\[fig:fig1\]) can be interpreted as a result of the interference between *“effective” electric and magnetic modes*. In particular, no directional scattering is obtained at the non-degenerate, fundamental TM$_{01}$ mode, where only the internal *electric* field shows a resonant enhancement while the *magnetic* field intensity follows a flat line beyond $\lambda \gtrsim 700\,$nm (see Fig. \[fig:fig1\]b). For illustration the electric and magnetic field intensity patterns inside the NW cross section are shown for an incident wavelength $\lambda=550\,$nm in Fig. \[fig:fig1\](c-d).

![image](fig5)

Spectroscopy on cylindrical silicon nanowires
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In order to compare the forward and backward scattering of a normally incident plane wave on silicon nanowires (SiNWs) we perform standard darkfield microscopy either in reflection (backward scattering, “BW”) or in transmission geometry (forward scattering, “FW”). The measurement geometry is schematically shown in Fig. \[fig:fig2\](a) and (b) for FW and BW scattering, respectively. For details on the measurement technique, see Methods. We compare our experimental results to 2D simulations (in $XZ$-plane, assuming infinitely long structures along $Y$) by the Green dyadic method. Likewise, the GDM simulation technique is explained in the methods section. In the [SI Figs. S5-S10]{}, the accuracy of the method is verified by comparing GDM simulations to Mie theory and 