Introduction to the Laser Processing of Materials

Femtosecond-laser-induced quasiperiodic nanostructures on TiO2 surfaces

“…Instead of quasiperiodic ripples, however, randomly meandering structures arise in the laser irradiated area similar to observations of other groups for the case of Si surfaces. 38 These irregular structures contain flat, broad crests and deep, narrow trenches ͓Fig. 2͑a͔͒ so that the corresponding 2D-FT data show the clear signature of a nonperiodic spatial frequency spectrum ͓Fig.…”

Post-deposition laser treatment of plasma sprayed titania-hydroxyapatite functionally graded coatings

“…In previous studies, a similar titania-HA graded coating underwent specific thermal treatments, which resulted to be beneficial not only for the degree of crystallinity, which was remarkably increased, but also for the mechanical properties of the FGM. 14,15,26 Such an improvement was not achieved by means of the laser treatment, however it was possible to increment the crystallinity of HA at the working surface in a very easy and quick way. In fact, it should be underlined that the thermal treatment is dramatically time-consuming with respect to the laser treatment.…”

“…13 Practical advantages of the laser treatments include generally small treating system, limited manipulations and transportations of the components to be treated, environmental and operative safety, low running cost and energy consumption. 14 Yet, laser treatments of thermally sprayed coatings are affected by several drawbacks still without solution, which are mostly ascribable to their aptitude for operating at too high fluence (power per unit of time and surface). 15 The thermal shock induced by the high-density power laser radiation into the thermal-sprayed coatings may induce massive damages, with horizontal and vertical cracks spreading widely.…”

Direct imaging of single cells and tissue at sub‐cellular spatial resolution using transmission geometry MALDI MS

“…The requirement of micron and sub-micron laser spot sizes significantly impacts the size and configuration of the laser focusing optical system. In the past 20 years, significant progress has been made in laser direct write micromachining instrumentation, resulting in a new generation of UV lasers with high quality laser beams and low aberration microscope optics capable of being focused to a sub-micron diameter spot [5–6] . In the case of a high quality Gaussian laser beam focused by a diffraction-limited lens, the minimal laser spot size is mainly determined by the laser wavelength and the focusing convergence angle.…”