yThis paper describes an automatic adjustment system designed to measure and automatically minimize the difference in angular mismatch between the optical axes of a working (probe) beam and a marker beam that simulates the optical axis of the detector channel in a laser ranging system. This paper is primarily focused on the specifications of the basic components of the measurement system (laser sources, controllable optomechanical components, and sensors used to measure the angular orientation of the laser beams) used to maintain precision angular matching of the working and marker laser beams in order to develop a process for semi-natural simulation of a precision laser ranging system to produce and study angular matching between the working and marker beam axes. This seminatural simulation was used to model angular matching of the working and marker laser beams in a high-precision laser ranging system; the simulation was implemented using a laser system specifically developed for the purpose. The main results include a novel laser facility developed for semi-natural simulation of the angular matching of the probe (1064 nm) and marker (671 nm) beams in a laser ranging system where this difference in matching does not exceed 100. The facility periodically relays images of the laser beams to a polarization-based unit for matching of the beams using spatial filters. The facility was used to obtain experimental data on the positional characteristics of a quadrant photodiode and CMOS-array digital camera used as a laser beam matching unit. We show that this type of digital camera is preferred since it does not require advance knowledge of the positional characteristic. Initially aligned laser beamswere observed to randomly become misaligned due to angular instability in the laser beams. We have shown that the angular matching of the pulsed probe andCWmarker beams can be automatically controlled using a motorized mirror installed outside the marker-beam optical system and also propose an algorithm for operation of the marker beam in this mode. The scientific value of this paper is based on the novel nature of the laser sensor facility, the experimentally measured characteristics of the hardware components used in the marker laser channel, and the fact that the matching of the pulsed and CW laser beams can be controlled by means of motorized mirrors. The paper has practical value in that a procedure has been developed for semi-natural simulation of the angular matching of probe and marker beams to support the design of high-precision laser ranging systems operating in the near-infrared spectrum. (c) 2022 Optica Publishing Group

The possibility of observing the stimulated de-excitation of nuclear isomers (SDENI) in plasma (plasma lifetime ∼1.5 ps, temperature of electrons ∼ 10 keV) formed by the impact of a high-power laser pulse (∼10 18 W cm −2 ) on a target is studied experimentally. Preliminary experiments are carried out with the 110 m Ag ( T 1/2 = 250 days) and 186 m Re ( T 1/2 = 2 × 10 5 years) isomers. A weak SDENI effect is observed only for the 110 m Ag isomer on a platinum backing.

This paper reports ultrafast scanning of space using monopulse chirped laser radiation when the temporal-frequency modulation of the initial pulse is transformed by means of a dispersion device into a spatial frequency scan along one of the spatial coordinates. An experimental setup and system for recording the radiation spectra incident on and reflected from the detected objects are described. Using a cylindrical lens, a radiation field was formed in a 5' x 8.6' solid angle, and the possibility of ultrafast scanning of space at this angle, as defined using a chirped pulse width of 300 ps, was demonstrated. It is shown that the direction-finding response is linear when space is scanned. A layout of an optical radar system with two beams of pulsed chirped laser radiation aligned in space is considered. The use of the proposed ranging method for the detection of space debris is discussed. (C) 2019 Optical Society of America

This paper presents the optical layout and composition of a system for automatically adjusting the multipass power module of a next-generation laser apparatus. An adjustment technique based on near-field and far-field markers is described. A control program under the Astra Linux operating system is described for the automatic-adjustment system.

This paper presents the results of studies of the acceleration of macroparticles consisting of fragments of matter from the back side of a solid target when its front surface is irradiated with a picosecond laser pulse with intensity 10(13) - 10(15) W/cm(2). It is experimentally shown that there are optimal conditions for maximizing the spalling momentum of the target fragments, depending on its thickness and the intensity of the laser pulse on the front surface. The focusing of melted fragments of the substance, split off from the back surface of a target made in the form of a hemisphere, is experimentally demonstrated. The spalling momentum from such a target is greater than the momentum from a flat target of the same thickness by a factor of 6-7. (C) 2009 Optical Society of America.

Basic optical material for any laser system will be active medium, and the value of output energy varies depending on the efficiency of energy accumulated in medium and on the efficiency of energy extraction during amplification. Potassium-barium-aluminum-phosphate glass KGSS-0180/35 doped with Nd3+ (3.5x1020 cm-3) is used in production of large-sized disc and rod active elements for high peak-power laser amplifiers. Such amplifiers need active elements with light aperture up to 400x400 mm. This wide range of neodymium concentration in glasses of the KGSS-0180 type enables one to use them in manufacturing rod active elements of amplifiers.

It was found that maximum particle output and best possible spatial uniformity of proton beam took place for two-layer target when the front layer was the high-Z film. It was shown that the ion radiography of the convenient objects with using the two-layer targets allow to get the projecting pictures with high spatial resolution that was about one micron. Threshold spatial sensitivity of proton radiography is estimated.

It was found that maximum particle output and best possible spatial uniformity of proton beam took place for two-layer target when the front layer was the high-Z film. It was shown that the ion radiography of the convenient objects with using the two-layer targets allow to get the projecting pictures with high spatial resolution that was about one micron. Threshold spatial sensitivity of proton radiography is estimated.

Laser plasma produced with high-intensity picosecond laser pulse like proton source for radiography was investigated. It was found that maximum particle output and best possible spatial uniformity of proton beam took place for two-layer target when the front layer was the high-Z film. It was shown that the ion radiography of the convenient objects with using the two-layer targets allow to get the projecting pictues with high spatial resolution that was about one micron. The explanation of such high spatial resolution is in laminar motion of ion flow. Threshold spatial sensitivity of proton radiography is estimated.

A method is proposed and experimentally implemented for superfast scanning of space with chirped laser pulses. A chirped pulse incident on a diffraction grating is expanded in space along one angular coordinate in accordance with the wavelength variation while the pulsewidth is simultaneously decreased in the propagation direction. In the method discussed here, the angular position of the object is determined from the position of the spectral maximum of the reflected radiation. It is shown that the angular coordinates and the size of objects can be determined. (C) 2001 The Optical Society of America.

The design and performance of front end system for the upgrade six-channel Nd:glass laser facility PROGRESS are presented. The system consists of a single-mode Q-switch Nd:YLF master oscillator, pulse shaping system and preamplifier. The pulse shaping system comprises a LiTaO3 electro optic deflector pair driven by high-voltage generators on drift step recovery diodes. The system produces the shaped laser pulses in 1-10 nanosecond duration range. In one-pass preamplifier including a sequence of Nd:glass rod amplifiers with output aperture of 30mm the shaped pulses are amplified up to 5 J energy level.

The interaction of a 1053 nm picosecond laser pulse with a solid target for focused intensities of up to 10(19) W/cm(2) are studied by measurements of the absorption of the laser light in the plasma and by measurements of the production of hard X-rays. Absorption measurements are made by collecting the scattered light in set of calorimeters. Light scattered in backward and specular directions is collected separately. Measurements are presented for both high and low Z targets. Hard X-ray spectrum in range 15 - 1000 keV and hot electron production in range 1 - 22 MeV are measured using a multichannel filter/scintillator and filter/semiconductor spectrometers. Spatial parameters of fast ions are studied.

Results are presented from an investigation of the hard X-ray spectrum and the parameters of fast particles in experiments on the interaction of laser pulses with solid targets in the PROGRESS-P facility at laser intensities of up to 5×10 18 W/cm 2 on the target surface. The maximum energy of fast electrons obtained from direct measurements is found to be 8–10 MeV.

We present the key features of design and performance of PROGRESS-P CPA Nd:YLF/Nd:glass laser facility capable of producing 1.5-ps pulses and a power up to 30 TW at the wavelength 1053 nm for laser-plasma experiments in ultrahigh irradiance on the target up to 10(19) W/cm(2). We describe voltage pulse drivers based on drift step recovery diodes which produce output voltage up to 15 kV, rise time similar to 1ns, jitter of 100 ps and repetition rate up to 10 kHz to electrooptical devices.

The scattering and absorption of a high-power picosecond laser pulse by a solid target were investigated experimentally making use of the 'Progress-P' Nd:glass laser facility (λ = 1053 nm, τ = 1.4 ps) at radiation intensities I = 1016 — 1019 W cm-2 on the target surface. It was found that, for I ≤ 1017 W cm-2, more than 30% of the intensity of the scattered light was contained in the specularly reflected component. The absorption coefficient of the laser radiation with intensities ranging from 1018 to 1019 W cm-2 was higher for targets made of materials with higher atomic numbers.