The creation of a caesium vapour laser with closed-cycle circulation of the laser-active medium is first reported. The power of the laser radiation amounted to {approx}1 kW with the 'light-to-light' ...conversion efficiency of {approx}48 %. Quasi-two-dimensional computational model of the laser operation that provides adequate description of experimental results is considered. Calculated and experimental dependences of the laser radiation power on the temperature of the cuvette walls, laser medium pressure and pump power are presented.
A new scheme of a cascaded converter of the first harmonic of broadband cw laser radiation into the second harmonic (SH) with compensation for the group walk-off in cascades is proposed and ...investigated. The conditions under which high conversion coefficients of broadband ({approx}33 cm{sup -1}) single-mode fibre laser radiation with low peak power ({approx}300 W) into the SH are determined for frequency doublers based on the most promising LBO crystal. Conversion of cw radiation with an average power of 300 W and efficiency {eta} = 4.5 % into the SH is obtained in a single LBO crystal. Effect of coherent addition of SH radiation excited in different cascades is demonstrated for two- and three-stage schemes. The expected conversion efficiencies, calculated disregarding loss but taking into account real aberrations of elements, are 18 % and 38 %, respectively. The effect of pumping depletion begins to manifest itself in the third cascade of a three-stage converter; it may reduce the latter value to {approx}30 %. (nonlinear optical phenomena)
We investigated the phasing of pulsed two- and fourchannel laser beams due to phase conjugation upon transient stimulated Brillouin scattering (SBS) in a double-pass amplification scheme. A high ...quality of beam phasing was experimentally demonstrated with the use of a microlens raster and an angular selector in the SBS-mirror scheme. The data obtained in the numerical simulation of transient SBS are in good agreement with experimental ones.
We study experimentally stimulated Brilluoin scattering (SBS) of vortex laser beams, namely, the LG{sub 1}{sup 1} and LG{sub 0}{sup 1} Laguerre -Gaussian modes. The wave front transformation is ...experimentally demonstrated in the case of SBS of the LG{sub 1}{sup 1} laser mode, directly focused into the SBS cell, when the fundamental Gaussian mode LG{sub 0}{sup 0} rather than the conjugate mode is selected from the Stokes beam. It is shown that optical vortices become phase conjugate by destroying the laser mode structure in the SBS cell. Phase conjugation (PC) of the LG{sub 0}{sup 1} and LG{sub 1}{sup 1} modes is obtained in the SBS mirror using a regular aberrator (microlens raster) in the system of laser beam focusing into the SBS cell.
The amplification of weak 80-240-mJ, 4-ns laser pulses with a gain of 0.035-0.045 cm{sup -1} is studied. The maximum energy of 3.3 kJ is obtained for 4-ns pulses. (lasers)
The main problem in developing high-power pulsed laser facilities (NIF, LMJ, and Iskra-6) is to provide the required quality of their output radiation. For this purpose, adaptive optical systems ...(AOSs) are used in all these facilities. The present research is devoted to determining the characteristics and working out the most troublesome elements of the AOS - the wavefront sensor and wide-aperture adaptive mirror for the Iskra-6 facility. (selected papers reported at the conference 'laser optics 2006')
Technological methods for applying dielectric coatings on glass substrates are proposed and studied, which substantially enhanced the radiation resistance of the coating to irradiation by nanosecond ...pulses. A rapid method for measuring the radiation resistance of optical elements by using an array of Gaussian laser beams is described. (laser applications and other topics in quantum electronics)
An adaptive system for the compensation of static and thermally induced wavefront aberrations of the amplification path of the 'Luch' laser facility is described. This system provided the reduction ...of the amplitude A of wavefront aberrations of high-power radiation and the standard deviation {sigma} by a factor of {approx}3: from A = 9.6 {mu}m, {sigma} = 2.4 {mu}m to A = 3.2 {mu}m, {sigma} = 0.6 {mu}m, which decreased the radiation divergence by half. (control of laser radiation parameters)
An efficient reflecting coating made of a MIRO foil with an oxide layer is fabricated, which enhances the reflection of radiation of pump lamps in the head of a high-power neodymium laser and allows ...a gain g{sub 0}=5x10{sup -2} cm{sup -1} to be achieved. (lasers)
The measuring technique is described and time-resolved measurements of the small-signal gain as a function of the pump energy in a disk amplification stage with neodymium phosphate glass active ...elements in the 'Luch' facility are presented. The distribution of the gain over the amplifier aperture in the horizontal plane is measured. (lasers)
