High-field experiments are very sensitive to the exact value of the peak intensity of an optical pulse due to the nonlinearity of the underlying processes. Therefore, precise knowledge of the pulse intensity, which is mainly limited by the accuracy of the temporal characterization, is a key prerequisite for the correct interpretation of experimental data. While the detection of energy and spatial profile is well established, the unambiguous temporal characterization of intense optical pulses, another important parameter required for intensity evaluation, remains a challenge, especially at relativistic intensities and a few-cycle pulse duration. Here, we report on the progress in the temporal characterization of intense laser pulses and present the relativistic surface second harmonic generation dispersion scan (RSSHG-D-scan)—a new approach allowing direct on-target temporal characterization of high-energy, few-cycle optical pulses at relativistic intensity.

由于基本过程的非线性，高场实验对光脉冲峰值强度的确切值非常敏感。因此，对脉冲强度的精确了解（主要受时间特征的准确性限制）是正确解释实验数据的关键前提。尽管能量和空间分布的检测已经很好地建立了，但是强光脉冲的明确的时间特性（强度评估所需的另一个重要参数）仍然是一个挑战，特别是在相对论强度和几个周期的脉冲持续时间的情况下。这里，