In dynamic interference smoothing (DIS) scheme, the speckles of focal spots are swept in multi-directions within several picoseconds, leading to the improvement of irradiation uniformity. In this work, the theoretical limitation of the smoothing performance of DIS scheme is revealed and then an optimized dynamic interference smoothing (ODIS) scheme is proposed. The ODIS scheme is implemented by applying asynchronous sinusoidal phase modulations induced by electro-optic modulators with time-delayed voltage signals to the beamlets in a laser quad. Results indicate that the irradiation uniformity of the ODIS scheme is further improved than that of DIS scheme owing to the asynchronous spatiotemporal phases. In addition, the polarization of the ODIS scheme also rotates on picosecond timescale, which may be potential to mitigate the parametric backscattering. Moreover, though the ODIS scheme has a relatively high requirement for temporal synchronization of beamlets, it shows a wide tolerance for the spatial wavefront distortion.

在动态干涉平滑（DIS）方案中，焦点的斑点散布在数个皮秒内的多个方向上，从而提高了照射均匀性。在这项工作中，揭示了DIS方案的平滑性能的理论局限性，然后提出了一种优化的动态干扰平滑（ODIS）方案。ODIS方案是通过将由电光调制器感应的具有时间延迟电压信号的异步正弦相位调制应用于激光器四边形中的子束来实现的。结果表明，由于时空相位的异步，ODIS方案的辐照均匀性比DIS方案得到了进一步的提高。此外，ODIS方案的极化也以皮秒级为单位旋转，这可能有助于减轻参数反向散射。此外，尽管ODIS方案对子束的时间同步有相对较高的要求，但它显示出对空间波前失真的宽容限。