在激光驱动惯性约束聚变研究中,束靶高效耦合依赖于采用合适的束匀滑措施.目前,结合光谱色散平滑(smoothing by spectral dispersion, 简称SSD)、相位板和光束叠加的技术是固体激光驱动器采用的主流束匀滑技术.瞄准间接驱动,实验研究了一套基于线性调频脉冲的SSD技术.在采用该技术后,远场色散方向上的高频调制得到了匀滑,色散后的近场也得到了匀滑.测量得到的光谱结构与理论模拟接近.该方法不需要相位调制器,而这类器件在传统SSD技术中是一个关键器件.
Precise physical experiments place strict requirements on target illumination uniformity in inertial confinement fusion research. Currently, the main stream of beam smoothing technology adopted in solid-state laser driver combines smoothing by spectral dispersion (SSD), phase plate and beam overlapping. A new smoothing method aimed at indirect-drive laser fusion is studied here, which uses linearly modulated light and angular spectral dispersion. After using this technique, high frequency modulations on the far field could be smoothed. In the meantime, near field after the dispersion grating could be smoothed too. Experimental results show that the measured spectrum is similar to the simulated one. Phase modulator is not necessary in this method, while it is a crucial element in traditional SSD method.