Femtosecond Laser Irradiation Research Articles

Targeted Microforming of Borosilicate Glass Induced by a Laser‐Ablation‐Free Process Using Femtosecond Pulses

AbstractThe use of ultrashort pulse lasers opens up a wide range of possibilities for processing dielectric materials. The present study focuses on the investigation of the ablation‐free microscopic surface modification of borosilicate glass using femtosecond laser radiation (350 fs at 515 nm wavelength) in a scanning machining process. Furthermore, its aim is to analyze the relationship between the laser process parameters and the microscopic changes in the surface topography observed. The characteristic of the generated surface structure, which takes place below the ablation threshold, shows both elevations and depressions within the irradiated field (2 × 2 mm2). The realized structures reach a profile height Peak‐to‐Valley (PV) of up to 10 µm. The amount of surface deformation depends on the selected parameters such as laser fluence, number of passes, and scanning strategy. The microdeformation is detected on both the top and bottom sides of the processed glass material with a thickness ≤1 mm. The influence of the temporal and spatial energy distribution on the material modification is discussed, demonstrating the possibilities of microforming of silicate glasses using ultrashort pulsed laser radiation.

Berberine-loaded nanoemulsions as a natural food preservative; the impact of femtosecond laser irradiation on the antibacterial activity

There is a growing concern among food safety regulators, the food industry, and consumers about foodborne illnesses. To improve food safety and increase shelf life, it is necessary to use natural preservatives. Natural antimicrobials are safer than artificial preservatives because they can prevent microbial resistance while also meeting consumers' demands for healthier food. This study used Berberine to enhance the antibacterial activity of Satureja Khuzistanica essential oil nanoemulsions (SKEO NE) against Staphylococcus aureus (S. aureus) bacteria, making them a promising option as preservatives. Response Surface Methodology (RSM) was employed to determine the optimized Berberine loaded SKEO NE (Berberine/SKEO NE), resulting in a mean droplet size of 88.60 nm at 6.91, 3.21, and 0.08% w/w of surfactant, essential oil, and Berberine, respectively. Berberine utilization in SKEO NE has led to an increase in antibacterial activity. The nanoemulsion samples significantly ruptured the S. aureus bacterial cell membrane, rapidly discharging cell contents. The use of a microfluidic system in tandem based on the conventional approach significantly accelerated this process. Enhancing the interaction between nanodroplets and the bacterial membrane can be achieved through the nanoemulsification process of EOs, which involves modifying their surface characteristics. This enhancement is particularly pronounced when employing microfluidic systems due to their substantial contact surface area. We investigated the potential of using femtosecond laser irradiation at a wavelength of 1040 nm to augment the antibacterial action of nanoemulsions. The combined treatment of laser and nanoemulsions significantly increased the antibacterial effect of nanoemulsions by approximately 15% for each bacterium, suggesting the potential utility of this treatment to bolster the antibacterial activity of nanoemulsions. Bacteria were trapped using optical tweezers for up to 20 min, with bacterial destruction observed starting at 3 min and exhaustive destruction evident after 20 min.

Ageing of commercial austenitic, martensitic and duplex stainless steel surfaces after formation of laser-induced periodic surface structures by fs-laser irradiation

The time-dependent wetting behavior was investigated for commercially available austenitic, martensitic and duplex stainless steel surfaces after femtosecond (fs) laser irradiation. For this purpose, highly regular LIPSS with almost identical geometric properties were generated on the stainless steels in an air environment by near-infrared fs-laser processing (λ = 1025 nm, τ = 300 fs, frep = 100 kHz, v = 0.67 m/s, Δx = 6 μm, F=1.1 J/cm2) and compared to the polished initial surfaces as reference. The wetting with distilled water was evaluated as a function of aging time by contact angle measurements using the sessile drop method. The laser-induced morphological, topographical and chemical alteration of the surface was characterized by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, glow-discharge optical emission spectroscopy as well as high-resolution imaging and scanning transmission electron microscopy. Despite an almost identical LIPSS-based topography alteration, the stainless steels revealed very different ageing behavior. For permanently used samples, it was shown that the ageing effect is less pronounced than for samples that were stored in ambient air following fs-laser irradiation until the wetting measurement. The results obtained make an important contribution to understanding and controlling the ageing effect of metal surfaces and thus facilitate the transfer of LIPSS-based functional surface engineering and design to industrial processes.

Reversible modulations of insulator–metal transition in an epitaxial VO2 film through thermal crystallization and femtosecond laser-induced-amorphization of capping Ge2Sb2Te5 layer

We demonstrate reversible modulation of an insulator–metal transition (IMT) of a VO2 film grown on an Al2O3 (001) substrate through crystallization and re-amorphization of a chalcogenide germanium–antimony–telluride (Ge2Sb2Te5: GST) capping layer. After succeeding in the negative shift of IMT temperature (Tr) of the VO2 film through the crystallization of the GST layer accompanied by volume reduction, we performed re-amorphization of the crystalline GST by femtosecond laser irradiation. Under the optimized conditions of laser irradiation considering the penetration depth, re-amorphization of the GST layer was fully achieved, resulting in the shift-back of Tr toward a high-temperature side. Such a reversal of IMT through the crystallization and re-amorphization of the capping GST layer was demonstrated over two cycles. It was suggested that capping GST effectively induces interfacial strain modifications in the VO2 film underneath. Although the shifts in the IMT are still small, reversible modulation of IMT shown here will be beneficial for applications of VO2 films with controllable IMT.

Ultrafast dynamics and internal processing mechanism of silica glass under double-pulse femtosecond laser irradiation

Femtosecond laser-induced plasma filaments have potential for various applications including attosecond physics, spectroscopy, and microprocessing. However, the use of plasma filaments to generate high-aspect-ratio internal modifications remains low-efficiency. Here, we experimentally demonstrated high-efficiency internal processing using plasma filaments induced by a double-pulse femtosecond laser. The processing mechanism was revealed through an investigation of the ultrafast dynamics of plasma filaments in experiments and simulations. We found that the excitation region of the first pulse (P1) exerted a temporal effect on the propagation and absorption of the second pulse (P2) due to the evolution of excited electrons, thus resulting in different processing characterizations. At a smaller inter-pulse delay (IPD), electrons and self-trapped excitons induced by P1 improved the absorption of P2 in the shallow region. Consequently, the main excitation regions of P1 and P2 were separated, resulting in a lower density of energy deposition and weak modifications. Whereas, at a larger IPD, P2 penetrated a deeper region with the relaxation of electrons and excitons induced by P1, leading to a better overlap of excitation regions between P2 and P1, thus improving the density of energy deposition and achieving efficient microprocessing. Besides, at an infinite IPD, P2 behaved like P1, but no modification was obtained owing to the complete energy diffusion of P1. Therefore, controlling the electron dynamic and energy diffusion contributes to the improvement of modification efficiency. Furthermore, the distribution of electron densities on the cross section was estimated to precisely analyze the microprocessing. These results are expected to aid in a better understanding of the interaction mechanism between dielectrics and intense ultrafast lasers and be useful for microprocessing applications.

Near-Field-Regulated Ultrafast Laser Supra-Wavelength Structuring Directly on Ultrahard Metallic Glasses.

The ultrafast-laser-matter interactions enable "top-down" laser surface structuring, especially for materials difficult to process, with "bottom-up" self-organizing features. The subwavelength scenarios of laser-induced structuring are improved in defects and long-range order by applying positive/negative feedbacks. It is still hardly reported for supra-wavelength laser structuring more associated with complicated thermo/hydro-dynamics. For the first time to the knowledge, the near-field-regulated ultrafast-laser lithography of self-arrayed supra-wavelength micro/nano-pores directly on ultra-hard metallic glass is developed here. The plasmonic hot spots on pre-structures, as the positive feedback, clamped the lateral geometries (i.e., position, size). Simultaneously, it drilled and self-organized into micro/nano-pore arrays by photo-dynamic plasma ablation and Marangoni removal confined under specific femtosecond-laser irradiation, as the negative feedback. The mechanisms and finite element modeling of the multi-physical transduction (based on the two-temperature model), the far-field/near-field coupling, and the polarization dependence during laser-matter interactions are studied. Large-area micro/nano-pore arrays (centimeter scale or larger) aremanufactured with tunable periods (1-5µm) and geometries (e.g., diameters of 500 nm-6µm using 343, 515, and 1030 lasers, respectively). Consequently, the mid/far-infrared reflectivity at 2.5-6.5µm iss decreased from ≈80% to ≈5%. The universality of multi-physical coupling and near-field enhancements makes this approach widely applicable, or even irreplaceable, in various applications.

Ultrafast spallation dynamics of a thin gold film characterized by imaging pump-probe interferometry

Interferometry allows to measure microscopic displacements in the nanometer scale. This work introduces an imaging pump-probe interferometer that enables to detect the spatially resolved phase shift of the probe radiation being reflected on a sample surface after ultrashort pulsed laser excitation with a temporal resolution of 40 fs and a maximum temporal delay of 3 ns. The capability of the pump-probe interferometer is demonstrated on the spallation of a thin gold film upon femtosecond laser irradiation. The pump-probe interferometer enables to measure a minimum phase change of Δφ<π/10\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta \\varphi <\\pi /10$$\\end{document} which corresponds to a displacement of Δh<\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta h<$$\\end{document} 12.5 nm for the applied probe wavelength of 500 nm. Upon irradiation, two distinct phase changes are observable: First, an abrupt minor phase shift has been measured in the femtosecond range, which is attributed to the changed optical properties of the sample surface after excitation. Second, a more pronounced continuing phase shift increase is detectable after a few tens of picoseconds resulting from the onset of spallation. Based on the measured spatially resolved phase shift, the transient surface topography during the spallation is reconstructed. The determined velocity of the ablated material reaches a maximum of a few 1000 m/s at ten picosecond after irradiation and decreases to 250 m/s afterwards. Consequently, the introduced imaging pump-probe interferometer provides important insights into the physical processes during laser excitation as well as the subsequent laser-induced ablation, and will enable to validate theoretical models quantitatively in following studies.

Femtosecond laser technology: A new approach for water disinfection

Water makes up around 60 % of the body, making it essential to all body systems and crucial to human health and survival. The lack of clean drinking water is currently a problem in many different countries. While there are several approaches for disinfecting drinking water, including the widely used ozonation, UV irradiation, and chlorination processes, each has some drawbacks. The purpose of this study is to evaluate the effectiveness of femtosecond laser technology in disinfecting water polluted with Escherichia coli (E. coli), for the first time. Bacterial cells were exposed to a femtosecond laser light with different wavelengths, intensities, and exposure times. E. coli was subjected to femtosecond laser irradiation for 5, 10, 15, 30, and 45 min at different powers of 50, 100, and 200 mW. Femtosecond laser light, ranging from 400 to 800 nm in wavelengths, was used to irradiate E. coli bacteria. These wavelengths cover the ultraviolet, visible, and infrared spectra. Under these experimental settings, the concentration of E. coli bacteria (in CFU/ml) was instantly determined using the MTT assay. Bacterial growth was dramatically decreased to 45.2 CFU/ml (%) after 45 min of exposure to 400 nm wavelength and 200 mW averaged power. The results obtained in this study provide evidence to conclude that femtosecond laser irradiation dramatically suppresses E. coli growth. Without making direct chemical contact, femtosecond laser irradiation offers a possible remote water disinfection approach. Therefore, the femtosecond laser light could be used for water disinfection as a promising eco-friendly technique.

In-line monitoring and modelling of particle size reduction of hexagonal boron nitride (hBN) suspension in femtosecond laser processing

This study investigates the particle-size reduction of hexagonal boron nitride (hBN) suspensions under femtosecond-laser irradiation. We propose an in-line monitoring method that uses transmission spectroscopy (TS) in the visible wavelength region to evaluate the changes in particle-size distribution. The Ångström exponent (α), derived from the wavelength dependence of optical thickness, is employed as an indicator of particle-size reduction. The effectiveness of α is validated through comparison with particle-size distributions obtained by the particle tracking method. We demonstrate real-time monitoring of particle-size variation in a flow system using in-line TS measurements. The dependence of α on laser energy and hBN concentration is also investigated. Furthermore, we introduce an indicator, the average number of size-reduction events per particle (N SR), and a model for estimating it under various experimental conditions. The N SR indicator and the model for its derivation provide a unified understanding of the experimental results obtained under various conditions, such as treatment volume, laser energy, and hBN concentration, suggesting that they capture the essential aspects of laser propagation in the suspension and the particle-size reduction process. This study highlights the potential of α as an in-line process monitoring tool and the significance of the N SR indicator and its model in understanding the underlying mechanisms of laser processing for particle-size reduction in suspensions.

Ultrafast dynamics and mechanism of structure formation in titanium nitride upon femtosecond laser irradiation for plasmonic enhanced photothermal effect

Femtosecond laser has great potential in controlling the surface structure of titanium nitride (TiN) to promote plasmonic photothermal effect. Studying the mechanism of femtosecond laser irradiation on the surface and inside of the TiN benefits the photothermal microdevices. Ultrafast dynamics of electrons and lattices of TiN films with different thicknesses were first studied through pump-probe technique, which found that the electron density is easier to reach the maximum on the surface than the electrons in deep-layers. High-frequency ripple was formed by tiny nucleation resulted from weak eruption of surface material on the thin TiN film, and low-frequency ripple was emerged through large nucleation of material clusters simultaneously on the thick TiN film. The blue shift and intensity changes of Raman peak on 200 nm TiN film indicate the heterogeneous structure changed from TiN to TiN0.26 after laser processing, and the vacancy occupies causes the lattice vibration weakened. The 200 nm TiN film after processing shows enhanced local surface plasma resonance absorption effect, which induced the reflectivity is reduced by 30 %, and the light and thermal conversion efficiency increased by 80 %. These results proved the promising utilization of TiN in biological and medical applications, energy collection and thermal auxiliary magnetic records.

Регенерация волоконных брэгговских решеток, записанных поточечным методом с помощью излучения фемтосекундного лазера

The relevance of studies on the thermal stability of fiber Bragg gratings arises from the prospects of their applications in difficult operating conditions at elevated temperatures. One of the highest-temperature types of such structures formed in silica glass fibers are regenerated Bragg gratings. Generally, the regeneration effect is observed in gratings inscribed in molecular hydrogen-loaded fibers and/or in highly-doped germanosilicate fibers. This paper describes the first reported regeneration of gratings created via point-by-point inscription with femtosecond laser radiation in standard telecommunication fiber Corning SMF-28 without the presence of hydrogen in technological processes. The paper proposes an explanation of the possible mechanism for the formation of such regenerated structures.

Corrosion resistance of magnesium alloy surfaces substantially upgraded by gradient energy irradiation of femtosecond lasers

The poor corrosion resistance of magnesium (Mg) alloys is known to constitute a major obstacle to their practical applications. In this work, we proposed an approach of femtosecond laser multi-grid-scanning with the gradual decreasing energy fluence, to modulate the surface oxide properties for the anti-corrosion performance enhancement. This kind of laser processing can significantly increase the oxide passivation layer thickness by more than 100 times compared with the bare sample, and improve the oxygen content on the material surface to as high as 55.87 %. Simultaneously, the available size of MgO nanograins is further refined and has more spatially uniform distribution. Moreover, the massive production of micro/nano-structures by the femtosecond laser irradiation tends to promote the surface into the superhydrophobic with a contact angle of CA=162 ± 2 ° and a slide angle of SA=1.5 ± 0.5 °. As a result, the obtained optimal values for the corrosion current density and the annual corrosion rate are reduced to Icorr = 0.5 μA/cm2 and CR = 7×10−3 mm/y, respectively, more than 2 orders of magnitude lower than the bare sample. Such a method provides an efficient strategy to enhance the corrosion resistance of metal surfaces for future applications.

High-temperature multi-vacancy mediated diffusion of nitrogen in diamond: MD simulations and mid-IR laser experiments

Utilizing classical molecular dynamics with the precise machine-learning interatomic potential MTP, we investigated the high-temperature (3000–3500 K) dynamics of NV and N2V centers in the presence of additional free vacancies. We propose a novel mechanism for nitrogen diffusion in diamond, which involves the intermediate step of additional vacancies being absorbed by a NV center. The simulation results align with the experimentally observed transformations of NV centers into H1b and H1c in IaAB-diamond under 4.7-μm femtosecond-laser irradiation.

Postfilament-Induced Two-Photon Fluorescence of Dyed Liquid Aerosol Enhanced by Structured Femtosecond Laser Pulse

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.

Femtosecond laser darkened copper surfaces: Characterization for possible application as laser beam blocker

This study focuses on the optical and mechanical properties of copper surfaces darkened by femtosecond laser irradiation, with regard to their applicability as laser beam blockers. Copper surfaces were processed with a Ti-Sapphire laser (1 kHz repetition rate, ∼100–600 mJ/cm2 fluence), while scanning parameters were optimized for low reflectivity and processing speed. A total reflectivity below 6 % was obtained for the 250–2500 nm wavelength range. SEM imaging and ion beam etching showed submicron period structures covered with high density nanoparticles, with a total depth of ∼3–4 μm. Numerical reflectivity simulations suggest that besides the structures, the formation of oxides also contributes to the observed darkening. Thermal and mechanical stability, chemical resistance and laser damage threshold were studied. Temperatures above 200 °C caused surface degradation. Scratch tests showed that the nanostructured layers could withstand ∼60 MPa contact pressure. The surfaces could resist 48 h treatment with various acids at 10−3 M concentration. The laser damage threshold for the applied femtosecond laser showed that the surface could withstand the unfocused beam of most high-frequency femtosecond lasers. The results indicate that laser darkened copper can be a promising candidate for use in laser beam blockers.

Effect of a three-dimensional nanotube array substrate on photocatalytic conversion performance of CO2 gas to methanol by amine-loaded CuO/ZnO catalysts

The photocatalytic conversion of CO2 gas into energy-dense hydrocarbons holds the potential to address both environmental and energy problems. Catalysts consisting of CuO clusters/nanoparticles and ZnO nanorods on a metallic nanotube array (MeNTA) silicon substrate were utilized for CO2 reduction. The surface of the catalysts was modified with 3-amino-propyltriethoxysilane (APTES), the amine terminal of which can selectively bind CO2 gas. When photocatalytic CO2 reduction was performed with varying APTES and CuO contents, the highest methanol production of 4.5 mmol/g(catalyst) was obtained at 10 wt% APTES and 7.5 mM CuO contents. The high yield in the present work in comparison with previous reports is due to some advantages of the present catalytic system such as its enhanced activity, significant selectivity, and easy production: Nanometer-sized CuO produced by femtosecond pulse laser irradiation provides a larger active surface per volume and a free surface without a protector, which is favorable for advancing the catalytic activity. The formation of a heterojunction interface in a nanocomposite of p-type CuO and n-type ZnO increases holes at the valence band level of CuO, resulting in advantageous photovoltaic efficiency. The introduction of APTES on the catalyst surface enhances CO2 adsorption and brings about CO2 gas near the catalyst to accelerate the reaction rate. Finally, a three-dimensional tube array on the substrate enlarges the surface per volume for catalyst-loading compared to the two-dimensional substrate. Thus, the proposed catalytic system consisting of amine-loaded CuO/ZnO constructed on a three-dimensional nanotube array substrate is preferable for the photocatalytic conversion of CO2 gas to methanol.

Study for Photo-Induced Enhanced Raman Spectroscopy with Laser-Induced Periodic Surface Structures on Lithium Niobate on Insulator.

Femtosecond laser irradiation (FLI) of laser-induced periodic surface structures (LIPSSs) has proven to be an efficient and robust strategy for surface modification in nanoscale. Lithium niobate on insulator (LNOI) retains the excellent optoelectric properties of bulk lithium niobate and features intrinsic roughness and defects, exhibiting promising potential in the applications of surface-enhanced Raman spectroscopy (SERS) and photo-induced enhancement Raman spectroscopy (PIERS). Herein, we proposed a novel LNOI-LIPSSs-AgNPs substrate that exhibited an increased SERS enhancement by a factor of 3.7 relative to that without LIPSSs. More remarkably, with UV pre-irradiation, a PIERS amplification up to 8.1 times in comparison to SERS was achieved. Detailed and comprehensive analyses of the enhancement mechanisms prove the synergy between the electromagnetic mechanism and chemical mechanism. Additionally, the PIERS substrate exhibits advantages of high-fabrication efficiency, long-term stability, excellent detection universality, and multicyclic self-cleaning ability, which may trigger new applications in various branches of analytical science.

Seed-guided high-repetition-rate femtosecond laser oxidation for functional three-dimensional silicon structure fabrication

Laser oxidation provides a flexible maskless functional three-dimensional silicon structure fabrication strategy. Here, oxide layers are fabricated on silicon substrates by high-repetition-rate femtosecond laser irradiation. Formation mechanisms of the femtosecond laser oxidation are analyzed to tune the oxide layer morphology. When the laser fluence is high, the oxidation process is accompanied by laser ablation, so the oxide layer is always on top of laser ablated groove. To obtain the flat oxide layer, defect is firstly generated on silicon substrate by the laser irradiation at a high laser fluence of 126 mJ/cm2, function as a high optical absorption. It is called seed as it can assist to achieve lower fluence laser oxidation at 38 mJ/cm2 and result in a flat oxide layer. Full width at half-maximum of the oxide layer is also reduced. The laser fabricated oxide layers are used as etching masks. Three-dimensional silicon gratings are fabricated by deep reactive ion etching, which demonstrate desirable beam diffraction properties.

Femtosecond laser ablation responses of kerogen-rich, argillaceous, and bituminous shale rocks

Shale rocks have become one of the major sources of natural gas and oil. Laser drilling has emerged as a promising technique that can be incorporated into horizontal drilling and hydraulic fracturing processes. In this study, we selected three types of shales (kerogen-rich, argillaceous, and bituminous) with distinct compositions and microstructures and performed femtosecond laser irradiation with different power and energy to investigate their ablation characteristics. Evidence of melting and solidification was observed in all samples, despite the ultra-high pulse frequency of the femtosecond laser. Among the three types of shale rocks, the kerogen-rich shale exhibited the highest ablation rate, while argillaceous and bituminous shale showed lower and comparable rates. The above observations highlight the significance of shale chemistry in influencing laser ablation characteristics under femtosecond laser irradiation. Furthermore, no ablation rate anisotropy was observed when irradiating the samples parallel with and perpendicular to the bedding direction, although shale rocks are microstructurally and mechanically anisotropic.

Investigating the ablation threshold and morphology of spots generated on graphite electrode by femtosecond Gaussian laser pulses

This study investigates the effects of femtosecond laser irradiation on graphite, a highly sought-after material known for its exceptional chemical stability and ability to withstand extreme temperatures. The ablation threshold and surface morphology of graphite were determined using a tightly focused laser beam with varying pulse numbers and laser fluences. The results showed that the laser beam produced diverse morphological structures within different regions of a single laser spot, and the ablation threshold and surface morphology were significantly influenced by the number of pulses and the energy density of the incident laser. The study found that the ablation threshold of graphite was 107, 90, 76, and 56 ± 0.5 mJ/cm2 for 5, 50, 200, and 500 laser pulses, respectively. The resulting surface structures ranged from quasi-periodic to periodic, with varying periodicities, and the ablation debris exhibited morphologies from fine particles to long filaments. The crystal structure of the specimen was analyzed via X-ray diffraction and micro-Raman spectroscopy, with compositional analysis performed using energy-dispersive X-ray spectroscopy (EDX). Notably, a significant broadening of the Raman spectrum peaks with increasing pulse energy suggested the formation of a more disordered structure. These findings demonstrate that femtosecond laser ablation can precisely manipulate the surface morphology and nanoparticle production, presenting potential applications in fields such as nanoparticle generation and engineering surface properties like adhesion, biocompatibility, spectral reflectivity, wear resistance, and wettability.