惯性约束聚变驱动器连续相位板前置时频率转换晶体内部光场研究

本文针对惯性约束聚变驱动器终端光学系统中连续相位板置于基频光路(前置)时,频率转换晶体内部光场分布进行了研究.经研究发现连续相位板前置对基频光的相位调制降低了频率转换效率,增大了频率转换晶体内部光场的不均匀性,它导致晶体激光诱导损伤风险的可能性加大.值得特别注意的是:在频率转换晶体入射和出射端面附近激光调制度和最大光强相对于其他区域高,发生激光诱导损伤的可能性相对更大.因此当不断增大频率转换系统输入的基频光光强时,为保证惯性约束聚变终端光学系统的正常运行需要把连续相位板前置对频率转换晶体内部光场分布的影响 关键词： 惯性约束聚变 连续相位板 频率转换晶体 激光诱导损伤

Study on intensity distribution inside the frequency conversion crystals for continuous phase plate front-located in inertial confinement fusion driver

This paper studies the intensity distribution inside the frequency conversion crystals when the continuous phase plate (CPP) is placed in 1ω light of final optics assembly for inertial confinement fusion (ICF) driver. Our study shows that the modulation of 1ω light caused by CPP makes the frequency conversion efficiency and the uniformity of intensity field inside the frequency conversion crystals decrease. It leads to the possibility of laser induced damage for frequency conversion crystals to increase. What worth paying special attention to is: the modulation and maximum intensity in the vicinity of entrance and exit surface of frequency conversion crystal is much higher than in other areas, so the possibility of laser induced damage is also relatively greater there. However, if the intensity of 1ω light before the frequency conversion system becomes even greater, for the normal running of final optics assembly the modulation and maximum intensity inside the frequency conversion crystals should be confined within the permitted range.