V. N. Puzyrev

Soft X-ray spectrum of laser-produced aluminum plasma

Soft X-ray spectra (30–70 Å) of aluminum plasma have been measured in experiments carried out at the Kanal-2 laser facility at laser intensities of (1–7) × 1013 W/cm2. It is shown that the measured spectra satisfactory agree with those calculated using the RADIAN numerical code.

Crater formation in a target under the action of a high-power laser pulse

The formation of craters in targets of various materials under the action of a high-power neodymium-laser pulse at radiation intensities from 1010 to 1014 W/cm2 was studied experimentally and theoretically. The interaction between the laser beam and solid targets is investigated to determine the efficiency of the ablation loading of various materials and the transformation of the laser energy into the energy of a shock wave.

Measurement of the Dead Time of an Optoelectronic Streak Camera with Different Linear Sweep Ranges

A method for measuring the dead time of an optoelectronic streak camera with different linear sweep ranges is described. The proposed method was used for the PN-1 streak camera. Photographs of the time-resolved emission of a DRSh350-2 mercury arc flash lamp for linear sweep ranges of 50 and 100 ns are presented. The dead times of the PN-1 streak camera for linear sweep ranges of 25, 50, and 100 ns were 5, 75, and 105 ns, respectively. The photographs of time-resolved second-harmonic spectra emitted by plasmas of copper and aluminum targets that were obtained in experiments on the interaction of nanosecond laser radiation with the matter using a streak camera are presented.

The image of a nanosecond laser plasma in its own optical radiation

The results of experiments on the interaction of nanosecond laser radiation (wavelength of 1.06 μm and a radiation power density of 1012–1013 W/cm2) with targets from various materials (Cu, (C2H4)n, TAC) are presented in the paper. In the experiments images of the plasma in own optical radiation in the wavelength range 0.4–1.1 μm were obtained. In one shot of laser images at wavelengths corresponding to the radiation of the harmonics 2ω 0, 3/2ω 0, 5/2ω 0, and at the frequency of laser radiation ω 0 were recorded. Using the obtained images the spatial characteristics of the radiating regions of the plasma, as well as the radiated energy for each of the harmonics, were estimated.

Emission of nanosecond laser plasma of gadolinium

The results of the study of laser plasma generated by nanosecond laser radiation with controlled spatial coherence incident on various targets containing gadolinium are presented. X-ray radiation of such plasma is studied using an X-ray diagnostic system developed and fabricated by the authors. Metal gadolinium, gadolinium oxide, gadolinium and aluminum alloy, and aluminum were used as targets. The electron temperature of generated plasma and the efficiency of laser-to-X-ray radiation conversion are estimated; the emitting region sizes are determined. Particular attention is paid to the study of laser plasma spectra in the X-ray region near the wavelength of 6.7 nm.

Second-harmonic conversion of partially coherent radiation of neodymium glass laser

The experimental results on the conversion of multimode radiation of a neodymium glass laser with controlled spatial and temporal coherence to the second optical harmonic in nonlinear KDP crystal during the oee interaction implementation are presented. The dependence of the efficiency of the conversion to the second harmonic on the fundamental radiation power density on the crystal in the range I = 0.2 − 5 GW/cm2 is studied at the number of transverse modes in the cavity N = 1000; the radiation divergence φ = 3.5, 4.7, and 5 mrad; the emission spectral width δλ = 5and 42 Å; and the pulse duration of 2.5 ns. The breakdown power density of the KDP crystal is determined, the interference properties of the converted radiation of the second harmonic are studied.

Second-harmonic conversion of neodymium glass laser radiation with controlled spatial coherence

The experimental results on the second optical harmonic conversion of neodymium glass laser radiation with controlled spatial coherence in a nonlinear KDP crystal are presented. The conversion efficiency is studied depending on the radiation power density on the crystal and the crystal rotation angle in the principal optical plane with respect to the radiation propagation direction. The experiments were performed in the radiation power density range I = 0.2–3 GW/cm2 for the number of cavity transverse modes N = 100–1000, radiation divergence 2ч = 0.5–3.5 mrad, spectrum width of 26 Å, and pulse duration of 2.5 ns.

Four-frequency polarizing microscope for recording plasma images in the wavelength range 0.4–1.1 μm

The optical scheme and design of a four-frequency polarizing microscope intended for simultaneous recording of plasma images in the wavelength range 0.4–1.1 μm with the spatial resolution 12 μm in the entire spectral range are described. The effectiveness of such a microscope in studies of plasmas produced on interaction of laser radiation with a target is demonstrated. The plasma images are obtained at the frequencies ω0, (3/2)ω0, 2ω0, and (5/2)ω0, where ω0 corresponds to the frequency of heating radiation. The transformation coefficient that characterizes the efficiency of conversion of heating radiation into the 2ω0, (3/2)ω0, and (5/2)ω0 harmonics generated in the plasma is determined.

Study of the spectral composition of the radiation of the neodymium-glass laser with combined active medium

A method for obtaining a broad (30–100 Å) emission line in neodymium-glass lasers is proposed. In this case, an active medium is a combination of two different glass matrices, silicate and phosphate, doped with Nd3+ ions. The structure and spectrum width of such lasers were experimentally studied depending on the active element properties, cavity type, and pump power. A radiation spectrum width more than twice larger in comparison with silicate-glass lasers was achieved.