Fig. 1. ATAS calculated for (a) 800 nm and (c) 2400 nm laser pulses with 3D-TDSE. For better observation, the region in (a) with the photon energy ranging from 16 to 20.5 eV is enlarged in (b). In (b) and (c), the absorption signals for $2{\mathrm{s}}^{-}$ and $2{\mathrm{p}}^{2-}$ are marked by white-dashed lines.

Fig. 2. Relative oscillation strength of the $2\mathit{\omega }$, $4\mathit{\omega }$, and $6\mathit{\omega }$ components calculated from the 3D-TDSE as a function of the dressing laser wavelength. (a) and (c) show the result for the $2{\mathrm{s}}^{-}$ state. (b) and (d) show the result for the $2{\mathrm{p}}^{2-}$ state. In (c) and (d), the blue solid lines indicate the strength of the $2\mathit{\omega }$ component as reference, while the red-dot and the carmine-dashed lines represent the $4\mathit{\omega }$ and $6\mathit{\omega }$ components, respectively.

Fig. 3. Modulation coefficients ${\mathit{f}}_1$, ${\mathit{f}}_2$, and ${\mathit{f}}_3$ as a function of wavelength for two different Floquet states: (a) $|2\mathrm{s},-1\rangle$ and (b) $|2\mathrm{p},-2\rangle$. The dressing laser intensity is the same as that in Fig. 2. The black-square, red-cycle, and blue-triangle lines represent the modulation coefficients ${\mathit{f}}_1$, ${\mathit{f}}_2$, and ${\mathit{f}}_3$, respectively.