Figure 6
Green and red UC fluorescence intensities at the wavelengths of 547 (black squares) and 656 nm (red circles) (I547 and I656) by varying the laser intensity for the unshaped femtosecond laser pulse
(a) and the shaped femtosecond laser pulse with the modulation time of Г = 6370 fs (b), together with the fluorescence intensity ratio I547/I656 (blue triangles). The two solid lines are used to linearly fit the experimental data in the low and high laser intensities, respectively.
