中国工程物理研究院 激光聚变研究中心,四川 绵阳 621900
精密高效的脉冲波形调控是大型激光装置满足惯性约束聚变实验需求的重要技术之一。脉冲波形生成原理是通过编辑任意波形发生器中每个子脉冲的电压值,经电光调制器转换为光脉冲强度形成任意形状的激光脉冲轮廓。在电光转换过程中,各子束响应过程并非线性且子束间存在个性差异。为实现此条件下精密高效的脉冲波形调控,制定并开发了基于闭环迭代思路的激光脉冲波形快速调控方法。实验结果表明,算法可在10 min内实现任意脉冲波形整形,并具备23∶1高对比度脉冲波形调控能力,调控精度均优于10% (rms),满足常规物理实验运行条件下对激光参数调控的精度和效率需求。
高功率激光装置 脉冲整形 迭代算法 high-power laser facility pulse shaping iterative algorithm 强激光与粒子束
2023, 35(8): 082001
中国工程物理研究院 激光聚变研究中心,四川 绵阳 621900
强激光与粒子束
2023, 35(2): 029901
强激光与粒子束
2022, 34(3): 031011
强激光与粒子束
2020, 32(6): 061002
强激光与粒子束
2020, 32(1): 011003
Author Affiliations
Abstract
Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621999, China
Fifth harmonic generation (5th HG) of a Nd:glass laser is an effective way to acquire high-energy coherent deep-ultraviolet radiation near 200 nm. In this work, cascade generation of the fifth harmonic of a Nd:glass laser in a 5 mm 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°C. 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 5 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.
140.3610 Lasers, ultraviolet 140.3515 Lasers, frequency doubled 190.2620 Harmonic generation and mixing Chinese Optics Letters
2019, 17(12): 121403
1 中国工程物理研究院激光聚变研究中心, 四川 绵阳 621900
2 等离子体物理重点实验室, 四川 绵阳 621900
3 西安交通大学机械制造系统工程国家重点实验室, 陕西 西安 710054
根据高功率激光装置中波前畸变分段的特点,提出通过构造不同频段的波前畸变来研究相干合成结果与波前畸变之间的关系。以神光-III原型装置的结构和参数为模型,利用蒙特卡罗方法进行了数值模拟,分析了低频、中高频波前畸变对相干合成的影响,并给出了低频和中高频波前畸变与相干合成结果的对应关系。为高功率激光装置中进行波前畸变控制, 实现相干合成提供一种分析思路和理论参考。
激光技术 相干合成 波前畸变 高功率激光装置
Author Affiliations
Abstract
Research Center of Laser Fusion, China Academy of Engineering Physics, Mianyang 621900, China
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.
140.3300 Laser beam shaping 350.2660 Fusion 350.4600 Optical engineering Chinese Optics Letters
2015, 13(4): 041406
1 中国工程物理研究院激光聚变研究中心,四川 绵阳 621900
2 中国工程物理研究院研究生部,北京 100088
小尺度自聚焦是威胁强激光装置安全运行的重要因素,需确定装置激光束发生小尺度自聚焦的临界点,以指导装置的安全运行。提出利用输出光束近场强度熵值变化来反映激光束小尺度自聚焦发展过程的方法,通过数值模拟研究了小尺度自聚焦发展过程中的近场强度熵值变化规律,利用此规律给出了强激光装置中发生显著小尺度自聚焦的近场强度熵值预警方法。通过与光束近场调制度及对比度方法的对比分析,发现该方法对小尺度自聚焦发生的表征更明显。
物理光学 小尺度自聚焦 图像熵 强激光 光学学报
2015, 35(s2): s226001
中国工程物理研究院 激光聚变研究中心, 四川 绵阳 621900
介质的三阶非线性性质会引起光场的非线性相移,而这类介质中当光强及介质的特性参数满足一定条件时,可以使光场的演化进入混沌的状态.从麦克斯韦方程组出发,推导了基于介质三阶非线性效应的麦克斯韦-布洛赫方程,并将其转化为归一化的洛伦兹方程形式.利用此方程,数值模拟了光场稳态及混沌态的演化过程.研究结果表明,三阶非线性介质中光场的演化可以进入混沌状态,这种状态对于控制材料中如自聚焦等有害的三阶非线性效应是不利的.
混沌 三阶非线性 强激光 chaos third order nonlinearity intense laser 强激光与粒子束
2015, 27(8): 081011