Alexander V. Charukchev

The “Progress-P” 30 TW picosecond Nd:glass facility

Chirped pulse amplification was implemented in one of six amplifier chains “Progress” phosphate Nd:glass laser system. Laser system configuration and performance are presented. Formation of 300 ps chirped pulse at 1053 nm with energy up to 1 J is made by using developed starting laser which consists of Nd:YLF oscillator, optical fiber, stretcher and three amplifiers with output aperture 20 mm. The large amplifier chain of the laser system includes three rod amplifiers with the aperture of output rod of 85 mm. Preliminary experiments have been carried out yielding output chirped pulses of up to 55 J and compression them to 1.5 ps by grating compressor.

Large aperture Nd-glass laser amplifiers

Rod amplifiers (RA) and disk amplifiers (DA) with apertures of Øw (20–140)mm and (200×200)mm and (300×300)mm are presented accordingly. Platinum-free Nd-glass with different concentration of neodymium ions is used.

Express method for estimating surface resistance of optical components to laser-induced damage

The study describes a method that, with a series of experimental data obtained from a single sample, allows not only to estimate the threshold fluences but to take into account statistical nature of surface-damage. In a number of experimental situations this method makes it possible to estimate damaging fluences even from the result of a singular exposure of the studied surface. Estimated threshold. Fluences for various optical elements are presented: K8-glass, experimental phosphate laser glass KGSS-0180, high-reflecting and anti-reflecting thin-film coating of elements. Half-height duration of 1.06 micrometers - radiation pulse of 4 ns and irradiation spot of approximately 4 mm in diameter were used in the experiment.

Absorption and transformation of laser energy in picosecond laser-plasma experiments at intensity of 10 16 to 10 19 W/cm 2

The interaction of a 1053 nm picosecond laser pulse with a solid target for focused intensities of up to 1019 W/cm2 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.

Front end of the high-energy Nd:glass laser fusion system with shaped nanosecond laser pulses

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.

Formation of high-contrast laser pulses on multiterawatt laser facility PROGRESS-P

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 1019 W/cm2. We describe voltage pulse drivers based on drift step recovery diodes which produce output voltage up to 15 kV, rise time approximately 1 ns, jitter of 100 ps and repetition rate up to 10 kHz to electro-optical devices.

Methods for the shaping high-power picosecond laser pulses with a high-contrast ratio

We present the performance of the electrooptical system based on four Pockels cells with 10 and 20 mm diameters, each of them is driving by its own drift step recovery diode pulse generator. We are developing electro-optic deflector system for CPA laser using two identical deflectors (diverging and converging) and three spatial filters. The results of numerical modeling of the time-dependent distributions of the intensity in the beam are presented. A peak-to-background intensity ratio more than five orders is achieved by this technique. We have developed a new pulse generator based on single drift step recovery diode producing two identical electrical pulses with output voltage up to 15 kV, FWHM of 1.5 ns, rise time of 0.7 ns and jitter of 100 ps at a 100 Hz repetition rate to electro-optic deflectors.

30 TW laser facility “Progress-P”

Chirped pulse amplification was implemented in one of six amplifier chains “Progress” phosphate Nd:glass laser system. Laser system configuration and performance are presented. Formation of 300ps chirped pulse at 1053 nm with energy up to 1 J is made by using developed starting laser which consists of Nd:YLF oscillator, optical fiber, stretcher and three amplifiers with output aperture 20 mm. The large amplifier chain of the laser system includes three rod amplifiers with the aperture of output rod of 85 mm. Preliminary experiments have been carried out yielding output chirped pulses of up to 45 J and compression them to 1.5 ps by grating compressor.

Performance of the high-power PROGRESS Nd:glass laser facility

We present performance of PROGRESS Nd:glass laser facility which consists of a six beam PROGRESS-M phosphate Nd:glass laser, 30 TW PROGRESS-P picosecond YLF:Nd glass laser, which uses chirped pulse amplification (CPA) technique and target chamber. Laser is capable to focus simultaneously at 1,054 micrometer the energy of 1.5 kJ in 1.5 ns and power of 3.5 TW in 200 ps on the fusion target. We report performance of a single beam 0.5 kJ PROGRESS-1M laser. This laser with output rod amplifier 14 cm is the prolongation of one of the beam of the multi-beam laser. PROGRESS-P CPA laser uses YLF:Nd oscillator, single mode optical fiber, Nd:glass rod amplifiers with output diameter of 85 mm. At the output, the chirped pulse with energy about 45 J is compressed up to 1.4 ps in the single-pass compressor on two holographic gratings, which produces power of 22 TW.

High-power PROGRESS Nd:glass laser facility

We present performance of PROGRESS Nd:glass laser facility which consists of a six beam phosphate Nd:glass laser, 30 TW PROGRESS-P picosecond YLF:Nd glass laser, which uses chirped pulse amplification technique and target chamber. PROGRESS-M laser is capable to focus simultaneously at 1,054 micrometers the energy of 1.5 kJ PROGRESS-1M laser. This laser with output rod amplifier 14 cm is the prolongation of one of the beam of the multi-beam laser. PROGRESS-P CPA laser uses YLF:Nd oscillator, single mode optical fiber, Nd:glass rod amplifiers with output diameter of 85 mm. At the output, the chirped pulse with energy about 45 J is compressed up to 1.4 ps in the single-pass compressor on two holographic gratings, which produces power of 22 TW.