A5017668071- Laser Material Processing Techniques
- Advanced Surface Polishing Techniques
- Laser-induced spectroscopy and plasma
- Laser-Plasma Interactions and Diagnostics
- Optical Coherence Tomography Applications
- Laser Design and Applications
- Laser-Matter Interactions and Applications
- Orbital Angular Momentum in Optics
- Advanced Fiber Laser Technologies
- High-pressure geophysics and materials
- Ocular and Laser Science Research
- Surface Roughness and Optical Measurements
- Glass properties and applications
- Chalcogenide Semiconductor Thin Films
- Laser and Thermal Forming Techniques
- Copper-based nanomaterials and applications
- Quantum Dots Synthesis And Properties
- Erosion and Abrasive Machining
- Nonlinear Optical Materials Studies
- Space Exploration and Technology
- Photonic Crystals and Applications
- Solid State Laser Technologies
Center for Physical Sciences and Technology
2013-2025
The extended focal depth of Bessel beams is a very attracting property for glass cutting applications. However, beam generation with non-ideal conical lens induces pattern distortions. We present our novel results on bulk modifications soda-lime using axicon-generated beam. Modelling the and experimental measurements indicated ellipticity central core diameter. That resulted in formation cracks transverse direction inside glass. Furthermore, we demonstrate possibility to control crack...
We report on the stable and continuous operation of a kilohertz laser-plasma accelerator. Electron bunches with 2.6 pC charge 2.5 MeV peak energy were generated via injection trapping in downward plasma density ramp. This transition was produced newly designed asymmetrically shocked gas nozzle. The reproducibility electron source also assessed over period week found to be satisfactory similar values beam energy. These results show that stability accelerator are greatly enhanced long-term...
It is known that Bessel beam generation with a non-ideal axicon induces pattern distortions. In this paper, we introduce simple method for axicon-generated reconstruction by tilting the perpendicular to its optical axis. We found an optimum tilt angle where distortions can be compensated inducing additional astigmatic aberrations. At optimal angle, central spot symmetry and focal depth was increased. By could control crack formation in bulk of glass, which essential many transparent material...
In this paper, the modelling and manufacturing of a two-stage supersonic gas jet nozzle enabling formation adaptive plasma concentration profiles for injection acceleration electrons using few-cycle laser beams are presented. The stages modelled rhoSimpleFoam algorithm OpenFOAM computational fluid dynamics software. first 200–300 ${\rm \mu}$ m diameter stage is dedicated to 1 % N 2 + He electron injection. By varying pressure between second injectors, location could be adjusted, maximum...
With the development of industrial lasers and novel glass processing techniques, which offer high speed, quality precision, this becomes an attractive alternative to conventional methods, such as mechanical scribing cleaving, diamond saw waterjet cutting, commonly used in industry. However, emerging techniques lack thorough validation with respect well-established methods. To end, we present a detailed comparison different cutting taking into account surface quality, side-wall roughness,...
Laser-based fabrication can be an alternative technology to mechanical grinding and polishing processes. However, the performance of these elements in real applications still needs validated. In this paper, we demonstrate that subtractive is able produce high-quality axicons from fused silica, which efficiently used for glass processing. We comprehensively investigate axicons, fabricated by ultrashort pulsed laser ablation with subsequent CO2 polishing, compare their commercially available...
In this report, an efficient hybrid laser technique, nanosecond rear-side processing and femtosecond laser-assisted selective etching (FLSE) for the manufacturing of high-density gas capillary targets, is demonstrated. Cylindrical nozzles betatron X-ray sources were numerically simulated, manufactured from fused silica by 3D inscription characterized using interferometry density reconstruction. The dependence concentration profiles on wall roughness cylindrical channels presented.
The control of laser-induced microcracks in the volume transparent materials is essential for scribing processes. In this paper, we investigate effect various amplitude and single-level phase masks on both transverse axial intensity distribution conventional axicon-generated Bessel beams. Furthermore, demonstrate volumetric crack induced by an asymmetrical central core with appropriately selected level to avoid influence peripheral maxima. Proper alignment cracks intra-distance between...
Controllable fracture propagation in glass can be obtained by locally weakening the material. The high aspect ratio laser-induced modifications, required for thick dicing, use of Bessel-like beams, which have a long non-diffractive length with small quasi-propagation-invariant central core. We demonstrate possibility to form elongated modifications dominant transverse crack direction using axicon-generated asymmetrical Bessel beam. Furthermore, axicon tilt operation is introduced add...
The growing applicability of glass materials drives the development novel processing methods, which usually lack comprehensive comparison to conventional or state-of-art ones. That is especially delicate for assessing flexural strength glass, highly dependent on many factors. This paper compares traditional top-down laser ablation methods in air those assisted with a flowing water film using picosecond pulses. Furthermore, bottom-up cutting method and nanosecond pulses investigated as well....
Shocks in supersonic flows offer both a high-density and sharp density gradients that can be used, for instance,for gradient injection laser-plasma accelerators. We report on parametric study of oblique shocks created by inserting straight axisymmetric section at the end "de Laval" nozzle. The impact different parameters such as throat diameter length is studied through computational fluid dynamics (CFD) simulations. Experimental characterizations shocked nozzle are compared to CFD...
Conventional processing tools of glass cannot fulfil the forever increasing industrial requirements for speed and quality. In future these methods can be replaced by emerging laser-based techniques. While nowadays most research is dedicated thin, especially chemically strengthened glass, used in electronic devices, there still a need suitable technique thick glasses. One material-efficient energy-efficient cutting techniques to locally weaken material along path generating cracks or...
Abstract Laser Plasma Wakefield Accelerated (LWFA) electron beams and efficiency of betatron X-ray sources is studied using laser micromachined supersonic gas jet nozzle arrays. Separate sections the target are used for injection, acceleration enhancement oscillation. In this report, we present results LWFA generation dynamic density grid built by shock-waves colliding jets. The experiment was done with 40 TW, 35 fs at Lund Centre. Electron energies 30–150 MeV 1.0 × 10 8 –5.5 photons per...
Laser-based fabrication, including the ultrashort laser ablation and subsequent CO2 polishing steps, is a very attractive tool for complex 2.5D surface structuring, which could be applied fabrication of compact optical elements. However, as an alternative to conventional optics, these elements require validation, especially high power applications, such material processing. In this contribution, we comprehensively investigate all-laser-fabricated axicons from fused silica. We demonstrate...
Laser–plasma acceleration at kilohertz repetition rates has recently been shown to work in two different regimes with pulse lengths of either 30 fs or 3.5 fs. We now report on a systematic study which large range durations and plasma densities were investigated through continuous tuning the laser spectral bandwidth. Indeed, laser–plasma accelerator (LPA) processes can be distinguished, where beams highest quality, charge 5.4 pC spectrum peaked 2–2.5 MeV, are obtained short pulses propagating...
We present a new interferometric technique for gas jets density characterization employing Wollaston shearing interferometer. The distinctive feature of this setup is the double pass probe beam through target facilitated by relay-imaging object arm that images on itself and preserves spatial information. results in two-fold increase sensitivity at same time as enables with arbitrary distribution tomographic reconstruction. capabilities double-pass interferometer are demonstrated...
Laser-plasma accelerators represent a promising technology for future compact accelerating systems, enabling the acceleration of tens pC to above $1\,$GeV over just few centimeters. Nonetheless, these devices currently lack stability, beam quality and average current conventional systems. While many efforts have focused on improving stability quality, little progress has been made in increasing beam's current, which is essential laser-plasma-based applications. In this paper, we investigate...
The intra-distance between laser-induced modifications is the limiting factor of glass dicing speed and efficiency. In this work, we present a novel method for generation directional cracks in bulk to enhance performance. asymmetrical Bessel-like laser beams with long non-diffractive length were formed by filtering their spectra spatial frequencies. Experiments carried out using mJ-level source sub-nanosecond pulse duration. process was optimised varying processing parameters. flexural...