Alexander B. Vankov

Investigations of ion streams emitted from plasma produced with a high-power picosecond laser

This work reports on investigations of parameters of ion streams emitted from a plasma produced with a picosecond laser at the power densities ≥10 16 W/cm 2 . Not many papers dealing with such investigations have been published up to now, in spite of the fact that the application of precise corpuscular diagnostics enables better learning of the physical properties of such a plasma. As a result of the investigations carried out, the average and maximum energies of Cu ions were 30 keV and 150 keV, respectively. The maximum charge of Cu ions was 13+. The dependencies of parameters of ions emitted from the plasma on the laser-pulse energy as well as on the location of the focus of the laser beam with respect to the targets surface were also found out. The results obtained from the ion measurements in relation to the results of measurements of X ray are discussed.

Picosecond, terawatt, all-Nd:glass CPA laser system

Abstract An all-Nd:glass fiberless chirped-pulse-amplification laser system capable of producing 1.2 ps pulses of 2 TW in power is presented. A potential for obtaining a high (≥ 10 8 ) long-time scale contrast ratio of a pulse by the use of an electro-optic deflector as well as good focusability of a high-power beam of rectangular cross-section produced by a single-pass grating compressor are demonstrated.

1-TW Nd:glass laser system

The construction of 1 TW Nd:glass laser system with pulse compression is described. The laser system consists of master oscillator with self-mode locking and negative feed-back, stretcher, regenerative amplifier, two preamplifiers, amplifier chain and diffraction gratings compressor. The possibilities of improving the laser system parameters are discussed.

Compression of high-energy laser pulses after self-phase modulation in a bulk nonlinear medium

The use of self phase modulation for spectrum broadening with subsequent pulse compression by diffraction gratings allow to compress high energy laser pulses in wide range of pulse lengths. We have discussed different feasibility of such method for pulse shortening.

Optical breakdown of transparent dielectrics by picosecond and subnanosecond laser pulses

While the optical breakdown of transparent dielectrics for nanosecond and longer laser pulses is well investigated theoretically and experimentally, the breakdown in a field of picosecond and femtosecond pulses has not been adequately explored. At the same time such investigation presents scientific interest, because short pulse duration can make some change for a mechanism of the optical breakdown. Also these data have practical importance for high energy laser development and management of temporal parameters of a pulse. Thus we have carried out measurements of the damage thresholds for pulse durations 450 ps and 3 ps (FWHM) for fused silica. Theoretical analysis is presented to explain experimental results. The possibility of applying the optical breakdown for pulse shortening is discussed.

Super‐strong laser field generation and their interaction with solid target in vacuum

We consider interaction of superstrong laser fields with condensed targets in vacuum. Our experiments were made on our laser system for the picosecond pulse generation, its recompression with chirp introduction and regeneration amplification. The results of laser radiation absorption and conversion efficiency into fast particles and X‐ray are presented for a broad range of parameters.

High-precision long-distance remote sensing using chirped-pulse interferometry

The use of a new method of interferometry of chirped pulse for precise remote measurement of lengths and velocities is proposed, evaluated and tested in experiments. The potentialities of the method in comparison with conventional methods are considered, and its possible applications are discussed.

Emission of highly-charged ions of heavy elements from a picosecond laser-produced plasma

The results of investigation of ion emission from picosecond laser-produced plasmas of various atomic number are presented. The emission of Ta38+, AU33+ as well as A113+ ions is demonstrated. Some characteristics of the picosecond plasma are also determined.

Using a chirp pulse amplification technique and temporal multiplexing for flexible shaping of broadband laser pulses

A pulse shaping and frequency modulation system based on chirped-pulse-amplification and pulse train multiplexing techniques in regenerative amplifier is proposed. It is shown that by using standard frequency modulators of MHz range one can obtain up to 100 GHz modulation frequencies. This system enables to generate arbitrary pulse-shaped pulses with temporal resolution determined by length of initial pulses from mode-locked master oscillator. Nd:glass CPA laser system has been used for demonstration of such type system operation.

Nonlinear reflection of high intensity picosecond laser pulse from overdense plasma

The interaction of 1.5 ps FWHM laser pulses with solid targets at intensity 1015–1017 W/cm2 and contrast ratio 106 is studied. Red shift of a “mirror” reflected fundamental wave and its second harmonic depending on the incident laser pulse energy and angle of incidence are observed. They are associated with Doppler shift corresponding to inward movement of the critical density surface from laser pondermotive pressure. Back scattered light has nonlinear dependence from laser intensity connected with SBS and changing of plasma surface.