Nanostructuring of the tungsten surface under the action of femtosecond laser radiation

In the paper, we show the possibility of nanostructured tungsten surface by femtosecond laser radiation. The features of the LIPPS formation are also shown. The dependence of the formation of the structuring region on the number of femtosecond laser pulses is shown. Based on the analysis of experimental data, the formation mechanisms of nanostructures are discussed.

Deposition of GaN nanoparticles on the surface of a copper film under the action of electrostatic field during the femtosecond laser ablation synthesis in ammonia environment

In this article, we show the possibility for obtaining and deposition of gallium nitride nanoparticles under the action of femtosecond laser radiation. Using the developed setup for thermal vacuum deposition of copper on silicon plates, we obtained the thin-film substrates following by the deposition of gallium nitride on them. The gallium nitride was formed by applying the femtosecond laser radiation to the gallium targets in ammonia medium. The controlled collection of ablation products following by their removal from the processing area by means of electrostatic field was used in the setup in order to efficiently collect gallium nitride nanoparticles. The formation of gallium nitride nanoparticles is verified by the results of X-ray diffraction analysis.

Local thermodynamic equilibrium in a laser-induced plasma channel formed by interaction of femtosecond laser radiation with argon

In this paper, we estimate the possibility of applying local thermodynamic equilibrium conditions for a laser-induced plasma channel formed by femtosecond laser radiation in an argon medium at different pressures. The presence of a local thermodynamic equilibrium was determined on the basis of the time of heat exchange of electrons with argon atoms. The Saha equation is used to estimate the concentration of free electrons, the temperature of the laser-induced plasma channel, and its conductivity. A necessary condition for using this ratio was the presence of a state of local thermodynamic equilibrium in the plasma under study.

Detection of THz waves in GaSe:S crystals by femtosecond laser radiation with a telecom wavelength of 1.55 μm

In this work, we study Ga50%Se50-x%Sx crystals (where x = 0, 1.5, 6, 8, 11) as an electrooptic detector of terahertz pulses using probing femtosecond laser radiation with the wavelength of 1.55 μm. It was found that the sample with x = 6 provides the highest detection efficiency. The efficient value of the electrooptic coefficient of GaSe:S crystals is estimated to be about twice higher than those of GaAs in the same conditions.