Wavefront control of high-power laser beams in the National Ignition Facility (NIF)
Wavefront control of high-power laser beams in the National Ignition Facility (NIF)
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DOI：
10.1117/12.380902
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发表时间：
1999-09
期刊：
影响因子：
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通讯作者：
R. Zacharias;E. Bliss;S. Winters;R. Sacks;M. Feldman;A. Grey;J. Koch;C. Stolz;J. Toeppen
中科院分区：
文献类型：
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作者：
R. Zacharias;E. Bliss;S. Winters;R. Sacks;M. Feldman;A. Grey;J. Koch;C. Stolz;J. Toeppen
使用激光作为惯性约束聚变和武器物理实验的驱动器是基于它们在低发散的光束中产生高能短脉冲的能力。事实上，高质量激光光束的聚焦能力远远超过替代技术，是为此类应用制造高功率激光的主要因素。国家点火设施(NIF)是劳伦斯·利弗莫尔国家实验室正在建设的一个大型、192束、高功率激光设施，用于聚变和武器物理实验。其未校正的最小焦斑尺寸受到激光系统像差的限制。NIF包括一个波前控制系统来校正这些像差，以产生一个足够小的焦点，以满足其应用。需要纠正的像差来源包括激光放大器中的瞬时泵浦引起的失真、先前激发的热失真、光束离轴效应以及重力、安装和镀膜引起的光学失真。气体密度变化和光学制造图形误差引起的像差也得到了部分校正。本文概述了NIF波前控制系统，并描述了它提供的目标光斑尺寸性能改进。它描述了为适应NIF的高通量(激光和手电筒)、较大的波前校正范围、波前时间带宽、温度和湿度变化、清洁度要求和异常处理要求(例如，波前超限条件)而制定的规定。
The use of lasers as the driver for inertial confinement fusion and weapons physics experiments is based on their ability to produce high-energy short pulses in a beam with low divergence. Indeed, the focusability of high quality laser beams far exceeds alternate technologies and is a major factor in the rationale for building high power lasers for such applications. The National Ignition Facility (NIF) is a large, 192-beam, high-power laser facility under construction at the Lawrence Livermore National Laboratory for fusion and weapons physics experiments. Its uncorrected minimum focal spot size is limited by laser system aberrations. The NIF includes a Wavefront Control System to correct these aberrations to yield a focal spot small enough for its applications. Sources of aberrations to be corrected include prompt pump-induced distortions in the laser amplifiers, previous-shot thermal distortions, beam off-axis effects, and gravity, mounting, and coating-induced optic distortions. Aberrations from gas density variations and optic-manufacturing figure errors are also partially corrected. This paper provides an overview of the NIF Wavefront Control System and describes the target spot size performance improvement it affords. It describes provisions made to accommodate the NIF's high fluence (laser beam and flashlamp), large wavefront correction range, wavefront temporal bandwidth, temperature and humidity variations, cleanliness requirements, and exception handling requirements (e.g. wavefront out-of-limits conditions).