Fig. 2

3D isosurface plots of the space-dependent probe absorption for the scheme -I with isovalue = 0.6. (a) \(R_{10}\) = 0, \(\phi\) = 0; (b) \(R_{10}\) = 0.314 MHz, \(\phi\) = 0; (c) \(R_{10}\) = 0.314 MHz, \(\phi\) = 0.1755\(\pi\). Other common parameters: \(R_1\) = \(R_2\) = 1.6 MHz, \(R_3\) = 1.13 MHz, \(\Delta _p\) = \(\Delta _1\) = \(\Delta _2\) = 0. The figures with notations (i) of the left panel and (ii) of the right panel correspond to the cases of probe absorption without employing the NDD effect and in the presence of the NDD effect with C = 6, respectively.