研究目的

Investigating the effects of a femtosecond laser pulse (FLP) on glass is important for numerous applications related to microprocessing materials. Mathematical modeling is required to optimize the latter. Its main significance is largely determined by the fact that diagnostics in a real experiment are very difficult because a laser pulse interacts with the glass in a volume of the order of a micrometer (μ m) for tens of femtoseconds (1 fsec = 10?15 sec). The main, and often the only measurable, quantity is transparency: the ratio of the energy of the transmitted radiation to the energy of the incident one. The FLP interaction with matter is also of interest for fundamental science. There are many physical phenomena used in practice (e.g., the formation of nanolattices), which have not yet been clearly explained. Mathematical modeling also remains the main instrument for testing various hypotheses explaining these phenomena.

研究成果

The paper presents the results of modeling the interaction between radially and azimuthally polarized doughnut-shaped femtosecond laser pulses and glass. It is shown that the effect of a strong gain (of several factors) in the maximum absorbed energy compared to the traditional Gaussian pulses is more pronounced in the case of radial polarization. It should be noted that the region of large absorbed energies in the case of a DSP looks like a tube (Fig. 4). At large times, at the stage of elastoplastic movements, this will lead to the appearance of high-pressure waves. Moreover, some of these waves will propagate to the axis of the system and accordingly be amplified. The estimates show that this creates a pressure equal to the pressure in the mantle of the Earth. Thus, DSPs are of interest not only for use in technology and medicine but also for studying substances in extreme conditions.

研究不足

The equations describing the interaction of FLP with materials are extremely complex and are too complex to solve analytically. It is often difficult even to estimate the relevant order of magnitude. Accordingly, there is a need to create effective numerical algorithms for solving these problems. This issue is the subject of this work.