Figure 7
(a) The dashed lines show the numerically calculated threshold ellipticities for the long trajectories in the plateau region according to our model. Correspondingly, the dotted lines show the threshold ellipticity given by ref. 25. For comparison, the experimental data for the long trajectories are shown. The simulations were done for a laser intensity of 8.5 ⋅ 1013 W/cm2 and a wavelength of 1030 nm. (b) Integrated harmonic spectra for in-focus generation with various ellipticities. The color scale corresponds to different ellipticities from black (ε = 0) to light gray (ε = 0.25) in steps of 0.05. The fillings between the different harmonics allow us to better visualize the differences. The various spectra have been normalized to the level of H15. The error bars used in (a) show the standard deviations of the threshold ellipticities of the corresponding harmonic.
