The study of high-order harmonic generation using ellipticity-modulated laser pulse

The high-order harmonic generation using ellipticity-modulated laser field is investigated experimentally and theoretically. The laser field with time-varying ellipticity is obtained using two quarter wave plates. The harmonic spectral intensity peaks appear periodic for the localization induced by the ellipticity modulation of the laser pulse. We calculate the single-atom response to the driving laser field using the Lewenstein model and compare the calculated and measured harmonic spectra generated with ellipticity-modulated driving laser pulses. The theoretical simulation and the experiment results agree well with each other.