Vectorial optical field reconstruction by attosecond spectral interferometry

An electrical pulse is completely defined by its time-dependent amplitude, phase and polarization state. For optical and near-infrared pulses the manipulation and characterization of the last one is fundamental due to its relevance in several scientific and technological fields. Although the complete characterization of optical waveform has been already demonstrated [1, 2], a technique both capable to fully characterize also weak probe pulses, with energy in the 10–100nJ, and, at the same time, free of systematic distortions, would be highly desirable. In this work we report on new theoretical and experimental results to demonstrate a novel approach for the complete characterization of the electric field of an optical pulse. Our method is based on the combination of two elements: the implementation of extreme ultraviolet (XUV) interferometry [3], with time resolution in the attosecond domain, and the demonstration that the motion of an attosecond electronic wave packet, created by an intense laser pulse, allows to sample an unknown electric field along a controllable, fixed direction. Combining these elements, we demonstrate the full reconstruction of electric fields with intensities as low as I∼10
⁹
W/cm
²
and with a generic time-dependent polarization state, with an all-optical method.