We report single-pass cutting of strong transparent glass materials of 700 μm thickness with a speed up to 270 mm/s using single-shot nanostructuring technique exploiting picosecond, zero-order ...Bessel beams at laser wavelength of 1030 nm. Particularly, we present results of a systematic study of cutting of tempered glass which has high resistance to thermal and mechanical shocks due to the inhomogeneous material properties along its thickness, and homogeneous glass that identify a unique focusing geometry and a finite pitch dependency, for which cutting with high quality and high reproducibility can be achieved. These results represent a significant advancement in the field of high-speed cutting of technologically important transparent materials.
Abstract
The Villa of Caddeddi, in the territory of Noto (Siracusa) is located on the south bank of the Tellaro river, about 3km from its mouth. The site, interpreted as a rural luxury residence ...dated to the 4th-5th century CE, was first discovered in 1972 and intermittently investigated in the subsequent decades and mostly studied from the perspectives of the splendid mosaic floors there uncovered. The excavated structure accounts for just a portion of the complex, which is partially covered by an 18th-19th century farmhouse. After a long period of neglect, the villa has been recently restored and opened to the public and become subject of new studies by the University of South Florida’s Institute for Digital Exploration (IDEx) which in 2019 and 2020 conducted a remote sensing campaign entailing terrestrial laserscanning and ground penetrating radar.
We propose a new experimental technique, which allows for a complete characterization of ultrashort optical pulses both in space and in time. Combining the well-known ...Frequency-Resolved-Optical-Gating technique for the retrieval of the temporal profile of the pulse with a measurement of the near-field made with an Hartmann-Shack sensor, we are able to retrieve the spatiotemporal amplitude and phase profile of a Bessel-X pulse. By following the pulse evolution along the propagation direction we highlight the superluminal propagation of the pulse peak.
In this paper we illustrate how the localization of the stationary two-dimensional solution of the propagation equation strongly depends on the features of its spatio-temporal spectral bandwidth. We ...especially investigate the role of the ultra-broad temporal support and of the spatial bandwidth of the spectrum on the high localization in one spatial dimension of "Bessel-like" or "blade-like" beams, quasi-stationarily propagating in normally dispersive materials, and potentially interesting for microfabrication applications.
In this paper, we propose an approach to enhance the electron energy gain in standard laser-driven plasma wakefield accelerators, using accelerating Bessel pulses with tunable group velocity so to ...avoid electron dephasing. We use in the numerical simulations a one-dimensional theoretical model in the linear regime, taking advantage of the “diffraction-free” properties of the localized Bessel beam and thus neglecting transverse effects during the acceleration process. With a multistage tailoring approach, we show a gain enhancement of more than 100 with electron energies that may reach the GeV range over distances shorter than 1 m.
We present a study on the micro-drilling process by means of a picosecond Bessel–Gauss beam, and the achievements obtained on a 200-µm-thick AF32 glass sample in different laser fabrication regimes. ...In particular, we compare the results and morphology of the holes generated with a high-repetition-rate pulsed laser, respectively, in the single-pulse mode and in the burst mode machining regimes. We highlight the advantages or drawbacks of these two types of microfabrication for the generation of through-holes. For a given pulse density, the burst mode turns out to be advantageous with respect to the single-pulse mode fabrication in terms of lower energy per pulse needed and higher speed of drilling, even if the stronger thermal effects can more easily lead to surface cracks. On the other hand, by adjusting the pulse density below a critical level, it can be shown that the single-pulse regime can be adopted for the generation of more regular through-holes and cleaner apertures, even if multiple pass operation is likely to be needed.
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