Problem of the modeling the filaments after laser-induced breakdown the matter

Abstract

The problems of the appearance of laser-induced filamets in the matter are discussed. A detailed analysis of the formation of such structures in various media: from air to silicon carbide, is represented. The influence of the spectral composition, the number of pulses and the duration of the irradiation and the medium on the geometric dimensions of the resulting structures and on their phase states is shown. In this case, the sizes of filaments vary from several hundred nanometers for silicon carbide to several hundred meters for air. The emission spectrum is continuous, and resembles the Cherenkov radiation. Therefore, the idea was developed that the radiation of filaments and the radiation of Cherenkov are of the same nature. The problems of the mechanisms of the formation of laser-induced destruction cascades in silicon carbide are discussed. To explain the experimental results, we used modified Rayleigh models (diffraction stratification of the laser beam and critical sizes of nanovoids), physicochemical models for determining critical energy values for the corresponding processes, and models for optically-induced Cherenkov radiation.