To study how laser pulse wavelength will affect the damage characteristics of optical elements with different degrees of contamination, we compare the extent of damage on optical glass between nanosecond pulsed laser of 1064 and 355 nm wavelength, respectively, and reach the following conclusions: the surface quality of clean optical elements determines its own anti-laser damage capability; the damage probability of optical sample caused by ultraviolet radiation-induced organic contamination is much higher than the infrared radiation-induced one; and contaminated metal particles can lower damage threshold of optical elements by 2–3 times.

采用一台输出波长为1064 nm的NdYAG调Q激光器，以不同辐照方式对光学元件表面污染物引起的损伤开展了系统的实验研究。在确定了K9 玻璃和熔石英元件基板零几率损伤阈值的基础上，针对金属粒子污染物和有机污染物分别进行了元件损伤特性实验研究，分析了表面污染物造成元件损伤阈值下降的诱导机理。

The system for effective area measurement of laser spot on target plane was designed based on the definition of effective area. A 12-bit CCD camera is used for the effecive area measurement. A bmp image of the beam profile is stored. This image is processing by software to evaluate the ratio of total energy and peak fluence (effective area). Some test results were given using effective area measurement system. The system was employed in the laser induced damage threshold test and it is helpful to improving the precision of laser induced damage threshold test.

从激光光斑有效面积的定义出发,采用CCD图像摄取技术,设计了一套激光光斑有效面积测量装置.在4种不同激光光斑能量分布和不同能量密度的情况下,用有效面积测量仪分别进行了实际测试验证.结果表明,该测量装置可以对任何能量非均匀分布的激光光斑的有效面积进行准确测试,有助于提高光学元件激光损伤阈值的测量精度.

Nd∶doped-glass-based sub-picosecond laser system with the maximum peak power of greater than 20 tara watts and the energy on target surface of 16 J is accomplished by using the chirped laser pulse amplification technology. While the laser pulse is focused by an off-axis parabolic mirror, the power density on target surface of approximately 2×10 18 W/cm 2 is acquired. In the performed neutron experiment, a C 8D 8 plate target is placed on the focal spot of the off-axis parabolic mirror. The maximum neutron yield for a single shot reaches 2.4×10 4. Still some other related problems are discussed

A high power laser system delivering a 20-TW, 0.5 - 0.8 ps ultra-short laser pulse and a 20-J, 500-ps long pulse simultaneously in one shot is completed. This two-beam laser operates at the wavelength of 1053 nm and uses Nd doped glass as the gain media of the main amplification chain. The chirped-pulse amplification (CPA) technology is used to compress the stretched laser pulse. After compression, the ultrashort laser pulse is measured: energy above 16.0 J, S/N contrast ratio ~ 10^(5) : 1, filling factor ~>52.7%. Another long pulse beam is a non-compressed chirped laser pulse, which is measured: energy ~ 20 J, pulse duration 500 ps. The two beams are directed onto the target surface at an angle of 15°.

利用啁啾脉冲放大技术，建成了一台基于钕玻璃放大器1053 nm波长的亚皮秒超短脉冲激光系统(SPS)。系统的输出峰值功率大于20 TW，靶面最高能量可达16 J，采用离轴抛物面反射镜聚焦，在靶面上获得2×10 18 W/cm 2的激光功率密度，以此激光脉冲轰击氘化聚苯乙烯平面靶，获得单次发射最高2.4×10 4个中子产额。对中子产生的机理进行了相关的讨论。

A high power laser system delivering a 20-TW, 0.5 - 0.8 ps ultra-short laser pulse and a 20-J, 500-ps long pulse simultaneously in one shot is completed. This two-beam laser operates at the wavelength of 1053 nm and uses Nd doped glass as the gain media of the main amplification chain. The chirped-pulse amplification (CPA) technology is used to compress the stretched laser pulse. After compression, the ultrashort laser pulse is measured: energy above 16.0 J, S/N contrast ratio ~ 10^(5) : 1, filling factor ~>52.7%. Another long pulse beam is a non-compressed chirped laser pulse, which is measured: energy ~ 20 J, pulse duration 500 ps. The two beams are directed onto the target surface at an angle of 15°.

用266.0nm紫外激光探针测量了柱状铜靶(Φ500μm和Φ140μm)等离子体电子密度的空间分布,发现了径向密度凹陷和凸起结构,观察到了轴向和偏轴向密度轮廓陡变随时间的发展过程,并用简单的理论模型进行了半定量分析,结果与实验基本一致。