The effect of environmental conditions and irradiances on femtosecond laser-induced breakdown spectroscopy of Aluminum (Al) plasma has been investigated. For this purpose, a femtosecond laser (1030nm, 220 fs) was employed to irradiate the Al targets under air and vacuum environments at different laser irradiances ranging from 1.8 TWcm-2 to 5.4 TWcm-2. LIBS analysis shows that optical intensity of emission spectra and plasma parameters (electron temperature “Te” and electron number density “ne”) are increased with increasing the laser irradiances of Al plasma under both environments. The electron temperature is evaluated by using both Boltzmann and Saha Boltzmann distributions, whereas electron density is evaluated by using Stark broadening. With increasing laser irradiances, the values of Te of Al plasma increases from 8061K to 8745K under vacuum environment, whereas, for air Te increases from 8203K to 8874K. In case of Saha Boltzmann plot, the values of Te under vacuum vary from 8467K to 8949K and in air environment the estimated values of Te increases from the 8600K to 9027K. Likewise, the values of ne of Al plasma vary from 8.52 x 1018cm-3 to 9.22 x 1018cm-3 under vacuum environmental condition, while in case of air, the values of ne vary from 8.72 x 1018cm-3 to 9.38 x 1018cm-3. Slightly higher values of Al plasma parameters in air as compared to vacuum are explainable on the basis of confinement effect offered by 760Torr atmospheric pressure. The air environment restricts free expansion of Al plasma that results into enhanced rate of collisional excitation, recombination with increased life time of plasma that slows down the plasma plume. The laser-target interaction process of air also causes exothermic reactions of reactive gases (H2, O2, CO2 etc) which are responsible for enhanced energy coupling to target in addition to laser energy deposition which in turn increases ablation rate and evaporation of the target. The increasing trends of emission intensity and plasma parameters with the increasing laser irradiances are attributed to enhanced mass ablation rate due to more energy deposition that increases the excitation and de-excitation within the plasma. The higher values of Al plasma parameters under certain environments make it more beneficial for various applications including surface structuring, electron ion implantation, pulse laser deposition of thin films and other industrial applications.

Femtosecond laser-induced plasma of tellurite-based glasses is used to modify structurally the surface of silicate glasses and silica-on-silicon to engineer optical and photonic components. The refractive index, doping, mechanical strength, and color can be altered using the methodology.

We characterise the thin-film structural properties and photoluminescence of femtosecond (40 fs, 800 nm) pulsed laser deposited Er3+-doped zinc-sodium tellurite glass on Si as a function of laser fluence. The laser fluence regime required for the formation of films composed of nanoparticles without droplets is found, the composition and crystallinity of the deposited material is reported and the photoluminescence of the films is characterised in dependence of film thickness.

We report the femtosecond laser (100 fs, 800 nm) ablation properties of Er3+ ion doped zinc-sodium tellurite glass. Ablation thresholds in dependence of the beam radius (13.9 and 32.0 μm), pulse number, and Er3+ ion dopant concentration have been determined. The ablation rate and crater profile depended on the applied fluence.

Tooth hypersensitivity is an acute oral condition, both in children and the ageing population worldwide and it is the result of continual erosion and loss of tooth enamel. As the disease has significant impact on the quality of life of the patients, there is an urgent need to provide a robust solution for restoring lost enamel, a problem that remains intractable for clinical dentistry. In this work a novel treatment technique for enamel restoration is investigated. Our research promotes the development of an acid resistant calcium phosphate based biomaterial which is applied on a tooth’s surface and is bonded with the underlying natural enamel/dentine by irradiation with ultra-fast pulsed lasers at near IR wavelength [1]. The use of femtosecond lasers is crucial because with these heat accumulation is not a major challenge, unlike irradiation by conventional continuous wave lasers, and thus the proposed technique can be applied in situ.