Quantum path analysis for arbitrary optical-waveform measurements

Abstract

An arbitrary optical waveform can be measured using a perturbative approach known as the petahertz optical oscilloscope, in which an electron trajectory in the process of high-order-harmonic generation is used as a temporal gate. Here, we report that the petahertz optical oscilloscope exhibits a significant frequency dependence for the short wavelength signal field due to the finite time span of the electron trajectory. We show that the intrinsic response of the atom to the signal field can be used to correct the frequency dependence of the measurement. It is shown that the optical waveform having the spectral components from the second harmonic to the fourth harmonic of the fundamental field can accurately be reconstructed after the correction of the frequency dependence. © 2016 American Physical Society.