Novel features of phase conjugation at SBS of beams passed through an ordered phase plate

Кочемасов, Г. Г.; Starikov, F. A.

doi:10.1016/s0030-4018(99)00431-9

Cited by 7 publications

(5 citation statements)

References 7 publications

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“…In this case the classical phase conjugation is realized. Under near-to-threshold conditions of SBS the conjugation coefficient is h~75% that is typical for linear SBS conditions [6]. At this the qualitative similarity is observed between the laser and Stokes beams and their interference patterns.…”

Section: Results Of Calculations and Experimentsmentioning

confidence: 73%

“…The region of transverse localization of laser beam in SBS-cell varies substantially that is a challenge for numerical integration of Eqs (6), (7). Therefore a transition is executed to variables [6]:…”

Section: Approximation Of Steady-state Linear Sbsmentioning

confidence: 99%

“…Positions of beam waist and main lens are z=0 and z=-F/(1+F 2 /z d 2 ), respectively. In view of (8), Eqs (6), (7) are transformed as [6]:…”

Section: Approximation Of Steady-state Linear Sbsmentioning

confidence: 99%

“…Both SBS cells of length L=100 cm are filled by a mixture of gases Xe and SF 6 . CCD camera 8 measures the distribution of energy density of the first laser beam passed through the phase plate and incident on the lens 7.…”

Section: Sbs Experimentalal Schemementioning

confidence: 99%

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<title>New phenomena at stimulated Brillouin scattering of Laguerre-Gaussian laser modes: theory, calculation, and experiments</title>

et al. 2008

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New phenomenon predicted earlier -failure of phase conjugation at the stimulated Brillouin scattering (SBS) of focused laser beams with screw dislocation of phase front (Laguerre-Gaussian vortex modes) -has been experimentally confirmed Phase conjugation of vortex beams does not take place as a phenomenon because of failure of selection of Stokes mode conjugated to laser one. It occurs since the SBS amplification coefficient does not depend on the laser field phase, and the Stokes field does not "feel" how the laser phase helix is twisted. Therefore the amplification coefficients of a Stokes conjugated mode and an analogous mode of opposite helicity are equal to each other. For example, in the case of a doughnut laser LG 0 1 mode the Stokes beam consists of a random superposition of a few modes including conjugated one. For rather wide class of vortex beams (for example, in the case of a laser LG 1 1 mode with two rings), a novel phenomenon takes place that can be called as phase transformation at SBS. Its essence is in the fact that in Stokes beam a mode with regular phase front is selected, which is orthogonal to laser mode at all. In the near-threshold SBS regime, this selected mode is close to a principal Gaussian mode. At SBS of the vortex laser beam the generation of the vortex hypersonic wave takes place in the SBS-medium so that the topologic charge in the system "Stokes wave+hypersonic wave" is equal to the charge of incident laser wave.

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Section: Results Of Calculations and Experimentsmentioning

confidence: 73%

Section: Approximation Of Steady-state Linear Sbsmentioning

confidence: 99%

“…Positions of beam waist and main lens are z=0 and z=-F/(1+F 2 /z d 2 ), respectively. In view of (8), Eqs (6), (7) are transformed as [6]:…”

Section: Approximation Of Steady-state Linear Sbsmentioning

confidence: 99%

Section: Sbs Experimentalal Schemementioning

confidence: 99%

See 2 more Smart Citations

<title>New phenomena at stimulated Brillouin scattering of Laguerre-Gaussian laser modes: theory, calculation, and experiments</title>

et al. 2008

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“…The latter is very important because in usual PC mirrors a close to ideal quality of PC in focused beams can be obtained only at high reflection coefficients, which is connected with a danger that some competing processes may develop in the SBS medium. Calculations for the SBS mirror geometry optimization [1][2][3][4][5][6][7][8][9][10][11][12][13] showed a good agreement with the experimental data on the reflection and transmission coefficients of the angular selector obtained under laboratory conditions, detailed description of which is given in work 14 The calculated quality of PC under various configurations of the SBS mirror was confirmed by detailed experimental comparison ofthe laser and Stokes energy distributions in the near field.…”

Section: Introductionmentioning

confidence: 99%

Explosively pumped photodissociation iodine laser with phase conjugation of super-high quality: modeling and experiment

Starikov¹,

Dolgopolov²,

Dudov³

et al. 2003

International Conference on Lasers, Applications, and Technologies 2002: Advanced Lasers and Systems

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A non-steady-state theoretical and mathematical model and a complex of computer codes have been developed for modeling a high-power double-pass explosively pumped photo-dissociation iodine laser (EPDL) with phase conjugation (PC) at SBS. The model and the complex of codes taking into account three-dimensionality of space consist of two blocks. The first block is devoted to detailed modeling of the SBS mirror consisting of an angular selector of Stokes radiation, an ordered raster of small diffraction lenses, a main focusing lens, and a SBS cell. The second block describes the dynamics of radiation in the laser system as a whole with using SBS mirror parameters calculated in the first block. The model takes into account parasitic reflections of laser radiation from the elements of the optical scheme, intrinsic amplified spontaneous emission ofthe amplifiers, radiation losses in the optical path, non-uniformity ofgain, and radiation refraction on optical non-uniformities of the active medium caused by a shock wave. As a result of calculations an optimal configuration of the SBS mirror has been determined, possessing unique properties if compared to the existing specimens of the SBS mirrors. It stably gives a nearly ideal quality of PC at any level of SBS saturation, i.e. any reflection coefficient that is confirmed by experimental laboratory investigations. Modeling of the laser system as a whole at working mixture 25 Torr C3F71+125 Torr Xe and amplifier aperture 15 cm has been shown a good agreement of calculated results with available experimental data in energy, time dependence of power and Strehl number of output radiation. The considered EPDL has output energy of about 400 J and brightness of about 1012J/ster. It is shown that parasitic reflections of laser radiation from the ends of amplifiers and elements of the optical scheme with a coefficient exceeding iO-7 considerably decrease the brightness of EPDL. Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/25/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx Proc. of SPIE Vol. 5137 173 Downloaded From: http://proceedings.spiedigitallibrary.org/ on 06/25/2016 Terms of Use: http://spiedigitallibrary.org/ss/TermsOfUse.aspx

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ISTC Projects from RFNC-VNIIEF Devoted to Improving Laser Beam Quality

Starikov¹,

Кочемасов²

Adaptive Optics for Industry and Medicine

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Novel features of phase conjugation at SBS of beams passed through an ordered phase plate

Cited by 7 publications

References 7 publications

<title>New phenomena at stimulated Brillouin scattering of Laguerre-Gaussian laser modes: theory, calculation, and experiments</title>

<title>New phenomena at stimulated Brillouin scattering of Laguerre-Gaussian laser modes: theory, calculation, and experiments</title>

Explosively pumped photodissociation iodine laser with phase conjugation of super-high quality: modeling and experiment

ISTC Projects from RFNC-VNIIEF Devoted to Improving Laser Beam Quality

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