Nanosecond laser pulses were used for texturing the biphilic surfaces coated by polydimethylsiloxane-silica. We have shown that the laser microstructuring enables high flexibility in texturing of biphilic patterns. The obtained results have great potential for different applications, since they indicate that the laser microstructuring can significantly improve heat transfer. Consequently, this endorses further research within this field, since it is expected that by laser microstructuring it will be possible to completely avoid coatings.
COBISS.SI-ID: 14131227
This work was performed within the international bilateral cooperation, where the member of this programme was principal investigator. Nanopowders based on gadolinium zirconium oxide (Gd2Zr2O7) doped by europium ions (Eu3+) were successfully prepared by using a flame combustion method. This material is suitable for various optical devices. The structure of prepared materials has been confirmed and characterized by using X-ray powder diffraction (XRD), scanning electron microscope (SEM) and photoluminescence (PL) techniques.
COBISS.SI-ID: 13766171
During the interaction of a laser pulse with the surface of a solid object, the object always gains momentum. The delivered force impulse is manifested as propulsion. Initially, the motion of the object is composed of elastic waves that carry and redistribute the acquired momentum as they propagate and reflect within the solid. Even though only ablation- and light-pressure-induced mechanical waves are involved in propulsion, they are always accompanied by the ubiquitous thermoelastic waves. This paper describes 1D elastodynamics of pulsed optical manipulation and presents two diametrical experimental observations of elastic waves generated in the confined ablation and in the radiation pressure regime.
COBISS.SI-ID: 13926427
In the study of ultrasound propagation in matter, displacement sensors are indispensable and of these, the most sensitive are piezoelectric sensors. In order to eliminate the intrinsic effects of the sensor from the measurements, the sensor has to be properly calibrated, which means that its transfer function has to be evaluated from a known sensor input signal and a measured sensor output signal. This has usually been done by comparing the sensor response signal to a known input signal, namely, an ultrasonic waveform, which can be theoretically calculated using mathematical models and numerical algorithms. Until now, the point-source-point-sensor model has been primarily used, while ultrasonic waves were induced mechanically either by a dropped ball or a capillary fracture. In this paper, a real-source-real-sensor model is presented. It provides a more faithful waveform construction and it enables the removal of the aperture effect from the calculated sensor transfer function, thus giving correct and universal sensor response characteristics. This was corroborated by high-frequency calibration measurements of the output signal of a Glaser-type conical sensor in two positions on both surfaces of a glass plate, while ultrasonic waves were induced by the radiation pressure of a nanosecond laser pulse.
COBISS.SI-ID: 14173211
We have developed an automated image processing of shadowgraphs of high-speed optodynamic phenomena, such as plasma development and the shock wave propagation. Within this study we have shown that such a processing is possible and we also proposed further steps that are necessary before its on-line implementation. The results provide an important basis for the development of monitoring systems that will improve the control of various laser material processes as well as laser medical procedures.
COBISS.SI-ID: 13977883