Fig. 5.
High harmonic signal for all observed harmonic orders. (Upper) Harmonic orders 23–47 are shown as a function of time delay. The high harmonic signal has been normalized by the signal without the pump pulse present. (Lower) Amplitude of the high harmonic modulation by the excited Raman-active modes as a function of harmonic order. The amplitude of all modes significantly increases with harmonic order. The modulation of the high harmonic signal due to the ν2 mode is above the noise level only for harmonic orders >37.