Sunlight-like lasers that have a continuous broad frequency spectrum, random phase spectrum, and random polarization are formulated theoretically. With a sunlight-like laser beam consisting of a sequence of temporal speckles, the resonant three-wave coupling that underlies parametric instabilities in laser–plasma interactions can be greatly degraded owing to the limited duration of each speckle and the frequency shift between two adjacent speckles. The wave coupling can be further weakened by the random polarization of such beams. Numerical simulations demonstrate that the intensity threshold of stimulated Raman scattering in homogeneous plasmas can be doubled by using a sunlight-like laser beam with a relative bandwidth of ∼1% as compared with a monochromatic laser beam. Consequently, the hot-electron generation harmful to inertial confinement fusion can be effectively controlled by using sunlight-like laser drivers. Such drivers may be realized in the next generation of broadband lasers by combining two or more broadband beams with independent phase spectra or by applying polarization smoothing to a single broadband beam.

中文翻译：

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通过类太阳光激光器减轻等离子体中的参数不稳定性

理论上制定了具有连续宽频谱、随机相位谱和随机偏振的类太阳光激光器。对于由一系列时间散斑组成的类太阳光激光束，由于每个散斑的持续时间有限以及两个相邻散斑之间的频移，导致激光-等离子体相互作用参数不稳定性的共振三波耦合可以大大降低. 这种光束的随机偏振可以进一步削弱波耦合。数值模拟表明，与单色激光束相比，使用相对带宽约为 1% 的类太阳光激光束可以使均质等离子体中受激拉曼散射的强度阈值加倍。最后，使用类似太阳光的激光驱动器可以有效控制对惯性约束聚变有害的热电子产生。这种驱动器可以在下一代宽带激光器中实现，方法是将两个或多个具有独立相位光谱的宽带光束组合起来，或者通过对单个宽带光束应用偏振平滑。