A comprehensive picture of the nanosecond-laser generation of colloidal nanoparticles in liquids is nowadays the demand of their high-throughput industrial fabrication for diverse perspective biomedical, material science, and optoelectronic applications. In this study, using silicon as an example, we present a self-consistent experimental visualization and theoretical description of key transient stages during nanosecond-laser generation of colloidal nanoparticles in liquids: plasma-mediated injection of ablated mass into the liquid and driving the vapor bubble, finalized by the colloid appearance in the liquid. The explored fundamental transient stages envision the basic temporal and spatial scales, as well as laser parameter windows, for the demanded high-throughput nanosecond-laser generation of colloidal nanoparticles in liquids.

Gold nanoparticles (NPs) have a wide range of applications in various fields. Here, we present high-order nonlinear optical studies of the plasmas produced from ablation of Au bulk targets and Au NP films deposited on paper and glass substrates. Experimentally, we analyze high-order harmonic generation (HHG) from gold NPs-containing plasmas. The HHG is produced by 35-fs pulses at 800 and 400 nm, while the plasmas are produced by femtosecond (35 fs, 800 nm), picosecond (200 ps, 800 nm), and nanosecond (5 ns, 1064 nm) pulses, respectively. High-order harmonics produced from ablated Au NPs on paper were 40 times stronger than the HHG from that ablated from the Au bulk targets. Through molecular dynamic simulations, we investigate the formation of gold NPs during laser ablation of a metal surface under different conditions.

The paper presents a compact source of soft X-ray radiation based on a fast capillary discharge developed for “water window” microscopy methods. The central part of the source is the specially designed nanosecond voltage pulse generator capable of operating at a frequency of 600 Hz, with 100 ns pulse duration and energy per pulse 5 J. The discharge is created in a borosilicate capillary non-uniformly filled with gas. The plasma emission spectra obtained for the case of source operation in argon-helium mixture demonstrate well-pronounced lines in the “carbon window” range, in carbon dioxide-lines in the “water window” range. An analysis of the emission spectra in the range of 2–9 nm in cases of different inlet gas pressures made it possible to estimate the degree of ablation of the inner wall of the capillary and to determine the suitable operating pressure range.

This paper presents a compact source of soft X-ray radiation for operation in the wavelength range of 2-5 nm with a pulse repetition frequency of more than 500 Hz. The source parameters were optimized to reduce the intensity of ablation of the discharge volume wall and obtain the maximum intensity of the spectral lines of multicharged ions C V --- 4 nm and Ar IX --- 4.87 nm. The obtained results can be used in the development of a microscope for the tasks of cell transmission microscopy with nanometer resolution. Keywords: High-voltage pulse generator, Capillary plasma, "Water-window" microscopy.

The results of the development and experimental investigation of vacuum system with micromembrane element for a compact soft X-ray source and their implementation are presented.

Research on the optical parameters of the plasma of a nanosecond capillary discharge in a gas mixture of argon and helium was presented in the spectral range of 2–10 nm. Dependences of the intensity of the glow of the emission spectra of the plasma on the gas pressure are obtained, and the possibility of obtaining a soft X-ray beam with a low divergence is shown.