V. N. Novikov

Transverse SRS in KDP, and KD*P crystals

Gain coefficients at transverse SRS in the particular samples of KDP and KD*P crystals, grown following the traditional and rapid-growth technology have been determined.

Stimulated Raman scattering in frequency conversion crystals

Transverse SRS with fluence 3.4 J/cm2 has been received in KDP crystal. The TSRS amplification increment for KDP, which was prepared as type II, has been calculated according to experimental results g equals 0.5 cm/GW.

Development of an adaptive optical system for phase correction of laser beams with wavefront dislocations: generation of an optical vortex

The development of an adaptive system for the transformation of optical vortex is undertaken. Content of work consists of generation of a vortex with preset properties, measurement of its wave front and its correction by means of an adaptive mirror. The first stage of work has been realized on formation a Laguerre-Gauss beam with the help of the amplitude diffraction gratings and special phase plates fabricated on kinoform technology.

Stimulated Brillouin scattering of CO2 radiation in compressed xenon

Stimulated Brillouin scattering (STBS) and phase conjugation of CO2 laser radiation have been demonstrated experimentally for the first time in compressed xenon (59 atm at 21°C) located inside the low-Q cavity of this laser. The nonlinear medium was exposed to the action of counterpropagating focused multimode radiation beams. The difference between the frequencies of the longitudinal cavity modes was set at the frequency of the acoustic wave (vs=32.2±0.3 MHz) excited as a result of STBS by 9.584 μm radiation. The duration of the radiation pulse τL was close to the acoustic phonon lifetime (τL<τph≈3× 10−6s). The excitation of STBS was manifested experimentally as the locking of longitudinal modes, an increase in power and energy, and also an increase in the duration of the lasing pulse and a reduction in the divergence to the diffraction limit.

CO2 and iodine lasers with SBS mirrors: experimental investigation and aspects of COIL with phase conjugation development

Phase conjugation of CO2 and iodine laser radiation in SBS cell placed into resonator of this same laser has been demonstrated experimentally. The first experimental results on simulating of operation of iodine-oxygen laser with SBS- mirror with the help of photolytic iodine laser are presented. The possibilities of creation of COIL with phase conjugation are discussed.

Stimulated Brillouin scattering of CO 2 laser radiation in compressed xenon

Stimulated Brillouin scattering (SBS) and wave front phase conjugation of CO2 laser radiation in compressed xenon placed into low Q resonator of this same laser has been demonstrated experimentally for the first time. The action on nonlinear medium was carried out by opposing focused beams of multimode radiation. The difference in resonator longitudinal mode frequencies was set equal to the frequency of the acoustic wave excited by the radiation with 9.584 micrometers wavelength at SBS. Radiation pulse duration was close to acoustic phonon lifetime. In experiments the SBS excitation was manifested longitudinal mode synchronizing, power and energy rise and also in increasing laser radiation oscillation duration and in decreasing divergence to diffraction limit.

SBS properties of high-pressure xenon

For xenon at temperature t equals 19.3 degrees Celsius in a range of density 0.3 g/cm3 less than or equal to (rho) less than or equal to 1.0 g/cm3 SBS gain coefficient (g) and phonon lifetimes are measured. It is shown that at the densities higher than (rho) equals 0.5 g/cm3 SBS gain g levels out, reaching the value g approximately equals 100 cm/GW, and the phonon lifetimes decrease down to (tau) ph equals 25 ns with approaching to a critical point of Xe.

Chemical laser emitting simultaneously from excited HF and DF molecules

Performance has been investigated of a broadband chemical laser utilizing chain and nonchain reactions and emitting simultaneously from excited HF* and DF* molecules. Simultaneous stimulated emission of radiation in the spectral ranges of 2.7 - 3.0 micrometer and 3.7 - 4.1 micrometer has been obtained. Theoretical dependencies are presented of laser energy characteristics on the ratio of initial H2 and D2 concentrations in a working mixture.