Unambiguous determination of the electric field of arbitrary ultrashort pulses is the key for time and frequency standards, attosecond science, and precision spectroscopy. However, a single-step technique that can simultaneously and directly characterize the spectrum, spectral phase, and the carrier-envelope phase (CEP) information of an arbitrary ultrashort pulse remains elusive. This technological roadblock hinders the current field from studying non-repeating single-shot events, since ultrashort laser pulses are often unstable. Here, we introduce a single-step reference-free technique through polarization interfering electric field with phase inverted electric field (PIE-PIE) to directly measure arbitrary ultrashort pulses in single-shot operation without using any retrieval algorithm. PIE-PIE utilizes highly efficient spectral phase conjugation based on four-wave-mixing. The ability to fully determine the spectrum, spectral phase, and CEP of relatively low intensity single-shot pulses will revolutionize ultrafast sciences and enable studies of arbitrary non-repeating ultrafast events.

明确确定任意超短脉冲的电场是时间和频率标准、阿秒科学和精密光谱学的关键。然而，能够同时直接表征任意超短脉冲的频谱、频谱相位和载波包络相位 (CEP) 信息的单步技术仍然难以捉摸。这一技术障碍阻碍了当前领域研究非重复单发事件，因为超短激光脉冲通常不稳定。在这里，我们引入了一种单步无参考技术，通过极化干涉电场与倒相电场（PIE-PIE）在单次操作中直接测量任意超短脉冲，而无需使用任何检索算法。PIE-PIE 利用基于四波混合的高效光谱相位共轭。完全确定相对低强度单次脉冲的光谱、光谱相位和 CEP 的能力将彻底改变超快科学，并使任意非重复超快事件的研究成为可能。