facility in Plzeň and surface modification was evaluated by contact stylus profilometry. Besides these main tasks, laser liquid-assisted scribing of silicon, indirect backside glass marking, and laser interaction with nano-particles were performed. Also the research of propagation and shaping of extremely powerful light beams (in collaboration with ELI project and industrial environment) has been pursued.

Latest publications of the group

  • Hrubantova, A; Hippler, R; Wulff, H; Cada, M; Gedeon, O; Jiricek, P; Houdkova, J; Olejnicek, J; Nepomniashchaia, N; Helm, CA; Hubicka, Z: Copper tungsten oxide (CuxWOy) thin films for optical and photoelectrochemical applications deposited by reactive high power impulse magnetron co-sputtering, J. Appl. Phys. 132 (21) 215301 (2022).
  • Hrubantova, A; Hippler, R; Wulff, H; Cada, M; Olejnicek, J; Nepomniashchaia, N; Helm, CA; Hubicka, Z: Deposition of tungsten oxide films by reactive magnetron sputtering on different substrates, J. Vac. Sci. Technol. A 40 (6) 63402 (2022).
  • Kmec, J; Pavlicek, P; Smid, P: Optical noncontact method to detect amplitude defects of polymeric objects, Polym. Test 116 107802 (2022).
  • Michal, S; Horvath, P; Hrabovsky, M; Chytka, L; Mandat, D; Nozka, L; Palatka, M; Pech, M; Schovanek, P; Vacula, M: Swing arm profilometer as a tool for measuring the shape of large optical surfaces, Optik 264 169419 (2022).
  • Vodak, R; Furst, T; Sir, M; Kmec, J: The difference between semi-continuum model and Richards' equation for unsaturated porous media flow, Sci Rep 12 (1) 7650 (2022).

Latest publications of the Pierre Auger Collaboration (including JLO members)

  • Aab, A et al. (Chytka, L.; Horvath, P.; Hrabovsky, M.; Michal, S.; Nozka, L.; Supik, J.; Vaclavek, L.; Vacula, M.; Hamal, P.; Mandat, D.; Palatka, M.; Pech, M.; Schovanek, P.): The FRAM robotic telescope for atmospheric monitoring at the Pierre Auger Observatory, J. Instrum. 16 (6) P06027 (2021).
  • Aab, A et al. (Chytka, L.; Horvath, P.; Hrabovsky, M.; Michal, S.; Nozka, L.; Supik, J.; Vaclavek, L.; Vacula, M.; Hamal, P.; Mandat, D.; Palatka, M.; Pech, M.; Schovanek, P.): Extraction of the muon signals recorded with the surface detector of the Pierre Auger Observatory using recurrent neural networks, J. Instrum. 16 (7) P07016 (2021).
  • Aab, A et al. (Chytka, L.; Horvath, P.; Hrabovsky, M.; Michal, S.; Nozka, L.; Supik, J.; Vaclavek, L.; Vacula, M.; Hamal, P.; Mandat, D.; Palatka, M.; Pech, M.; Schovanek, P.): Deep-learning based reconstruction of the shower maximum X(max)( )using the water-Cherenkov detectors of the Pierre Auger Observatory, J. Instrum. 16 (7) P07019 (2021).
  • Aab, A et al. (Chytka, L.; Horvath, P.; Hrabovsky, M.; Michal, S.; Nozka, L.; Supik, J.; Vaclavek, L.; Vacula, M.; Hamal, P.; Mandat, D.; Palatka, M.; Pech, M.; Schovanek, P.): Design and implementation of the AMIGA embedded system or data acquisition, J. Instrum. 16 (7) T07008 (2021).
  • Aab, A et al. (Chytka, L.; Horvath, P.; Hrabovsky, M.; Michal, S.; Nozka, L.; Supik, J.; Vaclavek, L.; Vacula, M.; Mandat, D.; Palatka, M.; Pech, M.; Schovanek, P.): Measurement of the Fluctuations in the Number of Muons in Extensive Air Showers with the Pierre Auger Observatory, Phys. Rev. Lett. 126 (15) 152002 (2021).

Group of Laser and Optical Technologies

Name Role Room Phone (++420 58 563 ...) ORCID Researcher ID
Ing. Petr Buchníček technician 229 1513, 1690
RNDr. Hana Chmelíčková researcher 227 1516, 1532 0000-0001-7539-8090 G-5849-2014
Mgr. Martina Havelková technician 217 1578 0000-0002-1790-5223 G-6221-2014
Mgr. Zdeněk Hubička Ph.D. researcher 309 1557 0000-0002-4051-057X H-1563-2014
Mgr. Vlastimil Jílek Ph.D. student 238 1677 0000-0001-5774-7285
Ing. Martin Kittler technician 135 1506 0000-0001-8514-8001 H-3116-2014
Mgr. Jakub Kmec researcher 303 1530 0000-0003-0956-1114
Mgr. Dušan Mandát Ph.D. researcher 220 1686 0000-0001-7748-7468 G-5580-2014
Mgr. Stanislav Michal Ph.D. student / technician 135 1766 0000-0001-6563-1573
Mgr. Libor Nožka Ph.D. researcher 216 1533, 1695 0000-0002-8774-7099 G-5550-2014
Mgr. Jana Osičková Ph.D. student - -
RNDr. Miroslav Palatka researcher 227 1516 0000-0003-2061-6059 G-5796-2014
Mgr. Miroslav Pech Ph.D. researcher 220 1686, 1690 0000-0002-8421-0456 G-5760-2014
Ing. Petr Písařík Ph.D. student 0000-0003-0098-9413 G-5622-2014
Ing. Aneta Písaříková Ph.D. student - - 0000-0002-0636-4134
RNDr. Petr Schovánek researcher / deputy head of the laboratory / head of the group 225 1503 0000-0002-5344-7645 G-7117-2014
Ing. Stanislav Stanček Ph.D. student - - 0000-0002-1695-2458
Mgr. Zuzana Svozilíková Ph.D. student 238 1677
Mgr. Jan Tomáštík Ph.D. researcher 219 1573, 1514 0000-0002-6784-7949 G-5857-2014
RNDr. Petr Trávníček Ph.D. researcher - - 0000-0002-1655-9584
Ing. Drahoslav Tvarog Ph.D. student - - 0000-0002-2351-7331
Vladimír Urbášek technician 411 1526 0000-0002-0686-3021
Mgr. Lukáš Václavek Ph.D. student 303 1530 0000-0002-0910-3415
Mgr. Martin Vacula Ph.D. student 303 1530 0000-0003-4844-3962