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Keywords = femtosecond laser-induced plasma spectroscopy

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14 pages, 3615 KiB  
Article
Properties of Zirconia, Lithium Disilicate Glass Ceramics, and VITA ENAMIC® Hybrid Ceramic Dental Materials Following Ultra-Short Femtosecond (30 fs) Laser Irradiation
by Victor L. Lagunov, Bakhtiar Ali, Laurence J. Walsh, Andrew B. Cameron, Igor V. Litvinyuk, Maksym Rybachuk and Roy George
Appl. Sci. 2024, 14(17), 7641; https://doi.org/10.3390/app14177641 - 29 Aug 2024
Cited by 1 | Viewed by 2080
Abstract
This study investigated the dose-dependent changes in the chemical composition of three dental ceramic materials—zirconia, lithium disilicate (LD), and VITA ENAMIC® hybrid composite (VITA En)—following irradiation with an ultra-short femtosecond (fs) laser (800 nm, 30 fs, 1 kHz) [...] Read more.
This study investigated the dose-dependent changes in the chemical composition of three dental ceramic materials—zirconia, lithium disilicate (LD), and VITA ENAMIC® hybrid composite (VITA En)—following irradiation with an ultra-short femtosecond (fs) laser (800 nm, 30 fs, 1 kHz) in an ambient air environment using average laser power (76 mW) and scanning speeds (50, 100, and 200 mm/s), simulating dental treatment processes. The chemical composition of the ablated regions was analyzed using energy dispersive spectroscopy. All irradiated samples showed increased carbon content (by up to 42%) and reduced oxygen (by up to 33%). The observed increase in C content is likely attributed to a combination of surface reactions, adsorption of carbon from the ambient environment, and carbon deposition from the laser-induced plasma, all facilitated by the high-energy conditions created by fs-laser pulses. Scanning electron microscopy revealed ablation with progressive controlled melting and recrystallization, with an absence of pile-up features typically associated with significant thermal damage. These findings demonstrate that ultra-short fs-laser irradiation induces highly controlled, dose-dependent changes in the chemical composition and surface morphology of dental ceramic materials. Full article
(This article belongs to the Special Issue New Advances in Laser Dental Science and Biophotonics)
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12 pages, 4264 KiB  
Article
Postfilament-Induced Two-Photon Fluorescence of Dyed Liquid Aerosol Enhanced by Structured Femtosecond Laser Pulse
by Dmitry V. Apeksimov, Pavel A. Babushkin, Yury E. Geints, Andrey M. Kabanov, Elena E. Khoroshaeva, Victor K. Oshlakov, Alexey V. Petrov and Alexander A. Zemlyanov
Atmosphere 2024, 15(7), 813; https://doi.org/10.3390/atmos15070813 - 6 Jul 2024
Cited by 1 | Viewed by 1500
Abstract
Laser-induced fluorescence spectroscopy (LIFS) is actively used for remote sensing of atmospheric aerosols and is currently one of the most sensitive and selective techniques for determining small concentrations of substances inside particles. The use of high-power femtosecond laser sources for LIFS-based remote sensing [...] Read more.
Laser-induced fluorescence spectroscopy (LIFS) is actively used for remote sensing of atmospheric aerosols and is currently one of the most sensitive and selective techniques for determining small concentrations of substances inside particles. The use of high-power femtosecond laser sources for LIFS-based remote sensing of aerosols contributes to the development of new-generation fluorescence atmospheric lidars since it makes it possible to overcome the energy threshold for the nonlinear-optical effects of multiphoton absorption in particles and receive the emission signal at long distances in the atmosphere. Our study is aimed at the development and experimental demonstration of the technique of nonlinear laser-induced fluorescence spectroscopy (NLIFS) based on the remote excitation of aerosol fluorescent emission stimulated by a spatially structured high-power femtosecond laser pulse. Importantly, for the first time to our knowledge, we demonstrate the advances in using stochastically structured plasma-free intense light channels (postfilaments) specially formed by the propagation of femtosecond laser radiation through a turbulent air layer to improve NLIFS efficiency. A multiple increase in the received signal of two-photon-excited fluorescence of polydisperse-dyed aqueous aerosols by the structured postfilaments is reported. Full article
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14 pages, 4040 KiB  
Article
THz Generation by Two-Color Plasma: Time Shaping and Ultra-Broadband Polarimetry
by Domenico Paparo, Anna Martinez, Andrea Rubano, Jonathan Houard, Ammar Hideur and Angela Vella
Sensors 2024, 24(13), 4265; https://doi.org/10.3390/s24134265 - 30 Jun 2024
Cited by 2 | Viewed by 1782
Abstract
The generation of terahertz radiation via laser-induced plasma from two-color femtosecond pulses in air has been extensively studied due to its broad emission spectrum and significant pulse energy. However, precise control over the temporal properties of these ultra-broadband terahertz pulses, as well as [...] Read more.
The generation of terahertz radiation via laser-induced plasma from two-color femtosecond pulses in air has been extensively studied due to its broad emission spectrum and significant pulse energy. However, precise control over the temporal properties of these ultra-broadband terahertz pulses, as well as the measurement of their polarization state, remain challenging. In this study, we review our latest findings on these topics and present additional results not previously reported in our earlier works. First, we investigate the impact of chirping on the fundamental wave and the effect of manipulating the phase difference between the fundamental wave and the second-harmonic wave on the properties of generated terahertz pulses. We demonstrate that we can tune the time shape of terahertz pulses, causing them to reverse polarity or become bipolar by carefully selecting the correct combination of chirp and phase. Additionally, we introduce a novel technique for polarization characterization, termed terahertz unipolar polarimetry, which utilizes a weak probe beam and avoids the systematic errors associated with traditional methods. This technique is effective for detecting polarization-structured terahertz beams and the longitudinal component of focused terahertz beams. Our findings contribute to the improved control and characterization of terahertz radiation, enhancing its application in fields such as nonlinear optics, spectroscopy, and microscopy. Full article
(This article belongs to the Special Issue Research Development in Terahertz and Infrared Sensing Technology)
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14 pages, 2984 KiB  
Article
Femtosecond Laser Ablation of a Bulk Graphite Target in Water for Polyyne and Nanomaterial Synthesis
by Nikolaos G. Semaltianos, Ona Balachninaitė, Remigijus Juškėnas, Audrius Drabavicius, Gediminas Niaura and Euan Hendry
Appl. Sci. 2023, 13(18), 10388; https://doi.org/10.3390/app131810388 - 17 Sep 2023
Cited by 1 | Viewed by 2260
Abstract
Laser ablation of a bulk graphite target in water using femtosecond laser pulses (pulse width ≤ 190 fs) was performed to investigate the synthesis of polyynes and carbon-based nanomaterials and compare them with the well-studied cases of longer pulse (picosecond or nanosecond) ablations. [...] Read more.
Laser ablation of a bulk graphite target in water using femtosecond laser pulses (pulse width ≤ 190 fs) was performed to investigate the synthesis of polyynes and carbon-based nanomaterials and compare them with the well-studied cases of longer pulse (picosecond or nanosecond) ablations. The laser ablation products were characterized using UV-vis absorption spectroscopy, Raman spectroscopy, X-ray diffraction, and transmission electron microscopy, whereas the induced plasma plumes were characterized using laser-induced breakdown spectroscopy. Carbon-based nanomaterials and short-chain polyynes (C6H2 and C8H2) are formed in the solutions as proven by their characteristic absorption band at ~262 nm and peaks in the region of 190–240 nm as well as at around 2100 cm−1 in the Raman spectra, respectively. Polyynes (C8H2) are present in the solutions that are produced under an ablation that is carried out in two intervals with a short pause between them, which is contrary to a continuous ablation that is performed for the same total time duration. The ablation products have a hexagonal graphite crystal structure. The carbon-based nanomaterials consist of large non-spherical and small spherical nanoparticles as well as sheet-like structures. The results of the study were compared with previous studies and discussed based on those studies. Full article
(This article belongs to the Special Issue Applied Laser Processing, Manufacturing, and Materials Science)
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14 pages, 2801 KiB  
Article
Angular Patterns of Nonlinear Emission in Dye Water Droplets Stimulated by a Femtosecond Laser Pulse for LiDAR Applications
by Yury E. Geints
Remote Sens. 2023, 15(16), 4004; https://doi.org/10.3390/rs15164004 - 12 Aug 2023
Cited by 2 | Viewed by 1538
Abstract
Femtosecond laser-induced fluorescence (FLIF) and femtosecond laser-induced optical breakdown spectroscopy (FIBS) are important tools for remote diagnostics of atmospheric aerosols using LiDAR (Light Identification Detection and Ranging) technology. They are based on light emission excitation in disperse media via multiphoton nonlinear processes in [...] Read more.
Femtosecond laser-induced fluorescence (FLIF) and femtosecond laser-induced optical breakdown spectroscopy (FIBS) are important tools for remote diagnostics of atmospheric aerosols using LiDAR (Light Identification Detection and Ranging) technology. They are based on light emission excitation in disperse media via multiphoton nonlinear processes in aerosol particles induced by high-power optical pulses. To date, the main challenge restraining the large-scale application of FLIF and FIBS in atmospheric studies is the lack of a valued theory of the stimulated light emission in liquid microparticles with a sufficiently broad range of sizes. In this paper, we fill this gap and present a theoretical model of dye water droplet emission under high intensity laser exposure that adequately simulates the processes of multiphoton excited fluorescence and optical breakdown plasma emission in microparticles and gives quantitative estimates of the angular and power characteristics of nonlinear emission. The model is based on the numerical solution to the inhomogeneous Helmholtz equations for stimulating (primary) and nonlinear (secondary) waves provided by the random nature of molecule emission in particles. We show that droplet fluorescence stimulated by multiphoton absorption generally becomes more intense with increasing particle size. Moreover, far-field plasma emission from liquid particles demonstrates a larger angular diversity when changing the droplet radius in comparison with multiphoton excited fluorescence, which is mainly due to the excitation of the internal optical field resonances in spherical particles. Full article
(This article belongs to the Special Issue Advances in Remote Sensing and Atmospheric Optics)
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13 pages, 5570 KiB  
Article
Homogeneity Measurements of Li-Ion Battery Cathodes Using Laser-Induced Breakdown Spectroscopy
by Moritz Kappeler, Carl Basler, Albrecht Brandenburg, Daniel Carl and Jürgen Wöllenstein
Sensors 2022, 22(22), 8816; https://doi.org/10.3390/s22228816 - 15 Nov 2022
Cited by 8 | Viewed by 2537
Abstract
We study the capability of nanosecond laser-induced breakdown spectroscopy (ns-LIBS) for depth-resolved concentration measurements of Li-Ion battery cathodes. With our system, which is optimized for quality control applications in the production line, we pursue the goal to unveil manufacturing faults and irregularities during [...] Read more.
We study the capability of nanosecond laser-induced breakdown spectroscopy (ns-LIBS) for depth-resolved concentration measurements of Li-Ion battery cathodes. With our system, which is optimized for quality control applications in the production line, we pursue the goal to unveil manufacturing faults and irregularities during the production process of cathodes as early as possible. Femtosecond laser-induced breakdown spectroscopy (fs-LIBS) is widely considered to be better suited for depth-resolved element analysis. Nevertheless, the small size and intensity of the plasma plume, non-thermal energy distribution in the plasma and high investment costs of fs-LIBS make ns-LIBS more attractive for inline application in the industrial surrounding. The system, presented here for the first time, is able to record quasi-depth-resolved relative concentration profiles for carbon, nickel, manganese, cobalt, lithium and aluminum which are the typical elements used in the binder/conductive additive, the active cathode material and the current collector. LIBS often causes high variations in signal intensity from pulse to pulse, so concentration determination is, in general, conducted on the average of many pulses. We show that the spot-to-spot variations we measure are governed by the microstructure of the cathode foil and are not an expression of the limited precision of the LIBS setup. Full article
(This article belongs to the Special Issue Recent Trends and Advances in Laser Spectroscopy and Sensing)
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10 pages, 2936 KiB  
Article
Elemental Analysis of V, Mo, Cr, Mn, Al, Ni, and Cu in Steel Alloy with Femtosecond Laser Ablation Spark-Induced Breakdown Spectroscopy
by Xiaoyong He, Qi Yang, Dongxiong Ling, Dongshan Wei and Hongcheng Wang
Chemosensors 2022, 10(9), 370; https://doi.org/10.3390/chemosensors10090370 - 17 Sep 2022
Cited by 3 | Viewed by 2717
Abstract
Femtosecond laser ablation spark-induced breakdown spectroscopy (fs LA-SIBS) was developed to quantitatively analyze vanadium, molybdenum, chromium, manganese, aluminum, nickel, and copper in a steel alloy. In the experiment, a femtosecond laser operating at a repetition rate of 1 kHz was used as the [...] Read more.
Femtosecond laser ablation spark-induced breakdown spectroscopy (fs LA-SIBS) was developed to quantitatively analyze vanadium, molybdenum, chromium, manganese, aluminum, nickel, and copper in a steel alloy. In the experiment, a femtosecond laser operating at a repetition rate of 1 kHz was used as the laser ablation source, and spark discharge was utilized to re-excite the plasma and enhance the atomic intensity. A compact fiber spectrometer was used to record and analyze the plasma emission spectra in a nongated signal-recording mode. The calibration curves of V, Mo, Cr, Mn, Al, Ni, and Cu elements in steel alloy samples were established, and the detection limits of these elements were determined to be 10.9, 12.6, 4.0, 5.7, 8.7, 7.9, and 3.1 ppm with fs LA-SIBS, respectively, which were 4–12-fold better than those achieved with femtosecond laser-induced breakdown spectroscopy (fs LIBS). Compared with conventional LIBS, the fs LA-SIBS technique provided a rapid and high spatial resolution approach to quantitative elemental analysis, with better analytical sensitivity. Full article
(This article belongs to the Special Issue Application of Laser-Induced Breakdown Spectroscopy)
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11 pages, 2862 KiB  
Article
Time-Resolved Imaging of Femtosecond Laser-Induced Plasma Expansion in a Nitrogen Microjet
by Anna Gabriella Ciriolo, Rebeca Martínez Vázquez, Gabriele Crippa, Michele Devetta, Aldo Frezzotti, Daniela Comelli, Gianluca Valentini, Roberto Osellame, Caterina Vozzi and Salvatore Stagira
Appl. Sci. 2022, 12(4), 1978; https://doi.org/10.3390/app12041978 - 14 Feb 2022
Cited by 1 | Viewed by 2356
Abstract
We report on the study of ultrafast laser-induced plasma expansion dynamics in a gas microjet. To this purpose, we focused femtosecond laser pulses on a nitrogen jet produced through a homemade De Laval micronozzle. The laser excitation led to plasma generation with a [...] Read more.
We report on the study of ultrafast laser-induced plasma expansion dynamics in a gas microjet. To this purpose, we focused femtosecond laser pulses on a nitrogen jet produced through a homemade De Laval micronozzle. The laser excitation led to plasma generation with a characteristic spectral line emission at 391 nm. By following the emitted signal with a detection system based on an intensified charge-coupled device (ICCD) we captured the two-dimensional spatial evolution of the photo-excited nitrogen ions with a temporal resolution on the nanosecond time scale. We fabricated the micronozzle on a fused silica substrate by femtosecond laser micromachining. This technique enabled high accuracy and three-dimensional capabilities, thus, providing an ideal platform for developing glass-based microfluidic structures for application to plasma physics and ultrafast spectroscopy. Full article
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25 pages, 3785 KiB  
Review
A Review of Femtosecond Laser-Induced Emission Techniques for Combustion and Flow Field Diagnostics
by Bo Li, Dayuan Zhang, Jixu Liu, Yifu Tian, Qiang Gao and Zhongshan Li
Appl. Sci. 2019, 9(9), 1906; https://doi.org/10.3390/app9091906 - 9 May 2019
Cited by 32 | Viewed by 8768
Abstract
The applications of femtosecond lasers to the diagnostics of combustion and flow field have recently attracted increasing interest. Many novel spectroscopic methods have been developed in obtaining non-intrusive measurements of temperature, velocity, and species concentrations with unprecedented possibilities. In this paper, several applications [...] Read more.
The applications of femtosecond lasers to the diagnostics of combustion and flow field have recently attracted increasing interest. Many novel spectroscopic methods have been developed in obtaining non-intrusive measurements of temperature, velocity, and species concentrations with unprecedented possibilities. In this paper, several applications of femtosecond-laser-based incoherent techniques in the field of combustion diagnostics were reviewed, including two-photon femtosecond laser-induced fluorescence (fs-TPLIF), femtosecond laser-induced breakdown spectroscopy (fs-LIBS), filament-induced nonlinear spectroscopy (FINS), femtosecond laser-induced plasma spectroscopy (FLIPS), femtosecond laser electronic excitation tagging velocimetry (FLEET), femtosecond laser-induced cyano chemiluminescence (FLICC), and filamentary anemometry using femtosecond laser-extended electric discharge (FALED). Furthermore, prospects of the femtosecond-laser-based combustion diagnostic techniques in the future were analyzed and discussed to provide a reference for the relevant researchers. Full article
(This article belongs to the Special Issue State-of-the-art Laser Gas Sensing Technologies)
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19 pages, 3642 KiB  
Article
The Potential of EuPRAXIA@SPARC_LAB for Radiation Based Techniques
by Antonella Balerna, Samanta Bartocci, Giovanni Batignani, Alessandro Cianchi, Enrica Chiadroni, Marcello Coreno, Antonio Cricenti, Sultan Dabagov, Andrea Di Cicco, Massimo Faiferri, Carino Ferrante, Massimo Ferrario, Giuseppe Fumero, Luca Giannessi, Roberto Gunnella, Juan José Leani, Stefano Lupi, Salvatore Macis, Rosa Manca, Augusto Marcelli, Claudio Masciovecchio, Marco Minicucci, Silvia Morante, Enrico Perfetto, Massimo Petrarca, Fabrizio Pusceddu, Javad Rezvani, José Ignacio Robledo, Giancarlo Rossi, Héctor Jorge Sánchez, Tullio Scopigno, Gianluca Stefanucci, Francesco Stellato, Angela Trapananti and Fabio Villaadd Show full author list remove Hide full author list
Condens. Matter 2019, 4(1), 30; https://doi.org/10.3390/condmat4010030 - 7 Mar 2019
Cited by 14 | Viewed by 5081
Abstract
A proposal for building a Free Electron Laser, EuPRAXIA@SPARC_LAB, at the Laboratori Nazionali di Frascati, is at present under consideration. This FEL facility will provide a unique combination of a high brightness GeV-range electron beam generated in a X-band RF linac, a 0.5 [...] Read more.
A proposal for building a Free Electron Laser, EuPRAXIA@SPARC_LAB, at the Laboratori Nazionali di Frascati, is at present under consideration. This FEL facility will provide a unique combination of a high brightness GeV-range electron beam generated in a X-band RF linac, a 0.5 PW-class laser system and the first FEL source driven by a plasma accelerator. The FEL will produce ultra-bright pulses, with up to 10 12 photons/pulse, femtosecond timescale and wavelength down to 3 nm, which lies in the so called “water window”. The experimental activity will be focused on the realization of a plasma driven short wavelength FEL able to provide high-quality photons for a user beamline. In this paper, we describe the main classes of experiments that will be performed at the facility, including coherent diffraction imaging, soft X-ray absorption spectroscopy, Raman spectroscopy, Resonant Inelastic X-ray Scattering and photofragmentation measurements. These techniques will allow studying a variety of samples, both biological and inorganic, providing information about their structure and dynamical behavior. In this context, the possibility of inducing changes in samples via pump pulses leading to the stimulation of chemical reactions or the generation of coherent excitations would tremendously benefit from pulses in the soft X-ray region. High power synchronized optical lasers and a TeraHertz radiation source will indeed be made available for THz and pump–probe experiments and a split-and-delay station will allow performing XUV-XUV pump–probe experiments. Full article
(This article belongs to the Special Issue High Precision X-Ray Measurements)
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12 pages, 1774 KiB  
Article
Dual THz Wave and X-ray Generation from a Water Film under Femtosecond Laser Excitation
by Hsin-hui Huang, Takeshi Nagashima, Wei-hung Hsu, Saulius Juodkazis and Koji Hatanaka
Nanomaterials 2018, 8(7), 523; https://doi.org/10.3390/nano8070523 - 13 Jul 2018
Cited by 36 | Viewed by 5985
Abstract
Simultaneous emission of the THz wave and hard X-ray from thin water free-flow was induced by the irradiation of tightly-focused femtosecond laser pulses (35 fs, 800 nm, 500 Hz) in air. Intensity measurements of the THz wave and X-ray were carried out at [...] Read more.
Simultaneous emission of the THz wave and hard X-ray from thin water free-flow was induced by the irradiation of tightly-focused femtosecond laser pulses (35 fs, 800 nm, 500 Hz) in air. Intensity measurements of the THz wave and X-ray were carried out at the same time with time-domain spectroscopy (TDS) based on electro-optic sampling with a ZnTe(110) crystal and a Geiger counter, respectively. Intensity profiles of the THz wave and X-ray emission as a function of the solution flow position along the incident laser axis at the laser focus show that the profile width of the THz wave is broader than that of the X-ray. Furthermore, the profiles of the THz wave measured in reflection and transmission directions show different features and indicate that THz wave emission is, under single-pulse excitation, induced mainly in laser-induced plasma on the water flow surface. Under double-pulse excitation with a time separation of 4.6 ns, 5–10 times enhancements of THz wave emission were observed. Such dual light sources can be used to characterise materials, as well as to reveal the sequence of material modifications under intense laser pulses. Full article
(This article belongs to the Special Issue Laser-Based Nano Fabrication and Nano Lithography)
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