The generation and measurement of complex ultraviolet laser pulse shapes is demonstrated in the SG-III laser facility. Relatively high contrast ratio of 300 ： 1 required by the physics experiment is achieved and succ...The generation and measurement of complex ultraviolet laser pulse shapes is demonstrated in the SG-III laser facility. Relatively high contrast ratio of 300 ： 1 required by the physics experiment is achieved and successfully measured. Two continuous main shots validate the reproduction and the stability of the pulse shape, which provide solid foundation for precise physics experiment and laser power balance.展开更多
Fifth harmonic generation(5th HG)of a Nd:glass laser is an effective way to acquire high-energy coherent deepultraviolet radiation near 200 nm.In this work,cascade generation of the fifth harmonic of a Nd:glass laser ...Fifth harmonic generation(5th HG)of a Nd:glass laser is an effective way to acquire high-energy coherent deepultraviolet radiation near 200 nm.In this work,cascade generation of the fifth harmonic of a Nd:glass laser in a 5mm ammonium dihydrogen phosphate(ADP)crystal was investigated,and maximum conversion efficiency of 14%and large angular acceptance of 45 mrad were demonstrated at a noncritical phase-matching temperature of-75.1℃.However,as the results reveal,the temperature sensitivity and nonlinear absorption would hinder its high-energy application.As for that,based on the complementary relationship of the angle and temperature in the phase-matching condition,an upgraded focusing 5th HG design coupled with the cylindrical temperature distribution scheme was proposed.By this upgraded focusing design,more than the improvement of the conversion efficiency,the output 5ω near-field intensity distribution turns out to be insensitive to the temperature gradient.Potentially,this idea can be applied for many other frequency conversion schemes such as high-repetition frequency lasers,which have similar temperature gradient problems.展开更多
Stray light in high-power laser facilities not only decreases the gain capacity of the main amplifier, but can also cause permanent damage to optical components, greatly threatening the safety operation of the SG-III....Stray light in high-power laser facilities not only decreases the gain capacity of the main amplifier, but can also cause permanent damage to optical components, greatly threatening the safety operation of the SG-III. This Letter reports a technique for quickly pinpointing the source of stray light in the main amplification optical path of the SG-III. The achieved results indicate that the accuracy of our method is up to 1 m in an optical path of 100 m. The judging method is effective for examining and removing harmful stray light in the SG-III laser facility and it can be promoted in huge laser facilities of this kind.展开更多
文摘The generation and measurement of complex ultraviolet laser pulse shapes is demonstrated in the SG-III laser facility. Relatively high contrast ratio of 300 ： 1 required by the physics experiment is achieved and successfully measured. Two continuous main shots validate the reproduction and the stability of the pulse shape, which provide solid foundation for precise physics experiment and laser power balance.
基金supported by the National Natural Science Foundation of China(Nos.11704352,61805223,and 61775199)
文摘Fifth harmonic generation(5th HG)of a Nd:glass laser is an effective way to acquire high-energy coherent deepultraviolet radiation near 200 nm.In this work,cascade generation of the fifth harmonic of a Nd:glass laser in a 5mm ammonium dihydrogen phosphate(ADP)crystal was investigated,and maximum conversion efficiency of 14%and large angular acceptance of 45 mrad were demonstrated at a noncritical phase-matching temperature of-75.1℃.However,as the results reveal,the temperature sensitivity and nonlinear absorption would hinder its high-energy application.As for that,based on the complementary relationship of the angle and temperature in the phase-matching condition,an upgraded focusing 5th HG design coupled with the cylindrical temperature distribution scheme was proposed.By this upgraded focusing design,more than the improvement of the conversion efficiency,the output 5ω near-field intensity distribution turns out to be insensitive to the temperature gradient.Potentially,this idea can be applied for many other frequency conversion schemes such as high-repetition frequency lasers,which have similar temperature gradient problems.
文摘Stray light in high-power laser facilities not only decreases the gain capacity of the main amplifier, but can also cause permanent damage to optical components, greatly threatening the safety operation of the SG-III. This Letter reports a technique for quickly pinpointing the source of stray light in the main amplification optical path of the SG-III. The achieved results indicate that the accuracy of our method is up to 1 m in an optical path of 100 m. The judging method is effective for examining and removing harmful stray light in the SG-III laser facility and it can be promoted in huge laser facilities of this kind.
