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 generate...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
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.
