F. Starikov, Y. Dolgopolov, A. V. Kopalkin, G. Kochemasov, S. M. Kulikov, S. Sukharev
{"title":"拉盖尔-高斯激光模式受激布里渊散射的新现象:理论、计算和实验","authors":"F. Starikov, Y. Dolgopolov, A. V. Kopalkin, G. Kochemasov, S. M. Kulikov, S. Sukharev","doi":"10.1117/12.793324","DOIUrl":null,"url":null,"abstract":"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 LG01 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 LG11 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.","PeriodicalId":300417,"journal":{"name":"Advanced Optoelectronics and Lasers","volume":"5 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2008-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"New phenomena at stimulated Brillouin scattering of Laguerre-Gaussian laser modes: theory, calculation, and experiments\",\"authors\":\"F. Starikov, Y. Dolgopolov, A. V. Kopalkin, G. Kochemasov, S. M. Kulikov, S. Sukharev\",\"doi\":\"10.1117/12.793324\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"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 LG01 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 LG11 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.\",\"PeriodicalId\":300417,\"journal\":{\"name\":\"Advanced Optoelectronics and Lasers\",\"volume\":\"5 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"2008-03-03\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Advanced Optoelectronics and Lasers\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.1117/12.793324\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Advanced Optoelectronics and Lasers","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1117/12.793324","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
New phenomena at stimulated Brillouin scattering of Laguerre-Gaussian laser modes: theory, calculation, and experiments
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 LG01 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 LG11 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.