We theoretically and experimentally investigate the wave front distortion in critically phase-matched continuouswave（CW） second harmonic generation（SHG）.Due to the walk-off effect in the nonlinear crystal,the gene...We theoretically and experimentally investigate the wave front distortion in critically phase-matched continuouswave（CW） second harmonic generation（SHG）.Due to the walk-off effect in the nonlinear crystal,the generated second harmonic is extremely elliptical and quite non-Gaussian,which causes a very low matching and coupling efficiency in experiment.Cylindrical lenses and walk-off compensating crystals are adopted to correct distorted wave fronts,and obtain a good TEM00 mode efficiently.Theoretically,we simulate the correction effect of 266-nm laser generated with SHG.The experiment results accord well with the theoretical simulation and an above 80% TEM_（00） component is obtained for 266-nm continuous-wave laser with a 4.8？-walk-off angle in beta barium borate（BBO） crystal.展开更多
A new method is developed for suppressing thermally induced wavefront distortions of the radiation in the active element of disk geometry.The method is based on controlling radial temperature gradients in the active e...A new method is developed for suppressing thermally induced wavefront distortions of the radiation in the active element of disk geometry.The method is based on controlling radial temperature gradients in the active element using a profiled heatsink.An active element with a zero thermal lens developed on the basis of numerical simulation was experimentally demonstrated in a disk laser head.Higher-order phase aberrations in the active element with a profiled heatsink were weaker than in the element with a flat heatsink.Using this method,a thermal-lens-free active-mirror ytterbium-doped yttrium aluminum garnet amplifier with an output energy of 54 mJ at an average pump power of 100 W and a repetition rate of 106 Hz was implemented.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.91436103)Research Programme of National University of Defense Technology,China(Grant No.JC15-02-03)
文摘We theoretically and experimentally investigate the wave front distortion in critically phase-matched continuouswave（CW） second harmonic generation（SHG）.Due to the walk-off effect in the nonlinear crystal,the generated second harmonic is extremely elliptical and quite non-Gaussian,which causes a very low matching and coupling efficiency in experiment.Cylindrical lenses and walk-off compensating crystals are adopted to correct distorted wave fronts,and obtain a good TEM00 mode efficiently.Theoretically,we simulate the correction effect of 266-nm laser generated with SHG.The experiment results accord well with the theoretical simulation and an above 80% TEM_（00） component is obtained for 266-nm continuous-wave laser with a 4.8？-walk-off angle in beta barium borate（BBO） crystal.
基金supported by the State Research Task for the Institute of Applied Physics,Russian Academy of Sciences(Project No.FFUF-2024-0043)by the scientific program of the National Center for Physics and Mathematics(project‘Physics of High Energy Densities.Stage 2023-2025’).
文摘A new method is developed for suppressing thermally induced wavefront distortions of the radiation in the active element of disk geometry.The method is based on controlling radial temperature gradients in the active element using a profiled heatsink.An active element with a zero thermal lens developed on the basis of numerical simulation was experimentally demonstrated in a disk laser head.Higher-order phase aberrations in the active element with a profiled heatsink were weaker than in the element with a flat heatsink.Using this method,a thermal-lens-free active-mirror ytterbium-doped yttrium aluminum garnet amplifier with an output energy of 54 mJ at an average pump power of 100 W and a repetition rate of 106 Hz was implemented.
