Characteristics of vacuum ultraviolet emission from a laser-plasma radiation source based on a gas-puff target Martyna Wardzińska, Przemysław Wachulak, Andrzej Bartnik, Tomasz Fok, Łukasz Węgrzyński, et al. Bulletin of the Polish Academy of Sciences Technical Sciences, 2026 The growing interest in solar corona and heliospheric backscatter glow observations in the vacuum ultraviolet, along with technological advancements in the feasibility of vacuum ultraviolet optical components for such applications, underscores the need for improved metrological solutions. This work presents a detailed characterisation of a compact laser‑produced plasma vacuum ultraviolet source based on a double-stream gas-puff target, relevant in the metrology of optical elements for space applications. The measurements include the source spectrum, the number of photons, and the source size for targets produced using different gases. Such a source was used to test optical components of the Lyman-alpha space-based observation systems and remains available for future metrology applications. To the best of our knowledge, this is the first application of a laser-produced plasma vacuum ultraviolet source for characterising space-relevant optical components.
GLObal Solar Wind Structure (GLOWS) Maciej Bzowski, Roman Wawrzaszek, Marek Strumik, Jȩdrzej Baran, Tomasz Barciński, et al. Space Science Reviews, 2025
INFLUENCE OF SPECTRAL CHARACTERISTICS OF RADIATION ON THE ACCURACY OF OPTICAL COHERENCE TOMOGRAPHY (OCT) USING A LASER-PLASMA SOURCE OF SOFT X-RAYS AND EXTREME ULTRAVIOLET Antony Jose Arikkatt, Karol Adam Janulewicz, Andrzej Bartnik, Henryk Fiedorowicz, Przemysław Wachulak Metrology and Measurement Systems, 2025 The paper presents an analysis of specific spectra manipulation and its metrological consequences for optical coherence tomography (OCT) in the nanometre wavelength range using a laser-plasma source of soft X-rays (SXR) and extreme ultraviolet (EUV). The focus is on extending the recorded spectra, predominantly through the stitching method. A model spectrum is used to validate the technique and transparently demonstrate the behaviour of the stitched spectral components. The model is followed by processing the experimental data and demonstrating two possible destructive factors for data processing. The first is an unbalanced spectrum. Although spectral extension toward higher photon energies significantly improves spatial resolution, it appears to be a second destructive factor. The results presented also highlighted certain technological and physical issues related to the material properties of the sample, such as potential plasmonic effects. Consequently, the results, although offering much greater flexibility and ability to adjust the final spectrum and providing better reconstruction, also recommend caution in the scope and choice of the applied modification method.
Thin layers of vanadium dioxide as electrical modulators of the optical signal amplitude Michal P. Nowak, Tomasz Stefaniuk, Tomasz Wojciechowski, Marcin Jakubaszek, Przemyslaw Wachulak, et al. Proceedings of SPIE the International Society for Optical Engineering, 2025 Phase change materials (PCMs), which undergo a phase transition in response to external stimuli such as, for example, heat or light, allow construction of active nanophotonic devices. Vanadium dioxide (VO2) is PCM which experiences an isolator-metal phase transition when heated from room to elevated temperature. The phase change of VO2 occurs at approximately 68 °C and results in substantial refractive index change, thus allows for simple, low power, near room temperature light modulation. VO2 modulators have significant advantages compared to other modulating techniques, such as operation in a broad spectral range from near-infrared to terahertz, non-binary signal changes, and low trigger pulse power. The highest recently reported modulation frequency is of the order of several tens of kHz. We demonstrate a broadband optical modulator based on vanadium oxide. The modulator is composed of a glass substrate on which a layer of VO2, a transparent indium tin oxide (ITO) layer, and gold electrodes were deposited. The VO2 films were fabricated in an electron-beam deposition system and annealed in a furnace at atmospheric pressure. The ITO layer enables resistive heating of VO2 with current pulses, thus allowing modulation of an optical signal transmitted or reflected by the structure. A macroscopic structure with an active area of 50 mm2 achieves a modulation frequency of 0.5 kHz. The modulation frequency is limited at the moment by heat dissipation and can be improved in the future. Our results show that VO2 can be used to build large area optical modulators with high on-off contrast.
Laser color printing on disordered metal-dielectric multilayer structures International Conference on Metamaterials Photonic Crystals and Plasmonics, 2025
Laser Control of Specular and Diffuse Reflectance of Thin Aluminum Film-Isolator-Metal Structures for Anti-Counterfeiting and Plasmonic Color Applications Michał P. Nowak, Bogusz Stępak, Mateusz Pielach, Yuriy Stepanenko, Tomasz Wojciechowski, et al. Coatings, 2024 Plasmonic structural color originates from the scattering and absorption of visible light by metallic nanostructures. Stacks consisting of thin, disordered semicontinuous metal films are attractive plasmonic color media, as they can be mass-produced using industry-proven physical vapor deposition techniques. These films are comprised of random nano-island structures of various sizes and shapes resonating at different wavelengths. When irradiated with short-pulse lasers, the nanostructures are locally restructured, and their optical response is altered in a spectrally selective manner. Therefore, various colors are obtained. We demonstrate the generation of structural plasmonic colors through femtosecond laser modification of a thin aluminum film–isolator–metal mirror (TAFIM) structure. Laser-induced structuring of TAFIM’s top aluminum film significantly alters the sample’s specular and diffuse reflectance depending on the fluence value and the number of times a region is scanned. A “negative image” effect is possible, where a dark field observation mode image is a negative of a bright field mode image. This effect is visible using an optical microscope, the naked eye, and a digital camera. The use of self-passivating aluminum results in a long-lasting, non-fading coloration effect. The reported technique could be used in anti-counterfeiting and security applications, as well as in plasmonic color printing and macroscopic and microscopic marking for personalized fine arts and aesthetic products such as jewelry.
Polycaprolactone scaffold surface modification with soft X-ray/extreme ultraviolet (SXR/EUV) radiation and low-temperature oxygen and nitrogen plasma for biomedical applications Joanna Czwartos, Agata Nowak-Stępniowska, Bogusław Budner, Tomasz Fok, Andrzej Bartnik, et al. Journal of Materials Science, 2024 Modification of the surfaces of polymeric scaffolds is often required to make the material suitable for specific tissue engineering applications. Physico-chemical properties of scaffolds can be altered using various methods, such as plasma treatment, laser processing, chemical modifications, grafting with nanoparticles, or surface coating. In this paper physico-chemical modification of polycaprolactone (PCL) surface fibers was performed by exposing PCL samples to simultaneous soft X-ray/extreme ultraviolet (SXR/EUV) radiation and low-temperature, SXR/EUV-induced, nitrogen, and oxygen plasmas. The physical and chemical changes on modified PCL surfaces were examined using a scanning electron microscope and X-ray photoelectron spectroscopy, respectively. The effects of physico-chemical scaffold surface changes were verified with biological tests, i.e., MTT assay and immunofluorescence on murine osteoblast cell line (7F2). It was found that exposure of scaffolds to ionizing radiation and low-temperature plasmas induced strong chemical changes on their surface, i.e., appearance of various new chemical groups. Also, smoothing of the surface of PCL fibers, i.e., disappearance or significant reduction of the size of micropores on their fibers was also observed. Increased viability and adhesion of 7F2 osteoblasts on modified PCL samples after 24 h cell culture compared to non-treated PCL was also confirmed. Graphical abstract
New approaches for low phototoxicity imaging of living cells and tissues Wiktoria Kasprzycka, Wiktoria Szumigraj, Przemysław Wachulak, Elżbieta Anna Trafny Bioessays, 2024 Fluorescence microscopy is a powerful tool used in scientific and medical research, but it is inextricably linked to phototoxicity. Neglecting phototoxicity can lead to erroneous or inconclusive results. Recently, several reports have addressed this issue, but it is still underestimated by many researchers, even though it can lead to cell death. Phototoxicity can be reduced by appropriate microscopic techniques and carefully designed experiments. This review focuses on recent strategies to reduce phototoxicity in microscopic imaging of living cells and tissues. We describe digital image processing and new hardware solutions. We point out new modifications of microscopy methods and hope that this review will interest microscopy hardware engineers. Our aim is to underscore the challenges and potential solutions integral to the design of microscopy systems. Simultaneously, we intend to engage biologists, offering insight into the latest technological advancements in imaging that can enhance their understanding and practice.
