Article
Chemistry, Analytical
Jernej Jan Kocica, Jaka Mur, Julien Didierjean, Arnaud Guillossou, Julien Saby, Jaka Petelin, Girolamo Mincuzzi, Rok Petkovsek
Summary: Laser microstructuring has been extensively studied for its contactless processing and exceptional precision. However, the use of high laser powers has been limited by scanner movement. In this study, a nanosecond UV laser was used in a pulse-on-demand mode to maximize scanner utilization. The effects of high-frequency pulse-on-demand operation were analyzed in terms of processing speeds, ablation efficiency, surface quality, repeatability, and precision. The study also investigated the effects of laser pulse duration on microstructuring. The results showed that pulse-on-demand operation is suitable for microstructuring, but scanner limitations still exist. Longer pulse durations improve ablation efficiency but degrade structure quality.
Article
Optics
Haibin Sun, Xiaolong Liu, Li Zhao, Jianxin Jia, Changhui Jiang, Jiamin Xiao, Yuwei Chen, Long Xu, Zhiyong Duan, Peng Rao, Shengli Sun
Summary: This study reveals the mechanism and influencing factors of infrared absorption in hyperdoped silicon through the measurement of optical absorptance and calculations based on coherent potential approximation. This has important implications for the optoelectronic applications of this material.
Article
Physics, Multidisciplinary
Jihoon Jeong, Xun Li, Sangyeop Lee, Li Shi, Yaguo Wang
Summary: The study reports experimental results on heat-pulse propagation in graphite, revealing transient lattice cooling in graphite at specific temperature range. Although different from previous studies on phonon transport in graphite, the observation is consistent with hydrodynamic phonon transport theory and prior heat-pulse measurements in a homogeneous solid.
PHYSICAL REVIEW LETTERS
(2021)
Review
Chemistry, Physical
Daniel J. Foerster, Beat Jaeggi, Andreas Michalowski, Beat Neuenschwander
Summary: The use of ultra-short double pulses for laser processing has been attracting attention since the early 2000s. Over the past decade, pulse bursts consisting of multiple pulses with delays of several tens of nanoseconds have entered the field of micromachining of metals, opening up new process regimes and improving the structuring rates and surface quality of machined samples. Various physical effects have led to a new understanding of machining strategies and processing regimes, with experimental and numerical investigations placing results in context for different time scales during laser processing.
Article
Optics
Raffaele De Palo, Annalisa Volpe, Caterina Gaudiuso, Pietro Patimisco, Vincenzo Spagnolo, Antonio Ancona
Summary: This study investigates the incubation effect on the laser ablation threshold of quartz after multi-shot irradiation with femtosecond pulses. The results show a significant decrease in the multi-pulse ablation threshold with an increasing number of pulses, while the influence of repetition rate is negligible.
Article
Optics
Zbynek Hubka, Roman Antipenkov, Robert Boge, Emily Erdman, Michael Greco, Jonathan T. Green, Martin Horacek, Karel Majer, Tomas Mazanec, Petr Mazurek, Jack A. Naylon, Jakub Novak, Vaclav Sobr, Petr Strkula, Murat Torun, Boguslaw Tykalewicz, Pavel Bakule, Bedrich Rus
Summary: This research presents a 1 kHz, 515 nm laser system based on commercially available equipment, developed for pumping the OPCPA stage of the Allegra laser system, with a series of techniques employed to ensure stability and high efficiency.
Article
Optics
Zijian Cui, Mingying Sun, DE'An Liu, Jianqiang Zhu
Summary: This study presents high-peak-power picosecond deep-UV laser sources and characterizes typical birefringent and nonlinear borate crystals. The demonstrated results contribute to the development of ultrahigh-peak-power deep-UV and vacuum-UV laser sources as well as important applications in high-energy-density physics, material science, and laser machining.
Article
Materials Science, Multidisciplinary
Sunita Kedia, J. Padma Nilaya
Summary: Surface texturing and protective coating were utilized to improve the surface properties of Ti6Al4V bio-alloy. The hierarchical grooved structure reduced the coefficient of friction and the embedded sub-patterns inhibited abrasive and delamination wears. The zirconia coated groove sample exhibited superior corrosion resistance due to the laser induced titanium oxide layer and the greater hardness of the zirconia film.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2023)
Article
Physics, Applied
Yudi Ma, Ruijuan Liu, Lingjing Ji, Liyang Qiu, Dianqiang Su, Yanting Zhao, Ni Yao, Wei Fang, Saijun Wu
Summary: This study demonstrates a method to control atomic electric dipole transitions using composite picosecond optical pulses, which can successfully control the atomic states even in the presence of spatially varying light-atom coupling strength. This technique enables nanoscale sensing and quantum optical functionalities in nanophotonic devices.
PHYSICAL REVIEW APPLIED
(2023)
Article
Optics
Mikhail N. Polyanskiy, Marcus Babzien, Igor Pogorelsky, Rotem Kupfer, Konstantin L. Vodopyanov, Mark A. Palmer
Summary: A new method was developed to measure the nonlinear refractive index of air by analyzing the spatial shape evolution of a laser beam. The study also reported the first measurement of the nonlinear refractive index of air for a very short LWIR laser pulse, showing a 40% lower value compared to a previous measurement with longer pulses.
Article
Optics
Muhammad Ghawas, Valerian Freysz, Lukas Mueller, Sebastien Cassagnere, Eric Freysz
Summary: An all-normal dispersion ytterbium rod-type fiber laser oscillator has been designed, which delivers continuously tunable picosecond pulses. The central wavelength and pulse duration of the pulses can be adjusted by manipulating the position and width of a spectral bandwidth filter.
Article
Materials Science, Multidisciplinary
Ping-Han Wu, Hong-Tsu Young, Kuan-Ming Li
Summary: This study discussed the ablation thresholds of picosecond laser dual pulses in fused silica with different temporal separations. The results indicated that the lowest damage threshold of the dual-pulse ablation was at a temporal separation of 100 ps, and the energy ratios of two sub-pulses were optimized to minimize the thresholds. The study also revealed that the first sub-pulses excited the electrons of the fused silica and induced free-electron shielding and self-trapped exciton seed generation, which affected the material absorption of the second sub-pulses.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Materials Science, Ceramics
W. Amsellem, H. Yazdani Sarvestani, V. Pankov, Y. Martinez-Rubi, J. Gholipour, B. Ashrafi
Summary: This study explores the use of a fiber picosecond laser for subtractive manufacturing of SiC ceramic, aiming for minimal surface damage and high precision. Various laser processing parameters were analyzed to achieve deep high-quality cuts with minimum surface roughness and redeposited material. The study also identified processing parameters for shallow and deep high-precision SiC cutting.
CERAMICS INTERNATIONAL
(2023)
Article
Optics
Shifei Han, Haijuan Yu, Chaojian He, Shusen Zhao, Chaoyu Ning, Lu Jiang, Xunchun Lin
Summary: This study demonstrates the successful fabrication of silicon carbide wafers using laser cutting technology, which overcomes the issues encountered in diamond wire cutting. By optimizing the processing parameters, the fabricated wafers have a small cutting width and surface roughness, with no residual stress. This technology has important applications in slicing hard and brittle materials and thinning the backsides of semiconductor devices.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Optics
Yu He, Haohan Shi, Nan Xue, Alexander Magunia, Shaohua Sun, Jingjie Ding, Bitao Hu, Zuoye Liu
Summary: This theoretical study investigates the excitation and manipulation of a two-level system with ultrashort intense extreme-ultraviolet laser fields. The focus is on the dynamical phase excursion of the energy states during the interaction and the resulting spectral modifications. The analysis includes fitting absorption line shapes using the Fano profile, quantifying the asymmetry parameter and dipole phase offset, and employing nonperturbative analytical calculations to understand the dependence of the dipole phase shift on the external field. The validity of the formulas is confirmed by comparing their predictions with numerical results.
Article
Engineering, Chemical
Luka Pirker, Anja Pogacnik Krajnc, Jan Malec, Vladimir Radulovic, Anton Gradisek, Andreja Jelen, Maja Remskar, Igor B. Mekjavic, Janez Kovac, Miran Mozetic, Luka Snoj
Summary: Ionizing radiation is an effective method for sterilization of masks when production cannot keep up with demand. Both gamma radiation and high energy electrons can penetrate deeply into materials for quick sterilization. It has been demonstrated that recharging the masks after sterilization can help maintain filtration efficiency.
JOURNAL OF MEMBRANE SCIENCE
(2021)
Article
Optics
Jernej Jan Kocica, Jaka Mur, Jaka Petelin, Rok Petkovsek
Summary: This study investigated the intermediate pulse duration regime using bursts of 70 ps pulses emitted from a custom-made fiber laser source. The goal was to observe and understand laser ablation processes on timescales from picoseconds to nanoseconds, and develop material processing approaches to achieve quality similar to ultra-short pulses and efficiency similar to nanosecond pulses. The variability of fiber laser operation modes was studied and compared to standard ultra-short and nanosecond pulses.
Article
Biochemical Research Methods
Rok Podlipec, Jaka Mur, Jaka Petelin, Janez Strancar, Rok Petkovsek
Summary: The study proposes a concept for real-time controlled tissue theranostics using a single adaptable laser source, conducted on ex-vivo human retinal pigment epithelium. Autofluorescence intensity and lifetime imaging diagnostics show promise in recognizing and quantifying laser effects. The developed algorithm for optimized theranostics based on fluorescence descriptors can potentially be a new personalized medicine method not limited to treating retinal diseases.
BIOMEDICAL OPTICS EXPRESS
(2021)
Review
Chemistry, Multidisciplinary
Luka Pirker, Bojana Visic
Summary: WO3 is increasingly being studied as a two-dimensional material, showing different characteristics and potential applications compared to its bulk form.
ISRAEL JOURNAL OF CHEMISTRY
(2022)
Article
Biochemical Research Methods
Jaka Mur, Vid Agrez, Jaka Petelin, Rok Petkovsek
Summary: This study focuses on the influence of boundaries on the dynamics and morphology of cavitation bubbles, particularly the observation and measurement of jetting behavior near tissue-phantom biointerfaces. The researchers used time-resolved optical microscopy to observe the important mechanism of boundary poration and explained it for different tissue-phantom surface densities and Young's modulus.
BIOMEDICAL OPTICS EXPRESS
(2022)
Article
Environmental Sciences
Luka Pirker, Ziga Velkavrh, Agnese Osite, Luka Drinovec, Grisa Mocnik, Maja Remskar
Summary: The study shows that fireworks have a negative impact on the environment by releasing air pollutants, including heavy metals. Findings reveal that after fireworks events, there is an increase in the concentrations of black carbon and nanoparticles in the air, as well as significant increases in the mass concentrations of PM10 and PM2.5.
AIR QUALITY ATMOSPHERE AND HEALTH
(2022)
Article
Nanoscience & Nanotechnology
Bojana Visic, Luka Pirker, Marko Opacic, Ana Milosavljevic, Nenad Lazarevic, Boris Majaron, Maja Remskar
Summary: Four distinct tungsten suboxide nanomaterials were synthesized and their crystal structures were found to play a significant role in their optical properties. The different crystal structures affect the bandgap, localized surface plasmon resonances, and excitonic transitions.
Article
Optics
Jaka Mur, Fabian Reuter, Jernej Jan Kocica, Ziga Lokar, Jaka Petelin, Vid Agrez, Claus-Dieter Ohl, Rok Petkovsek
Summary: This paper presents a multi-frame multi-exposure shock wave velocity measurement technique that can measure the propagation speed of shock waves in different directions, verified by a fiber-optic probe hydrophone. The experimental results show that the pressure is higher at closer distances to the plasma center.
Article
Chemistry, Multidisciplinary
Luka Pirker, Robert Lawrowski, Rupert Schreiner, Maja Remskar, Bojana Visic
Summary: Transition metal dichalcogenide (TMDC) nanotubes, with their quasi-1D morphology and intriguing properties, complement the field of low-dimensional materials. The properties of TMDC nanotubes can be tailored for specific purposes and applications by introducing different transition metals into the crystal structure. This study presents the characterization and preparation of single-nanotube field emission devices of MoxWx-1S2 nanotubes, prepared via chemical vapor transport reaction.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Robin T. K. Schock, Jonathan Neuwald, Wolfgang Moeckel, Matthias Kronseder, Luka Pirker, Maja Remskar, Andreas K. K. Huettel
Summary: It is demonstrated that adding a bismuth semimetal layer between the contact metal and the nanomaterial significantly improves the properties of the contacts, leading to better stability and less trap states.
ADVANCED MATERIALS
(2023)
Article
Acoustics
Vid Agrez, Jaka Mur, Jaka Petelin, Rok Petkovsek
Summary: For the first time, the nucleation and growth of micrometer-sized cavitation bubbles in water generated by a 60 ps 515 nm fiber laser were observed and visualized. Two types of cavitation events were identified and visualized, showing a significant difference in excitation energy converted to mechanical effects. This finding has potential positive implications for laser treatments of biological tissue.
ULTRASONICS SONOCHEMISTRY
(2023)
Article
Mechanics
Jaka Mur, Vid Agrez, Jure Zevnik, Rok Petkovsek, Matevz Dular
Summary: This article presents a novel experimental method and numerical simulations to study the collapse of microbubbles near a fiber. Two different modes of bubble collapse were identified, and a planar jet formation towards the fiber was observed. The experimental and numerical results were in good agreement.
Article
Chemistry, Physical
Gregor Filipic, Luka Pirker, Anja Pogacnik Krajnc, Marjan Jeselnik, Maja Remskar
Summary: Pollutants and infectious diseases can spread through air, but respiratory masks can reduce inhalation and protect against airborne diseases. However, the single-use nature of masks has led to a significant increase in non-recyclable waste, polluting the environment with plastic. Researchers investigated the filtration efficiency of aerosols using natural materials enhanced with electrospun polymer fibers, achieving up to 80% increase in efficiency. By optimizing the thickness of the polymer fibers, the amount of plastic used can be minimized while maintaining high filtration efficiency.
Article
Chemistry, Analytical
Jernej Jan Kocica, Jaka Mur, Julien Didierjean, Arnaud Guillossou, Julien Saby, Jaka Petelin, Girolamo Mincuzzi, Rok Petkovsek
Summary: Laser microstructuring has been extensively studied for its contactless processing and exceptional precision. However, the use of high laser powers has been limited by scanner movement. In this study, a nanosecond UV laser was used in a pulse-on-demand mode to maximize scanner utilization. The effects of high-frequency pulse-on-demand operation were analyzed in terms of processing speeds, ablation efficiency, surface quality, repeatability, and precision. The study also investigated the effects of laser pulse duration on microstructuring. The results showed that pulse-on-demand operation is suitable for microstructuring, but scanner limitations still exist. Longer pulse durations improve ablation efficiency but degrade structure quality.
Article
Materials Science, Multidisciplinary
Vaibhav Varade, Golam Haider, Luka Pirker, Jaganandha Panda, Jan Sykora, Otakar Frank, Martin Kalbac, Jana Vejpravova
Summary: In this study, sulfur isotope engineering is used to investigate the role of excitons in the optoelectronic properties of 2D TMDCs. The introduction of heavier isotopes in MoS2 leads to a variation in lattice phonon energy and alters the photoluminescence spectra. The isotopically pure monolayers exhibit enhanced emission efficiencies compared to isotopically mixed MLs.